Preoperative CA 15-3 levels predict the prognosis of nonmetastatic luminal A breast cancer

Background

The prognostic value of serum tumor markers (STMs) in nonmetastatic breast cancer patients with different molecular subtypes (luminal A, luminal B, and nonluminal) remains unknown. It is our institutional policy to assess the STMs in nonmetastatic patients. This retrospective single-center study is to investigate the association between STMs and clinical outcomes in nonmetastatic patients and the impact of molecular subtypes.

Methods

A total of 368 patients with available clinical outcomes, tumor node metastasis stages, and STMs levels were included. The serum level of preoperative STMs (carcinoembryonic antigen [CEA], cancer antigen 125 [CA-125], and cancer antigen 15-3 [CA 15-3]) was analyzed and compared among distinct molecular subtypes. Univariate and multivariate analyses were used to investigate the relationship among STMs concentrations and patient outcomes.

Results

The median levels of CA 15-3 were 10.2, 8.1 and 7.1 U/mL in patients with luminal A, luminal B, and nonluminal diseases, respectively (P = 0.015). The levels of CEA and CA-125 were similar among the subtypes. Multivariate analysis showed that higher CA 15-3 was significantly associated with worse clinical outcomes exclusively in luminal A patients (P = 0.033 for metastasis-free survival and P = 0.030 for relapse-free survival). In contrast, higher CEA was a significant prognostic factor for worse clinical outcomes (P = 0.003 for metastasis-free survival and P = 0.015 for metastasis-free survival) in nonluminal groups.

Conclusions

The prognostic value of preoperative STMs may be different among molecular subtypes. Patients with luminal A diseases had higher levels of CA 15-3. Higher preoperative CA 15-3 was associated with worse clinical outcomes exclusively in patients with luminal A diseases.