Increased risk of skin cancer in 1851 long-term retinoblastoma survivors

Hereditary retinoblastoma patients are at risk for developing cutaneous melanoma, but little is known about the role of sun exposure or other factors, and incidence of non-melanoma skin cancer (NMSC) is poorly understood. We investigated the incidence of melanoma and NMSC in a cohort of 1851 white, long-term retinoblastoma survivors (1020 hereditary and 831 nonhereditary) diagnosed from 1914-2006. During follow-up through 2016, 33 hereditary and 7 nonhereditary survivors developed melanoma, and 26 hereditary and 9 nonhereditary survivors developed NMSC. Most NMSC were on the head/neck whereas melanomas were more broadly distributed with patterns similar to melanoma-prone families. For both outcomes, median age at diagnosis was ∼20 years younger among hereditary than nonhereditary survivors. Fifty years following retinoblastoma diagnosis, the cumulative incidence in hereditary survivors was 4.5% for melanoma and 3.7% for NMSC; for nonhereditary survivors, it was 0.7% and 1.5%, respectively. Sun sensitivity and phenotypic characteristics generally did not vary by skin cancer status. Hereditary retinoblastoma survivors have an increased risk for melanoma and NMSC that occurred earlier compared with nonhereditary survivors, likely reflecting genetic factors. These findings among white retinoblastoma survivors support consensus-based recommendations for skin cancer screening and sun protection starting at young ages and continuing long-term.

Benign Tumors in Long-Term Survivors of Retinoblastoma

Simple Summary

It is well-established that hereditary retinoblastoma survivors have a substantially increased risk of developing subsequent malignant neoplasms (SMNs). Although clinicians have long suspected that this population is also at increased risk for developing benign neoplasms, the evidence is unclear. Benign tumors can substantially impact health status and quality of life, while raising questions for clinicians, when faced with a mass in a retinoblastoma survivor. By 60 years following retinoblastoma diagnosis, 17.6% of hereditary survivors had developed a benign tumor, with lipomas and leiomyomas being the most frequently diagnosed types. Additionally, we report both an increased risk of benign tumors after SMNs and a reciprocal increased risk of SMNs after benign tumors among hereditary retinoblastoma survivors. If confirmed, the large magnitude of the absolute risks and the association between benign tumors and SMNs in this population may have implications for long-term surveillance.

Abstract

Hereditary retinoblastoma survivors have substantially increased risk of subsequent malignant neoplasms (SMNs). The risk of benign neoplasms, a substantial cause of morbidity, is unclear. We calculated the cumulative incidence of developing benign tumors at 60 years following retinoblastoma diagnosis among 1128 hereditary (i.e., bilateral retinoblastoma or unilateral with family history, mutation testing was not available) and 924 nonhereditary retinoblastoma survivors diagnosed during 1914–2006 at two US medical centers with follow-up through 2016. Using Cox proportional hazards regression, we compared benign tumor risk by hereditary status and evaluated the association between benign tumors and SMNs. There were 100 benign tumors among 73 hereditary survivors (cumulative incidence = 17.6%; 95% confidence interval [CI] = 12.9–22.8%) and 22 benign tumors among 16 nonhereditary survivors (cumulative incidence = 3.9%; 95%CI = 2.2–6.4%), corresponding to 4.9-fold (95%CI = 2.8–8.4) increased risk for hereditary survivors. The cumulative incidence after hereditary retinoblastoma was highest for lipoma among males (14.0%; 95%CI = 7.7–22.1%) and leiomyoma among females (8.9%; 95%CI = 5.2–13.8%). Among hereditary survivors, having a prior SMN was associated with 3.5-fold (95%CI = 2.0–6.1) increased risk of developing a benign tumor; the reciprocal risk for developing an SMN after a benign tumor was 1.8 (95%CI = 1.1–2.9). These large-scale, long-term data demonstrate an increased risk for benign tumors after hereditary versus nonhereditary retinoblastoma. If confirmed, the association between benign tumors and SMNs among hereditary patients may have implications for long-term surveillance.

General cancer screening practices among adult survivors of retinoblastoma: Results from the Retinoblastoma Survivor Study

We assessed breast, cervical, and colorectal cancer screening practices in adult retinoblastoma (Rb) survivors and non-Rb controls. We found that most Rb survivors adhered to general population cancer screening recommendations. Rates did not differ among Rb survivors and non-Rb controls, or among survivors by laterality, even though bilateral survivors reported higher levels of concern about future health and cancer risk. Older age, being overweight/obese, and lack of recent contact with medical personnel were independently associated with decreased utilization of Pap smear among female Rb survivors. Future studies are warranted to determine whether these associations might provide an opportunity for intervention.

Low-grade glioma: A rare second tumor in retinoblastoma survivors

Retinoblastoma survivors with a germline RB1 mutation are at elevated risk for secondary (nonocular) malignancy, but their risk for low-grade glioma (LGG) is unknown. We performed a retrospective review of the Memorial Sloan Kettering Cancer Center and the NCI databases that revealed that three of the 837 5-year survivors of hereditary retinoblastoma were diagnosed with an LGG and a fourth patient (but unilateral and without a germline mutation) was identified at another center. Retinoblastoma survivors may be at increased risk for LGG.

Recommendations for Long-Term Follow-up of Adults with Heritable Retinoblastoma

PURPOSE

To generate recommendations for long-term follow-up of adult survivors of heritable retinoblastoma.

DESIGN

We convened a meeting of providers from retinoblastoma centers around the world to review the state of the science and to evaluate the published evidence.

PARTICIPANTS

Retinoblastoma is a rare childhood cancer of the retina. Approximately 40% of retinoblastoma cases are heritable, resulting from a germline mutation in RB1. Dramatic improvements in treatment and supportive care have resulted in a growing adult survivor population. However, survivors of heritable retinoblastoma have a significantly increased risk of subsequent malignant neoplasms, particularly bone and soft tissue sarcomas, uterine leiomyosarcoma, melanomas, and radiotherapy-related central nervous system tumors, which are associated with excess morbidity and mortality. Despite these risks, no surveillance recommendations for this population currently are in place, and surveillance practices vary widely by center.

METHODS

Following the Institute of Medicine procedure for clinical practice guideline development, a PubMed, EMBASE, and Web of Science search was performed, resulting in 139 articles; after abstract and full-text review, 37 articles underwent detailed data abstraction to quantify risk and evidence regarding surveillance, if available. During an in-person meeting, evidence was presented and discussed, resulting in consensus recommendations.

MAIN OUTCOME MEASURES

Diagnosis and mortality from subsequent neoplasm.

RESULTS

Although evidence for risk of subsequent neoplasm, especially sarcoma and melanoma, was significant, evidence supporting routine testing of asymptomatic survivors was not identified. Skin examination for melanoma and prompt evaluation of signs and symptoms of head and neck disease were determined to be prudent.

CONCLUSIONS

This review of the literature confirmed some of the common second cancers in retinoblastoma survivors but found little evidence for a benefit from currently available surveillance for these malignancies. Future research should incorporate international partners, patients, and family members.

Patterns of Cause-Specific Mortality Among 2053 Survivors of Retinoblastoma, 1914-2016

BACKGROUND

Previous studies of hereditary retinoblastoma survivors have reported elevated mortality, particularly for sarcomas, compared with the general population. However, cause-specific mortality patterns for long-term hereditary and nonhereditary retinoblastoma survivors are poorly understood.

METHODS

Among 2053 retinoblastoma patients diagnosed during 1914-2006 at two major US treatment centers and followed to 2016, we estimated cumulative mortality, standardized mortality ratios (SMRs), and absolute excess risks (AERs) compared with the US general population.

RESULTS

Most deaths occurred in 1129 hereditary retinoblastoma patients (n = 518 deaths, cumulative mortality 70 years after retinoblastoma = 75.8%, 95% CI = 69.0% to 82.6%; SMR = 8.5, 95% CI = 7.7 to 9.2). Of these, 267 were due to subsequent cancers (SMR = 27.4, 95% CI = 24.2 to 30.9; AER = 72.3 deaths/10 000 person-years), for which SMRs were highest 15-29 years after diagnosis (n = 69, SMR = 89.9, 95% CI = 70.0 to 113.8) but remained statistically significantly elevated at 60 and more years (n = 14, SMR = 6.7, 95% CI = 3.6 to 11.2), whereas AERs increased with time (AER<15years = 38.0; AER60+years = 327.5). Increased risk of death due to cancers of pancreas, large intestines, and kidney were noted for the first time. Overall risk of subsequent cancers was greater for those treated with radiotherapy and chemotherapy compared to radiotherapy alone, although patterns varied by organ site. For 924 patients with nonhereditary retinoblastoma, we noted a modestly increased risk of death for subsequent cancers (n = 27, SMR = 1.8, 95% CI = 1.2 to 2.6) possibly due to treatment or misclassification of hereditary status. Risks of noncancer causes of death were not elevated for hereditary or nonhereditary patients.

