The purpose of this study is to quantify cancer mortality in relationship to organ-specific radiation dose among women irradiated for benign gynecologic disorders. Included in this study are 12,955 women treated for benign gynecologic disorders at hospitals in the Northeastern U.S. between 1925 and 1965; 9,770 women treated by radiation and 3,186 women treated by other methods. The average age at treatment was 45.9 years (range, 13–88 years), and the average follow-up period was 30.1 years (maximum, 69.9 years). Radiation doses to organs and active bone marrow were reconstructed by medical physicists using original radiotherapy records. The highest doses were received by the uterine cervix (median, 120 Gy) and uterine corpus (median, 34 Gy), followed by the bladder, rectum and colon (median, 1.7–7.2 Gy), with other abdominal organs receiving median doses ≤1 Gy and organs in the chest and head receiving doses <0.1 Gy. Standardized mortality rate ratios relative to the general U.S. population were calculated. Radiation-related risks were estimated in internal analyses using Poisson regression models. Mortality was significantly elevated among irradiated women for cancers of the uterine corpus, ovary, bladder, rectum, colon and brain, as well as for leukemia (exclusive of chronic lymphocytic leukemia) but not for cancer of the cervix, Hodgkin or non-Hodgkin lymphoma, multiple myeloma, or chronic lymphocytic leukemia. Evidence of a dose-response was seen for cancers of the ovary [excess relative risk (ERR) 0.31/Gy, P < 0.001], bladder (ERR = 0.21/Gy, P = 0.02) and rectum (ERR = 0.23/Gy, P = 0.05) and suggested for colon (ERR = 0.09/Gy, P = 0.10), but not for cancers of the uterine corpus or brain nor for non-chronic lymphocytic leukemia. Relative risks of mortality due to cancers of the stomach, pancreas, liver and kidney were close to 1.0, with no evidence of dose-response over the range of 0–1.5 Gy. Breast cancer was not significantly associated with dose to the breast or ovary. Mortality due to cancers of heavily irradiated organs remained elevated up to 40 years after irradiation. Significantly elevated radiation-related risk was seen for cancers of organs proximal to the radiation source or fields (bladder, rectum and ovary), as well as for non-chronic lymphocytic leukemia. Our results corroborate those from previous studies that suggest that cells of the uterine cervix and lymphopoietic system are relatively resistant to the carcinogenic effects of radiation. Studies of women irradiated for benign gynecologic disorders, together with studies of women treated with higher doses of radiation for uterine cancers, provide quantitative information on cancer risks associated with a broad range of pelvic radiation exposures.
To quantify the risk of second primary breast cancer in the contralateral breast (CB) following radiation therapy (RT) for first breast cancer.
Methods and Materials
The study population included participants in the Women’s Environmental, Cancer, and Radiation Epidemiology (WECARE) study: 708 cases (women with asynchronous bilateral breast cancer) and 1399 controls (women with unilateral breast cancer) counter-matched on radiation treatment. Participants were < 55 years of age at first breast cancer. Absorbed doses to quadrants of the CB were estimated. Rate ratios (RR) and 95% confidence intervals were calculated using multivariable-adjusted conditional logistic regression models.
Across all patients, the mean radiation dose to the specific quadrant of the CB tumor was 1.1 Gy. Women < 40 years of age who received > 1.0 Gy of absorbed dose to the specific quadrant of the CB had a 2.5-fold greater risk for CB cancer than unexposed women (RR=2.5, 95% CI= 1.4 – 4.5). No excess risk was observed in women >40 years of age. Women < 40 years of age with followup periods > 5 years had a RR of 3.0 (95% CI=1.1–8.1), and the dose response was significant (excess RR per Gy of 1.0, 95% CI=0.1–3.0).
Women < 40 years of age who received a radiation dose > 1.0 Gy to the CB had an elevated, long-term risk of developing a second primary CB cancer. The risk is inversely related to age at exposure and is dose dependent.
Contralateral breast; Radiation risk; Secondary breast cancer
To investigate minisatellite germline mutation rates in survivors of childhood and young adult cancer who received radiotherapy.
Materials and Methods
DNA samples from 100 families, where one parent was a cancer survivor, were analysed for mutations at eight hypervariable minisatellite loci (B6.7, CEB1, CEB15, CEB25, CEB36, MS1, MS31, MS32) by Southern hybridisation.
No significant difference was observed between the paternal mutation rate of 5.6% in exposed fathers with a mean preconceptional testicular dose of 1.23 Gy (56 mutations in 998 informative alleles) and that of 5.8% in unexposed fathers (17 in 295 informative alleles). Subgrouping the exposed fathers into dose groups of <0.10 Gy, 0.10 – 0.99 Gy, 1.00 – 1.99 Gy, ≥ 2.00 Gy revealed no significant differences in paternal mutation rate in comparison with the unexposed fathers. Maternal mutation rates of 1.6% in cancer survivor mothers with a mean preconceptional ovarian dose of 0.58 Gy (five mutations in 304 informative alleles) and 2.1% in unexposed mothers (21 in 987 informative alleles) were not significantly different. There were no differences in minisatellite mutation rates associated with treatment with chemotherapeutic agents.
This study provides evidence that preconception radiotherapy for childhood or early adulthood cancer does not increase the germline minisatellite mutation rate.
