Vascular-related toxicities have been reported among survivors of Hodgkin lymphoma (HL), but their genesis is not well understood.
Fasting blood samples from 25 previously irradiated HL survivors were analyzed for biomarkers that can reveal underlying inflammation and/or endothelial cell activation: high-sensitivity C-reactive protein (hsCRP), triglycerides, total cholesterol, high-density lipoprotein (HDL), apolipoprotein ß, lipoprotein (a), fibrinogen, circulating endothelial cells (CECs) and vascular cell adhesion molecule-1 (VCAM-1) expression. Values were compared to subjects in the Coronary Artery Risk Development in Young Adults (CARDIA) study. CECs and VCAM-1 were compared to healthy controls.
Survivors (76% male), median age 17.6 yrs (5-33) at diagnosis, 33.0 yrs (19-55) at follow-up, included stages IA (n=6), IIA (n=10), IIB (n=2), IIIA (n=4), and IVA (n=3) patients. Twenty-four received at least chest radiation therapy (RT) (median dose 3,150 cGy; range: 175-4,650 cGy), one received neck only; 14 (56%) had a history of anthracycline exposure (median dose: 124 mg/m2 range: 63-200 mg/m2). Compared to CARDIA subjects, mean hsCRP (3.0 mg/L ± 2.0 vs. 1.6 ± 1.9), total cholesterol (194.1 mg/dl ± 33.2 vs. 179.4 ± 32.9), lipoprotein (a) (34.2 mg/dl ± 17.5 vs. 13.8 ± 17.5), and fibrinogen (342.0 mg/dl ± 49.1 vs. 252.6 ± 48.4) were significantly elevated. CECs (2.3 cells/ml ± 1.5 vs. 0.34 ± 1.4) were significantly elevated compared to controls. No difference in VCAM-1 expression (51.1% ± 36.8 vs. 42.3 ± 35.6) was detected.
HL survivors exposed to RT have evidence of vascular inflammation, dyslipidemia, and injury suggestive of early atherogenesis.
Survivorship; Hodgkin lymphoma; Vascular late effects
Chronic health conditions are common among long-term childhood cancer survivors, but hospitalization rates have not been reported. The objective of this study was to determine overall and cause-specific hospitalization rates among survivors of childhood cancer and compare rates to the U.S. population.
The Childhood Cancer Survivor Study (CCSS) is a retrospective cohort of 5+ year survivors of childhood malignancies treated at 26 participating centers. Self-reported hospitalizations from 10,366 survivors (diagnosed 1970–1986) were compared to U.S. population rates using age-and sex-stratified standardized incidence ratios (SIRs). Reasons for hospitalization were evaluated and associations between demographic, cancer and treatment-related risk factors with hospitalization were investigated.
Survivors were, on average, 20.9 years from cancer diagnosis (SD: 4.6, range: 13–32) and 28.6 years of age (SD: 7.7, range: 13–51). Survivor hospitalization rates were 1.6 times the U.S. population (95% CI: 1.6; 1.7). Increased hospitalization rates were noted irrespective of gender, age at follow-up and cancer diagnosis, with highest SIRs noted among male (SIR=2.6, 95% CI: 2.2; 3.0) and female (SIR=2.7, 95% CI: 2.4; 3.1) survivors aged 45–54. Female gender, an existing chronic health condition and/or a second neoplasm, and prior treatment with radiation were associated with an increased risk of non-obstetrical hospitalization.
Survivors of childhood cancer demonstrate substantially higher hospitalization rates. Additional research is needed to further quantify the healthcare utilization and economic impact of treatment-related complications as this population ages.
childhood cancer; cancer survivor; hospitalization
Carbonyl reductases (CBRs) catalyze reduction of anthracyclines to cardiotoxic alcohol metabolites. Polymorphisms in CBR1 and CBR3 influence synthesis of these metabolites. We examined whether single nucleotide polymorphisms in CBR1 (CBR1 1096G>A) and/or CBR3 (CBR3 V244M) modified the dose-dependent risk of anthracycline-related cardiomyopathy in childhood cancer survivors.
