Topic search filters: a systematic scoping review.

BACKGROUND: Searching for topics within large biomedical databases can be challenging, especially when topics are complex, diffuse, emerging or lack definitional clarity. Experimentally derived topic search filters offer a reliable solution to effective retrieval; however, their number and range of subject foci remain unknown. OBJECTIVES: This systematic scoping review aims to identify and describe available experimentally developed topic search filters. METHODS: Reports on topic search filter development (1990-) were sought using grey literature sources and 15 databases. Reports describing the conception and prospective development of a database-specific topic search and including an objectively measured estimate of its performance ('sensitivity') were included. RESULTS: Fifty-four reports met inclusion criteria. Data were extracted and thematically synthesised to describe the characteristics of 58 topic search filters. DISCUSSION: Topic search filters are proliferating and cover a wide range of subjects. Filter reports, however, often lack clear definitions of concepts and topic scope to guide users. Without standardised terminology, filters are challenging to find. Information specialists may benefit from a centralised topic filter repository and appraisal checklists to facilitate quality assessment. CONCLUSION: Findings will help information specialists identify existing topic search filters and assist filter developers to build on current knowledge in the field.

Impact of oropharyngeal dysphagia on healthcare cost and length of stay in hospital: a systematic review.

BACKGROUND: Healthcare systems internationally are under an ever-increasing demand for services that must be delivered in an efficient, effective and affordable manner. Several patient-related and organisational factors influence health-care expenditure and utilisation, including oropharyngeal dysphagia. Here, we present a systematic review of the literature and meta-analyses investigating how oropharyngeal dysphagia influences healthcare utilisation through length of stay (LOS) and cost. METHODS: Using a standardised approach, eight databases were systematically searched for relevant articles reporting on oropharyngeal dysphagia attributable inpatient LOS and healthcare costs through June 2016. Study methodologies were critically appraised and where appropriate, extracted LOS data were analysed in an overall summary statistic. RESULTS: Eleven studies reported on cost data, and 23 studies were included reporting on LOS data. Descriptively, the presence of dysphagia added 40.36% to health care costs across studies. Meta-analysis of all-cause admission data from 13 cohort studies revealed an increased LOS of 2.99 days (95% CI, 2.7, 3.3). A subgroup analysis revealed that admission for stroke resulted in higher and more variable LOS of 4.73 days (95% CI, 2.7, 7.2). Presence of dysphagia across all causes was also statistically significantly different regardless of geographical location: Europe (8.42 days; 95% CI, 4.3; 12.5), North America (3.91 days; 95% CI, 3.3, 4.5). No studies included in meta-analysis were conducted in Asia. CONCLUSIONS: This systematic review demonstrated that the presence of oropharyngeal dysphagia significantly increases healthcare utilisation and cost, highlighting the need to recognise oropharyngeal dysphagia as an important contributor to pressure on healthcare systems.

Temporal Trends in Treatment and Subsequent Neoplasm Risk Among 5-Year Survivors of Childhood Cancer, 1970-2015.

