The impact of childhood cranial radiation therapy (CRT) on stroke risk in adulthood, and the role of modifiable atherosclerotic risk factors, remains poorly defined. We assessed long-term incidence rates and stroke risk factors in survivors of childhood cancer followed by the Childhood Cancer Survivor Study (CCSS).
Patients and Methods
CCSS is a multi-institutional retrospective cohort study of 14,358 five-year survivors of childhood cancer and 4,023 randomly selected sibling controls with longitudinal follow up. Age-adjusted incidence rates of self-reported late-occurring (≥ 5 years after diagnosis) first-stroke were calculated. Multivariable Cox Proportional Hazards models were used to identify independent stroke predictors.
During a mean follow-up of 23.3 years, 292 survivors reported a late-occurring stroke. The age-adjusted stroke rate per 100,000 person-years was 77 (95% Confidence Interval [CI] 62–96) compared to 9.3 (95% CI 4–23) for siblings. Treatment with CRT increased stroke risk in a dose dependent manner: hazard ratio (HR) 5.9 (95% CI 3.5–9.9) for 30–49 Gy CRT, and 11.0 (7.4–17.0) for 50+ Gy CRT. The cumulative stroke incidence in survivors treated with 50+ Gy CRT was 1.1% (95% CI 0.4–1.8) at 10 years post-diagnosis and 12% (95% CI 8.9–15.0) at 30 years. Hypertension (HTN) increased stroke hazard by 4-fold (95% CI 2.8–5.5) and in black survivors by 16-fold (95% CI 6.9–36.6).
Young adult pediatric cancer survivors have an increased stroke risk that is associated with CRT in a dose dependent manner. Atherosclerotic risk factors enhanced this risk and should be treated aggressively.
Cancer survivors experience treatment-related complications that can be exacerbated by tobacco use. This study reports the prevalence of smokeless (ST) and dual tobacco (DT) use, compares these rates to the US population, and examines tobacco risk factors among males surviving childhood cancer. Data from the Childhood Cancer Survivor Study (CCSS) 2007 survey were used (N = 3378). Standardized incidence ratios (SIR) were obtained by comparing CCSS data to the National Survey on Drug Use and Health. Logistic regression was used to evaluate associations between risk factors and tobacco use. Among male survivors, 8.3% and 2.3% were current ST and DT users, respectively. Survivors were less likely than population males to report ST (SIR = 0.64, 95% CI = 0.57 – 0.72) or DT (SIR = 0.37, CI = 0.29 – 0.46) use; however, non-white survivors aged 35–49 years were more likely to use ST (SIR = 2.32, CI = 1.27 – 3.90). ST use was associated (p < 0.05) with younger age at diagnosis, lower education, being married or divorced/separated, and not living in the Northeastern US, while history of cardiovascular- and/or pulmonary-toxic treatment was protective. DT use was associated with younger age at diagnosis, lower education, divorce/separation, and high psychological distress. Having active heart or circulatory conditions was protective. Although ST/DT use is generally low among childhood cancer survivors, these findings suggest that tobacco use screening should be expanded to include ST use and that ST-specific education and cessation interventions should be provided to users. Screening and intervening for ST/DT use in childhood cancer survivors will reduce tobacco-related morbidity and mortality.
smokeless tobacco; dual tobacco; cancer survivors; health behaviors
To evaluate health status and participation restrictions in childhood
extremity sarcoma survivors.
Members of the CCSS cohort with extremity sarcomas, who completed
1995, 2003 or 2007 questionnaires, were included.
Cohort Study of extremity sarcomas survivors.
Childhood cancer survivors diagnosed and treated between
Main Outcome Measure
Prevalence rates for poor health status in six domains and five
sub-optimal social participation categories were compared by tumor location
and treatment exposure with generalized estimating equations adjusted for
demographic/personal factors and time/age.
Among 1094 survivors, median age at diagnosis 13 years (range
0–20), current age 33 years (range 10–53), 49% were
male, 87.5% Caucasian, and 75% had lower extremity tumors.