Minisatellite; germline mutation; ionising radiation; childhood and young adult cancer
Childhood cancer survivors have an increased risk of secondary sarcomas. To better identify those at risk, the relationship between therapeutic dose of chemotherapy and radiation and secondary sarcoma should be quantified.
Methods and Materials
We conducted a nested case-control study of secondary sarcomas (105 cases, 422 matched controls) in a cohort of 14,372 childhood cancer survivors. Radiation dose at the second malignant neoplasm (SMN) site and use of chemotherapy were estimated from detailed review of medical records. Odds ratios (ORs) and 95% confidence intervals were estimated by conditional logistic regression. Excess odds ratio (EOR) was modeled as a function of radiation dose, chemotherapy, and host factors.
Sarcomas occurred a median of 11.8 years (range: 5.3-31.3 years) from original diagnosis. Any exposure to radiation was associated with increased risk of subsequent sarcoma (OR = 4.1, 95% CI = 1.8-9.5). A dose-response relation was observed, with elevated risks at doses between 10 - 29.9 Gy (OR = 15.6, 95% CI = 4.5-53.9), 30 - 49.9 Gy (OR = 16.0, 95% CI 3.8-67.8) and >50 Gy (OR = 114.1, 95% CI 13.5-964.8). Anthracycline exposure was associated with sarcoma risk (OR = 3.5, 95% CI = 1.6-7.7) adjusting for radiation dose, other chemotherapy, and primary cancer. Adjusting for treatment, survivors with a first diagnosis of Hodgkin lymphoma (HL; OR=10.7, 95% CI = 3.1-37.4) or primary sarcoma (OR=8.4, 95% CI = 3.2-22.3) were more likely to develop a sarcoma.
Of the risk factors evaluated, radiation exposure was the most important for secondary sarcoma development in childhood cancer survivors; anthracycline chemotherapy exposure was also associated with increased risk.
Childhood cancer survivors; secondary sarcomas; radiation late effects
Describe frequencies and risk factors of altered oral health and odontogenesis in childhood cancer survivors.
Patients and Methods
9308 survivors, diagnosed between 1970–1986, and 2951 siblings from Childhood Cancer Survivor Study completed a survey containing oral-dental health information. We analyzed treatment impact, socioeconomic data and patient demographics on dental outcomes using univariate and multivariate logistic regression models to estimate odds ratios (OR).
In multivariate analysis, survivors more likely reported microdontia (OR 3.0, 95% confidence interval [CI] 2.4–3.8), hypodontia (OR 1.7, 95% CI 1.4–2.0), root abnormalities (OR 3.0, 95% CI 2.2–4.0), abnormal enamel (OR 2.4, 95% CI 2.0–2.9), teeth loss ≥6 (OR 2.6, 95% CI 1.9–3.6), severe gingivitis (OR 1.2, 95% CI 1.0–1.5), xerostomia (OR 9.7, 95% CI 4.8–19.7). Controlling for chemotherapy and socio-economic factors, radiation exposure of ≥20Gy to dentition was significantly associated with increased risk of ≥1 dental abnormality. Dose-dependent alkylating agent therapy significantly increased risk ≥1 anatomic/developmental dental abnormalities in survivors diagnosed <5 years of age (OR 1.7, 2.7, 3.3 for alkylating agent score of 1, 2, 3, respectively).
Radiation and chemotherapy are independent risk factors for adverse oral-dental sequelae among childhood cancer survivors. Patients receiving alkylating agents at < 5 years should be closely monitored.
radiation; chemotherapy; pediatric oncology; dental abnormalities
Psychological or neurocognitive impairment is often seen in medulloblastoma survivors after craniospinal radiation; however, significant variability in outcomes exists. This study investigated the role of antioxidant enzyme polymorphisms in moderating this outcome and hypothesized that patients who had polymorphisms associated with lower antioxidant enzyme function would have a higher occurrence of impairment. From the Childhood Cancer Survivor Study (CCSS) cohort, 109 medulloblastoma survivors and 143 siblings were identified who completed the CCSS Neurocognitive Questionnaire (NCQ) and the Brief Symptom Inventory-18 (BSI-18) and who provided buccal DNA samples. Real-time polymerase chain reaction (PCR) allelic discrimination was used for SOD2 (rs4880), GPX1 (rs1050450), and GSTP1 (rs1695 and rs1138272) genotyping and PCR for GSTM1 and GSTT1 gene deletions. Outcomes on NCQ and BSI-18 subscale scores were examined in association with genotypes and clinical factors, including age at diagnosis, sex, and radiation dose, using univariate and multivariate analysis of variance. Patients <7 years of age at diagnosis displayed more problems with task efficiency (P < .001) and fewer problems with somatic complaints (P = .004) than did patients ≥7 years of age. Female patients reported more organization problems than did male patients (P = .02). Patients with homozygous GSTM1 gene deletion reported higher anxiety (mean null genotype = 47.3 ± 9.2, non-null = 43.9 ± 7.8; P = .04), more depression (null = 51.0 ± 9.8, non-null = 47.0 ± 9.4; P = .03), and more global distress (null = 50.2 ± 9.7, non-null = 45.2 ± 9.9; P = .01). All associations for the GSTM1 polymorphism remained statistically significant in a multivariate model controlling for age, sex, and radiation dose. Homozygous GSTM1 gene deletion was consistently associated with greater psychological distress in medulloblastoma survivors across multiple domains, suggesting that this genotype may predispose patients for increased emotional late effects.