Importance: Cancer treatments are associated with subsequent neoplasms in survivors of childhood cancer. It is unknown whether temporal changes in therapy are associated with changes in subsequent neoplasm risk. Objective: To quantify the association between temporal changes in treatment dosing and subsequent neoplasm risk. Design, Setting, and Participants: Retrospective, multicenter cohort study of 5-year cancer survivors diagnosed before age 21 years from pediatric tertiary hospitals in the United States and Canada between 1970-1999, with follow-up through December 2015. Exposures: Radiation and chemotherapy dose changes over time. Main Outcomes and Measures: Subsequent neoplasm 15-year cumulative incidence, cumulative burden, and standardized incidence ratios for subsequent malignancies, compared by treatment decade. Multivariable models assessed relative rates (RRs) of subsequent neoplasms by 5-year increments, adjusting for demographic and clinical characteristics. Mediation analyses assessed whether changes in rates of subsequent neoplasms over time were mediated by treatment variable modifications. Results: Among 23 603 survivors of childhood cancer (mean age at diagnosis, 7.7 years; 46% female) the most common initial diagnoses were acute lymphoblastic leukemia, Hodgkin lymphoma, and astrocytoma. During a mean follow-up of 20.5 years (374 638 person-years at risk), 1639 survivors experienced 3115 subsequent neoplasms, including 1026 malignancies, 233 benign meningiomas, and 1856 nonmelanoma skin cancers. The most common subsequent malignancies were breast and thyroid cancers. Proportions of individuals receiving radiation decreased (77% for 1970s vs 33% for 1990s), as did median dose (30 Gy [interquartile range, 24-44] for 1970s vs 26 Gy [interquartile range, 18-45] for 1990s). Fifteen-year cumulative incidence of subsequent malignancies decreased by decade of diagnosis (2.1% [95% CI, 1.7%-2.4%] for 1970s, 1.7% [95% CI, 1.5%-2.0%] for 1980s, 1.3% [95% CI, 1.1%-1.5%] for 1990s). Reference absolute rates per 1000 person-years were 1.12 (95% CI, 0.84-1.57) for subsequent malignancies, 0.16 (95% CI, 0.06-0.41) for meningiomas, and 1.71 (95% CI, 0.88-3.33) for nonmelanoma skin cancers for survivors with reference characteristics (no chemotherapy, splenectomy, or radiation therapy; male; attained age 28 years). Standardized incidence ratios declined for subsequent malignancies over treatment decades, with advancing attained age. Relative rates declined with each 5-year increment for subsequent malignancies (RR, 0.87 [95% CI, 0.82-0.93]; P < .001), meningiomas (RR, 0.85 [95% CI, 0.75-0.97]; P = .03), and nonmelanoma skin cancers (RR, 0.75 [95% CI, 0.67-0.84]; P < .001). Radiation dose changes were associated with reduced risk for subsequent malignancies, meningiomas, and nonmelanoma skin cancers. Conclusions and Relevance: Among survivors of childhood cancer, the risk of subsequent malignancies at 15 years after initial cancer diagnosis remained increased for those diagnosed in the 1990s, although the risk was lower compared with those diagnosed in the 1970s. This lower risk was associated with reduction in therapeutic radiation dose.

Long-term risk for subsequent leukemia after treatment for childhood cancer: a report from the Childhood Cancer Survivor Study.

Previous investigations of cancer survivors report that the cumulative incidence of subsequent leukemia plateaus between 10 and 15 years after primary therapy. Risk beyond 15 years has not been comprehensively assessed, primarily because of lack of long-term follow-up. Among 5-year survivors from the Childhood Cancer Survivor Study cohort, 13 pathologically confirmed cases of subsequent leukemia occurred ≥ 15 years after primary malignancy, with a mean latency of 21.6 years (range, 15-32 years). Seven were acute myeloid leukemia (2 acute promyelocytic leukemia with t(15;17), 2 with confirmed preceding myelodysplastic syndrome), 4 acute lymphoblastic leukemia (2 pre-B lineage, 1 T cell, 1 unknown), and 2 other. Two acute myeloid leukemia cases had the 7q- deletion. The standardized incidence ratio was 3.5 (95% confidence interval, 1.9-6.0). Median survival from diagnosis of subsequent leukemia was 2 years. This is the first description of a statistically significant increased risk of subsequent leukemia ≥ 15 years from primary diagnosis of childhood cancer.

Induction of a regenerative microenvironment in skeletal muscle is sufficient to induce embryonal rhabdomyosarcoma in p53-deficient mice.