Patients and Methods
One hundred seventy survivors with cardiomyopathy (patient cases) were compared with 317 survivors with no cardiomyopathy (controls; matched on cancer diagnosis, year of diagnosis, length of follow-up, and race/ethnicity) using conditional logistic regression techniques.
A dose-dependent association was observed between cumulative anthracycline exposure and cardiomyopathy risk (0 mg/m2: reference; 1 to 100 mg/m2: odds ratio [OR], 1.65; 101 to 150 mg/m2: OR, 3.85; 151 to 200 mg/m2: OR, 3.69; 201 to 250 mg/m2: OR, 7.23; 251 to 300 mg/m2: OR, 23.47; > 300 mg/m2: OR, 27.59; Ptrend < .001). Among individuals carrying the variant A allele (CBR1:GA/AA and/or CBR3:GA/AA), exposure to low- to moderate-dose anthracyclines (1 to 250 mg/m2) did not increase the risk of cardiomyopathy. Among individuals with CBR3 V244M homozygous G genotypes (CBR3:GG), exposure to low- to moderate-dose anthracyclines increased cardiomyopathy risk when compared with individuals with CBR3:GA/AA genotypes unexposed to anthracyclines (OR, 5.48; P = .003), as well as exposed to low- to moderate-dose anthracyclines (OR, 3.30; P = .006). High-dose anthracyclines (> 250 mg/m2) were associated with increased cardiomyopathy risk, irrespective of CBR genotype status.
This study demonstrates increased anthracycline-related cardiomyopathy risk at doses as low as 101 to 150 mg/m2. Homozygosis for G allele in CBR3 contributes to increased cardiomyopathy risk associated with low- to moderate-dose anthracyclines, such that there seems to be no safe dose for patients homozygous for the CBR3 V244M G allele. These results suggest a need for targeted intervention for those at increased risk of cardiomyopathy.
Investigations of long-term outcomes have been instrumental in designing safer and more effective contemporary therapies for pediatric hematological malignancies. Despite the significant therapeutic changes that have occurred over the last five decades, therapy modifications largely represent refinements of treatment protocols using agents and modalities that have been available for more than 30 years. This review summarizes major trends in the evolution of treatment of pediatric hematological malignancies since 1960 to support the relevance of the study of late effects of historical therapeutic approaches to the design and evaluation of contemporary treatment protocols and the follow-up of present-day survivors.
Childhood cancer therapy; late effects; long-term follow-up
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
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
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.
Previous studies have indicated that thyroid cancer risk after a first childhood malignancy is curvilinear with radiation dose, increasing at low to moderate doses and decreasing at high doses. Understanding factors that modify the radiation dose response over the entire therapeutic dose range is challenging and requires large numbers of subjects. We quantified the long-term risk of thyroid cancer associated with radiation treatment among 12,547 5-year survivors of a childhood cancer (leukemia, Hodgkin lymphoma and non-Hodgkin lymphoma, central nervous system cancer, soft tissue sarcoma, kidney cancer, bone cancer, neuroblastoma) diagnosed between 1970 and 1986 in the Childhood Cancer Survivor Study using the most current cohort follow-up to 2005. There were 119 subsequent pathologically confirmed thyroid cancer cases, and individual radiation doses to the thyroid gland were estimated for the entire cohort. This cohort study builds on the previous case-control study in this population (69 thyroid cancer cases with follow-up to 2000) by allowing the evaluation of both relative and absolute risks. Poisson regression analyses were used to calculate standardized incidence ratios (SIR), excess relative risks (ERR) and excess absolute risks (EAR) of thyroid cancer associated with radiation dose. Other factors such as sex, type of first cancer, attained age, age at exposure to radiation, time since exposure to radiation, and chemotherapy (yes/no) were assessed for their effect on the linear and exponential quadratic terms describing the dose–response relationship. Similar to the previous analysis, thyroid cancer risk increased linearly with radiation dose up to approximately 20 Gy, where the relative risk peaked at 14.6-fold (95% CI, 6.8–31.5). At thyroid radiation doses >20 Gy, a downturn in the dose–response relationship was observed. The ERR model that best fit the data was linear-exponential quadratic. We found that age at exposure modified the ERR linear dose term (higher radiation risk with younger age) (P < 0.001) and that sex (higher radiation risk among females) (P = 0.008) and time since exposure (higher radiation risk with longer time) (P < 0.001) modified the EAR linear dose term. None of these factors modified the exponential quadratic (high dose) term. Sex, age at exposure and time since exposure were found to be significant modifiers of the radiation-related risk of thyroid cancer and as such are important factors to account for in clinical follow-up and thyroid cancer risk estimation among childhood cancer survivors.
