highly significantP <0.001
Results: Multivariate analysis shows that adjuvant-treated stage III or high-risk stage II patients experienced a highly significant increase in OS (hazard ratio [HR]: 0.34, 95% confidence interval [CI]: 0.20–0.59, P <0.001) and CSS (HR: 0.39, 95% CI: 0.20–0.75, P = 0.005) compared with the control group without adjuvant chemotherapy.