CA125 Serum Levels in BRCA1/BRCA2 Pathogenic Sequence Variant Carriers as an Ovarian Cancer Screening Tool: A Longitudinal Study

BACKGROUND: BRCA1/BRCA2 female pathogenic sequence variant (PSV) carriers in Israel are offered semiannual cancer antigen 125 (CA125) serum level determination and transvaginal ultrasound until performing risk reducing salpingo-oophorectomy (RRSO), even with the lack of proven efficacy of these procedures in providing adequate early detection of ovarian cancer. OBJECTIVES: To report the results of longitudinal CA125 measurements in BRCA1/BRCA2 carriers as a tool for ovarian cancer detection in a single medical center in Israel. METHODS: Asymptomatic BRCA1/BRCA2 PSV carriers attending the Meirav High Risk Clinic at Sheba Medical Center for more than 3 years were eligible. Data on specific PSV, risk reducing surgeries, and cancer diagnoses were obtained from participant records. We used chi-square and Wilcoxon-Rank tests for statistical analyses. RESULTS: Overall, 739 (399 BRCA1, 336 BRCA2, 4 BRCA1 + BRCA2) PSV carriers were included. Mean age at the start of follow-up was 38.96 ± 11.13 years, mean follow-up time was 7.93 ± 2.34 years, (5860.80 women/years). Most participants (490/739 [66.3%]) had stable CA125 levels (± 5 U/µl). Of participants, 61 had CA125 levels > 35 U/µl at least twice (n=42) or at least doubling of marker levels to a minimum of 20 U/µl (n=19), results that have led to further cancer defining investigations. Of these, 14 and 4 were diagnosed with breast and ovarian cancer, respectively. CONCLUSIONS: Longitudinally stable CA125 levels were noted in most BRCA1/BRCA2 PSV carriers and elevated levels were a poor marker for ovarian cancer development.