Survivors of childhood acute myeloid leukemia (AML) face increased risks of chronic disease and secondary malignancies. Substance exposure may compound these risks.
Participants were diagnosed with AML at <21 years of age and survived ≥5 years following diagnosis. All underwent chemotherapy alone or followed by autologous BMT (chemo ± autoBMT) or underwent allogeneic BMT (alloBMT) if an HLA-matched related donor was available. Survivors completed a health questionnaire and a Youth Risk Behavior Survey (YRBS).
Of eligible survivors, 117 were ≥18 years of age and completed a YRBS. Survivors were a mean age of 10 years at diagnosis and 24 years at interview. Of the substance exposures assessed by YRBS, tobacco, alcohol, and marijuana were most common. Twenty-two percent (22%) had smoked cigarettes in the last 30 days. One-quarter (25%) reported binge drinking in the last month. None of these exposures varied by treatment group. Less than 10% of survivors reported cocaine, heroin, or methamphetamine use. Men were more likely to report high substance exposure (P = 0.004). Sadness/suicidality score was associated with cancer-related anxiety (P = 0.006) and multiple health conditions (P = 0.006).
This analysis reveals exposure to tobacco, alcohol, and marijuana in young adults with few differences based on treatment received. Survivors with cancer-related anxiety or multiple health conditions were more likely to report sadness/hopelessness.
leukemia; pediatric; smoking; survivor
A combined cohort of 8,884 North American, 2,893 British and 1,574 Nordic subjects with Wilms tumor (WT) diagnosed before 15 years of age during 1960–2004 was established to determine the risk of secondary malignant neoplasms (SMN). After 169,641 person-years (PY) of observation through 2005, 174 solid tumors (exclusive of basal cell carcinomas) and 28 leukemias were ascertained in 195 subjects. Median survival time following a solid SMN diagnosis 5 years or more from WT was 11 years; it was 10 months for all leukemia. Age-specific incidence of secondary solid tumors increased from approximately 1 case per 1,000 PY at age 15 to 5 cases per 1,000 PY at age 40. The cumulative incidence of solid tumors at age 40 for subjects who survived free of SMNs to age 15 was 6.7%. Leukemia risk, by contrast, was highest during the first 5 years following WT diagnosis. Standardized incidence ratios (SIRs) for solid tumors and leukemias were 5.1 and 5.0, respectively. Results for solid tumors for the 3 geographic areas were remarkably consistent; statistical tests for differences in incidence rates and SIRs were all negative. Age-specific incidence rates and SIRs for solid tumors were lower for patients whose WT was diagnosed after 1980, though the trends with decade of diagnosis were not statistically significant. Incidence rates and SIRs for leukemia were highest among those diagnosed after 1990 (p-trend =0.003). These trends may reflect the decreasing use of radiation therapy and increasing intensity of chemotherapy in modern protocols for treatment of WT.
Wilms tumor; childhood cancer; secondary malignant neoplasm
The occurrence of subsequent neoplasms has direct impact on the quantity and quality of life in cancer survivors. We have expanded our analysis of these events in the Childhood Cancer Survivor Study (CCSS) to better understand the occurrence of these events as the survivor population ages.
