• Sweden;
  • BRCA1/2 mutations;
  • ovarian cancer;
  • family history;
  • SIR;
  • PAF


Age-specific familial risks in ovarian cancer have not been assessed by histologic types of medically verified cancers. We used the nationwide Swedish Family-Cancer Database on 10.2 million individuals and 19,175 invasive and 3,436 borderline ovarian cancers to calculate, by affected family members, standardized incidence ratios (SIRs) and 95% confidence intervals (CIs) for familial ovarian cancer in 0–66 year old daughters. SIRs for all invasive ovarian cancer were 2.68 (95% CI 2.22–3.21) by ovarian cancer in mother, 2.94 (1.40–5.94) by an affected sister and 24.03 (6.12–74.46) by both an affected mother and sister. The population-attributable fraction from mothers was 2.52%. Seropapillary cystadenocarcinoma showed the highest familial risk, but the effect of histopathol subtype could not be fully assessed because of lack of data in probands. Age-specific data showed some early-onset components and an unusual maximal incidence in the 40s. A comparison to an earlier study on BRCA1/2 mutation analysis and relative risks of ovarian and breast cancer suggests that these mutations could account for 26% of the familial aggregation of ovarian cancer. Histopathology and age of onset appear to be important attributes of familial ovarian cancer, suggesting that further gene identification efforts should target a specific histopathology in early-onset patients. © 2003 Wiley-Liss, Inc.