High levels of serum CA15-3 and residual invasive tumor size are associated with poor prognosis for breast cancer patients with non-pathological complete response after neoadjuvant chemotherapy.

The combination of residual invasive size and serum CA15-3 levels at baseline seems to be a significant and independent surrogate marker of poor outcome for patients with non-pCR. These findings suggest that these markers may be useful for identifying patients with inferior prognosis and candidates for additional adjuvant treatments.