The incidence of and risk for subsequent neoplasms occurring 5 years or more after the childhood cancer diagnosis were determined among 14 359 5-year survivors in the CCSS who were treated from 1970 through 1986 and who were at a median age of 30 years (range = 5–56 years) for this analysis. At 30 years after childhood cancer diagnosis, we calculated cumulative incidence at 30 years of subsequent neoplasms and calculated standardized incidence ratios (SIRs), excess absolute risks (EARs) for invasive second malignant neoplasms, and relative risks for subsequent neoplasms by use of multivariable Poisson regression.
Among 14 359 5-year survivors, 1402 subsequently developed 2703 neoplasms. Cumulative incidence at 30 years after the childhood cancer diagnosis was 20.5% (95% confidence interval [CI] = 19.1% to 21.8%) for all subsequent neoplasms, 7.9% (95% CI = 7.2% to 8.5%) for second malignant neoplasms (excluding nonmelanoma skin cancer), 9.1% (95% CI = 8.1% to 10.1%) for nonmelanoma skin cancer, and 3.1% (95% CI = 2.5% to 3.8%) for meningioma. Excess risk was evident for all primary diagnoses (EAR = 2.6 per 1000 person-years, 95% CI = 2.4 to 2.9 per 1000 person-years; SIR = 6.0, 95% CI = 5.5 to 6.4), with the highest being for Hodgkin lymphoma (SIR = 8.7, 95% CI = 7.7 to 9.8) and Ewing sarcoma (SIR = 8.5, 95% CI = 6.2 to 11.7). In the Poisson multivariable analysis, female sex, older age at diagnosis, earlier treatment era, diagnosis of Hodgkin lymphoma, and treatment with radiation therapy were associated with increased risk of subsequent neoplasm.
As childhood cancer survivors progress through adulthood, risk of subsequent neoplasms increases. Patients surviving Hodgkin lymphoma are at greatest risk. There is no evidence of risk reduction with increasing duration of follow-up.
For the majority of children with acute lymphoblastic leukemia (ALL), CNS prophylaxis consists of either intrathecal (IT) methotrexate or triple IT therapy (ie, methotrexate with both cytarabine and hydrocortisone). The long-term neurotoxicities of these two IT strategies have not yet been directly compared.
Patients and Methods
In this multisite study, 171 children with standard-risk ALL, age 1 to 9.99 years at diagnosis, previously randomly assigned to IT methotrexate (n = 82) or to triple IT therapy (n = 89) on CCG 1952, underwent neurocognitive evaluation by a licensed psychologist at a mean of 5.9 years after random assignment.
Patients who received IT methotrexate had a mean Processing Speed Index that was 3.6 points lower, about one fourth of a standard deviation, than those who received triple IT therapy (P = .04) after analysis was adjusted for age, sex, and time since diagnosis. Likewise, 19.5% of children in the IT methotrexate group had a Processing Speed Index score in the below-average range compared with 6.9% in the triple IT therapy group (P = .02). Otherwise, the groups performed similarly on tests of full-scale intelligence quotient, academic achievement, attention/concentration, memory, and visual motor integration. The association of treatment with measures of cognitive functioning was not modified by sex or age at diagnosis. In the post-therapy period, there were no group differences in special education services, neurologic events, or use of psychotropic medications.
This study did not show any clinically meaningful differences in neurocognitive functioning between patients previously randomly assigned to IT methotrexate or triple IT therapy except for a small difference in processing speed in the IT methotrexate group.
The purpose of this study was to quantify the risk of breast cancer in relation to radiation dose and chemotherapy among survivors of childhood cancer.
We conducted a case-control study of breast cancer in a cohort of 6,647 women who were 5-year survivors of childhood cancer and who were treated during 1970 through 1986. One hundred twenty patients with histologically confirmed breast cancer were identified and were individually matched to four selected controls on age at initial cancer and time since initial cancer. Medical physicists estimated radiation dose to the breast tumor site and ovaries on the basis of medical records.
