C-erbB-2, CEA and CA 15.3 serial serum determinations were performed in 250 patients (follow-up: 1-4 years, mean 2.5 years) with primary breast cancer and no evidence of residual disease (NED) after radical treatment (radical mastectomy or simple mastectomy and radiotherapy). Ninety-five patients developed metastases during follow-up.
Results: Abnormal c-erbB-2, CEA and CA 15.3 serum levels (> 20 U/ml, > 10 ng/ml or > 60 U/ml, respectively) prior to diagnosis were found in 28.4%, 31.6% and 46.3% of the 95 patients with recurrence, with a lead time of 4.2 +/- 2.4, 5.0 +/- 2.5 and 4.6 +/- 2.7 months, respectively. One of the tumor markers was the first sign of recurrence in 69.5% of the patients. Tumor marker specificity was 100% with levels lower than the cut-point in all 155 patients without recurrence. Tumor marker sensitivity was clearly related to the site of recurrence, with the lowest sensitivity found in locoregional relapse and the highest in patients with liver or bone metastases. C-erbB-2 sensitivity in early diagnosis was significantly higher in patients with c-erbB-2 overexpression in tissue (10/12, 83.3%) than in those without overexpression (1/34, 2.9%) (p = 0.0001). Likewise, higher levels of both, c-erbB-2 and CA 15.3 at diagnosis of recurrence, higher sensitivity in early diagnosis of relapse and a higher lead time were found in PgR+ patients (CA 15.3) or in PgR- patients (C-erbB-2) (p < 0.015). In conclusion, tumor markers are useful tools for the early diagnosis of metastases, being the first sign of recurrence in 69.5% of patients with relapse (76.3% in patients with metastases).