In adjusted models, when compared to upper extremity survivors, lower
extremity survivors had increased risk of activity limitations but lower
risk of not completing college. Compared to those who did not have surgery,
those with limb-sparing (LS) and upper extremity amputations (UEA) were 1.6
times more likely to report functional impairment; while those with an above
the knee amputation (AKA) were 1.9 times more likely to report functional
impairment. Survivors treated with LS were 1.5 times more likely to report
activity limitations. Survivors undergoing LS were more likely to report
inactivity, incomes < $20,000, unemployment and no college
degree. Those with UEA more likely reported inactivity, unmarried status and
no college degree. Lastly, those with AKA more likely reported no college
degree. Treatment with abdominal irradiation was associated with increased
risk of poor mental health, functional impairment and activity
Treatment for lower extremity sarcomas is associated with a
50% increased risk for activity limitations; upper extremity
survivors are at 10% higher risk for not completing college. Type of
local control influences health status and participation restrictions. Both
these outcomes decline with age.
upper extremity; lower extremity; sarcoma; survivors; childhood cancer
The aims of this study are to compare self-reported sleep quality in adult survivors of childhood brain tumors and a population-based comparison group, to identify treatment-related factors associated with sleep disturbances, and to identify the impact of post-treatment obesity and depression on sleep scores in adult survivors of childhood brain tumors.
Randomly selected adult survivors of childhood brain tumors (n = 78) and age, sex and zip code matched population-group members (n = 78) completed the Pittsburgh Sleep Quality Index and the Brief Symptom Inventory. Sleep quality and the effect of demographic, treatment, and post-treatment characteristics were evaluated with linear and logistic regression analyses.
Brain tumor survivors were 2.7 (95% CI: 1.1, 6.0) times more likely than the comparison group to take greater than 30 minutes to fall asleep. Females in both groups reported worse sleep quality and impaired daytime functioning. Among survivors, post-treatment obesity was associated with daytime dysfunction.
These results agree with previous studies associating sleep, sex and obesity and identified longer sleep latency as being a problem among childhood brain tumor survivors. Further study identifying factors contributing to sleep latency, and its impact on quality of life among adult survivors of childhood brain tumors is needed.
Sleep quality; sleep latency; adult survivors; childhood brain tumors
Survivors of pediatric brain tumors are at-risk for late effects
which may affect mobility within and access to the physical environment.
This study examined the prevalence of and risk factors for restricted
environmental access in survivors of childhood brain tumors and investigated
the associations between reduced environmental access, health-related
quality of life (HRQOL), and survivors’ social functioning.
In-home evaluations were completed for 78 brain tumor survivors and
78 population-based controls matched on age, sex, and zip-code. Chi-square
tests and multivariable logistic regression models were used to calculate
odds ratios (OR) and 95% confidence intervals (CI) for poor environmental
access and reduced HRQOL.
The median age of survivors was 22 years at the time of study.
Compared to controls, survivors were more likely to report avoiding most
dimensions of their physical environment, including a single flight of
stairs (p<0.001), uneven surfaces (p<0.001), traveling alone
(p=0.01), and traveling to unfamiliar places (p=0.001). Overall, survivors
were 4.8 times more likely to report poor environmental access (95% CI,
2.0-11.5, p<0.001). In survivors, poor environmental access was
associated with reduced physical function (OR=3.6, 95% CI, 1.0-12.8,
p=0.04), general health (OR=6.0, 95% CI, 1.8-20.6, p=0.002), and social
functioning (OR=4.3, 95% CI, 1.1-17.3, p=0.03).
Adult survivors of pediatric brain tumors were more likely to avoid
their physical environment than matched controls. Restricted environmental
access was associated with reduced HRQOL and diminished social functioning.
Interventions directed at improving physical mobility may have significant
impact on survivor quality of life.