Childhood Cancer Survivor Study; glutathione S-transferase polymorphisms; medulloblastoma; neuropsychological impairment; radiation therapy
Basal cell carcinoma (BCC) is the most common malignancy in the United States. Ionizing radiation is an established risk factor in certain populations, including cancer survivors. We quantified the association between ionizing radiation dose and the risk of BCC in childhood cancer survivors.
Participants in the Childhood Cancer Survivor Study who reported a BCC (case subjects, n = 199) were matched on age and length of follow-up to three study participants who had not developed a BCC (control subjects, n = 597). The radiation-absorbed dose (in Gy) to the BCC location was calculated based on individual radiotherapy records using a custom-designed dosimetry program. Conditional logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for associations between demographic and treatment factors, therapeutic radiation dose, and surrogate markers of sun sensitivity (skin and hair color) and the risk of BCC. A linear dose–response model was fitted to evaluate the excess odds ratio per Gy of radiation dose.
Among case subjects, 83% developed BCC between the ages of 20 and 39 years. Radiation therapy, either alone or in combination with chemotherapy, was associated with an increased risk of BCC compared with no chemotherapy or radiation. The odds ratio for subjects who received 35 Gy or more to the skin site vs no radiation therapy was 39.8 (95% CI = 8.6 to 185). Results were consistent with a linear dose–response relationship, with an excess odds ratio per Gy of 1.09 (95% CI = 0.49 to 2.64). No other treatment variables were statistically significantly associated with an increased risk of BCC.
Radiation doses to the skin of more than 1 Gy are associated with an increased risk of BCC.
Childhood cancer survivors are at increased risk for adverse outcomes and chronic medical conditions. Treatment-related scarring, disfigurement, and persistent hair loss, in addition to their long-term impact on psychological distress or health-related quality of life (HRQOL), have received little attention.
Patients and Methods
Self-reported scarring/disfigurement and persistent hair loss were examined in 14,358 survivors and 4,023 siblings from the Childhood Cancer Survivor Study. Multivariable models were used to examine associations with demographic and cancer treatment. The impact of disfigurement and hair loss on HRQOL (ie, Medical Outcomes Short Form–36) and emotional distress (ie, Brief Symptom Inventory–18) was examined.
Survivors reported a significantly higher rate of scarring/disfigurement compared with siblings for head/neck (25.1% v 8.4%), arms/legs (18.2% v 10.2%), and chest/abdomen (38.1% v 9.1%), as well as hair loss (14.0% v 6.3%). In age-, sex-, and race-adjusted models, cranial radiation exposure ≥ 36 Gy increased risk for head/neck disfigurement (relative risk [RR], 2.42; 95% CI, 2.22 to 2.65) and hair loss (RR, 4.24; 95% CI, 3.63 to 4.95). Adjusting for cranial radiation, age, sex, race, education, and marital status, survivor hair loss increased risk of anxiety (RR, 1.60; 95% CI, 1.23 to 2.07), whereas head/neck disfigurement increased risk of depression (RR, 1.19; 95% CI, 1.01 to 1.41). Limitations due to emotional symptoms were associated with head/neck disfigurement (RR, 1.24; 95% CI, 1.10 to 1.41), arm/leg disfigurement (RR, 1.19; 95% CI, 1.05 to 1.35), and hair loss (RR, 1.26; 95% CI, 1.09 to 1.47).
Survivors of childhood cancer are at increased risk for disfigurement and persistent hair loss, which is associated with future emotional distress and reduced quality of life. Future studies are needed to better identify and manage functional outcomes in these patients.
Childhood cancer survivors develop gastrointestinal malignancies more frequently and at a younger age than the general population, but risk factors for their development have not been well characterized.
To determine the risk and associated risk factors for gastrointestinal subsequent malignant neoplasms (SMN) in childhood cancer survivors.
Retrospective cohort study.
The Childhood Cancer Survivor Study, a multi-center study of childhood cancer survivors diagnosed between 1970 and 1986.
14,358 survivors of a malignancy diagnosed at < 21 years who had survived for 5 or more years from initial diagnosis.
Standardized incidence ratios (SIR) for gastrointestinal SMN were calculated using age-specific population data. Multivariate Cox regression models identified associations between risk factors and gastrointestinal SMN development.
At median follow-up of 22.8 years (range: 5.5-30.2), 45 gastrointestinal malignancies were identified. Gastrointestinal SMN risk was 4.6-fold higher in childhood cancer survivors than the general population (95% confidence interval [CI]: 3.5-6.1). Colorectal cancer SIR was 4.2 (95% CI: 2.8-6.3). The highest gastrointestinal SMN risk was associated with abdominal radiation (SIR=11.2, 95% CI: 7.6-16.4). However, survivors not exposed to radiation had a significantly increased risk (SIR=2.4, 95% CI-1.4-3.9). In addition to abdominal radiation, high dose procarbazine (RR=3.2, 95% CI 1.1-9.4) and platinum drugs (RR 7.6, 95% CI: 2.3-25.5) independently increased the gastrointestinal SMN risk.