The odds ratio for breast cancer increased linearly with radiation dose, and it reached 11-fold for local breast doses of approximately 40 Gy relative to no radiation (P for trend < .0001). Risk associated with breast irradiation was sharply reduced among women who received 5 Gy or more to the ovaries (P = .002). The excess odds ratio per Gy was 0.36 for those who received ovarian doses less than 5 Gy and was 0.06 for those who received higher doses. Radiation-related risk did not vary significantly by age at exposure. Borderline significantly elevated risks were seen for doxorubicin, dactinomycin, dacarbazine, and carmustine.
Results confirm the radiation sensitivity of the breast in girls age 10 to 20 years but do not demonstrate a strong effect of age at exposure within this range. Irradiation of the ovaries at doses greater than 5 Gy seems to lessen the carcinogenic effects of breast irradiation, most likely by reducing exposure of radiation-damaged breast cells to stimulating effects of ovarian hormones.
Survival for childhood cancer has increased dramatically over the last 40 years with 5-year survival rates now approaching 80%. For many diagnostic groups, rapid increases in survival began in the 1970s with the broader introduction of multimodality approaches, often including combination chemotherapy with or without radiation therapy. With this increase in rates of survivorship has come the recognition that survivors are at risk for adverse health and quality-of-life outcomes, with risk being influenced by host-, disease-, and treatment-related factors. In 1994, the US National Cancer Institute funded the Childhood Cancer Survivor Study, a multi-institutional research initiative designed to establish a large and extensively characterized cohort of more than 14,000 5-year survivors of childhood and adolescent cancer diagnosed between 1970 and 1986. This ongoing study, which reflects the single most comprehensive body of information ever assembled on childhood and adolescent cancer survivors, provides a dynamic framework and resource to investigate current and future questions about childhood cancer survivors.
The Childhood Cancer Survivor Study (CCSS) has assembled the largest cohort to date for assessment of late mortality. Vital status and cause of death of all patients eligible for participation in CCSS was determined using the National Death Index and death certificates to characterize the mortality experience of 20,483 survivors, representing 337,334 person-years of observation. A total of 2,821 deaths have occurred as of December 31, 2002. The overall cumulative mortality is 18.1% (95% CI, 17.3 to 18.9) at 30 years from diagnosis. With time, while all-cause mortality rates have been stable, the pattern of late death is changing. Mortality attributable to recurrence or progression of primary disease is decreasing, with increases in rates of mortality attributable to subsequent neoplasms (standardized mortality ratios [SMR], 15.2; 95% CI, 13.9 to 16.6), cardiac death (SMR, 7.0; 95% CI, 5.9 to 8.2), and pulmonary death (SMR, 8.8; 95% CI, 6.8 to 11.2) largely due to treatment-related causes. In addition, the CCSS has identified specific treatment-related risk factors for late mortality. Radiotherapy (relative risk [RR], 2.9; 95% CI, 2.1 to 4.2), alkylating agents (RR, 2.2; 95% CI, 1.6 to 3.0), and epipodophyllotoxins (RR, 2.3; 95% CI, 1.2 to 4.5) increase the risk of death due to subsequent malignancy. Cardiac radiation exposure (RR, 3.3; 95% CI, 2.0 to 5.5) and high dose of anthracycline exposure (RR, 3.1; 95% CI, 1.6 to 5.8) are associated with late cardiac death. By continued longitudinal follow-up of the cohort and expansion of the cohort to include patients diagnosed between 1987 and 1999, the CCSS will remain a primary resource for assessment of late mortality of survivors of childhood cancers.
Childhood cancer survivors often experience complications related to cancer and its treatment that may adversely affect quality of life and increase the risk of premature death. The purpose of this manuscript is to review how data derived from Childhood Cancer Survivor Study (CCSS) investigations have facilitated identification of childhood cancer survivor populations at high risk for specific organ toxicity and secondary carcinogenesis and how this has informed clinical screening practices. Articles previously published that used the resource of the CCSS to identify risk factors for specific organ toxicity and subsequent cancers were reviewed and results summarized. CCSS investigations have characterized specific groups to be at highest risk of morbidity related to endocrine and reproductive dysfunction, pulmonary toxicity, cerebrovascular injury, neurologic and neurosensory sequelae, and subsequent neoplasms. Factors influencing risk for specific outcomes related to the individual survivor (eg, sex, race/ethnicity, age at diagnosis, attained age), sociodemographic status (eg, education, household income, health insurance) and cancer history (eg, diagnosis, treatment, time from diagnosis) have been consistently identified. These CCSS investigations that clarify risk for treatment complications related to specific treatment modalities, cumulative dose exposures, and sociodemographic factors identify profiles of survivors at high risk for cancer-related morbidity who deserve heightened surveillance to optimize outcomes after treatment for childhood cancer.
