Platinum-based chemotherapy in early-stage triple negative breast cancer: A meta-analysis

The addition of platinum agents to anthracycline and taxane-based chemotherapy in early-stage triple negative breast cancer (TNBC) patients improves pathological complete response (pCR). Long-term outcomes, such as disease-free survival (DFS) and overall survival (OS), have not been well-established.

A systematic literature review identified studies using platinum-based treatment in TNBC patients in the neoadjuvant or adjuvant setting with reportable long-term outcomes. Hazard ratios (HR) from collected data were pooled in a meta-analysis using generic inverse-variance and random effects modeling. Subgroup analyses were conducted based on treatment setting and study design.

Fourteen studies comprising 3518 patients met the inclusion criteria. Median follow up was 56.2 months. All studies reported DFS and 9 studies (64%) reported OS. DFS was significantly better in platinum-based treatment (HR 0.71, 95% confidence interval (CI) 0.56-0.89; p = 0.03). However, OS was no different (HR 0.98, 95% CI 0.75-1.27; p = 0.87). There was a non-significant difference between platinum exposure in the adjuvant compared to neoadjuvant setting for both DFS (HR 0.75 vs 0.62, p = 0.43) and for OS (HR 0.90 vs 1.10, p = 0.58). The addition of platinum was associated with more thrombocytopenia and all-grade neuropathy and non-significant increases in neutropenia and grade 3-4 neuropathy.

Platinum-based treatment improves DFS but not OS. The reporting of toxicity was suboptimal, but in general adding platinum increased toxicity. The discordant effect of platinum-based treatment on DFS and OS suggest the potential development of platinum resistance and worse outcomes after recurrence. Platinum-based chemotherapy cannot be recommended in unselected patients with early TNBC.