CONCLUSION

Hereditary retinoblastoma survivors died mainly from an excess risk of subsequent cancers up to six decades later, highlighting the need to develop long-term clinical management guidelines for hereditary retinoblastoma survivors treated in the past.

Bone and Soft-Tissue Sarcoma Risk in Long-Term Survivors of Hereditary Retinoblastoma Treated With Radiation

PURPOSE

Survivors of hereditary retinoblastoma have excellent survival but substantially increased risks of subsequent bone and soft-tissue sarcomas, particularly after radiotherapy. Comprehensive investigation of sarcoma risk patterns would inform clinical surveillance for survivors.

PATIENTS AND METHODS

In a cohort of 952 irradiated survivors of hereditary retinoblastoma who were originally diagnosed during 1914 to 2006, we quantified sarcoma risk with standardized incidence ratios (SIRs) and cumulative incidence analyses. We conducted analyses separately for bone and soft-tissue sarcomas occurring in the head and neck (in/near the radiotherapy field) versus body and extremities (out of field).

RESULTS

Of 105 bone and 124 soft-tissue sarcomas, more than one half occurred in the head and neck (bone, 53.3%; soft tissue, 51.6%), one quarter in the body and extremities (bone, 29.5%; soft tissue, 25.0%), and approximately one fifth in unknown/unspecified locations (bone, 17.1%; soft tissue, 23.4%). We noted substantially higher risks compared with the general population for head and neck versus body and extremity tumors for both bone (SIR, 2,213; 95% CI, 1,671 to 2,873 v SIR, 169; 95% CI, 115 to 239) and soft-tissue sarcomas (SIR, 542; 95% CI, 418 to 692 v SIR, 45.7; 95% CI, 31.1 to 64.9). Head and neck bone and soft-tissue sarcomas were diagnosed beginning in early childhood and continued well into adulthood, reaching a 60-year cumulative incidence of 6.8% (95% CI, 5.0% to 8.7%) and 9.3% (95% CI, 7.0% to 11.7%), respectively. In contrast, body and extremity bone sarcoma incidence flattened after adolescence (3.5%; 95% CI, 2.3% to 4.8%), whereas body and extremity soft-tissue sarcoma incidence was rare until age 30, when incidence rose steeply (60-year cumulative incidence, 6.6%; 95% CI, 4.1% to 9.2%), particularly for females (9.4%; 95% CI, 5.1% to 13.8%).

CONCLUSION

Strikingly elevated bone and soft-tissue sarcoma risks differ by age, location, and sex, highlighting important contributions of both radiotherapy and genetic susceptibility. These data provide guidance for the development of a risk-based screening protocol that focuses on the highest sarcoma risks by age, location, and sex.

Vision-Targeted Health-Related Quality of Life in Adult Survivors of Retinoblastoma

Importance

Retinoblastoma survivors are at risk for adverse oculo-visual outcomes. Limited data are available regarding long-term vision-targeted health-related quality of life (HRQoL) of adult retinoblastoma survivors.

Objective

To examine vision-targeted HRQoL as reported on the 25-item National Eye Institute Visual Field Questionnaire for overall and specific scale scores among adult survivors of retinoblastoma.

Design, Setting, and Participants

The Retinoblastoma Survivor Study is a retrospective cohort of adult retinoblastoma survivors treated at 3 academic medical centers in New York between 1932 and 1994. Participants completed a comprehensive questionnaire between April 2008 and June 2010. Items were scored in January 2013 and preliminary analyses were performed in July 2015. Models were finalized in May 2017.

Main Outcomes and Measures

Self-reported vision-targeted HRQoL as reported on the 25-item National Eye Institute Visual Field Questionnaire. Items are scored from 0 to 100, with 100 representing the highest quality of life.

Results

Among 470 adult retinoblastoma survivors (53.6% with bilateral disease; 52.1% female; 86.4% white and non-Hispanic; mean age at study, 43.3 years; range, 18.0-77.0 years), 86% had at least 1 eye removed (1 eye, 74.5%; both eyes, 11.5%); 56.5% were previously treated with radiotherapy; and 61.3% rated their eyesight as excellent/good while 16.2% reported complete blindness. The overall mean (SD) VFQ composite score for all survivors was 81.1 (17.2) (mean [SD] score for unilateral retinoblastoma survivors, 91.4 [7.7]; bilateral retinoblastoma survivors, 72.3 [18.2]; difference between survivors with unilateral and bilateral disease, 19.1 [95% CI, 16.5-21.7; P < .001]). Prior exposure to radiotherapy was not associated with decreased overall VFQ (β = -0.08; 95% CI, -0.15 to 0.002; P = .06) but was related to a few specific subdomains of visual functioning.

Conclusions and Relevance

These findings suggest retinoblastoma-related oculo-visual problems are associated with functional status and vision-targeted HRQoL of adult survivors, particularly among those with bilateral disease.

Risk of Second Primary Bone and Soft-Tissue Sarcomas Among Young Adulthood Cancer Survivors

Excess sarcoma risks after childhood cancer are well established, but risks among young adulthood cancer survivors are poorly understood. Using US population-based cancer registry data, we compared bone and soft-tissue sarcoma risk vs the general population among 186 351 individuals who were diagnosed with nonsarcoma first primary malignancies at ages 20-39 years from 1975 to 2014 (follow-up through 2015) and survived at least 1 year. Bone sarcomas were rare (n = 50), but risk was statistically significantly elevated overall (2.9-fold) and greater than fivefold after Hodgkin lymphoma, non-Hodgkin lymphoma, and central nervous system tumors. Soft-tissue sarcomas were more common (n = 284) and risks were statistically significantly elevated approximately twofold overall and after melanoma and carcinomas of the breast, thyroid, and testis, and greater than fourfold after Hodgkin lymphoma and central nervous system tumors. Risks varied markedly by subtype, with the highest risks (greater than fourfold) for osteosarcoma and the soft-tissue subtypes of rhabdomyosarcoma and blood vessel and nerve sheath sarcomas. These data demonstrate elevated risk for sarcoma after a range of young adulthood cancers.

Thyroid Cancer Following Childhood Low-Dose Radiation Exposure: A Pooled Analysis of Nine Cohorts

CONTEXT

The increased use of diagnostic and therapeutic procedures that involve radiation raises concerns about radiation effects, particularly in children and the radiosensitive thyroid gland.

OBJECTIVES

Evaluation of relative risk (RR) trends for thyroid radiation doses <0.2 gray (Gy); evidence of a threshold dose; and possible modifiers of the dose-response, e.g., sex, age at exposure, time since exposure.

DESIGN AND SETTING

Pooled data from nine cohort studies of childhood external radiation exposure and thyroid cancer with individualized dose estimates, ≥1000 irradiated subjects or ≥10 thyroid cancer cases, with data limited to individuals receiving doses <0.2 Gy.

PARTICIPANTS

Cohorts included the following: childhood cancer survivors (n = 2); children treated for benign diseases (n = 6); and children who survived the atomic bombings in Japan (n = 1). There were 252 cases and 2,588,559 person-years in irradiated individuals and 142 cases and 1,865,957 person-years in nonirradiated individuals.

INTERVENTION

There were no interventions.

MAIN OUTCOME MEASURE

Incident thyroid cancers.

RESULTS

For both <0.2 and <0.1 Gy, RRs increased with thyroid dose (P < 0.01), without significant departure from linearity (P = 0.77 and P = 0.66, respectively). Estimates of threshold dose ranged from 0.0 to 0.03 Gy, with an upper 95% confidence bound of 0.04 Gy. The increasing dose-response trend persisted >45 years after exposure, was greater at younger age at exposure and younger attained age, and was similar by sex and number of treatments.