We have previously reported that mice with muscular dystrophy, including mdx mice, develop embryonal rhabdomyosarcoma (eRMS) with a low incidence after 1 year of age and that almost all such tumours contain cancer-associated p53 mutations. To further demonstrate the relevance of p53 inactivation, we created p53-deficient mdx mice. Here we demonstrate that loss of one or both p53 (Trp53) alleles accelerates eRMS incidence in the mdx background, such that almost all Trp53(-/-) mdx animals develop eRMS by 5 months of age. To ascertain whether increased tumour incidence was due to the regenerative microenvironment found in dystrophic skeletal muscles, we induced muscle regeneration in Trp53(+/+) and Trp53(-/-) animals using cardiotoxin (Ctx). Wild-type (Trp53(+/+) ) animals treated with Ctx, either once every 7 days or once every 14 days from 1 month of age onwards, developed no eRMS; however, all similarly Ctx-treated Trp53(-/-) animals developed eRMS by 5 months of age at the site of injection. Most of these tumours displayed markers of human eRMS, including over-expression of Igf2 and phosphorylated Akt. These data demonstrate that the presence of a regenerative microenvironment in skeletal muscle, coupled with Trp53 deficiency, is sufficient to robustly induce eRMS in young mice. These studies further suggest that consideration should be given to the potential of the muscle microenvironment to support tumourigenesis in regenerative therapies for myopathies.

Secondary gastrointestinal cancer in childhood cancer survivors: a cohort study.

BACKGROUND: Childhood cancer survivors develop gastrointestinal cancer more frequently and at a younger age than the general population, but the risk factors have not been well-characterized. OBJECTIVE: To determine the risk and associated risk factors for gastrointestinal subsequent malignant neoplasms (SMNs) in childhood cancer survivors. DESIGN: Retrospective cohort study. SETTING: The Childhood Cancer Survivor Study, a multicenter study of childhood cancer survivors diagnosed between 1970 and 1986. PATIENTS: 14 358 survivors of cancer diagnosed when they were younger than 21 years of age who survived for 5 or more years after the initial diagnosis. MEASUREMENTS: Standardized incidence ratios (SIRs) for gastrointestinal SMNs were calculated by using age-specific population data. Multivariate Cox regression models identified associations between risk factors and gastrointestinal SMN development. RESULTS: At median follow-up of 22.8 years (range, 5.5 to 30.2 years), 45 cases of gastrointestinal cancer were identified. The risk for gastrointestinal SMNs was 4.6-fold higher in childhood cancer survivors than in the general population (95% CI, 3.4 to 6.1). The SIR for colorectal cancer was 4.2 (CI, 2.8 to 6.3). The highest risk for gastrointestinal SMNs was associated with abdominal radiation (SIR, 11.2 [CI, 7.6 to 16.4]). However, survivors not exposed to radiation had a significantly increased risk (SIR, 2.4 [CI, 1.4 to 3.9]). In addition to abdominal radiation, high-dose procarbazine (relative risk, 3.2 [CI, 1.1 to 9.4]) and platinum drugs (relative risk, 7.6 [CI, 2.3 to 25.5]) independently increased the risk for gastrointestinal SMNs. LIMITATION: This cohort has not yet attained an age at which risk for gastrointestinal cancer is greatest. CONCLUSION: Childhood cancer survivors, particularly those exposed to abdominal radiation, are at increased risk for gastrointestinal SMNs. These findings suggest that surveillance of at-risk childhood cancer survivors should begin at a younger age than that recommended for the general population. PRIMARY FUNDING SOURCE: National Cancer Institute.

Mice lacking dystrophin or alpha sarcoglycan spontaneously develop embryonal rhabdomyosarcoma with cancer-associated p53 mutations and alternatively spliced or mutant Mdm2 transcripts.

Altered expression of proteins in the dystrophin-associated glycoprotein complex results in muscular dystrophy and has more recently been implicated in a number of forms of cancer. Here we show that loss of either of two members of this complex, dystrophin in mdx mice or alpha sarcoglycan in Sgca(-/-) mice, results in the spontaneous development of muscle-derived embryonal rhabdomyosarcoma (RMS) after 1 year of age. Many mdx and Sgca(-/-) tumors showed increased expression of insulin-like growth factor 2, retinoblastoma protein, and phosphorylated Akt and decreased expression of phosphatase and tensin homolog gene, much as is found in a human RMS. Further, all mdx and Sgca(-/-) RMS analyzed had increased expression of p53 and murine double minute (mdm)2 protein and contained missense p53 mutations previously identified in human cancers. The mdx RMS also contained missense mutations in Mdm2 or alternatively spliced Mdm2 transcripts that lacked an exon encoding a portion of the p53-binding domain. No Pax3:Fkhr or Pax7:Fkhr translocation mRNA products were evident in any tumor. Expression of natively glycosylated alpha dystroglycan and alpha sarcoglycan was reduced in mdx RMS, whereas dystrophin expression was absent in almost all human RMS, both for embryonal and alveolar RMS subtypes. These studies show that absence of members of the dystrophin-associated glycoprotein complex constitutes a permissive environment for spontaneous development of embryonal RMS associated with mutation of p53 and mutation or altered splicing of Mdm2.