The Childhood Cancer Survivor Study (CCSS) is a comprehensive multicenter study designed to quantify and better understand the effects of pediatric cancer and its treatment on later health, including behavioral and sociodemographic outcomes. The CCSS investigators have published more than 100 articles in the scientific literature related to the study. As with any large cohort study, high standards for methodologic approaches are imperative for valid and generalizable results. In this article we describe methodological issues of study design, exposure assessment, outcome validation, and statistical analysis. Methods for handling missing data, intrafamily correlation, and competing risks analysis are addressed; each with particular relevance to pediatric cancer survivorship research. Our goal in this article is to provide a resource and reference for other researchers working in the area of long-term cancer survivorship.
To review the reports of subsequent neoplasms (SNs) in the Childhood Cancer Survivor Study (CCSS) cohort that were made through January 1, 2006, and published before July 31, 2008, and to discuss the host-, disease-, and therapy-related risk factors associated with SNs.
Patients and Methods
SNs were ascertained by survivor self-reports and subsequently confirmed by pathology findings or medical record review. Cumulative incidence of SNs and standardized incidence ratios for second malignant neoplasms (SMNs) were calculated. The impact of host-, disease-, and therapy-related risk factors was evaluated by Poisson regression.
Among 14,358 cohort members, 730 reported 802 SMNs (excluding nonmelanoma skin cancers). This represents a 2.3-fold increase in the number of SMNs over that reported in the first comprehensive analysis of SMNs in the CCSS cohort, which was done 7 years ago. In addition, 66 cases of meningioma and 1,007 cases of nonmelanoma skin cancer were diagnosed. The 30-year cumulative incidence of SMNs was 9.3% and that of nonmelanoma skin cancer was 6.9%. Risk of SNs remains elevated for more than 20 years of follow-up for all primary childhood cancer diagnoses. In multivariate analyses, risks differ by SN subtype, but include radiotherapy, age at diagnosis, sex, family history of cancer, and primary childhood cancer diagnosis. Female survivors whose primary childhood cancer diagnosis was Hodgkin's lymphoma or sarcoma and who received radiotherapy are at particularly increased risk. Analyses of risk associated with radiotherapy demonstrated different dose-response curves for specific SNs.
Childhood cancer survivors are at a substantial and increasing risk for SNs, including nonmelanoma skin cancer and meningiomas. Health care professionals should understand the magnitude of these risks to provide individuals with appropriate counseling and follow-up.
Women treated with therapeutic chest radiation may develop breast cancer.
Summarize breast cancer risk and breast cancer surveillance in women following chest radiation for a pediatric or young adult cancer.
Studies from MEDLINE, EMBASE, Cochrane Library, and CINAHL (1966 through December 2008).
Articles selected to answer any of 3 questions: 1) What is the incidence and excess risk of breast cancer in women following chest radiation for a pediatric or young adult cancer? 2) For these women, are the clinical characteristics of the breast cancer and the outcomes following therapy different than for women with sporadic breast cancer in the general population? 3) What are the potential benefits and harms associated with breast cancer surveillance among women exposed to chest radiation?
Three investigators independently extracted data and assessed study quality.
Standardized incidence ratios ranged from 13.3 to 55.5; cumulative incidence of breast cancer by 40–45 years of age ranged from 13–20%. Risk of breast cancer increased linearly with chest radiation dose. Available limited evidence suggests that the characteristics of the breast cancers in these women and the outcomes following diagnosis are similar to those in the general population; these breast cancers can be detected by mammography, though sensitivity is limited.