CONCLUSIONS

Our analyses reaffirmed linearity of the dose response as the most plausible relationship for "as low as reasonably achievable" assessments for pediatric low-dose radiation-associated thyroid cancer risk.

Mortality in U.S. Physicians Likely to Perform Fluoroscopy-guided Interventional Procedures Compared with Psychiatrists, 1979 to 2008

Purpose To compare total and cause-specific mortality rates between physicians likely to have performed fluoroscopy-guided interventional (FGI) procedures (referred to as FGI MDs) and psychiatrists to determine if any differences are consistent with known radiation risks. Materials and Methods Mortality risks were compared in nationwide cohorts of 45 634 FGI MDs and 64 401 psychiatrists. Cause of death was ascertained from the National Death Index. Poisson regression was used to estimate relative risks (RRs) and 95% confidence intervals (CIs) for FGI MDs versus psychiatrists, with adjustment (via stratification) for year of birth and attained age. Results During follow-up (1979-2008), 3506 FGI MDs (86 women) and 7814 psychiatrists (507 women) died. Compared with psychiatrists, FGI MDs had lower total (men: RR, 0.80 [95% CI: 0.77, 0.83]; women: RR, 0.80 [95% CI: 0.63, 1.00]) and cancer (men: RR, 0.92 [95% CI: 0.85, 0.99]; women: RR, 0.83 [95% CI: 0.58, 1.18]) mortality. Mortality because of specific types of cancer, total and specific types of circulatory diseases, and other causes were not elevated in FGI MDs compared with psychiatrists. On the basis of small numbers, leukemia mortality was elevated among male FGI MDs who graduated from medical school before 1940 (RR, 3.86; 95% CI: 1.21, 12.3). Conclusion Overall, total deaths and deaths from specific causes were not elevated in FGI MDs compared with psychiatrists. These findings require confirmation in large cohort studies with individual doses, detailed work histories, and extended follow-up of the subjects to substantially older median age at exit. ^© RSNA, 2017 Online supplemental material is available for this article.

Stomach Cancer Following Hodgkin Lymphoma, Testicular Cancer and Cervical Cancer: A Pooled Analysis of Three International Studies with a Focus on Radiation Effects

To further understand the risk of stomach cancer after fractionated high-dose radiotherapy, we pooled individual-level data from three recent stomach cancer case-control studies. These studies were nested in cohorts of five-year survivors of first primary Hodgkin lymphoma (HL), testicular cancer (TC) or cervical cancer (CX) from seven countries. Detailed data were abstracted from patient records and radiation doses were reconstructed to the site of the stomach cancer for cases and to the corresponding sites for matched controls. Among 327 cases and 678 controls, mean doses to the stomach were 15.3 Gy, 24.7 Gy and 1.9 Gy, respectively, for Hodgkin lymphoma, testicular cancer and cervical cancer survivors, with an overall mean dose of 10.3 Gy. Risk increased with increasing radiation dose to the stomach cancer site (P < 0.001) with no evidence of nonlinearity or of a downturn at the highest doses (≥35 Gy). The pooled excess odds ratio per Gy (EOR/Gy) was 0.091 [95% confidence interval (CI): 0.036-0.20] with estimates of 0.049 (95% CI: 0.007-0.16) for Hodgkin lymphoma, 0.27 (95% CI: 0.054-1.44) for testicular cancer and 0.096 (95% CI: -0.002-0.39) for cervical cancer (P homogeneity = 0.25). The EOR/Gy increased with time since exposure (P trend = 0.004), with an EOR/Gy of 0.38 (95% CI: 0.12-1.04) for stomach cancer occurring ≥20 years postirradiation corresponding to odds ratios of 4.8 and 10.5 at radiation doses to the stomach of 10 and 25 Gy, respectively. Of 111 stomach cancers occurring ≥20 years after radiotherapy, 63.8 (57%) could be attributed to radiotherapy. Our findings differ from those based on Japanese atomic-bomb survivors, where the overall EOR/Gy was higher and where there was no evidence of an increase with time since exposure. By pooling data from three studies, we demonstrated a clear increase in stomach cancer risk over a wide range of doses from fractionated radiotherapy with the highest risks occurring many years after exposure. These findings highlight the need to directly evaluate the health effects of high-dose fractionated radiotherapy rather than relying on the data of persons exposed at low and moderate acute doses.

Increased pancreatic cancer risk following radiotherapy for testicular cancer

Background:

Pancreatic cancer risk is elevated among testicular cancer (TC) survivors. However, the roles of specific treatments are unclear.

Methods:

Among 23 982 5-year TC survivors diagnosed during 1947–1991, doses from radiotherapy to the pancreas were estimated for 80 pancreatic cancer patients and 145 matched controls. Chemotherapy details were recorded. Logistic regression was used to estimate odds ratios (ORs).

Results:

Cumulative incidence of second primary pancreatic cancer was 1.1% at 30 years after TC diagnosis. Radiotherapy (72 (90%) cases and 115 (80%) controls) was associated with a 2.9-fold (95% confidence interval (CI) 1.0–7.8) increased risk. The OR increased linearly by 0.12 per Gy to the pancreas (P-trend<0.001), with an OR of 4.6 (95% CI 1.9–11.0) for ⩾25 Gy vs <25 Gy. Radiation-related risks remained elevated ⩾20 years after TC diagnosis (P=0.020). The risk increased with the number of cycles of chemotherapy with alkylating or platinum agents (P=0.057), although only one case was exposed to platinum.

Conclusions:

A dose–response relationship exists between radiation to the pancreas and subsequent cancer risk, and persists for over 20 years. These excesses, although small, should be considered when radiotherapy with exposure to the pancreas is considered for newly diagnosed patients. Additional data are needed on the role of chemotherapy.

Long-term Mortality in 43 763 U.S. Radiologists Compared with 64 990 U.S. Psychiatrists

Purpose To compare mortality rates from all causes, specific causes, total cancers, and specific cancers to assess whether differences between radiologists and psychiatrists are consistent with known risks of radiation exposure and the changes in radiation exposure to radiologists over time. Materials and Methods The authors used the American Medical Association Physician Masterfile to construct a cohort of 43 763 radiologists (20% women) and 64 990 psychiatrists (27% women) (comparison group) who graduated from medical school in 1916-2006. Vital status was obtained from record linkages with the Social Security Administration and commercial databases, and cause of death was obtained from the National Death Index. Poisson regression was used to estimate relative risks (RRs) and 95% confidence intervals (CIs) for all causes and specific causes of death. Results During the follow-up period (1979-2008), 4260 male radiologists and 7815 male psychiatrists died. The male radiologists had lower death rates (all causes) compared with the psychiatrists (RR = 0.94; 95% CI: 0.90, 0.97), similar cancer death rates overall (RR = 1.00; 95% CI: 0.93, 1.07), but increased acute myeloid leukemia and/or myelodysplastic syndrome death rates (RR = 1.62; 95% CI: 1.05, 2.50); these rates were driven by those who graduated before 1940 (RR = 4.68; 95% CI: 0.91, 24.18). In these earliest workers (before 1940) there were also increased death rates from melanoma (RR = 8.75; 95% CI: 1.89, 40.53), non-Hodgkin lymphoma (NHL) (RR = 2.69; 95% CI: 1.33, 5.45), and cerebrovascular disease (RR = 1.49; 95% CI: 1.11, 2.01). The 208 deaths in female radiologists precluded detailed investigation, and the number of female radiologists who graduated before 1940 was very small (n = 47). Conclusion The excess risk of acute myeloid leukemia and/or myelodysplastic syndrome mortality in radiologists who graduated before 1940 is likely due to occupational radiation exposure. The melanoma, NHL, and cerebrovascular disease mortality risks are possibly due to radiation. The authors found no evidence of excess mortality in radiologists who graduated more recently, possibly because of increased radiation protection and/or lifestyle changes. ^© RSNA, 2016 Online supplemental material is available for this article.