Characteristics of responders to a request for a buccal cell specimen among survivors of childhood cancer and their siblings.

PURPOSE: Analysis of biological samples in large cohort studies may provide insight into the mechanism of, and risk factors for, disease onset and progression. METHODS: This study describes the methods used to collect biological samples from a large multi-center cohort of childhood cancer survivors and siblings of childhood cancer survivors and evaluates the predictors of a positive response among these individuals. RESULTS: Among survivors, female sex, white race/ethnicity, college graduation, never smoking, accessing the healthcare system in the past 2 years, and having a second malignant neoplasm were the strongest predictors of returning a sample. Among siblings, a similar demographic profile defined those likely to submit the requested sample. CONCLUSION: To reduce selection bias and increase the value of these samples for future analysis, additional phone calls and reminders targeting non-responders are needed to improve response rates among those least likely to respond to a single mailed request.

Genomic and clinical analyses of 2p24 and 12q13-q14 amplification in alveolar rhabdomyosarcoma: a report from the Children's Oncology Group.

Alveolar rhabdomyosarcoma (ARMS) is an aggressive pediatric cancer that is related to the skeletal muscle lineage and characterized by recurrent chromosomal translocations. Within the ARMS category, there is clinical and genetic heterogeneity, consistent with the premise that "primary" genetic events collaborate with "secondary" events to give rise to subsets with varying clinical features. Previous studies demonstrated that genomic amplification occurs frequently in ARMS. In the current study, we used oligonucleotide arrays to localize two common amplicons to the 2p24 and 12q13-q14 chromosomal regions. Based on the copy number array data, we sublocalized the minimum common regions of 2p24 and 12q13-q14 amplification to a 0.83 Mb region containing the DDX1 and MYCN genes, and a 0.55 Mb region containing 27 genes, respectively. Using fluorescent in situ hybridization assays to measure copy number of the 2p24 and 12q13-q14 regions in over 100 cases, we detected these amplicons in 13% and 12% of cases, respectively. Comparison with fusion status revealed that 2p24 amplification occurred preferentially in cases positive for PAX3-FOXO1 or PAX7-FOXO1 while 12q13-q14 amplification occurred preferentially in PAX3-FOXO1-positive cases. Expression studies demonstrated that MYCN was usually overexpressed in cases with 2p24 amplification while multiple genes were overexpressed in cases with 12q13-q14 amplification. Finally, although 2p24 amplification did not have a significant association with clinical outcome, 12q13-q14 amplification was associated with significantly worse failure-free and overall survival that was independent of gene fusion status.

The coinheritance of beta- and alpha- thalassemia: a review of one patient and her family.

The diagnosis and management of alpha-thalassemia may be complicated by the variability of the phenotype, which is due to the interaction of coinherited alpha-thalassemia and the variable severity of beta-thalassemia mutations. A well-documented case of complex beta- and alpha-thalassemia coinheritance is described. Laboratory and clinical data for the patient and her family are reviewed. The patient is an asymptomatic girl, one of identical twins. She presented at 1 month of age for follow-up of an abnormal newborn-screening result (hemoglobin F only), which initially suggested homozygosity for beta-thalassemia. Extensive studies on the patient and family revealed that she had coinherited alpha-thalassemia traits and homozygous beta-thalassemia. This case demonstrates the interaction of coinherited alpha- and beta-thalassemia with the resultant amelioration of the clinical phenotype. It also highlights the importance of family studies and close follow-up in diagnosing complex hemoglobinopathies.

