The Characteristics Comparison of Breast Cancer Patients in Southern China and America: A Multicentre Study in China Versus SEER Database

Abstract

Background and Objective: The morbidity and mortality of breast cancer are increasing in recent years, which had become the second main cause of cancer death in women. However, there are different characteristics of breast cancer in developing countries and developed countries. What’s more, it has not reported the comparison of breast cancer between southern China and the United States. We intend to compare the age, different stages and grades of tumor and treatment methods, in order to study the factors which influence the survival and prognosis of breast cancer patients. Methods: To study the two groups which have been diagnosed with breast cancer in southern China from 2001 to 2016 and SEER database from 1975 to 2016. To register, collect and analyze the clinicopathological features and treatment information. To follow up the patients who have been diagnosed before 2016. Kaplan-Meier method was used to evaluate disease-free survival (DFS) and overall survival (OS). Results: Young breast cancer patients accounted for 19.8% and 6.14% respectively in southern China and SEER cohort. The early diagnostic rate of breast cancer is high in southern China, but still lower than SEER cohort. Our study found that there are significant differences in tumor size and positive lymph node status between southern China and SEER cohort (P=0.000), which notably affect the OS of breast cancer patients (P=0.018 and P=0.000). Furthermore, KI-67 is also an important prognostic factor of breast cancer patients in southern China, which also affect the OS of patients (P=0.034). In treatment, there are also significant differences between the two regions. In southern China, there are 4.91% of breast cancer patients performed breast conserving surgery and 95.09% patients performed mastectomy. But in SEER cohort, there are only 4.91% patients preformed breast surgery. Conclusions: The age, tumor size, positive-node and KI-67 may cause the difference of morbidity and mortality of breast cancer patients in southern China and SEER cohort. Overall, the prognosis of breast cancer patients in SEER cohort is better than southern China.