This cohort has not yet attained an age at which gastrointestinal malignancy risk is greatest.
Childhood cancer survivors, particularly those exposed to abdominal radiation, are at increased risk for gastrointestinal SMN. These findings suggest that surveillance of at-risk childhood cancer survivors should commence at a younger age than recommended for the general population.
The human mitochondrial genome has an exclusively maternal mode of inheritance. Mitochondrial DNA (mtDNA) is particularly vulnerable to environmental insults due in part to an underdeveloped DNA repair system, limited to base excision and homologous recombination repair. Radiation exposure to the ovaries may cause mtDNA mutations in oocytes, which may in turn be transmitted to offspring. We hypothesized that the children of female cancer survivors who received radiation therapy may have an increased rate of mtDNA heteroplasmy mutations, which conceivably could increase their risk of developing cancer and other diseases. We evaluated 44 DNA blood samples from 17 Danish and 1 Finnish families (18 mothers and 26 children). All mothers had been treated for cancer as children and radiation doses to their ovaries were determined based on medical records and computational models. DNA samples were sequenced for the entire mitochondrial genome using the Illumina GAII system. Mother’s age at sample collection was positively correlated with mtDNA heteroplasmy mutations. There was evidence of heteroplasmy inheritance in that 9 of the 18 families had at least one child who inherited at least one heteroplasmy site from his or her mother. No significant difference in single nucleotide polymorphisms between mother and offspring, however, was observed. Radiation therapy dose to ovaries also was not significantly associated with the heteroplasmy mutation rate among mothers and children. No evidence was found that radiotherapy for pediatric cancer is associated with the mitochondrial genome mutation rate in female cancer survivors and their children.
Adult survivors of childhood lower-extremity sarcoma are largely physically inactive, a behavior which potentially compounds their health burden. Altering this behavior requires understanding those factors that contribute to their physical inactivity. Therefore, this investigation sought to identify factors associated with inactivity in this subpopulation of cancer survivors.
Demographic, personal, treatment and physical activity information from adult survivors of childhood lower-extremity sarcomas was obtained from the Childhood Cancer Survivor Study (CCSS) cohort. Generalized linear models were used to identify variables that best identified those individuals who were physically inactive.
Only 41% of survivors met Center for Disease Control (CDC) activity guidelines. Survivors were 1.20 (95% CI 1.11–1.30) more likely compared to CCSS sibling cohort and 1.12 (95% CI 1.10–1.15) times more likely than the general population to fail to meet CDC guidelines. Significant predictors of physical inactivity included female sex, hemipelvectomy surgery, and platinum and vinca alkaloid chemotherapy.
The primary findings of this study are that survivors of childhood onset lower-extremity sarcoma are 1) highly likely to be physically inactive and 2) less likely than their siblings or the general population to regularly exercise. This study has identified treatment related risk factors associated with inactivity that will help health and wellness practitioners develop successful exercise interventions to help these survivors achieve recommended levels of physical activity for health.
IMPLICATIONS FOR CANCER SURVIVORS
These results suggest that physical activity interventions for adult survivors of childhood lower-extremity sarcomas should be sex specific and responsive to unique physical late effects experienced by these survivors.
Childhood cancer; physical activity; exercise; late-effects; sedentary
Young adult survivors of childhood brain tumors (BT) may have late-effects that compromise physical performance and everyday task participation.
To evaluate muscle strength, fitness, physical performance, and task participation among adult survivors of childhood BT.
In-home evaluations and interviews were conducted for 156 participants (54% male). Results on measures of muscle strength, fitness, physical performance, and participation were compared between survivors and population-group members with chi-squared statistics and two-sample t-tests. Associations between late effects and physical performance, and physical performance and participation, were evaluated in regression models.
BT survivors were a median age of 22 (18–58), and 14.7 (6.5–45.9) years from diagnosis. Survivors had lower estimates of grip strength (Female: 24.7±9.2 vs. 31.5±5.8, Male: 39.0±12.2 vs. 53.0±10.1 kilograms), knee extension strength (Female: 246.6±95.5 vs. 331.5±5.8, Male: 304.7±116.4 vs. 466.6±92.1 Newtons) and peak oxygen uptake (Female: 25.1±8.8 vs. 31.3±5.1, Male: 24.6±9.5 vs. 33.2±3.4 milliliters/kilogram/minute) than population-group members. Physical performance was lower among survivors and associated with not living independently (OR=5.0, 95% CI=2.0–12.2) and not attending college (OR=2.3, 95% CI 1.2–4.4).
Muscle strength and fitness values among BT survivors are similar to those among persons 60+ years, and are associated with physical performance limitations. Physical performance limitations are associated with poor outcomes in home and school environments. These data indicate an opportunity for interventions targeted at improving long-term physical function in this survivor population.
physical performance; disability; brain tumor; cancer survivor; pediatric
Children with cancer receive mutagenic treatments, which raises concern about the potential transmissibility of germline damage to their offspring. This question has been inadequately studied to date because of a lack of detailed individual treatment exposure assessment such as gonadal radiation doses.