Gastric outlet obstruction due to adenocarcinoma in a patient with Ataxia-Telangiectasia syndrome: a case report and review of the literature.

BACKGROUND: Ataxia-Telangiectasia syndrome is characterized by progressive cerebellar dysfunction, conjuctival and cutaneous telangiectasias, severe immune deficiencies, premature aging and predisposition to cancer. Clinical and radiographic evaluation for malignancy in ataxia-telangiectasia patients is usually atypical, leading to delays in diagnosis. CASE PRESENTATION: We report the case of a 20 year old ataxia-telangiectasia patient with gastric adenocarcinoma that presented as complete gastric outlet obstruction. CONCLUSION: A literature search of adenocarcinoma associated with ataxia-telangiectasia revealed 6 cases. All patients presented with non-specific gastrointestinal complaints suggestive of ulcer disease. Although there was no correlation between immunoglobulin levels and development of gastric adenocarcinoma, the presence of chronic gastritis and intestinal metaplasia seem to lead to the development of gastric adenocarcinoma. One should consider adenocarcinoma in any patient with ataxia-telangiectasia who presents with non-specific gastrointestinal complaints, since this can lead to earlier diagnosis.

Prediction of second malignant neoplasm incidence in a large cohort of long-term survivors of childhood cancers.

BACKGROUND: The ability to predict adverse-event occurrences accurately in long-term survivors of childhood cancer is of high importance in late effects research, both clinically and methodologically. PROCEDURE: This article considers a statistical prediction of future events in a cohort, taking second malignant neoplasm (SMN) incidence in a large cohort of long-term childhood cancer survivors as an example. The method consists of dividing the follow-up period of the cohort into two non-overlapping periods, using the first period as "training data," with which we model the patterns of SMN occurrences in the cohort, and the subsequent period as "testing data," with which we validate the model based on the training data. Future predictions are also applied beyond the testing-data period to calculate the SMN incidence of the cohort in the next five years for overall and specific types of SMNs. RESULTS: The proposed statistical prediction is shown empirically to perform well with respect to the prediction accuracy. Overall, the models were able to predict the future second cancers rates very well, with exceptions of a few cancer types that had very small observed counts in the testing period. CONCLUSIONS: Our proposed statistical method predicts future events in a cohort of long-term childhood cancer survivors and, as such, is a useful tool for late effects research on childhood cancer survivors.

Endothelial nitric oxide synthase in human intestine resected for necrotizing enterocolitis.

OBJECTIVE: To determine the expression and function of endothelial nitric oxide synthase (eNOS) in submucosal arterioles harvested from human intestine resected for necrotizing enterocolitis (NEC) or congenital bowel disease. STUDY DESIGN: eNOS expression was determined by using immunohistochemistry. The arteriolar diameter was measured in vitro at pressures of 10 to 40 mm Hg and also in response to the eNOS agonist acetylcholine (ACh), the exogenous nitric oxide (NO) donor S-nitroso-N-acetylpenicillamine, and the smooth muscle relaxant papaverine. Arteriolar release of NO in response to ACh was determined with a Sievers NOAnalyzer. Hemodynamics were also determined at flow rates of 50 and 100 microL/min. RESULTS: eNOS was present in microvessels from both groups, but NEC arterioles failed to demonstrate physiological evidence of eNOS function: they constricted in response to pressure, failed to dilate or generate NO in response to ACh, and failed to dilate in response to flow. However, they dilated in response to exogenous NO and papaverine, indicating functional vascular smooth muscle and vasodilator reserve. CONCLUSION: eNOS-derived NO, a vasodilator in the newborn intestine, did not contribute to vasoregulation in arterioles harvested from intestine resected for NEC. These vessels were constricted; lack of eNOS-derived NO may contribute to this vasoconstriction.

Survivin and Granzyme B-induced apoptosis, a novel anticancer therapy.

