Adjuvant chemotherapy in stage I triple-negative breast cancer: A systematic review and meta-analysis of survival outcomes
A partir d'une revue systématique de la littérature (27 études, 98 499 patients), cette méta-analyse évalue l'efficacité, du point de vue de la survie globale et de la survie spécifique, d'une chimiothérapie adjuvante chez les patientes atteintes d'un cancer du sein triple négatif de stade I
Background: The benefit of adjuvant chemotherapy in patients with surgically-resected, stage-I TNBC remains controversial, especially when tumors are smaller than 10 mm in maximum diameter. We conducted a meta-analysis to evaluate the impact of adjuvant chemotherapy on survival outcomes in this setting, with prespecified subgroup analyses by pathological tumor size (pT1a/b/c).
Methods: This study followed PRISMA guidelines and was registered in PROSPERO. Literature search from PubMed, EMBASE, Cochrane (2000–2025) and recent conference proceedings was reviewed for studies comparing overall survival (OS) and/or breast cancer-specific survival (BCSS) in stage I TNBC patients receiving adjuvant chemotherapy versus no chemotherapy. Hazard ratios (HR) were pooled using fixed- or random-effects models according to prespecified heterogeneity criteria (Q statistic, P < 0.10 and/or I2 > 25%). Small-study effects and robustness were evaluated with Egger’s test and influence diagnostics.
Results: Twenty-seven studies including 98,499 patients were analysed. Adjuvant chemotherapy resulted in significantly improved OS (HR 0.53, 95%CI 0.42–0.68; p < 0.001) and BCSS (HR 0.70, 95%CI 0.62–0.79; p < 0.001). In pT1a tumors, we found no benefit in terms of OS (HR 0.97, p = 0.91) or BCSS (HR 1.49, p = 0.12). In pT1b disease, chemotherapy use was associated with improved OS (HR 0.68, p < 0.0001), while no BCSS benefit was observed (HR 1.01, p = 0.94); this subgroup analysis should be interpreted cautiously. Finally, in pT1c tumors, adjuvant chemotherapy was associated with improved OS (HR 0.46, p < 0.0001) and BCSS (HR 0.68, p < 0.001).
Conclusions: In surgically-resected stage I TNBC, the association between adjuvant chemotherapy and better survival appears to vary according to tumor-size, with more consistent benefit in patients with tumors > 5 mm and no significant survival advantage observed in pT1a disease. These findings support a tailored, size-based approach, although the OS results should be interpreted cautiously given the observational nature of the evidence and the substantial heterogeneity of the pooled OS analysis.
Cancer Treatment Reviews , résumé, 2026