The Risk of Cataract among Survivors of Childhood and Adolescent Cancer: A Report from the Childhood Cancer Survivor Study

With therapeutic successes and improved survival after a cancer diagnosis in childhood, increasing numbers of cancer survivors are at risk of subsequent treatment-related morbidities, including cataracts. While it is well known that the lens of the eye is one of the most radiosensitive tissues in the human body, the risks associated with radiation doses less than 2 Gy are less understood, as are the long- and short-term cataract risks from exposure to ionizing radiation at a young age. In this study, we followed 13,902 five-year survivors of childhood cancer in the Childhood Cancer Survivor Study cohort an average of 21.4 years from the date of first cancer diagnosis. For patients receiving radiotherapy, lens dose (mean: 2.2 Gy; range: 0-66 Gy) was estimated based on radiotherapy records. We used unconditional multivariable logistic regression models to evaluate prevalence of self-reported cataract in relationship to cumulative radiation dose both at five years after the initial cancer diagnosis and at the end of follow-up. We modeled the radiation effect in terms of the excess odds ratio (EOR) per Gy. We also analyzed cataract incidence starting from five years after initial cancer diagnosis to the end of follow-up using Cox regression. A total of 483 (3.5%) cataract cases were identified, including 200 (1.4%) diagnosed during the first five years of follow-up. In a multivariable logistic regression model, cataract prevalence at the end of follow-up was positively associated with lens dose in a manner consistent with a linear dose-response relationship (EOR per Gy = 0.92; 95% CI: 0.65-1.20). The odds ratio for doses between 0.5 and 1.5 Gy was elevated significantly relative to doses <0.5 Gy (OR = 2.2; 95% CI: 1.3-3.7). The results from this study indicate a strong association between ocular exposure to ionizing radiation and long-term risk of pre-senile cataract. The risk of cataract increased with increasing exposure, beginning at lens doses as low as 0.5 Gy. Our findings are in agreement with a growing body of evidence of an elevated risk for lens opacities in populations exposed to doses of ionizing radiation below the previously suggested threshold level of 2 Gy.

Chronic medical conditions in adult survivors of retinoblastoma: Results of the Retinoblastoma Survivor Study

BACKGROUND

Limited data are available regarding long-term morbidity in adult survivors of retinoblastoma (Rb).

METHODS

The Retinoblastoma Survivor Study is a retrospective cohort of adult survivors of Rb diagnosed between 1932 and 1994. Participants completed a comprehensive questionnaire adapted from the Childhood Cancer Survivor Study surveys. Chronic conditions were classified using the National Cancer Institute's Common Terminology Criteria for Adverse Events (version 4.03). Multivariate Poisson regression was used to compare survivors of Rb with 2377 non-Rb controls, consisting of the Childhood Cancer Survivor Study sibling cohort and survivors with bilateral versus unilateral disease.

RESULTS

Survivors of Rb (53.6% with bilateral disease) and non-Rb controls had a mean age of 43.3 years (standard deviation, 11 years) and 37.6 years (SD, 8.6 years), respectively, at the time of study enrollment. At a median follow-up of 42 years (range, 15-75 years), 86.6% of survivors of Rb had at least 1 condition and 71.1% had a severe/life-threatening (grade 3-4) condition. The adjusted relative risk (RR) of a chronic condition in survivors compared with non-Rb controls was 1.4 (95% confidence interval [95% CI], 1.3-1.4; P<.01); for a grade 3 to 4 condition, the RR was 7.6 (95% CI, 6.4-8.9; P<.01). Survivors were at an excess risk regardless of laterality. After stratifying by laterality and excluding ocular conditions and second malignant neoplasms (SMNs), only those with bilateral disease were found to be at an increased risk of any nonocular, non-SMN condition (RR, 1.2; 95% CI, 1.1-1.2) and for grade 3 to 4 nonocular, non-SMN conditions (RR, 1.7; 95% CI, 1.2-2.5).

CONCLUSIONS

Survivors of Rb have an increased risk of chronic conditions compared with non-Rb controls. After excluding ocular conditions and SMNs, this excess risk was found to persist only for those with bilateral disease. Cancer 2016;122:773-781. © 2016 American Cancer Society.

Differences in characteristics of pediatric patients undergoing computed tomography between hospitals and primary care settings: implications for assessing cancer follow-up studies

BACKGROUND

Recently published analyses showed that computed tomography (CT) scans in pediatric patients are associated with increased risk of radiation-related cancer. These analyses were based on data collected both from either hospitals and primary care services. Study objectives were to characterize cohorts of pediatric patients in Israel undergoing CT scans in primary care compared to hospitals settings. These cohorts will be further used for evaluating cancer risks.

METHODS

The present study was conducted in Schneider Children Medical Center in Israel (SCMCI), the largest tertiary pediatric hospital in the country. Data were collected directly from the listings of the pediatric radiology department for the period 1985-2005. Results were compared with previously published data on pediatric CT in the primary healthcare service performed between 1999 and 2003 in a large health organization, Maccabi Healthcare Services (MHS).

RESULTS

During the study observation periods, 38,351 and 22,223 examinations were documented in 13,726 and 18,075 pediatric patients in SCMCI and MHS, respectively. Compared to pediatric patients in the primary care, patients undergoing CT scans in the hospital were more likely to be younger, to have multiple CT scans, and to be scanned in the trunk. Also, cancer-related indications accounted for nearly 50 % of all CT scans conducted in the hospital compared to only 3 % in primary care settings.

CONCLUSIONS

The results indicate major differences in the characteristics of children and adolescents scanned in hospitals compared to primary care settings. Some of these characteristics may be associated with cancer risk later in life, and should be taken into account in cancer risk assessments.

Psychosocial Outcomes in Adult Survivors of Retinoblastoma

PURPOSE

Survival rates for individuals diagnosed with retinoblastoma (RB) exceed 95% in the United States; however, little is known about the long-term psychosocial outcomes of these survivors.

PATIENTS AND METHODS

Adult RB survivors, diagnosed from 1932 to 1994 and treated in New York, completed a comprehensive questionnaire adapted from the Childhood Cancer Survivor Study (CCSS), by mail or telephone. Psychosocial outcomes included psychological distress, anxiety, depression, somatization, fear of cancer recurrence, satisfaction with facial appearance, post-traumatic growth, and post-traumatic stress symptoms; noncancer CCSS siblings served as a comparison group.

RESULTS

A total of 470 RB survivors (53.6% with bilateral RB; 52.1% female) and 2,820 CCSS siblings were 43.3 (standard deviation [SD], 11) years and 33.2 (SD, 8.4) years old at the time of study, respectively. After adjusting for sociodemographic factors, RB survivors did not have significantly higher rates of depression, somatization, distress, or anxiety compared with CCSS siblings. Although RB survivors were more likely to report post-traumatic stress symptoms of avoidance and/or hyperarousal (both P < .01), only five (1.1%) of 470 met criteria for post-traumatic stress disorder. Among survivors, having a chronic medical condition did not increase the likelihood of psychological problems. Bilateral RB survivors were more likely than unilateral RB survivors to experience fears of cancer recurrence (P < .01) and worry about their children being diagnosed with RB (P < .01). However, bilateral RB survivors were no more likely to report depression, anxiety, or somatic complaints than unilateral survivors.

CONCLUSION

Most RB survivors do not have poorer psychosocial functioning compared with a noncancer sample. In addition, bilateral and unilateral RB survivors seem similar with respect to their psychological symptoms.

Increased stomach cancer risk following radiotherapy for testicular cancer

BACKGROUND

Abdominal radiotherapy for testicular cancer (TC) increases risk for second stomach cancer, although data on the radiation dose-response relationship are sparse.

METHODS

In a cohort of 22,269 5-year TC survivors diagnosed during 1959-1987, doses to stomach subsites were estimated for 92 patients who developed stomach cancer and 180 matched controls. Chemotherapy details were recorded. Odds ratios (ORs) were estimated using logistic regression.

RESULTS

Cumulative incidence of second primary stomach cancer was 1.45% at 30 years after TC diagnosis. The TC survivors who received radiotherapy (87 (95%) cases, 151 (84%) controls) had a 5.9-fold (95% confidence interval (CI) 1.7-20.7) increased risk of stomach cancer. Risk increased with increasing stomach dose (P-trend<0.001), with an OR of 20.5 (3.7-114.3) for ⩾50.0 Gy compared with <10 Gy. Radiation-related risks remained elevated ⩾20 years after exposure (P<0.001). Risk after any chemotherapy was not elevated (OR=1.1; 95% CI 0.5-2.5; 14 cases and 23 controls).

CONCLUSIONS

Radiotherapy for TC involving parts of the stomach increased gastric cancer risk for several decades, with the highest risks after stomach doses of ⩾30 Gy. Clinicians should be aware of these excesses when previously irradiated TC survivors present with gastrointestinal symptoms and when any radiotherapy is considered in newly diagnosed TC patients.