Limitations include study heterogeneity, design and small sample size.
Women treated with chest radiation have a substantially elevated risk of breast cancer at a young age, which does not appear to plateau. Among this high risk population, there appears to be a benefit associated with early detection. Further research is required to better define the harms and benefits of lifelong surveillance.
The proportion of pediatric and adolescent cancer patients surviving 5 years has increased during the past four decades. This growing population of survivors remains at risk for disease- and treatment-associated late mortality.
A total of 20 483 five-year survivors of childhood and adolescent cancer diagnosed between January 1, 1970, and December 31, 1986, and enrolled in the Childhood Cancer Survivor Study (CCSS) were included in a National Death Index search for deaths occurring between January 1, 1979, and December 31, 2002. Treatment information was abstracted from primary medical records. Survival probabilities, standardized mortality ratios (SMRs), and absolute excess risks were calculated for overall and cause-specific deaths. Diagnosis- and sex-specific survival probabilities were estimated by the product-limit method. All statistical tests were two-sided.
Among the CCSS cohort, 2821 (13.8%) 5-year survivors had died by the end of the follow-up period. The cause of death was obtained for 2534 individuals, with 57.5% of deaths attributed to recurrent disease. Estimated probability of survival 30 years from diagnosis was 82%. When compared with the US population, the absolute excess risk of death from any cause was 7.36 deaths per 1000 person-years. The overall SMR was 8.4 (95% confidence interval [CI] = 8.0 to 8.7). Increases in cause-specific mortality were seen for deaths due to subsequent malignancy (SMR = 15.2, 95% CI = 13.9 to 16.6) and cardiac (SMR = 7.0, 95% CI = 5.9 to 8.2), pulmonary (SMR = 8.8, 95% CI = 6.8 to 11.2), and other medical (SMR = 2.6, 95% CI = 2.3 to 3.0) causes. At 20 years of follow-up (25 years after first cancer diagnosis), the death rate due to a subsequent malignancy exceeded that due to all other causes.
Our extended follow-up of 5-year survivors of pediatric and adolescent cancer indicates that excess mortality persists long after diagnosis. Continued observation is needed to further define lifetime risk and to determine the potential contribution of chronic health conditions and modifiable health behaviors.
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
Neuroblastoma is the most common cancer in infants worldwide but little is known about its etiology. Infectious etiologies involving the immune system have been hypothesized for some childhood cancers, especially leukemia, but the role of infectious agents in neuroblastoma has not been fully investigated. We used data from a large case-control study conducted by the Children’s Oncology Group over the period 1992–1994 in United States or Canada to investigate if there was any relation between day care attendance, childhood infections, allergies and neuroblastoma. We interviewed mothers of 538 case and 504 age-matched control children by telephone about several factors including pregnancy, medical history, lifestyle, and childhood medical conditions and exposures. Our results suggested decreased risks associated with day care attendance (odds ratio (OR) = 0.81; 95% confidence interval ([CI]: 0.56–1.17), childhood infectious diseases (chickenpox, mumps, red and German measles) (OR = 0.60;CI: 0.39–0.93) and allergies (OR = 0.68; CI: 0.44–1.07). We found reduced neuroblastoma risk associated with markers of potential childhood infections, which suggests a possible role of infectious agents in neuroblastoma etiology. Future epidemiologic studies should incorporate more direct infection data.
Adult; Birth Order; Breast Feeding; statistics & numerical data; Canada; epidemiology; Case-Control Studies; Child; Child Day Care Centers; utilization; Child, Preschool; Communicable Diseases; complications; epidemiology; immunology; Female; Humans; Hypersensitivity; complications; Immunocompetence; Infant; Life Style; Logistic Models; Male; Neuroblastoma; epidemiology; microbiology; Population Surveillance; Questionnaires; Risk Assessment; Risk Factors; Socioeconomic Factors; United States; epidemiology; Neuroblastoma; Day Care; Infection; Allergy; Childhood