[Clinical usefulness of tumor markers in breast cancer]

Currently, many tumor markers are routinely measured in patient serum, but none appears to adequately detect cancer-specific substances for breast cancer. Four tumor markers (CEA, CA15-3, BCA225, c-erbB-2) were compared for sensitivity and specificity to breast cancer in 393 patients with breast disease (fibrocystic disease; 40, benign tumor; 21, primary cancer; 22, recurrent or advanced cancer; 22, non-recurrent; 288), and the following results were obtained: In cases of primary breast cancer excluding stage IV cases, the positive rates of CEA, CA15-3 and BCA225 were 4.5%, 13.6% and 13.6%, respectively. These rates were not higher than the positive rates found in fibrocystic disease or benign tumor. In cases of recurrent or advanced breast cancer, the positive rates of CEA, CA15-3, BCA225 and c-erbB-2 were 31.8%, 50.0%, 40.9% and 27.3%, respectively. In the recurrent cases, the combination assay using CA15-3, BCA225 and c-erbB-2, showed more useful diagnostic value (72.7%) than other combination assays with three tumor markers. High levels of CA15-3 in eight cases, BCA225 in five and CEA in one were found during the follow up of 15 patients with initial recurrence. Serum c-erbB-2 exceeded the normal range in 6 of 7 cases with advanced breast cancer. Serum c-erbB-2 should be considered a marker of progressive breast cancer. These results suggested that CA15-3, BCA225, c-erbB-2 and combination assays are useful tumor markers for not only detecting the recurrence of breast cancer, but also diagnosing the progression of primary breast cancer.