Pancreatic cancer risk after treatment of Hodgkin lymphoma

BACKGROUND

Although elevated risks of pancreatic cancer have been observed in long-term survivors of Hodgkin lymphoma (HL), no prior study has assessed the risk of second pancreatic cancer in relation to radiation dose and specific chemotherapeutic agents.

PATIENTS AND METHODS

We conducted an international case-control study within a cohort of 19 882 HL survivors diagnosed from 1953 to 2003 including 36 cases and 70 matched controls.

RESULTS

Median ages at HL and pancreatic cancer diagnoses were 47 and 60.5 years, respectively; median time to pancreatic cancer was 19 years. Pancreatic cancer risk increased with increasing radiation dose to the pancreatic tumor location (Ptrend = 0.005) and increasing number of alkylating agent (AA)-containing cycles of chemotherapy (Ptrend = 0.008). The odds ratio (OR) for patients treated with both subdiaphragmatic radiation (≥10 Gy) and ≥6 AA-containing chemotherapy cycles (13 cases, 6 controls) compared with patients with neither treatment was 17.9 (95% confidence interval 3.5-158). The joint effect of these two treatments was significantly greater than additive (P = 0.041) and nonsignificantly greater than multiplicative (P = 0.29). Especially high risks were observed among patients receiving ≥8400 mg/m(2) of procarbazine with nitrogen mustard or ≥3900 mg/m(2) of cyclophosphamide.

CONCLUSION

Our study demonstrates for the first time that both radiotherapy and chemotherapy substantially increase pancreatic cancer risks among HL survivors treated in the past. These findings extend the range of nonhematologic cancers associated with chemotherapy and add to the evidence that the combination of radiotherapy and chemotherapy can lead to especially large risks.

Risk of subsequent malignant neoplasms in long-term hereditary retinoblastoma survivors after chemotherapy and radiotherapy

PURPOSE

Hereditary retinoblastoma (Rb) survivors have increased risk of subsequent malignant neoplasms (SMNs). Previous studies reported elevated radiotherapy (RT) -related SMN risks, but less is known about chemotherapy-related risks.

PATIENTS AND METHODS

In a long-term follow-up study of 906 5-year hereditary Rb survivors diagnosed from 1914 to 1996 and observed through 2009, treatment-related SMN risks were quantified using cumulative incidence analyses and multivariable Cox proportional hazards regression models with age as the underlying time scale.

RESULTS

Nearly 90% of Rb survivors were treated with RT, and almost 40% received alkylating agent (AA) -containing chemotherapy (predominantly triethylenemelamine). Median follow-up time to first SMN diagnosis was 26.3 years. Overall SMN risk was not significantly elevated among survivors receiving AA plus RT versus RT without chemotherapy (hazard ratio [HR], 1.27; 95% CI, 0.99 to 1.63). AA-related risks were significantly increased for subsequent bone tumors (HR, 1.60; 95% CI, 1.03 to 2.49) and leiomyosarcoma (HR, 2.67; 95% CI, 1.22 to 5.85) but not for melanoma (HR, 0.74; 95% CI, 0.36 to 1.55) or epithelial tumors (HR, 0.89; 95% CI, 0.48 to 1.64). Leiomyosarcoma risk was significantly increased for survivors who received AAs at age < 1 (HR, 5.17; 95% CI, 1.76 to 15.17) but not for those receiving AAs at age ≥ 1 year (HR, 1.75; 95% CI, 0.68 to 4.51). Development of leiomyosarcoma was significantly more common after AA plus RT versus RT (5.8% v 1.6% at age 40 years; P = .01).

CONCLUSION

This comprehensive quantification of SMN risk after chemotherapy and RT among hereditary Rb survivors also demonstrates an AA-related contribution to risk. Although triethylenemelamine is no longer prescribed, our findings warrant further follow-up to investigate potential SMN risks associated with current chemotherapies used for Rb.

Retinoblastoma incidence patterns in the US Surveillance, Epidemiology, and End Results program

IMPORTANCE Several studies have found no temporal or demographic differences in the incidence of retinoblastoma except for age at diagnosis, whereas other studies have reported variations in incidence by sex and race/ethnicity. OBJECTIVE To examine updated US retinoblastoma incidence patterns by sex, age at diagnosis, laterality, race/ethnicity, and year of diagnosis. DESIGN, SETTING, AND PARTICIPANTS The Surveillance, Epidemiology, and End Results (SEER) databases were examined for retinoblastoma incidence patterns by demographic and tumor characteristics. We studied 721 children in SEER 18 registries, 659 in SEER 13 registries, and 675 in SEER 9 registries. MAIN OUTCOMES AND MEASURES Incidence rates, incidence rate ratios (IRRs), and annual percent changes in rates. RESULTS During 2000-2009 in SEER 18, there was a significant excess of total retinoblastoma among boys compared with girls (IRR, 1.18; 95% CI, 1.02 to 1.36), in contrast to earlier reports of a female predominance. Bilateral retinoblastoma among white Hispanic boys was significantly elevated relative to white non-Hispanic boys (IRR, 1.81; 95% CI, 1.22 to 2.79) and white Hispanic girls (IRR, 1.75; 95% CI, 1.11 to 2.91) because of less rapid decreases in bilateral rates since the 1990s among white Hispanic boys than among the other groups. Retinoblastoma rates among white non-Hispanics decreased significantly since 1992 among those younger than 1 year and since 1998 among those with bilateral disease. CONCLUSIONS AND RELEVANCE Although changes in the availability of prenatal screening practices for retinoblastoma may have contributed to these incidence patterns, further research is necessary to determine their actual effect on the changing incidence of retinoblastoma in the US population. In addition, consistent with other cancers, an excess of retinoblastoma diagnosed in boys suggests a potential effect of sex on cancer origin.

Breast cancer risk after radiotherapy for heritable and non-heritable retinoblastoma: a US-UK study

BACKGROUND

Retinoblastoma is a rare childhood eye cancer caused by germline or somatic mutations in the RB1 gene. Previous studies observed elevated breast cancer risk among retinoblastoma survivors. However, there has been no research on breast cancer risk in relation to radiation (primarily scatter radiation from the primary treatment) and genetic susceptibility of retinoblastoma survivors.

METHODS

Two groups of retinoblastoma survivors from the US and UK were selected, and breast cancer risk analysed using a case-control methodology, nesting within the respective cohorts, matching on heritability (that is to say, having bilateral retinoblastoma or being unilateral cases with at least one relative with retinoblastoma), and using exact statistical methods. There were a total of 31 cases and 77 controls.

RESULTS

Overall there was no significant variation of breast cancer risk with dose (P>0.5). However, there was a pronounced and significant (P=0.047) increase in the risk of breast cancer with increasing radiation dose for non-heritable retinoblastoma patients and a slight and borderline significant (P=0.072) decrease in risk of breast cancer with increasing radiation dose for heritable retinoblastoma patients, implying significant (P=0.024) heterogeneity in radiation risk between the heritable and non-heritable retinoblastoma groups; this was unaffected by the blindness status. There was no significant effect of any type of alkylating-agent chemotherapy on breast cancer risk (P>0.5).

CONCLUSIONS

There is significant radiation-related risk of breast cancer for non-heritable retinoblastoma survivors but no excess risk for heritable retinoblastoma survivors, and no significant risk overall. However, these results are based on very small numbers of cases; therefore, they must be interpreted with caution.

Genes and environment: effects on the development of second malignancies in retinoblastoma survivors

Although it is a rare cancer, retinoblastoma has served as an important model in our understanding of genetic cancer syndromes. All patients with a germinal rb1 mutation possess a risk of the development of second malignancies. Approximately 40-50% of all retinoblastoma cases are considered germinal cases and recent work has indicated that nearly all retinoblastoma patients probably demonstrate a degree of mosaicism for the rb1 mutation, and thus are at risk of secondary malignancies. The risk of the development of these cancers continues throughout the patients' lives due to the loss of a functional RB1 protein and its critical tumor suppressive function in all cells. These cancers can develop in diverse anatomic locations, including the skull and long bones, soft tissues, nasal cavity, skin, orbit, brain, breast and lung. Treatments used for retinoblastoma such as external-beam radiation and chemotherapy can have a significant impact on the risk for and pattern of development of these secondary cancers. Second malignancies are the leading cause of death in germinal retinoblastoma survivors in the USA and thus continue to be an important subject of study in this patient population. Second malignancies following the germinal form of retinoblastoma are the subject of this review.