Within the Childhood Cancer Survivor Study, we performed a retrospective cohort analysis of validated cases of congenital anomalies among 4,699 children of 1,128 male and 1,627 female childhood cancer survivors. We quantified chemotherapy with alkylating agents and radiotherapy doses to the testes and ovaries and related these exposures to risk of congenital anomalies using logistic regression.
One hundred twenty-nine children had at least one anomaly (prevalence = 2.7%). For children whose mothers were exposed to radiation or alkylating agents versus neither, the prevalence of anomalies was 3.0% versus 3.5% (P = .51); corresponding figures were 1.9% versus 1.7% (P = .79) for the children of male survivors. Neither ovarian radiation dose (mean, 1.19 Gy; odds ratio [OR] = 0.59; 95% CI, 0.20 to 1.75 for 2.50+ Gy) nor testicular radiation dose (mean, 0.48 Gy; OR = 1.01; 95% CI, 0.36 to 2.83 for 0.50+ Gy) was related to risk of congenital anomalies. Treatment with alkylating agents also was not significantly associated with anomalies in the children of male or female survivors.
Our findings offer strong evidence that the children of cancer survivors are not at significantly increased risk for congenital anomalies stemming from their parent's exposure to mutagenic cancer treatments. This information is important for counseling cancer survivors planning to have children.
Many Childhood Cancer Survivor Study (CCSS) participants are at increased risk for obesity. The etiology of their obesity is likely multifactorial but not well understood.
Patients and Methods
We evaluated the potential contribution of demographic, lifestyle, treatment, and intrapersonal factors and self-reported pharmaceutical use to obesity (body mass index ≥ 30 kg/m2) among 9,284 adult (> 18 years of age) CCSS participants. Independent predictors were identified using multivariable regression models. Interrelationships were determined using structural equation modeling (SEM).
Independent risk factors for obesity included cancer diagnosed at 5 to 9 years of age (relative risk [RR], 1.12; 95% CI, 1.01 to 1.24; P = .03), abnormal Short Form–36 physical function (RR, 1.19; 95% CI, 1.06 to 1.33; P < .001), hypothalamic/pituitary radiation doses of 20 to 30 Gy (RR, 1.17; 95% CI, 1.05 to 1.30; P = .01), and paroxetine use (RR, 1.29; 95% CI, 1.08 to 1.54; P = .01). Meeting US Centers for Disease Control and Prevention guidelines for vigorous physical activity (RR, 0.90; 95% CI, 0.82 to 0.97; P = .01) and a medium amount of anxiety (RR, 0.86; 95% CI, 0.75 to 0.99; P = .04) reduced the risk of obesity. Results of SEM (N = 8,244; comparative fit index = 0.999; Tucker Lewis index = 0.999; root mean square error of approximation = 0.014; weighted root mean square residual = 0.749) described the hierarchical impact of the direct predictors, moderators, and mediators of obesity.
Treatment, lifestyle, and intrapersonal factors, as well as the use of specific antidepressants, may contribute to obesity among survivors. A multifaceted intervention, including alternative drug and other therapies for depression and anxiety, may be required to reduce risk.
We examined whether survivors from the Childhood Cancer Survivor Study were less likely to be in higher skill occupations than a sibling comparison and whether certain survivors were at higher risk.
We created three mutually-exclusive occupational categories for participants aged ≥25 years: Managerial/Professional and Non-Physical and Physical Service/Blue Collar. We examined currently employed survivors (N=4845) and siblings (N=1727) in multivariable generalized linear models to evaluate the likelihood of being in the three occupational categories. Among all participants, we used multinomial logistic regression to examine the likelihood of these outcomes in comparison to being unemployed (survivors N=6671; siblings N=2129). Multivariable linear models were used to assess survivor occupational differences by cancer and treatment variables. Personal income was compared by occupation.
Employed survivors were less often in higher skilled Managerial/Professional occupations (Relative Risk=0.93, 95% Confidence Interval 0.89–0.98) than siblings. Survivors who were Black, were diagnosed at a younger age, or had high-dose cranial radiation were less likely to hold Professional occupations than other survivors. In multinomial models, female survivors’ likelihood of being in full-time Professional occupations (27%) was lower than male survivors (42%) and female (41%) and male (50%) siblings. Survivors’ personal income was lower than siblings within each of the three occupational categories in models adjusted for sociodemographic variables.
Adult childhood cancer survivors are employed in lower skill jobs than siblings. Survivors with certain treatment histories are at higher risk and may require vocational assistance throughout adulthood.
Neoplasms; Occupations; Survivors; Socioeconomic Factors; Late Effects; Female
Ionizing radiation is a breast carcinogen that induces DNA double strand breaks (DSBs), and variation in genes involved in the DNA DSB response has been implicated in radiation-induced breast cancer. The Women’s Environmental, Cancer and Radiation Epidemiology (WECARE) Study is a population-based study of cases with contralateral breast cancer (CBC) and matched controls with unilateral breast cancer. The location-specific radiation dose received to the contralateral breast was estimated from radiotherapy records and mathematical models. 152 SNPs in six genes (CHEK2, MRE11A, MDC1, NBN, RAD50, TP53BP1) involved in the DNA DSBs response were genotyped. No variants or haplotypes were associated with CBC risk (649 cases, 1284 controls) and no variants were found to interact with radiation dose. Carriers of a RAD50 haplotype exposed to ≥1Gy had an increased risk of CBC compared with unexposed carriers (RR=4.31 (95% CI 1.93-9.62)); with an excess relative risk (ERR)/Gy = 2.13 (95% CI 0.61-5.33)). Although the results of this study were largely null, carriers of a haplotype in RAD50 treated with radiation, had a greater CBC risk than unexposed carriers. This suggests that carriers of this haplotype may be susceptible to the DNA-damaging effects of radiation therapy associated with radiation-induced breast cancer.
