FBL blood test as a predictive marker of breast cancer in high risk women.

The potential use of the ferritin bearing lymphocytes (FBL) blood test which enumerates oncofetal FBL as a biomarker for early breast cancer was explored. Analysis of the FBL positive test results carried out on high risk women who underwent biopsy in 1983-84 was found to be a significant predictor for early breast cancer (relative risk (RR) = 2.9, 95% confidence interval (CI) 1.4-5.8). A group of 635 women from the above study diagnosed in 1983-84 as having no evidence of breast cancer was further traced 8 years later with the aid of the National Cancer Registry. We identified 35 malignancies, including 19 cases of breast cancer. The RR of breast cancer for the FBL positive group was 2.51; 95% CI = 1.04-6.07 while for the other malignancies it was 0.93, 95% CI = 0.30-2.84. All the breast cancer cases in the FBL positive group were of the infiltrative duct carcinoma category and 71% were in early stage. In contrast, in the FBL negative group, 60% of the cases were infiltrative ductal carcinoma and most of them were at stage III. Positive FBL is associated with early manifestation of breast cancer and may be considered as a tool for the screening of breast cancer in high risk women.