Stomach cancer risk after treatment for hodgkin lymphoma

PURPOSE

Treatment-related stomach cancer is an important cause of morbidity and mortality among the growing number of Hodgkin lymphoma (HL) survivors, but risks associated with specific HL treatments are unclear.

PATIENTS AND METHODS

We conducted an international case-control study of stomach cancer nested in a cohort of 19,882 HL survivors diagnosed from 1953 to 2003, including 89 cases and 190 matched controls. For each patient, we quantified cumulative doses of specific alkylating agents (AAs) and reconstructed radiation dose to the stomach tumor location.

RESULTS

Stomach cancer risk increased with increasing radiation dose to the stomach (Ptrend < .001) and with increasing number of AA-containing chemotherapy cycles (Ptrend = .02). Patients who received both radiation to the stomach ≥ 25 Gy and high-dose procarbazine (≥ 5,600 mg/m(2)) had strikingly elevated stomach cancer risk (25 cases, two controls; odds ratio [OR], 77.5; 95% CI, 14.7 to 1452) compared with those who received radiation < 25 Gy and procarbazine < 5,600 mg/m(2) (Pinteraction < .001). Risk was also elevated (OR, 2.8; 95% CI, 1.3 to 6.4) among patients who received radiation to the stomach ≥ 25 Gy but procarbazine < 5,600 mg/m(2); however, no procarbazine-related risk was evident with radiation < 25 Gy. Treatment with dacarbazine also increased stomach cancer risk (12 cases, nine controls; OR, 8.8; 95% CI, 2.1 to 46.6), after adjustment for radiation and procarbazine doses.

CONCLUSION

Patients with HL who received subdiaphragmatic radiotherapy had dose-dependent increased risk of stomach cancer, with marked risks for patients who also received chemotherapy containing high-dose procarbazine. For current patients, risks and benefits of exposure to both procarbazine and subdiaphragmatic radiotherapy should be weighed carefully. For patients treated previously, GI symptoms should be evaluated promptly.

Radiation dose and subsequent risk for stomach cancer in long-term survivors of cervical cancer

PURPOSE

To assess the dose-response relationship for stomach cancer after radiation therapy for cervical cancer.

METHODS AND MATERIALS

We conducted a nested, matched case-control study of 201 cases and 378 controls among 53,547 5-year survivors of cervical cancer diagnosed from 1943 to 1995, from 5 international, population-based cancer registries. We estimated individual radiation doses to the site of the stomach cancer for all cases and to corresponding sites for the matched controls (overall mean stomach tumor dose, 2.56 Gy, range 0.03-46.1 and after parallel opposed pelvic fields, 1.63 Gy, range 0.12-6.3).

RESULTS

More than 90% of women received radiation therapy, mostly with external beam therapy in combination with brachytherapy. Stomach cancer risk was nonsignificantly increased (odds ratio 1.27-2.28) for women receiving between 0.5 and 4.9 Gy to the stomach cancer site and significantly increased at doses ≥ 5 Gy (odds ratio 4.20, 95% confidence interval 1.41-13.4, Ptrend=.047) compared with nonirradiated women. A highly significant radiation dose-response relationship was evident when analyses were restricted to the 131 cases (251 controls) whose stomach cancer was located in the middle and lower portions of the stomach (Ptrend=.003), whereas there was no indication of increasing risk with increasing dose for 30 cases (57 controls) whose cancer was located in the upper stomach (Ptrend=.23).

CONCLUSIONS

Our findings show for the first time a significant linear dose-response relationship for risk of stomach cancer in long-term survivors of cervical cancer.

Risk of treatment-related esophageal cancer among breast cancer survivors

BACKGROUND

Radiotherapy for breast cancer may expose the esophagus to ionizing radiation, but no study has evaluated esophageal cancer risk after breast cancer associated with radiation dose or systemic therapy use.

DESIGN

Nested case-control study of esophageal cancer among 289 748 ≥5-year survivors of female breast cancer from five population-based cancer registries (252 cases, 488 individually matched controls), with individualized radiation dosimetry and information abstracted from medical records.

RESULTS

The largest contributors to esophageal radiation exposure were supraclavicular and internal mammary chain treatments. Esophageal cancer risk increased with increasing radiation dose to the esophageal tumor location (P(trend )< 0.001), with doses of ≥35 Gy associated with an odds ratio (OR) of 8.3 [95% confidence interval (CI) 2.7-28]. Patients with hormonal therapy ≤5 years preceding esophageal cancer diagnosis had lower risk (OR = 0.4, 95% CI 0.2-0.8). Based on few cases, alkylating agent chemotherapy did not appear to affect risk. Our data were consistent with a multiplicative effect of radiation and other esophageal cancer risk factors (e.g. smoking).

CONCLUSIONS

Esophageal cancer is a radiation dose-related complication of radiotherapy for breast cancer, but absolute risk is low. At higher esophageal doses, the risk warrants consideration in radiotherapy risk assessment and long-term follow-up.

Patterns of bone sarcomas as a second malignancy in relation to radiotherapy in adulthood and histologic type

BACKGROUND

Radiotherapy decreases cancer mortality, but is associated with an increased incidence of second primary cancers, including osteosarcomas, especially after exposure in childhood. It remains uncertain whether radiation is related to other histologic types of bone sarcomas such as chondrosarcomas that are more common in adulthood.

METHODS

Using data from 1973 to 2008 Surveillance Epidemiology and End Results registries, we evaluated long-term risk of bone cancer in 1,284,537 adult 5-year cancer survivors. We used standardized incidence ratios (SIR) to compare second bone sarcoma rates to the general population for each histologic type. We also used multivariate Poisson regression to estimate the relative risk (RR) associated with radiotherapy for the most common subtypes, osteosarcoma and chondrosarcoma.

RESULTS

By the end of 2008, 159 second bone sarcomas were reported. Compared with the general population, the risk of developing any bone sarcoma was increased by 25% in patients with no history of radiotherapy [Observed (O) = 89, SIR = 1.25 (1.00-1.54)] and by 257% in patients with a history of radiotherapy [O = 70, SIR = 3.57 (2.78-4.50)]. For each histologic subtype, SIRs were higher among patients who had previously received radiotherapy than among those who had not. The RR for radiotherapy for osteosarcoma (n = 63) was 5.08 (3.05-8.59) and for chondrosarcoma (n = 69) was 1.54 (0.88-2.59), and these risks were even greater for second sarcomas that arose in the radiotherapy field used to treat the first cancer [osteosarcoma, RR = 10.35 (4.96-23.66); chondrosarcoma RR = 8.21 (2.09-39.89)].

CONCLUSIONS

Our findings provide the first evidence of a likely association between radiation exposure and chondrosarcoma.

IMPACT

These results further our understanding of radiotherapy-related cancer risks and will potentially direct practices in long-term surveillance of cancer survivors.

Sarcomas in hereditary retinoblastoma

Children diagnosed with the hereditary form of retinoblastoma (Rb), a rare eye cancer caused by a germline mutation in the RB1 tumor suppressor gene, have excellent survival, but face an increased risk of bone and soft tissue sarcomas. This predisposition to sarcomas has been attributed to genetic susceptibility due to inactivation of the RB1 gene as well as past radiotherapy for Rb. The majority of bone and soft tissue sarcomas among hereditary Rb survivors occur in the head, within the radiation field, but they also occur outside the radiation field. Sarcomas account for almost half of the second primary cancers in hereditary Rb survivors, but they are very rare following non-hereditary Rb. Sarcomas among hereditary Rb survivors arise at ages similar to the pattern of occurrence in the general population. There has been a trend over the past two decades to replace radiotherapy with chemotherapy and other focal therapies (laser or cryosurgery), and most recently, chemosurgery in order to reduce the incidence of sarcomas and other second cancers in Rb survivors. Given the excellent survival of most Rb patients treated in the past, it is important for survivors, their families and health care providers to be aware of the heightened risk for sarcomas in hereditary patients.