DNA repair; haplotypes; polymorphisms; radiation; contralateral breast cancer
While ionizing radiation is an established environmental risk factor for thyroid cancer, the effect of chemotherapy drugs on thyroid cancer risk remains unclear. We evaluated the chemotherapy-related risk of thyroid cancer in childhood cancer survivors, and the possible joint effects of chemotherapy and radiotherapy.
The study included 12,547 five-year survivors of childhood cancer diagnosed during 1970 through 1986. Chemotherapy and radiotherapy information was obtained from medical records, and radiation dose was estimated to the thyroid gland. Cumulative incidence and relative risks were calculated using life-table methods and Poisson regression. Chemotherapy-related risks were evaluated separately by categories of radiation dose.
Histologically confirmed thyroid cancer occurred in 119 patients. Thirty years after the first childhood cancer treatment, the cumulative incidence of thyroid cancer was 1.3% (95% CI, 1.0–1.6) for females and 0.6% (0.4–0.8) for males. Among patients with thyroid radiation doses ≤ 20 Gy, treatment with alkylating agents was associated with a significant 2.4-fold increased risk of thyroid cancer (95% CI, 1.3–4.5; P = 0.002). Chemotherapy risks decreased as radiation dose increased, with a significant decrease for patients treated with alkylating agents (P-trend = 0.03). No chemotherapy-related risk was evident for thyroid radiation doses >20 Gy.
Treatments with alkylating agents increased thyroid cancer risk, but only in the radiation dose range under 20 Gy, where cell sparing likely predominates over cell killing.
Our study adds to the evidence for chemotherapy agent-specific increased risks of thyroid cancer, which to date, were mainly thought to be related to prior radiotherapy.
Thyroid cancer; second cancer; chemotherapy; radiation risk; cohort study
Preconception radiation and chemotherapy have the potential to produce germ cell mutations leading to genetic disease in the next generation. Dose-response relationships were evaluated between cancer treatments and untoward pregnancy outcomes.
Patients and Methods
A case-cohort study was conducted involving 472 Danish survivors of childhood and adolescent cancer and their 1,037 pregnancies. Adverse outcomes included 159 congenital malformations, six chromosomal abnormalities, seven stillbirths, and nine neonatal deaths. Preconception radiation doses to the gonads, uterus, and pituitary gland and administered chemotherapy were quantified based on medical records and related to adverse outcomes using a generalized estimating equation model.
No statistically significant associations were found between genetic disease in children and parental treatment with alkylating drugs or preconception radiation doses to the testes in male and ovaries in female cancer survivors. Specifically, the risk of genetic disease was similar among the children of irradiated survivors when compared with nonirradiated survivors (relative risk [RR], 1.02; 95% CI, 0.59 to 1.44; P = .94). A statistically significant association between abdomino-pelvic irradiation and malformations, stillbirths, and neonatal deaths was not seen in the children of female survivors overall (P = .07) or in the children of mothers receiving high uterine doses (mean, 13.5 Gy; max, 100 Gy; RR, 2.3; 95% CI, 0.95 to 5.56).
Mutagenic chemotherapy and radiotherapy doses to the gonads were not associated with genetic defects in children of cancer survivors. However, larger studies need to be conducted to further explore potential associations between high-dose pelvic irradiation and specific adverse pregnancy outcomes.
Childhood cancer survivors are at increased risk of morbidity and mortality. To further characterize this risk, this study aimed to compare the prevalence of diabetes mellitus (DM) in childhood cancer survivors and their siblings.
Participants included 8599 survivors in the Childhood Cancer Survivor Study (CCSS), a retrospectively ascertained North American cohort of long-term survivors who were diagnosed 1970–1986, and 2936 randomly selected siblings of CCSS survivors. The main outcome was self-reported DM.
Survivors and siblings had mean ages of 31.5 years (range, 17.0–54.1) and 33.4 years (range, 9.6–58.4), respectively. DM was reported in 2.5% of survivors and 1.7% of siblings. Adjusting for body mass index (BMI), age, sex, race/ethnicity, household income, and insurance, survivors were 1.8 times more likely to report DM (95% confidence interval [CI], 1.3–2.5; P<0.001) than siblings, with survivors who received total body irradiation (odds ratio [OR], 12.6; 95% CI, 6.2–25.3; P<0.001), abdominal irradiation (OR, 3.4; 95% CI, 2.3–5.0; P<0.001) and cranial irradiation (OR, 1.6; 95% CI 1.0–2.3; P=0.03) at increased risk. In adjusted models, increased risk of DM was associated with: total body irradiation (OR 7.2; 95% CI, 3.4–15.0; P<0.001); abdominal irradiation (OR 2.7; 95% CI, 1.9–3.8; P<0.001); alkylating agents (OR 1.7; 95% CI, 1.2–2.3; P<0.01); and younger age at diagnosis (0–4 years; OR 2.4; 95% CI 1.3–4.6; P<0.01).