CNS malignancies; survivorship; quality of life; environmental access
Exposure to ionizing radiation has been consistently associated with increased risk of female breast cancer. Although the majority of DNA damage caused by ionizing radiation is corrected by the base-excision repair pathway, certain types of multiple-base damage can only be repaired through the nucleotide excision repair pathway. In a nested case–control study of breast cancer in US radiologic technologists exposed to low levels of ionizing radiation (858 cases, 1,083 controls), we examined whether risk of breast cancer conferred by radiation was modified by nucleotide excision gene polymorphisms ERCC2 (XPD) rs13181, ERCC4 (XPF) rs1800067 and rs1800124, ERCC5 (XPG) rs1047769 and rs17655; and ERCC6 rs2228526. Of the 6 ERCC variants examined, only ERCC5 rs17655 showed a borderline main effect association with breast cancer risk (ORGC = 1.1, ORCC = 1.3; p-trend = 0.08), with some indication that individuals carrying the C allele variant were more susceptible to the effects of occupational radiation (EOR/GyGG = 1.0, 95% CI = <0, 6.0; EOR/GyGC/CC = 5.9, 95% CI = 0.9, 14.4; phet = 0.10). ERCC2 rs13181, although not associated with breast cancer risk overall, statistically significantly modified the effect of occupational radiation dose on risk of breast cancer (EOR/GyAA = 9.1, 95% CI = 2.1–21.3; EOR/GyAC/CC = 0.6, 95% CI = <0, 4.6; phet = 0.01). These results suggest that common variants in nucleotide excision repair genes may modify the association between occupational radiation exposure and breast cancer risk.
We studied cancer mortality in a cohort of 5,573 women with scoliosis and other spine disorders diagnosed between 1912 and 1965, and who were exposed to frequent diagnostic X-ray procedures. Patients were identified from medical records in 14 orthopedic medical centers in the United States and followed for vital status and address through Dec 31, 2004, using publicly available regional, state, and nation-wide databases. Causes of death were obtained from death certificates or through linkage with the National Death Index (NDI). Statistical analyses included standardized mortality ratios (SMR=observed/expected) based on death rates for U.S. females, and internal comparisons using Cox regression models with attained age as the time scale. Diagnostic radiation exposure was estimated from radiology files for over 137,000 procedures; estimated average cumulative radiation doses to the breast, lung, thyroid and bone marrow were 10.9, 4.1, 7.4, and 1.0 cGy, respectively. After a median follow-up period of 47 years, 1527 women died including 355 from cancer. Cancer mortality was 8% higher than expected (95% CI=0.97–1.20). Mortality from breast cancer was significantly elevated (SMR=1.68; 95% CI: 1.38–2.02), whereas death rates from several other cancers were below expectation, in particular lung (SMR=0.77), cervical (SMR=0.31), and liver (SMR=0.17). The excess relative risk (ERR) for breast cancer mortality increased significantly with 10-yr lagged radiation dose to the breast (ERR/Gy=3.9; 95% CI: 1.0–9.3).
breast neoplasms; radiation-induced; mortality; radiation; radiography; scoliosis; cohort study; epidemiology
Adult survivors of childhood cancer are known to be at increased risk of subsequent malignancy, but only limited data exist describing the incidence and risk factors for secondary renal carcinoma. Among 14 358 5-year survivors diagnosed between 1970 and 1986, we estimated standardized incidence ratios (SIRs) for subsequent renal carcinoma and identified associations with primary cancer therapy using Poisson regression. Twenty-six survivors were diagnosed with renal carcinoma (median = 22.6 years from diagnosis; range = 6.3–35.7 years), reflecting a statistically significant excess (SIR = 8.0, 95% confidence interval [CI] = 5.2 to 11.7) compared with the general population. Highest risk was observed among neuroblastoma survivors (SIR = 85.8, 95% CI = 38.4 to 175.2) and, in multivariable analyses, with renal-directed radiotherapy of 5 Gy or greater (relative risk [RR] = 3.8, 95% CI = 1.6 to 9.3) and platinum-based chemotherapy (RR = 3.5, 95% CI = 1.0 to 11.2). To our knowledge, this is the first report of an association between cisplatin and subsequent renal carcinoma among survivors of childhood cancer.
Adult survivors of childhood cancer are at risk for long-term morbidities, which may be managed pharmacologically. Psychoactive medication treatment has been associated with adverse effects on specific neurocognitive processes in non-cancer populations, yet these associations have not been examined in adult survivors of childhood cancer.
