Prognostic value of initial clinical disease stage after achieving pathological complete response

Abstract

The aim of this retrospective study was to determine the prognostic impact of initial clinical stage in patients who achieved a pathological complete response (pCR) after receiving primary systemic chemotherapy (PST). Between 1977 and 2006, 489 patients who had achieved a pCR after receiving an anthracycline-based PST regimen were identified. Recurrence-free survival (RFS) and overall survival (OS) were estimated with the Kaplan-Meier product limit method and the differences between groups were compared using the log-rank statistic. Cox proportional hazards models were fit to determine the association of initial clinical stage with survival outcomes after adjusting for patient and tumor characteristics. The median age was 47 years. Twenty (4.1%) patients had stage I disease, 243 (49.7%) had stage II disease, 189 (38.7%) had stage III disease, and 37 (7.5%) had inflammatory breast cancer (IBC). At a median follow-up of 45 months, 59 (12%) patients had experienced disease recurrence. The 5-year RFS and OS rates for the whole cohort were 87.8% and 89.3%, respectively. Lower clinical stage at diagnosis was associated with statistically significant higher RFS and OS rates. In a multivariate model, patients with clinical stage IIIB/C disease and those with IBC had lower RFS rates than patients with clinical stage I/II/IIIA disease. In addition, patients with clinical stage IIIB/C disease and those with IBC had a greater hazard of death than patients with clinical stage I/II/IIIA disease. Overall, patients who achieved a pCR had a low rate of recurrence. However, higher clinical stage and IBC were associated with worse outcomes in breast cancer patients who achieved a pCR after PST.