Childhood cancer survivors treated with total body or abdominal irradiation have an increased risk of diabetes that appears unrelated to BMI or physical inactivity.
Childhood cancer survivor; diabetes mellitus; abdominal radiation; total body irradiation
Our study examines whether reproductive and hormonal factors prior to, at the time of, or subsequent to, radiation treatment for a first primary breast cancer, modify the risk of radiation-induced second primary breast cancer.
Methods and Materials
The Women’s Environmental, Cancer and Radiation Epidemiology (WECARE) Study is a multi-center, population-based study of 708 women (cases) with asynchronous contralateral breast cancer (CBC) and 1,399 women (controls) with unilateral breast cancer. Radiotherapy (RT) records, coupled with anthropomorphic phantom simulations, were used to estimate quadrant-specific radiation dose to the contralateral breast for each patient. Rate ratios (RR) and 95% confidence intervals (CI) were computed to assess the relationship between reproductive factors and risk of CBC.
Women who were nulliparous at diagnosis and exposed to ≥1 gray (Gy) to the contralateral breast, had a greater risk of CBC than matched unexposed nulliparous women (RR=2.2, 95% CI 1.2–4.0). No increased risk was seen in RT-exposed parous women (RR=1.1, 95% CI 0.8–1.4). Women treated with RT who later became pregnant (n=8 cases and 9 controls) had a greater risk of CBC (RR=6.0, 95% CI 1.3, 28.4) than unexposed women (n=4 cases and 7 controls) who also became pregnant. The association of radiation with risk of CBC did not vary by number of pregnancies, history of breastfeeding or menopausal status at the time of first breast cancer diagnosis.
Nulliparous women treated with RT were at an increased risk of CBC. Although based on small numbers, women who become pregnant after first diagnosis also appear to be at an increased risk of radiation-induced CBC.
Reproductive factors; radiation treatment; second primary contralateral breast cancer
Little is known about pain among long-term adult survivors of childhood cancers. The study investigated pain prevalence in this population compared with sibling controls and examined pain-related risk factors. Three self-reported pain outcomes including pain conditions, prescription analgesics used, and pain attributed to cancer and treatment were assessed among 10,397 cancer survivors and 3,034 sibling controls from the Childhood Cancer Survivor Study (CCSS). Pain conditions (pain/abnormal sensation, migraines, and other headaches) were reported by 12.3%, 15.5%, and 20.5% of survivors respectively; 16.7% of survivors reported use of prescription analgesics, and 21% attributed pain to cancer and treatment. Risks of reporting pain conditions and using prescription analgesics were higher among survivors than siblings adjusting for sociodemographic factors. Younger age at diagnosis and a history of non-Hodgkin lymphoma, Wilms tumor, or neuroblastoma (compared to leukemia) were associated with greater risk of reporting pain conditions. A history of bone cancer or soft tissue sarcoma (compared to leukemia) was associated with greater risks of using prescription analgesics and cancer-related pain attribution. Non-brain directed scatter irradiation was associated with elevated risk for migraines and cancer-related pain attribution. Female gender and lower educational attainment were associated with increased reports of all three pain outcomes; minority status, unemployment, and being single were associated with greater risks for reporting pain conditions. These findings contribute to the understanding of pain and associated risk factors among adult survivors of childhood cancer and suggest areas of focus for pain intervention.
Long-term adult survivors of childhood cancer; Self-reported pain; Pain attribution; Risk factors
Long-term survivors of childhood cancer are at risk for fatigue, sleep problems, and neurocognitive impairment, though the association between these outcomes has not been previously examined.
Outcomes were evaluated in 1426 survivors from the Childhood Cancer Survivor Study using a validated Neurocognitive Questionnaire. Relative risks for neurocognitive impairment were calculated using demographic and treatment factors, and survivors’ report on the FACIT-Fatigue, the Short Form-36 Vitality Scale (SF-36-V), the Pittsburgh Sleep Quality Index (PSQI), and the Epworth Sleepiness Scale (ESS).
Neurocognitive impairment was identified in over 20% of survivors, using sibling-based norms for comparison. Multivariable logistic regression models revealed that fatigue (RR=1.34, 1.13–1.59), daytime sleepiness (RR=1.68, 1.55–1.83), poor sleep quality (RR=1.23, 1.01–1.49) and decreased vitality (RR=1.75, 95% CI 1.33–2.30) were all associated with impaired task efficiency. Likewise, fatigue (RR=1.77, 1.23–2.55), sleepiness (RR=1.38, 1.14–1.67) and decreased vitality (RR=3.08, 1.98–4.79) were predictive of emotional regulation problems. Diminished organization was associated with increased sleepiness (RR=1.80, 1.31–2.48) and decreased vitality (RR=1.90, 1.37–2.63). Impaired memory was associated with poor sleep quality (RR=1.45, 1.19–1.76), increased sleepiness (RR=2.05, 1.63–2.58), and decreased vitality (RR=2.01, 1.42–2.86). The impact of fatigue, sleepiness, sleep quality and vitality on neurocognitive outcomes was independent of the effects of cranial radiation therapy, steroids and antimetabolite chemotherapy, sex, and current age.