Outcomes were evaluated in 7,080 adult survivors from the Childhood Cancer Survivor Study using a validated self-report Neurocognitive Questionnaire. Multivariable logistic regression models were used to calculate odds ratios (OR) and 95% confidence intervals (CI) for neurocognitive impairment using demographic and treatment factors and survivors’ report of prescription medication use.
Controlling for cranial radiation, pain, psychological distress, and stroke/seizure, use of antidepressant medications was associated with impaired task efficiency (OR=1.80, 95% CI=1.47–2.21), organization (OR=1.83, 95% CI=1.48–2.25), memory (OR=1.53, 95% CI=1.27–1.84) and emotional regulation (OR=2.06, 95% CI=1.70–2.51). Neuroleptics and stimulants were associated with impaired task efficiency (OR=2.46, 95% CI=1.29–4.69; OR=2.82, 95% CI=1.61–4.93, respectively) and memory (OR=2.08, 95% CI=1.13–3.82; OR=2.69, 95% CI=1.59–4.54, respectively). Anticonvulsants were associated with impaired task efficiency, memory and emotional regulation, although survivors who use these medications may be at risk for neurocognitive impairment on the basis of seizure disorder and/or underlying tumor location (CNS).
These findings suggest that specific psychoactive medications and/or mental health conditions may be associated with neurocognitive function in adult survivors of childhood cancer. The extent to which these associations are causal or indicative of underlying neurological impairment for which the medications are prescribed remains to be ascertained.
psychoactive medication; neurocognition; survivorship
To evaluate effects of radiotherapy, chemotherapy, cigarette smoking and alcohol consumption on the risk of second primary salivary gland cancer (SGC) in the Childhood Cancer Survivor Study (CCSS).
Standardized incidence ratios (SIR) and excess absolute risks (EAR) of SGC in the CCSS were calculated using incidence rates from Surveillance, Epidemiology and End Results population-based cancer registries. Radiation dose to the salivary glands was estimated based on medical records. Poisson regression was used to assess risks with respect to radiation dose, chemotherapy, smoking and alcohol consumption.
During the time period of the study, 23 cases of SGC were diagnosed among 14,135 childhood cancer survivors. The mean age at diagnosis of the first primary cancer was 8.3 years, and the mean age at SGC diagnosis was 24.8 years. The incidence of SGC was 39-fold higher in the cohort than in the general population (SIR=39.4; 95% CI: 25.4–7.8). The EAR was 9.8 per 100,000 person years. Risk increased linearly with radiation dose (excess relative risk=0.36 per gray; 95% CI: 0.06 to 2.5) and remained elevated after 20 years. There was no significant trend of increasing risk with increasing dose of chemotherapeutic agents, pack-years of cigarette smoking or alcohol intake.
While the cumulative incidence of SGC was low, childhood cancer survivors treated with radiation experienced significantly increased risk for at least two decades following exposure, and risk was positively associated with radiation dose. Results underscore the importance of long-term follow up of childhood cancer survivors for the development of new malignancies.
To assess the shape of the dose response for various cancer endpoints, and modifiers by age and time.
Methods and Materials
Re-analysis of the US peptic ulcer data testing for heterogeneity of radiogenic risk by cancer endpoint (stomach, pancreas, lung, leukemia, all other).
There are statistically significant (p<0.05) excess risks for all cancer, and lung cancer, and borderline statistically significant risks for stomach cancer (p=0.07), and leukemia (p=0.06), with excess relative risks Gy−1 of 0.024 (95% CI 0.011, 0.039), 0.559 (95% CI 0.221, 1.021), 0.042 (95% CI −0.002, 0.119), and 1.087 (95% CI −0.018, 4.925), respectively. There is statistically significant (p=0.007) excess risk of pancreatic cancer when adjusted for dose-response curvature. General downward curvature is apparent in the dose response, statistically significant (p<0.05) for all cancers, pancreatic cancer and all other cancers (than stomach, pancreas, lung, leukemia). There are indications of reduction in risk with increasing age at exposure (for all cancers, pancreatic cancer), but no evidence for quadratic variations in relative risk with age at exposure. If a linear-exponential dose response is used there is no significant heterogeneity in the dose response between the five endpoints considered, or in the speed of variation of relative risk with age at exposure. The risks are generally consistent with those observed in the Japanese atomic bomb survivors and in groups of nuclear workers.
