Elevated serum CA15-3 levels correlate with positive estrogen receptor and initial favorable outcome in patients who died from recurrent breast cancer

The clinical usefulness of circulating tumor markers in breast cancer as recurrence indicators during follow-up or monitoring treatment response is still an open question. There are some patients with normal tumor marker levels who have apparent recurrence foci. In this study, we evaluated the relationships between CEA or CA15-3 levels and clinicopathological factors or outcome in patients who had died from recurrent breast cancer. Two hundred-twenty deceased patients who had had recurrent or advanced breast cancer and who had been treated between 1986 and 2000 were enrolled in a retrospective study. Serum CEA and CA 15-3 were measured regularly during the clinical course until death. The rates of CEA and CA15-3 positivity were 41.4% and 50.9% at the time of recurrence, and rose to 67.3% and 76.8% after recurrence, respectively. The CA15-3 and CEA positivity rates significantly correlated with ER and PgR status. Serum CA15-3 status correlated significantly with survival after recurrence. Patients with CA15-3 negativity had poorer prognoses than CA15-3 positive patients. Multivariate analysis revealed that CA15-3 status was one of the significant factors for survival after recurrence. Tumor markers, especially CA15-3, might reflect the biological characteristics of tumors such as ER or PgR status, and may be useful prognostic predictors in recurrent breast cancer. Elevated CA15-3 levels correlated with positive estrogen receptor and favorable outcome in deceased patients with recurrent breast cancer.