The Prognosis Between Subtypes And Metastases In Stage Ⅳ Breast Cancer At Initial Diagnosis: A Seer Based Study

Objective: To understand the correlation between different molecular types and different metastatic sites in newly diagnosed stage IV breast cancer patients,and to understand the influence of different treatment methods on the prognosis of different molecular types and different metastatic sites.Methods: Female breast cancer patients newly diagnosed in stage IV from 2010 to2016 were searched from the SEER database.Chi-square test was used to determine whether the different metastatic sites was associated with molecular subtypes.Kaplan-Meier method was used for survival analysis,and Cox proportional hazard regression model was used to compare mortality risk.Results: A total of 14,476 patients with newly diagnosed stage IV breast cancer were included in this study.Among the molecular types,58.8% of patients with Luminal A,Luminal B patients accounted for 17.5%,9.6% of patients with HER-2positive,Patients with triple negative accounted for 14.0%.Among the distant metastatic sites,bone metastasis accounted for 66.1%,brain metastasis 7.0%,Patients with liver metastasis accounted for 25.3%,and patients with lung metastasis accounted for 30.0%.In two sites,the Luminal A patients and the triple negative patients merge the highest incidence of bone and lung metastases,accounting for about 51.3%,31.1%,the Luminal B patients and HER-2 positive patients with bone and liver metastases accounting for 47.1%,47.6%.In the case of simultaneous metastasis of the three sites,among the four molecular types,patients with bone,liver and lung metastases were the most common.Triple negative patients had the worst prognosis at any of the sites of metastasis,the median survival time in bone,brain,liver and lung metastasis sites was 11,7,10 and 12 months,respectively.Of all the molecular subtypes,patients with brain metastasis had the worst prognosis,the median survival time of patients with Luminal A,Luminal B,HER-2 positive and triple negative was 13,29,22 and 8 months,respectively.When two sites of metastasis occur simultaneously,the prognosis of bone metastasis combined with lung metastasis is the best(median survival time: Luminal A: 36 months,Luminal B: 49months).Luminal A and Luminal B,triple negative receive radiation and chemotherapy at the same time in patients with median survival time of 43 months 58 months and 16 months,respectively,HER-2 positive patients undergoing chemotherapy,median survival time was 49 months.Bone metastases,liver metastases,lung metastases received radiotherapy and chemotherapy at the same time with the median survival time of 52 months,56 months,37 months,respectively.Conclusion: Luminal A patients were the most common,while HER-2 positive patients were the least common.The incidence of bone metastasis was the highest,while the incidence of brain metastasis was the lowest.Among patients with Luminal A and triple negative,the incidence of bone metastasis combined with lung metastasis is the highest;among patients with Luminal B and HER-2 positive,bone metastasis combined with liver metastasis is the most common,when the three sites of metastasis occur simultaneously,the patients with bone metastasis combined with liver metastasis and lung metastasis are the most common.Among all the molecular types,the prognosis of brain metastasis patients was the worst.Triple negative patients had the worst prognosis of any metastatic site,bone metastasis combined with lung metastasis had the best prognosis,patients with Luminal A,Luminal B and triple negative had the best prognosis after receiving radiotherapy and chemotherapy simultaneously,patients with positive HER-2 had the best prognosis after chemotherapy,patients with bone metastases,liver metastases,and lung metastases receiving radiotherapy and chemotherapy at the same time had the best prognosis.