Risk factors for non-invasive lesions of the fallopian tube in BRCA mutation carriers

To identify risk factors for the presence of a non-invasive lesion of the fallopian tube in women with a BRCA1 or BRCA2 mutation.

173 BRCA mutation carriers underwent a prophylactic salpingo-oophorectomy at the University Health Network, Toronto between 2000 and 2008 and were evaluated for the presence of a non-invasive lesion of the fallopian tube. Patients were classified as having p53 overexpression ("p53-signature"), a tubal intra-epithelial carcinoma (TIC) or normal tubal epithelium. We obtained a risk factor questionnaire from all patients. We calculated odds ratios for several risk factors, comparing patients with a tubal abnormality to those with normal histology.

Of the 173 patients, 43 (25%) were found to have a tubal lesion, including 23% of the BRCA1 mutation carriers and 27% of the BRCA2 mutation carriers. The prevalence of a non-invasive tubal lesion increased with age; an abnormality was present in 5% of women who had surgery before the age of 40 (1 of 12) and in 56% of women who underwent surgery at age 60 or above (6 of 13; p=0.004). A non-invasive lesion of either type was found in 31.2% of women with a BMI > 25 kg/m2) compared to 18.0% of patients with a BMI < 25 kg/m2 at the time of surgery (p=0.05). The average duration of oral contraceptive use among women with normal tubes was 6.0 years, compared to an average duration of 4.0 years for women with a p53 signature (p=0.09) and was 2.7 years for women with a TIC (p=0.0003).

The prevalence of tubal p53 signature and TIC increases with age at salpingectomy and with BMI. Oral contraceptive use is associated with a decrease in the prevalence of TICs.