Survivin is an antiapoptotic protein highly expressed in malignant cells that confers resistance to cytotoxic therapy. Granzyme B is a potent cytotoxic protein that is released from mammalian natural killer cells and CTLs following noxious stimuli, including foreign invaders. Here, we took advantage of the properties of these two functionally divergent molecules to create a molecular agent that specifically activates Granzyme B within tumor cells. We designed Survivin and Granzyme B-induced apoptosis (SAGA), which consists of a fusion of the Survivin gene promoter to the coding sequence of active Granzyme B. In cultured human tumor cells transfected with SAGA DNA, Granzyme B is rapidly expressed and results in significant tumor cell death. In vivo, mice harboring human ovarian tumors had statistically significant clinical responses to SAGA treatment that were magnified following combination therapy with SAGA and paclitaxel. At the completion of a 3-week therapeutic trial, 3 of 15 animals were free of disease in the SAGA-treated group, and an additional eight animals had tumors that were nonpalpable and only detected on surgical resection. In contrast, 15 of 15 animals in the control and paclitaxel-only-treated groups had tumors at end of therapy. Treatment with SAGA with or without paclitaxel also prevented disease dissemination in 19 of 20 animals. These results strongly suggest that SAGA has the potential to be a potent agent for the treatment of primary and recurrent human ovarian carcinoma. Moreover, we predict that SAGA will be useful therapeutically in any human cancer that expresses Survivin.

Somatic and Germline TP53 Alterations in Second Malignant Neoplasms from Pediatric Cancer Survivors.

Purpose: Second malignant neoplasms (SMNs) are severe late complications that occur in pediatric cancer survivors exposed to radiotherapy and other genotoxic treatments. To characterize the mutational landscape of treatment-induced sarcomas and to identify candidate SMN-predisposing variants, we analyzed germline and SMN samples from pediatric cancer survivors.Experimental Design: We performed whole-exome sequencing (WES) and RNA sequencing on radiation-induced sarcomas arising from two pediatric cancer survivors. To assess the frequency of germline TP53 variants in SMNs, Sanger sequencing was performed to analyze germline TP53 in 37 pediatric cancer survivors from the Childhood Cancer Survivor Study (CCSS) without any history of a familial cancer predisposition syndrome but known to have developed SMNs.Results: WES revealed TP53 mutations involving p53's DNA-binding domain in both index cases, one of which was also present in the germline. The germline and somatic TP53-mutant variants were enriched in the transcriptomes for both sarcomas. Analysis of TP53-coding exons in germline specimens from the CCSS survivor cohort identified a G215C variant encoding an R72P amino acid substitution in 6 patients and a synonymous SNP A639G in 4 others, resulting in 10 of 37 evaluable patients (27%) harboring a germline TP53 variant.Conclusions: Currently, germline TP53 is not routinely assessed in patients with pediatric cancer. These data support the concept that identifying germline TP53 variants at the time a primary cancer is diagnosed may identify patients at high risk for SMN development, who could benefit from modified therapeutic strategies and/or intensive posttreatment monitoring. Clin Cancer Res; 23(7); 1852-61. ©2016 AACR.

Genome-Wide Association Study to Identify Susceptibility Loci That Modify Radiation-Related Risk for Breast Cancer After Childhood Cancer.