Secondary skull base malignancies in survivors of retinoblastoma: the memorial sloan kettering cancer center experience

We report the pathology and outcome of secondary skull base tumors in patients previously treated with external beam radiation for retinoblastoma (Rb). Rb patients are at increased risk of second head and neck primary malignancies due to early radiation exposure during treatment and loss of RB1 protein in genetic carriers. An institutional database was reviewed for patients with retinoblastoma who had previously received radiation therapy and subsequently developed skull base tumors. Seventeen patients met the selection criteria. The median age of Rb diagnosis was 12 months. Thirteen cases underwent enucleation in addition to radiation therapy as part of initial Rb treatment. A median of 19 years elapsed between the diagnosis of Rb and diagnosis of skull base malignancy. The most common tumors were osteogenic sarcoma (39%) and leiomyosarcoma (22%). Eleven (71%) patients received postoperative chemotherapy, and 7 (41%) received postoperative radiotherapy. Three (24%) patients underwent salvage surgery for recurrent disease. Five-year survival was 68%, and 10-year survival was 51% by Kaplan-Meier analysis. Secondary malignancy in Rb patients is a well-defined event. The use of surgery with appropriate adjuvant therapy was associated with a 51% 10-year survival in this study population.

Occupational radiation doses to operators performing fluoroscopically-guided procedures

In the past 30 y, the numbers and types of fluoroscopically-guided (FG) procedures have increased dramatically. The objective of the present study is to provide estimated radiation doses to physician specialists, other than cardiologists, who perform FG procedures. The authors searched Medline to identify English-language journal articles reporting radiation exposures to these physicians. They then identified several primarily therapeutic FG procedures that met specific criteria: well-defined procedures for which there were at least five published reports of estimated radiation doses to the operator, procedures performed frequently in current medical practice, and inclusion of physicians from multiple medical specialties. These procedures were percutaneous nephrolithotomy (PCNL), vertebroplasty, orthopedic extremity nailing for treatment of fractures, biliary tract procedures, transjugular intrahepatic portosystemic shunt creation (TIPS), head/neck endovascular therapeutic procedures, and endoscopic retrograde cholangiopancreatography (ERCP). Radiation doses and other associated data were abstracted, and effective dose to operators was estimated. Operators received estimated doses per patient procedure equivalent to doses received by interventional cardiologists. The estimated effective dose per case ranged from 1.7-56 μSv for PCNL, 0.1-101 μSv for vertebroplasty, 2.5-88 μSv for orthopedic extremity nailing, 2.0-46 μSv for biliary tract procedures, 2.5-74 μSv for TIPS, 1.8-53 μSv for head/neck endovascular therapeutic procedures, and 0.2-49 μSv for ERCP. Overall, mean operator radiation dose per case measured over personal protective devices at different anatomic sites on the head and body ranged from 19-800 (median = 113) μSv at eye level, 6-1,180 (median = 75) μSv at the neck, and 2-1,600 (median = 302) μSv at the trunk. Operators' hands often received greater doses than the eyes, neck, or trunk. Large variations in operator doses suggest that optimizing procedure protocols and proper use of protective devices and shields might reduce occupational radiation dose substantially.

A reanalysis of curvature in the dose response for cancer and modifications by age at exposure following radiation therapy for benign disease

PURPOSE

To assess the shape of the dose response for various cancer endpoints and modifiers by age and time.

METHODS AND MATERIALS

Reanalysis of the US peptic ulcer data testing for heterogeneity of radiogenic risk by cancer endpoint (stomach, pancreas, lung, leukemia, all other).

RESULTS

There are statistically significant (P<.05) excess risks for all cancer and for lung cancer and borderline statistically significant risks for stomach cancer (P=.07), and leukemia (P=.06), with excess relative risks Gy(-1) of 0.024 (95% confidence interval [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=.007) excess risk of pancreatic cancer when adjusted for dose-response curvature. General downward curvature is apparent in the dose response, statistically significant (P<.05) for all cancers, pancreatic cancer, and all other cancers (ie, other than stomach, pancreas, lung, leukemia). There are indications of reduction in relative 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 among the 5 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.

CONCLUSIONS

There are excess risks for various malignancies in this data set. Generally there is a 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.

Analysis of dose response for circulatory disease after radiotherapy for benign disease

PURPOSE

To assess the shape of the dose-response for various circulatory disease endpoints, and modifiers by age and time since exposure.

METHODS AND MATERIALS

This was an analysis of the US peptic ulcer data testing for heterogeneity of radiogenic risk by circulatory disease endpoint (ischemic heart, cerebrovascular, other circulatory disease).

RESULTS

There were 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 were no statistically significant (p > 0.2) differences between risks by endpoint, and few indications of curvature in the dose-response. There were significant (p < 0.001) modifications of relative risk by time since exposure, the magnitude of which did not vary between endpoints (p > 0.2). Risk modifications were similar if analysis was restricted to patients receiving radiation, although the relative risks were slightly larger and the risk of stroke failed to be significant. The slopes of the dose-response were generally consistent with those observed in the Japanese atomic bomb survivors and in occupationally and medically exposed groups.

CONCLUSIONS

There were 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 effect of fractionation of dose or low-dose-rate exposure.

Variation of second cancer risk by family history of retinoblastoma among long-term survivors

PURPOSE

To evaluate the risk of second cancer (SC) in long-term survivors of retinoblastoma (Rb) according to classification of germline mutation, based on family history of Rb and laterality.

PATIENTS AND METHODS

We assembled a cohort of 1,852 1-year survivors of Rb (bilateral, n = 1,036; unilateral, n = 816). SCs were ascertained by medical records and self-reports and confirmed by pathology reports. Classification of RB1 germline mutation, inherited or de novo, was inferred by laterality of Rb and positive family history of Rb. Standardized incidence ratios and cumulative incidence for all SCs combined and for soft tissue sarcomas, bone cancers, and melanoma were calculated. The influence of host- and therapy-related risk factors for SC was assessed by Poisson regression for bilateral survivors.

RESULTS

We observed a relative risk (RR) of 1.37 (95% CI, 1.00 to 1.86) for SCs in bilateral survivors associated with a family history of Rb, adjusted for treatment, age, and length of follow-up. The risk for melanoma was significantly elevated for survivors with a family history of Rb (RR, 3.08; 95% CI, 1.23 to 7.16), but risks for bone or soft tissue sarcomas were not elevated. The cumulative incidence of SCs 50 years after diagnosis of bilateral Rb, with adjustment for competing risk of death, was significantly higher for survivors with a family history (47%; 95% CI, 35% to 59%) than survivors without a family history (38%; 95% CI, 32% to 44%; P = .004).

CONCLUSION

Rb survivors with bilateral disease and an inherited germline mutation are at slightly higher risk of an SC compared with those with a de novo germline mutation, in particular melanoma, perhaps because of shared genetic alterations.

Analysis of retinoblastoma age incidence data using a fully stochastic cancer model

Retinoblastoma (RB) is an important ocular malignancy of childhood. It has been commonly accepted for some time that knockout of the two alleles of the RB1 gene is the principal molecular target associated with the occurrence of RB. In this article, we examine the validity of the two-hit theory for RB by comparing the fit of a stochastic model with two or more mutational stages. Unlike many such models, our model assumes a fully stochastic stem cell compartment, which is crucial to its behavior. Models are fitted to a population-based dataset comprising 1,553 cases of RB for the period 1962-2000 in Great Britain (England, Scotland and Wales). The population incidence of RB is best described by a fully stochastic model with two stages, although models with a deterministic stem cell compartment yield equivalent fit; models with three or more stages fit much less well. The results strongly suggest that knockout of the two alleles of the RB1 gene is necessary and may be largely sufficient for the development of RB, in support of Knudson's two-hit hypothesis.

