Tubal ligation and risk of ovarian cancer subtypes: a pooled analysis of case-control studies.

BACKGROUND: Tubal ligation is a protective factor for ovarian cancer, but it is unknown whether this protection extends to all invasive histological subtypes or borderline tumors. We undertook an international collaborative study to examine the association between tubal ligation and ovarian cancer subtypes. METHODS: We pooled primary data from 13 population-based case-control studies, including 10,157 patients with ovarian cancer (7942 invasive; 2215 borderline) and 13,904 control women. Invasive cases were analysed by histological type, grade and stage, and borderline cases were analysed by histological type. Pooled odds ratios were estimated using conditional logistic regression to match on site, race/ethnicity and age categories, and to adjust for age, oral contraceptive use duration and number of full-term births. RESULTS: Tubal ligation was associated with significantly reduced risks of invasive serous (OR, 0.81; 95% CI, 0.74-0.89; P < 0.001), endometrioid (OR, 0.48; 95% CI, 0.40-0.59; P < 0.001), clear cell (OR, 0.52; 95% CI, 0.40-0.67; P < 0.001) and mucinous (OR, 0.68; 95% CI, 0.52-0.89; P = 0.005) cancers. The magnitude of risk reduction was significantly greater for invasive endometrioid (P < 0.0001) and clear cell (P = 0.0018) than for serous cancer. No significant associations were found with borderline serous or mucinous tumours. CONCLUSIONS: We found that the protective effects of tubal ligation on ovarian cancer risk were subtype-specific. These findings provide insights into distinct aetiologies of ovarian cancer subtypes and mechanisms underlying the protective effects of tubal ligation.

IVF and retinoblastoma revisited.

OBJECTIVE: To evaluate the suggested association between IVF, retinoblastoma, and tumor methylation characteristics. DESIGN: Laboratory analysis. SETTING: National Retinoblastoma Center in the Netherlands. PATIENT(S): Retinoblastoma tumors from seven children conceived by IVF or intracytoplasmic sperm injection (ICSI). INTERVENTION(S) AND MAIN OUTCOME MEASURE(S): DNA from frozen retinoblastoma tumors was tested for mutations in the RB1 gene and for methylation status of the RB1 promoter. RESULT(S): For all tumors two causative RB1 mutations were found. None of the tumors showed hypermethylation of the RB1 promoter. CONCLUSION(S): Examination of retinoblastoma tumors of seven children conceived by IVF or ICSI did not show hypermethylation of the RB1 promoter. This demonstrates that an association between IVF or ICSI and retinoblastoma through this epigenetic mechanism is unlikely.

RB1 mutations and second primary malignancies after hereditary retinoblastoma.

Survivors of hereditary retinoblastoma have a high risk of second primary malignancies, but it has not been investigated whether specific RB1 germline mutations are associated with greater risk of second primary malignancies in a large cohort. We conducted a retrospective cohort study of 199 survivors of hereditary retinoblastoma with a documented RB1 germline mutation diagnosed between 1905 and 2005. In total, 44 hereditary retinoblastoma survivors developed a second primary malignancy after a median follow-up of 30.2 years (range 1.33-76.0). A significantly increased risk of second primary malignancy was observed among carriers of one of the 11 recurrent CGA>TGA nonsense RB1 mutations (hazard ratio (HR) = 3.53; [95% confidence interval (CI) = 1.82-6.84]; P = .000), and there was a significantly lower risk for subjects with a low penetrance mutation (HR = .19; [95% CI = .05-.81]; P = .025). Our findings suggest a genotype-phenotype correlation for second primary cancers of retinoblastoma survivors and may impact on long-term surveillance protocols of patients with hereditary retinoblastoma, if confirmed by future studies.

Functional polymorphisms in the TERT promoter are associated with risk of serous epithelial ovarian and breast cancers.

Genetic variation at the TERT-CLPTM1L locus at 5p15.33 is associated with susceptibility to several cancers, including epithelial ovarian cancer (EOC). We have carried out fine-mapping of this region in EOC which implicates an association with a single nucleotide polymorphism (SNP) within the TERT promoter. We demonstrate that the minor alleles at rs2736109, and at an additional TERT promoter SNP, rs2736108, are associated with decreased breast cancer risk, and that the combination of both SNPs substantially reduces TERT promoter activity.

Risk of second malignancies in survivors of retinoblastoma: more than 40 years of follow-up.

BACKGROUND: Survivors of hereditary retinoblastoma have an elevated risk of developing second malignancies, but data on the risk in middle-aged retinoblastoma survivors (ie, those with more than 40 years of follow-up) are scarce. METHODS: Data from the Dutch retinoblastoma registry were used to analyze risks of second malignancies in 668 retinoblastoma survivors, diagnosed from 1945 to 2005 (median age = 24.9 years) and classified as having had hereditary or nonhereditary disease based on the presence of family history, bilateral disease, or a germline RB1 mutation. Standardized incidence ratios (SIRs) and absolute excess risks (AERs) of subsequent cancers in patients with hereditary and nonhereditary disease were estimated by comparison with Dutch sex-, age-, and calendar year-specific rates. Multivariable Cox regression and competing risk analyses were used to determine associations of treatment with risks of second malignancies. All statistical tests were two-sided. RESULTS: After a median follow-up of 21.9 years, the risk of second malignancies in survivors of hereditary retinoblastoma (SIR = 20.4, 95% confidence interval [CI] = 15.6 to 26.1) far exceeded the risk of survivors of nonhereditary retinoblastoma (SIR = 1.86, 95% CI = 0.96 to 3.24). Among patients with hereditary disease, treatment with radiotherapy was associated with a further increase in the risk of a subsequent cancer (hazard ratio = 2.81, 95% CI = 1.28 to 6.19). After 30 years of follow-up, elevated risks of epithelial cancers (lung, bladder, and breast) were observed among survivors of hereditary retinoblastoma. After 40 years of follow-up, the AER of a second malignancy among survivors of hereditary retinoblastoma had increased to 26.1 excess cases per 1000 person-years. The cumulative incidence of any second malignancy 40 years after retinoblastoma diagnosis was 28.0% (95% CI = 21.0% to 35.0%) for patients with hereditary disease. CONCLUSION: Our analysis of middle-aged hereditary retinoblastoma survivors suggests that these individuals have an excess risk of epithelial cancer. Lifelong follow-up studies are needed to evaluate the full spectrum of subsequent cancer risk in hereditary retinoblastoma survivors.