Background: Childhood cancer survivors treated with chest-directed radiotherapy have substantially elevated risk for developing breast cancer. Although genetic susceptibility to breast cancer in the general population is well studied, large-scale evaluation of breast cancer susceptibility after chest-directed radiotherapy for childhood cancer is lacking. Methods: We conducted a genome-wide association study of breast cancer in female survivors of childhood cancer, pooling two cohorts with detailed treatment data and systematic, long-term follow-up: the Childhood Cancer Survivor Study and St. Jude Lifetime Cohort. The study population comprised 207 survivors who developed breast cancer and 2774 who had not developed any subsequent neoplasm as of last follow-up. Genotyping and subsequent imputation yielded 16 958 466 high-quality variants for analysis. We tested associations in the overall population and in subgroups stratified by receipt of lower than 10 and 10 or higher gray breast radiation exposure. We report P values and pooled per-allele risk estimates from Cox proportional hazards regression models. All statistical tests were two-sided. Results: Among survivors who received 10 or higher gray breast radiation exposure, a locus on 1q41 was associated with subsequent breast cancer risk (rs4342822, nearest gene PROX1 , risk allele frequency in control subjects [RAF controls ] = 0.46, hazard ratio = 1.92, 95% confidence interval = 1.49 to 2.44, P = 7.09 × 10 -9 ). Two rare variants also showed potentially promising associations (breast radiation ≥10 gray: rs74949440, 11q23, TAGLN , RAF controls = 0.02, P = 5.84 × 10 -8 ; <10 gray: rs17020562, 1q32.3, RPS6KC1 , RAF controls = 0.0005, P = 6.68 × 10 -8 ). Associations were restricted to these dose subgroups, with consistent findings in the two survivor cohorts. Conclusions: Our study provides strong evidence that germline genetics outside high-risk syndromes could modify the effect of radiation exposure on breast cancer risk after childhood cancer.

Nonmelanoma skin cancer in survivors of childhood and adolescent cancer: a report from the childhood cancer survivor study.

PURPOSE: Nonmelanoma skin cancer (NMSC) has become the most common type of cancer in many populations throughout the world. Ultraviolet and ionizing radiation are known risk factors. Because NMSCs are rarely lethal and most cancer registries do not routinely report data regarding these cancers, they have received little attention in studies evaluating long-term effects of cancer therapy. This article reports on the occurrence of secondary NMSC as a long-term effect of cancer therapy in survivors of childhood cancer. PATIENTS AND METHODS: The Childhood Cancer Survivor Study (CCSS) is a cohort study of 5-year survivors of childhood and adolescent cancer from 25 participating institutions in North America. NMSC patients were defined by a history of basal cell or squamous cell carcinoma of the skin after primary malignancy treatment. Demographic and treatment data were collected and analyzed. RESULTS: Among the 13,132 eligible CCSS participants, 213 have reported NMSC; 99 patients (46%) have had multiple occurrences. Median age of occurrence was 31 years (range, 7 to 46 years). Location of NMSC included head and neck (43%), back (24%), chest (22%), abdomen and pelvis (5%), extremity (3%), and unknown (4%). Ninety percent of patients had previously received radiation therapy (RT); 90% of tumors occurred within the RT field. RT was associated with a 6.3-fold increase in risk (95% CI, 3.5- to 11.3-fold). CONCLUSION: Long-term survivors of childhood and adolescent cancer who were treated with RT are at highest risk for developing NMSC. Educational efforts need to be directed to this population to facilitate early diagnosis of NMSC and reduction in sun exposure.

Primary thyroid cancer after a first tumour in childhood (the Childhood Cancer Survivor Study): a nested case-control study.

BACKGROUND: Survivors of malignant disease in childhood who have had radiotherapy to the head, neck, or upper thorax have an increased risk of subsequent primary thyroid cancer, but the magnitude of risk over the therapeutic dose range has not been well established. We aimed to quantify the long-term risk of thyroid cancer after radiotherapy and chemotherapy. METHODS: In a nested case-control study, 69 cases with pathologically confirmed thyroid cancer and 265 matched controls without thyroid cancer were identified from 14,054 5-year survivors of cancer during childhood from the Childhood Cancer Survivor Study cohort. Childhood cancers were diagnosed between 1970 and 1986 with cohort follow-up to 2000. FINDINGS: Risk of thyroid cancer increased with radiation doses up to 20-29 Gy (odds ratio 9.8 [95% CI 3.2-34.8]). At doses greater than 30 Gy, a fall in the dose-response relation was seen. Both the increased and decreased risks were more pronounced in those diagnosed with a first primary malignant disease before age 10 years than in those older than 10 years. Furthermore, the fall in risk remained when those diagnosed with Hodgkin's lymphoma were excluded. Chemotherapy for the first cancer was not associated with thyroid-cancer risk, and it did not modify the effect of radiotherapy. 29 (42%) cases had a first diagnosis of Hodgkin's lymphoma compared with 49 (19%) controls. 11 (42%) of those who had Hodgkin's lymphoma had subsequent thyroid cancers smaller than 1 cm compared with six (17%) of those who had other types of childhood cancer (p=0.07). INTERPRETATION: The reduction in radiation dose-response for risk of thyroid cancer after childhood exposure to thyroid doses higher than 30 Gy is consistent with a cell-killing effect. Standard long-term follow-up of patients who have had Hodgkin's lymphoma for detection of thyroid cancer should also be undertaken for survivors of any cancer during childhood who received radiotherapy to the thorax or head and neck region.

