Abstract:Objective: To systematically assess the factors that influence the prognosis of HER-2-positive breast cancer. Methods: Publicly published domestic studies regarding the prognosis of HER-2-positive breast cancer were searched, and the eligible studies were selected based on the inclusion and exclusion criteria, and then the 5-year survival rates for different observational factors were extracted and Meta-analysis was performed by RevMan 5.3 software. Results: A total of 4 studies with 558 patients were included. Results of Meta-analysis for different observational factors showed that the 5-year survival rate in patients ≥35 years of age was better than that in those <35 years of age (OR=0.01, 95% CI=0.01–0.02, P<0.00001), in patients without family history was better than those with a family history (OR=0.00, 95% CI=0.00–0.00, P<0.00001), in patients with tumor size < 5 cm was better that those with tumor size ≥5 cm (OR=14.83, 95% CI=1.03–212.53, P=0.05), in patients without lymph node metastasis was better than in those with lymph node metastasis (OR=0.47, 95% CI=0.27–0.82, P=0.007), in patients with histological grade I or II was better than in those with histological grade III (OR=2.84, 95% CI=1.63–4.97, P=0.0002), and in patients with other pathological types was better than in those with invasive ductal carcinoma (OR=35.5, 95% CI=21.71–58.03, P<0.00001); the menopausal status had no significant influence on prognosis of the patients (OR=0.64, 95% CI=0.26–1.59, P=0.34). Conclusion: Age, family history, tumor size, lymph node metastasis, histological grade and pathological type are associated with the prognosis of HER-2-positive breast cancer, but the influence of menopausal status on prognosis remains to be identified.