Dose-dense neoadjuvant chemotherapy in triple-negative breast cancer: Real-world data from a developing country

Abstract

Background: Dose-dense adjuvant chemotherapy has been shown to be associated with improved long-term survival outcomes in triple-negative breast cancer (TNBC). However, there is a lacuna of data on the benefits of dose-dense neoadjuvant chemotherapy (NACT) in TNBC.

Methods: This retrospective study included 217 newly diagnosed cases of TNBC treated with a sequential anthracycline and taxane-based NACT, followed by definitive surgery. Study groups consisted of 137 patients who received 3-weekly conventional chemotherapy (cNACT group) and 80 patients with 2-weekly dose-dense NACT (ddNACT group). Pathological complete response (pCR) rates, relapse-free survival (RFS), overall survival (OS), and grade-3/4 chemotoxicities were compared across the groups.

Results: No significant difference in the pCR rate (32.8% versus 31.3%; P = 0.808) was observed across the study groups. Relapse rate was lower in the ddNACT group compared to the cNACT group (odds ratio [OR]: 0.51, 95% confidence interval [CI]: 0.27-0.95). However, ddNACT had no RFS advantage over conventional chemotherapy (median RFS: not reached versus 56.1 months in cNACT; hazard ratio: 0.90, 95% CI: 0.52-1.53). OS was also comparable in both the groups with a 3-year survival rate of 78.8% (95% CI: 60.9-89.2) in the ddNACT group versus 84.3% (95% CI: 74.8-90.4) in the cNACT group. Younger age, menopause, the Eastern Cooperative Oncology Group ECOG status, and pCR were significantly associated with OS in our cohort. Grade-3 toxicities were comparable in both groups.

Conclusions: This observational study focusing on ddNACT among TNBC patients demonstrated significant differences in the relapse rate with no survival benefits. Differential effects of ddNACT by tumor presentation (early vs. late), tumor size, tumor biology, and cost-benefits of granulocyte colony-stimulating factor support with such regimens need further exploration.