There are excess risks for various malignancies in this dataset. Generally there is marked downward curvature in the dose response, and significant reduction in relative risk with increasing age at exposure. The consistency of risks with those observed in the Japanese atomic bomb survivors, and in groups of nuclear workers, implies that there may be little sparing effect of fractionation of dose or low dose rate exposure.
stomach cancer; lung cancer; pancreatic cancer; leukemia
To fully characterize the risk of contralateral breast cancer (CBC) in patients with breast cancer with a family history who test negative for BRCA1 and BRCA2 mutations.
Patients and Methods
From our population-based case-control study comparing women with CBC to women with unilateral breast cancer (UBC), we selected women who tested negative for BRCA1 and BRCA2 mutations (594 patients with CBC/1,119 control patients with UBC). Rate ratios (RRs) and 95% CIs were estimated to examine the association between family history of breast cancer and risk of asynchronous CBC. Age- and family history–specific 10-year cumulative absolute risks of CBC were estimated.
Family history of breast cancer was associated with increased CBC risk; risk was highest among young women (< 45 years) with first-degree relatives affected at young ages (< 45 years; RR, 2.5; 95% CI, 1.1 to 5.3) or women with first-degree relatives with bilateral disease (RR, 3.6; 95% CI, 2.0 to 6.4). Women diagnosed with UBC before age 55 years with a first-degree family history of CBC had a 10-year risk of CBC of 15.6%.
Young women with breast cancer who have a family history of breast cancer and who test negative for deleterious mutations in BRCA1 and BRCA2 are at significantly greater risk of CBC than other breast cancer survivors. This risk varies with diagnosis age, family history of CBC, and degree of relationship to an affected relative. Women with a first-degree family history of bilateral disease have risks of CBC similar to mutation carriers. This has important implications for the clinical management of patients with breast cancer with family history of the disease.
The differential effects of cranial (CRT), spinal (SRT), and total body irradiation (TBI) on growth and endocrine outcomes have rarely been examined in combination among childhood acute leukemia survivors.
Self-reported height/weight, hypothyroidism, and pregnancy/live birth were determined among acute lymphoblastic and myeloid leukemia survivors (n=3,467) participating in the Childhood Cancer Survivor Study, an ongoing cohort study of 5-year survivors of pediatric cancers diagnosed from 1970 to 1986.
Compared with no radiotherapy, risk estimates were consistent across outcomes (adult short stature, hypothyroidism, absence of pregnancy/live birth) with CRT treatment associated with 2–3 fold increased risks, TBI associated with 5–10 fold increased risks, and CRT+TBI associated with >10 fold increased risks. Exposure to any SRT further increased risk of these outcomes 2–3 fold. Changes in body composition were more nuanced as CRT only was associated with an increased risk of being overweight/obese (OR 1.6, 95% CI 1.3–1.9) whereas TBI only was associated with an increased risk of being underweight (OR 6.0, 95% CI 2.4–14.9).
Although patients treated with CRT+TBI were at greatest risk for short stature, hypothyroidism, and a reduced likelihood of pregnancy/live birth, those treated with either modality alone had significantly increased risks as well, including altered body composition. Any SRT exposure further increased risk in an independent fashion.
leukemia; childhood; survivor; growth; hypothyroidism; pregnancy
We developed three absolute risk models for second primary thyroid cancer to assist with long-term clinical monitoring of childhood cancer survivors.
Patients and Methods
We used data from the Childhood Cancer Survivor Study (CCSS) and two nested case-control studies (Nordic CCSS; Late Effects Study Group). Model M1 included self-reported risk factors, model M2 added basic radiation and chemotherapy treatment information abstracted from medical records, and model M3 refined M2 by incorporating reconstructed radiation absorbed dose to the thyroid. All models were validated in an independent cohort of French childhood cancer survivors.