Thyroid cancer in childhood cancer survivors: a detailed evaluation of radiation dose response and its modifiers.

Radiation exposure at a young age is a strong risk factor for thyroid cancer. We conducted a nested case-control study of 69 thyroid cancer cases and 265 controls from a cohort of 14,054 childhood cancer survivors to evaluate the shape of the radiation dose-response relationship, in particular at high doses, and to assess modification of the radiation effects by patient and treatment characteristics. We considered several types of statistical models to estimate the excess relative risk (ERR), mainly guided by radiobiological models. A two-parameter model with a term linear in dose and a negative exponential in dose squared provided the best parsimonious description with an ERR of 1.3 per gray (95% confidence interval 0.4-4.1) at doses below 6 Gy and a relative decrease in ERR of 0.2% per unit dose squared with increasing dose, that is, decreases in the ERR/Gy of 53% at 20 Gy and 95% at 40 Gy. Further analyses using spline models suggested that the significant nonlinearity at high doses was characterized most appropriately as a true downturn rather than a flattening of the dose-response curve. We found no statistically significant modification of the dose-response relationship by patient characteristics; however, the linear parameter (i.e., the ERR/ Gy at doses less than 6 Gy) did decrease consistently and linearly with increasing age at childhood cancer diagnosis, from 4.45 for 0-1-year-olds to 0.48 for 15-20-year-olds. In summary, we applied models derived from radiobiology to describe the radiation dose-response curve for thyroid cancer in an epidemiological study and found convincing evidence for a downturn in risk at high doses.

Radiation-Related New Primary Solid Cancers in the Childhood Cancer Survivor Study: Comparative Radiation Dose Response and Modification of Treatment Effects.

OBJECTIVES: The majority of childhood cancer patients now achieve long-term survival, but the treatments that cured their malignancy often put them at risk of adverse health outcomes years later. New cancers are among the most serious of these late effects. The aims of this review are to compare and contrast radiation dose-response relationships for new solid cancers in a large cohort of childhood cancer survivors and to discuss interactions among treatment and host factors. METHODS: This review is based on previously published site-specific analyses for subsequent primary cancers of the brain, breast, thyroid gland, bone and soft tissue, salivary glands, and skin among 12,268 5-year childhood cancer survivors in the Childhood Cancer Survivor Study. Analyses included tumor site-specific, individual radiation dose reconstruction based on radiation therapy records. Radiation-related second cancer risks were estimated using conditional logistic or Poisson regression models for excess relative risk (ERR). RESULTS: Linear dose-response relationships over a wide range of radiation dose (0-50 Gy) were seen for all cancer sites except the thyroid gland. The steepest slopes occurred for sarcoma, meningioma, and nonmelanoma skin cancer (ERR/Gy > 1.00), with glioma and cancers of the breast and salivary glands forming a second group (ERR/Gy = 0.27-0.36). The relative risk for thyroid cancer increased up to 15-20 Gy and then decreased with increasing dose. The risk of thyroid cancer also was positively associated with chemotherapy, but the chemotherapy effect was not seen among those who also received very high doses of radiation to the thyroid. The excess risk of radiation-related breast cancer was sharply reduced among women who received 5 Gy or more to the ovaries. CONCLUSIONS: The results suggest that the effect of high-dose irradiation is consistent with a linear dose-response for most organs, but they also reveal important organ-specific and host-specific differences in susceptibility and interactions between different aspects of treatment.