Neurocognitive function in long-term survivors of childhood cancer appears particularly vulnerable to the effects of fatigue and sleep disruption. These findings suggest sleep hygiene should be emphasized among survivors, as it may provide an additional mechanism for intervention to improve neurocognitive outcomes.
Childhood Cancer Survivor Study; CCSS; neurocognitive; sleep; fatigue; vitality
We examined the relationship of physical, mental, and neurocognitive function with employment and occupational status in the Childhood Cancer Survivor Study.
We included survivors ≥25 years of age with available Short Form-36 (physical and mental health component scores), Brief Symptom Inventory (depression, anxiety and somatization), and Neurocognitive Questionnaire (task efficiency, emotional regulation, organization, and memory). We generated relative risks (RR) from generalized linear models for these measures on unemployment (N=5386) and occupation (N=3763) outcomes adjusted for demographic and cancer-related factors, and generated sex-stratified models.
Poor physical health was associated with an almost 8-fold higher risk of health-related unemployment (p<0.001) compared to survivors with normal physical health. Male survivors with somatization and memory problems were approximately 50% (p<0.05 for both) more likely to report this outcome, while task efficiency limitations was significant for both sexes (males: RR=2.43, p<0.001; females: RR=2.28, p<0.001). Employed female survivors with task efficiency, emotional regulation, and memory limitations were 13%-20% (p<0.05 for all) less likely to work in professional or managerial occupations than unaffected females.
Physical problems may cause much of the health-related unemployment among childhood cancer survivors. While both male and female survivors with neurocognitive deficits – primarily in task efficiencies – are at risk for unemployment, employed female survivors with neurocognitive deficits may face poor occupational outcomes more often than males.
Childhood cancer survivors are at risk for poor employment outcomes. Screening and intervention for physical, mental and neurocognitive limitations could improve employment outcomes for this population.
pediatric cancer; employment status; physical health; mental health; neurocognitive function
Adult childhood cancer survivors report high levels of unemployment although it is unknown whether this is due to health or employability limitations.
We examined two employment outcomes from 2002–2005 in the Childhood Cancer Survivor Study (CCSS): 1. health-related unemployment and 2. unemployed but seeking work. We compared survivors to a nearest-age CCSS sibling cohort and examined demographic and treatment-related risk groups for each outcome.
We studied 6339 survivors and 2280 siblings aged ≥25 years excluding those unemployed by choice. Multivariable generalized linear models evaluated whether survivors were more likely to be unemployed than siblings and whether certain survivors were at a higher risk for unemployment.
Survivors (10.4%) reported health-related unemployment more often than siblings (1.8%; Relative Risk [RR] 6.07, 95% Confidence Interval [CI] 4.32–8.53). Survivors (5.0%) were more likely to report being unemployed but seeking work than siblings (2.7%; RR 1.90, 95% CI 1.43–2.54). Health-related unemployment was more common in female survivors than males (Odds Ratio [OR] 1.73, 95% CI 1.43–2.08). Cranial radiotherapy doses ≥25 Gy were associated with higher odds of unemployment (health-related: OR 3.47, 95% CI 2.54–4.74; seeking work: OR 1.77, 95% CI 1.15–2.71). Unemployed survivors reported higher levels of poor physical functioning than employed survivors, and had lower education and income and were more likely to be publicly insured than unemployed siblings.
Childhood cancer survivors have higher levels of unemployment due to health or being between jobs. High-risk survivors may need vocational assistance.
Childhood cancer survivors experience an increased incidence of subsequent neoplasms (SNs). Those surviving the first SN (SN1) remain at risk to develop multiple SNs. Because SNs are a common cause of late morbidity and mortality, characterization of rates of multiple SNs is needed.
Patients and Methods
In a total of 14,358 5-year survivors of childhood cancer diagnosed between 1970 and 1986, analyses were carried out among 1,382 survivors with an SN1. Cumulative incidence of second subsequent neoplasm (SN2), either malignant or benign, was calculated.
A total of 1,382 survivors (9.6%) developed SN1, of whom 386 (27.9%) developed SN2. Of those with SN2, 153 (39.6%) developed more than two SNs. Cumulative incidence of SN2 was 46.9% (95% CI, 41.6% to 52.2%) at 20 years after SN1. The cumulative incidence of SN2 among radiation-exposed survivors was 41.3% (95% CI, 37.2% to 45.4%) at 15 years compared with 25.7% (95% CI, 16.5% to 34.9%) for those not treated with radiation. Radiation-exposed survivors who developed an SN1 of nonmelanoma skin cancer (NMSC) had a cumulative incidence of subsequent malignant neoplasm (SMN; ie, malignancies excluding NMSC) of 20.3% (95% CI, 13.0% to 27.6%) at 15 years compared with only 10.7% (95% CI, 7.2% to 14.2%) for those who were exposed to radiation and whose SN1 was an invasive SMN (excluding NMSC).
Multiple SNs are common among aging survivors of childhood cancer. SN1 of NMSC identifies a population at high risk for invasive SMN. Survivors not exposed to radiation who develop multiple SNs represent a population of interest for studying genetic susceptibility to neoplasia.