M1 included birth year, initial cancer type, age at diagnosis, sex, and past thyroid nodule diagnosis. M2 added radiation (yes/no), radiation to the neck (yes/no), and alkylating agent (yes/no). Past thyroid nodule was consistently the strongest risk factor (M1 relative risk [RR], 10.8; M2 RR, 6.8; M3 RR, 8.2). In the validation cohort, 20-year absolute risk predictions for second primary thyroid cancer ranged from 0.04% to 7.4% for M2. Expected events agreed well with observed events for each model, indicating good calibration. All models had good discriminatory ability (M1 area under the receiver operating characteristics curve [AUC], 0.71; 95% CI, 0.64 to 0.77; M2 AUC, 0.80; 95% CI, 0.73 to 0.86; M3 AUC, 0.75; 95% CI, 0.69 to 0.82).
We developed and validated three absolute risk models for second primary thyroid cancer. Model M2, with basic prior treatment information, could be useful for monitoring thyroid cancer risk in childhood cancer survivors.
To assess the shape of the dose response for various circulatory disease endpoints, and modifiers by age and time since exposure.
Methods and Materials
Analysis of the US peptic ulcer data testing for heterogeneity of radiogenic risk by circulatory disease endpoint (ischemic heart, cerebrovascular, other circulatory disease).
There are significant excess risks for all circulatory disease, with an excess relative risk Gy−1 of 0.082 (95% CI 0.031, 0.140), and ischemic heart disease, with an excess relative risk Gy−1 of 0.102 (95% CI 0.039, 0.174) (both p<0.01), and indications of excess risk for stroke. There are no statistically significant (p>0.2) differences between risks by endpoint, and few indications of curvature in the dose response. There are significant modifications of relative risk by time since exposure, the magnitude of which does not vary between endpoints (p>0.2). Risk modifications are similar if analysis is restricted to those receiving radiation, although relative risks are slightly larger and the risk of stroke fails to be significant. The slopes of the dose response are generally consistent with those observed in the Japanese atomic bomb survivors and in occupationally and medically exposed groups.
There are excess risks for a variety of circulatory diseases in this dataset, with significant modification of risk by time since exposure. The consistency of the dose-response slopes with those observed in radiotherapeutically-treated groups at much higher dose, as well as in lower-dose exposed cohorts such as the Japanese atomic bomb survivors and nuclear workers implies that there may be little sparing effects of fractionation of dose or low dose-rate exposure.
circulatory disease; ischemic heart disease; stroke; peptic ulcer; benign disease
Although reductions in bone mineral density are well-documented among children during treatment for cancer and among childhood cancer survivors, little is known about the long-term risk of fracture. The aim of this study was to ascertain the prevalence of and risk factors for fractures among individuals participating in the Childhood Cancer Survivor Study (CCSS).
Analyses included 7414 5+ year survivors of childhood cancer diagnosed between 1970-86 who completed the 2007 CCSS follow-up questionnaire and a comparison group of 2374 siblings. Generalized linear models stratified by sex were used to compare the prevalence of reported fractures between survivors and siblings.
The median ages at follow-up among survivors and siblings were 36.2, (range: 21.2-58.8) and 38.1 years (range: 18.4-62.6), respectively with a median 22.7 years of follow-up after cancer diagnosis for survivors. Approximately 35% of survivors and 39% of siblings reported ≥1 fractures during their lifetime. The prevalence of fractures was lower among survivors than siblings, both in males (prevalence ratio=0.87, 95%CI=0.81-0.94, p<0.001) and females (prevalence ratio=0.94, 95%CI=0.86-1.04, p=0.22). In multivariable analyses, increasing age at follow-up, white race, methotrexate treatment and balance difficulties were associated with increased prevalence of fractures among female survivors (p=0.05). Among males, only smoking history and white race were associated with an increased prevalence of fracture (p<0.001).
Findings from this study indicate that the prevalence of fractures among adult survivors is not increased compared to that of siblings. Additional studies of bone health among aging female cancer survivors may be warranted.
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.