Mutation risk associated with paternal and maternal age in a cohort of retinoblastoma survivors

Autosomal dominant conditions are known to be associated with advanced paternal age, and it has been suggested that retinoblastoma (Rb) also exhibits a paternal age effect due to the paternal origin of most new germline RB1 mutations. To further our understanding of the association of parental age and risk of de novo germline RB1 mutations, we evaluated the effect of parental age in a cohort of Rb survivors in the United States. A cohort of 262 Rb patients was retrospectively identified at one institution, and telephone interviews were conducted with parents of 160 survivors (65.3%). We classified Rb survivors into three groups: those with unilateral Rb were classified as sporadic if they had no or unknown family history of Rb, those with bilateral Rb were classified as having a de novo germline mutation if they had no or unknown family history of Rb, and those with unilateral or bilateral Rb, who had a family history of Rb, were classified as familial. We built two sets of nested logistic regression models to detect an increased odds of the de novo germline mutation classification related to older parental age compared to sporadic and familial Rb classifications. The modeling strategy evaluated effects of continuous increasing maternal and paternal age and 5-year age increases adjusted for the age of the other parent. Mean maternal ages for survivors classified as having de novo germline mutations and sporadic Rb were similar (28.3 and 28.5, respectively) as were mean paternal ages (31.9 and 31.2, respectively), and all were significantly higher than the weighted general US population means. In contrast, maternal and paternal ages for familial Rb did not differ significantly from the weighted US general population means. Although we noted no significant differences between mean maternal and paternal ages between each of the three Rb classification groups, we found increased odds of a survivor being in the de novo germline mutation group for each 5-year increase in paternal age, but these findings were not statistically significant (de novo vs. sporadic ORs 30-34 = 1.7 [0.7-4], ≥ 35 = 1.3 [0.5-3.3]; de novo vs. familial ORs 30-34 = 2.8 [1.0-8.4], ≥ 35 = 1.6 [0.6-4.6]). Our study suggests a weak paternal age effect for Rb resulting from de novo germline mutations consistent with the paternal origin of most of these mutations.

Increased risk of secondary uterine leiomyosarcoma in hereditary retinoblastoma

OBJECTIVE

In the US, second non-ocular malignancies are the primary cause of death in retinoblastoma survivors with the germline RB1 mutation. Soft tissue sarcomas are one of the most likely malignancies to pose a risk to these patients, with leiomyosarcoma (LMS) being the most common subtype. As our cohort is followed for a longer period, we discover new second malignancy risks for these patients.

METHODS

We estimated the risk for uterine leiomyosarcoma (ULMS) in a cohort of 1854 patients with retinoblastoma who were diagnosed at two US institutions from 1914 through 1996. The standardized incidence ratio and excess absolute risk were calculated by comparison with population data from the Connecticut Tumor Registry or from National Cancer Institute Surveillance, Epidemiology, and End Results (SEER) database. The cumulative risk at 50 years of age was also calculated.

RESULTS

Seven of 525 female hereditary retinoblastoma patients developed ULMS. Five of these patients were used in the risk analysis, resulting in an excess risk of 3.87 per 10,000 women. Among hereditary patients who developed ULMS the excess risk increases dramatically with age: to 20/10,000 for female hereditary retinoblastoma patients aged between 30 and 39 years, and to 27/10,000 for patients aged 40+ years.

CONCLUSION

There is a substantial excess risk of ULMS in female hereditary retinoblastoma patients. As more patients survive into their thirties, this number is likely to increase. These findings raise the question of early childbearing, screening and prophylactic measures in hereditary retinoblastoma patients: all issues that would benefit from confirmation from other retinoblastoma cohorts, to allow for better guided counsel of these patients.

Sinonasal adenocarcinoma: a rare second malignancy in long term retinoblastoma survivors

Retinoblastoma is the most common primary cancer of the eye in children. The incidence of second tumors in survivors of bilateral retinoblastoma and in survivors of unilateral retinoblastoma who presumably carry a germline RB1 mutation is documented. This article describes the previously unrecognized association of sinonasal adenocarcinoma as a second malignancy in retinoblastoma survivors. We present three cases who received radiation therapy as a part of their treatment and developed sinonasal adenocarcinoma as a second malignancy. Sinonasal adenocarcinoma should be considered as a second malignancy in retinoblastoma survivors who present with vague sinus symptoms.

Historical review of occupational exposures and cancer risks in medical radiation workers

Epidemiological studies of medical radiation workers have found excess risks of leukemia, skin and female breast cancer in those employed before 1950 but little consistent evidence of cancer risk increases subsequently. Occupational radiation-related dose-response data and recent and lifetime cancer risk data are limited for radiologists and radiologic technologists and lacking for physicians and technologists performing fluoroscopically guided procedures. Survey data demonstrate that occupational doses to radiologists and radiologic technologists have declined over time. Eighty mostly small studies of cardiologists and fewer studies of other physicians reveal that effective doses to physicians per interventional procedure vary by more than an order of magnitude. For medical radiation workers, there is an urgent need to expand the limited information on average annual, time-trend and organ doses from occupational radiation exposures and to assess lifetime cancer risks of these workers. For physicians and technologists performing interventional procedures, more information about occupational doses should be collected and long-term follow-up studies of cancer and other serious disease risks should be initiated. Such studies will help optimize standardized protocols for radiologic procedures, determine whether current radiation protection measures for medical radiation workers are adequate, provide guidance on cancer screening needs, and yield valuable insights on cancer risks associated with chronic radiation exposure.

Risk of cataract extraction among adult retinoblastoma survivors

OBJECTIVE

To investigate the risk of cataract extraction among adult retinoblastoma survivors.

DESIGN

A retrospective cohort study was performed on retinoblastoma survivors who received the diagnosis from 1914 to 1984 and were interviewed in 2000. Lens doses were estimated from radiotherapy records. The cumulative time interval to cataract extraction between dose groups was compared using the log-rank test and Cox regression.

RESULTS

Seven hundred fifty-three subjects (828 eyes) were available for analysis for an average of 32 years of follow-up. During this period, 51 cataract extractions were reported. One extraction was reported in an eye with no radiotherapy compared with 36 extractions in 306 eyes with 1 course of radiotherapy and 14 among 38 eyes with 2 or 3 treatments. The average time interval to cataract extraction in irradiated eyes was 51 years (95% confidence interval [CI], 48-54) following 1 treatment and 32 years (95% CI, 27-37) after 2 or 3 treatments. Eyes exposed to a therapeutic radiation dose of 5 Gy or more had a 6-fold increased risk (95% CI, 1.3-27.2) of cataract extraction compared with eyes exposed to 2.5 Gy or less.

CONCLUSIONS

The results emphasize the importance of ophthalmologic examination of retinoblastoma survivors who have undergone radiotherapy. The risk of cataract extraction in untreated eyes with retinoblastoma is comparable with the risk of the general population.

Cause-specific mortality in long-term survivors of retinoblastoma

BACKGROUND

Subsequent malignant neoplasms are a major cause of premature death in survivors of hereditary retinoblastoma. Radiotherapy further increases the risk of death. Mortality information is limited among long-term survivors who were irradiated for hereditary retinoblastoma.

METHODS

We examined cause-specific mortality among 1854 retinoblastoma survivors who were diagnosed from January 1, 1914, through December 31, 1996, at two US institutions. Standardized mortality ratios (SMRs) were calculated by use of US mortality data to estimate expected numbers of deaths. The relative rates (RRs) of mortality due to subsequent malignant neoplasms associated with multiple risk factors were evaluated with Poisson regression models. Cumulative mortality from subsequent malignant neoplasms was calculated by treating other causes of death as competing risks.

RESULTS

A total of 151 deaths due to subsequent malignant neoplasms occurred among 1092 hereditary retinoblastoma survivors (SMR = 35, 95% confidence interval [CI] = 30 to 41) compared with 12 deaths among 762 nonhereditary retinoblastoma survivors (SMR = 2.5, 95% CI = 1.3 to 4.4). In this extended follow-up of retinoblastoma survivors, we found no evidence of excess mortality from non-neoplastic causes compared with the general population. However, excess mortality from subsequent malignant neoplasms (particularly sarcomas, melanomas, and cancers of the brain and other parts of the nervous system) among hereditary retinoblastoma survivors extended beyond 40 years after retinoblastoma diagnosis. The additional 13 years of follow-up since our last mortality study revealed a previously unreported increased risk of death due to cancers of the corpus uteri (primarily sarcomas) and confirmed the previously reported elevated risk of death from lung cancer among hereditary retinoblastoma survivors. Among hereditary and nonhereditary retinoblastoma survivors, the relative rates of mortality from subsequent malignant neoplasm were higher in those who had been treated with radiotherapy than in those who had not. Cumulative mortality from subsequent malignant neoplasms at 50 years after retinoblastoma diagnosis was 25.5% (95% CI = 20.8% to 30.2%) for hereditary retinoblastoma survivors and 1.0% (95% CI = 0.2% to 1.8%) for nonhereditary retinoblastoma survivors.

CONCLUSIONS

The temporal patterns of site-specific excess risks of subsequent malignant neoplasms in retinoblastoma survivors should inform screening programs designed for the early detection and treatment of subsequent malignant neoplasms.