BRCA1 and BRCA2 mutations among ovarian cancer patients from Colombia

Objective: The contribution of BRCA1 and BRCA2 mutations to ovarian cancer in Colombia has not yet been explored. Five founder mutations have been identified in two previous studies of breast cancer patients in the Bogota region [1,2]. It is important that the frequency of mutations be established among unselected cases of ovarian cancer in order to estimate the genetic burden of this cancer in Colombia and to plan genetic and preventive services.

Methods: We enrolled 100 unselected women with ovarian cancer from the Bogota region, and from northern and southern central regions of Colombia. A detailed family history was obtained from each patient and a blood sample was processed for DNA analysis. DNA quality was adequate for BRCA testing for 96 women. Mutations in BRCA1 and BRCA2 were sought using a Hispanic BRCA mutation testing panel. All mutations were confirmed by direct sequencing.

Results: Fifteen mutations were identified (two in BRCA2 and thirteen in BRCA1) representing 15.6% of the total (95% CI: 7.8% to 21.3%). Among the 15 mutation-positive families there were nine breast-ovarian cancer families, one gastric cancer family, one prostate cancer family, three uterine cancer families, and one family with no history of cancer. A single founder mutation in BRCA1 (3450del4) was seen in 11 patients.

Conclusion: In summary, BRCA1 founder mutations are common in Colombian women with ovarian cancer. Approximately 11.5% of all ovarian cancer cases in the Bogota region are attributable to a single BRCA1 founder mutation.