Pingping Bao1, Peng Peng1, Kai Gu1, Chunxiao Wu1, Zhezhou Huang1, Yangming Gong1, Minlu Zhang1, Ying Zheng2. 1. Department of Cancer Control and Prevention, Shanghai Municipal Center for Disease Control and Prevention, Shanghai 200336, China. 2. Department of Cancer Control and Prevention, Shanghai Municipal Center for Disease Control and Prevention, Shanghai 200336, China; Email: zhengying@scdc.sh.cn.
Abstract
OBJECTIVES: To analyze the survival of breast cancer molecular subtypes and to examine the effect of therapy on the long-term prognosis of different subtypes. METHODS: This study included 3 586 breast cancer patients with estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor-2 (HER2) information in Shanghai Breast Cancer Survival Study, a population-based prospective cohort study established in 2002. Molecular subtypes, based on immunohistochemistry were categorized as follows: Luminal A, Luminal B, HER2, and triple-negative subtype. Characteristics and clinical data were collected through questionnaires and medical records at baseline survey and sequential follow-up surveys. Survival rates of different molecular subtypes were analyzed and compared with Log-rank tests. Multiple Cox regression models were used to evaluate the effect of therapy on long-term prognosis of different molecular subtypes. RESULTS: Among the 3 586 cases, Luminal A, Luminal B, HER2 and triple-negative breast cancer subtypes accounted for 54.5%, 16.6%, 13.9%, and 14.9%, respectively. With a median follow-up of 10.3 years (ranging 0.6 to 12.8 years), the 10-year overall survival (OS) rates for the four subtypes were 82.7% (95% CI: 80.9% to 84.4%), 77.7% (95% CI: 74.1% to 80.8%), 76.3% (95% CI: 72.3% to 79.8%), and 74.8% (95% CI: 70.9% to 78.3%), respectively. The 10-year disease to free survival (DFS) rates were 79.0% (95% CI: 76.7% to 81.0%), 76.0% (95% CI: 71.9% to 79.5%), 73.6% (95% CI: 68.9% to 77.7%), and 74.5% (95% CI: 69.4% to 78.9%), respectively. Significant difference in survival among four subtypes was observed (Log-rank test, P<0.01). Multivariate Cox regression indicated that hormonal therapy can significantly reduce the long-term risk of total mortality and recurrence breast cancer specific mortality among Luminal A subtype patients. Adjuvant chemotherapy could improve the long-term prognosis of triple-negative breast cancer. No benefit from radiotherapy was observed for four subtypes of breast cancer in terms of long-term prognosis. CONCLUSIONS: Molecular subtypes based on ER/PR/HER2 could provide important information to predict breast cancer prognosis. The hormonal status was an important basis for individualized therapy and precision medicine.
OBJECTIVES: To analyze the survival of breast cancer molecular subtypes and to examine the effect of therapy on the long-term prognosis of different subtypes. METHODS: This study included 3 586 breast cancerpatients with estrogen receptor (ER), progesterone receptor (PR) and humanepidermal growth factor receptor-2 (HER2) information in Shanghai Breast Cancer Survival Study, a population-based prospective cohort study established in 2002. Molecular subtypes, based on immunohistochemistry were categorized as follows: Luminal A, Luminal B, HER2, and triple-negative subtype. Characteristics and clinical data were collected through questionnaires and medical records at baseline survey and sequential follow-up surveys. Survival rates of different molecular subtypes were analyzed and compared with Log-rank tests. Multiple Cox regression models were used to evaluate the effect of therapy on long-term prognosis of different molecular subtypes. RESULTS: Among the 3 586 cases, Luminal A, Luminal B, HER2 and triple-negative breast cancer subtypes accounted for 54.5%, 16.6%, 13.9%, and 14.9%, respectively. With a median follow-up of 10.3 years (ranging 0.6 to 12.8 years), the 10-year overall survival (OS) rates for the four subtypes were 82.7% (95% CI: 80.9% to 84.4%), 77.7% (95% CI: 74.1% to 80.8%), 76.3% (95% CI: 72.3% to 79.8%), and 74.8% (95% CI: 70.9% to 78.3%), respectively. The 10-year disease to free survival (DFS) rates were 79.0% (95% CI: 76.7% to 81.0%), 76.0% (95% CI: 71.9% to 79.5%), 73.6% (95% CI: 68.9% to 77.7%), and 74.5% (95% CI: 69.4% to 78.9%), respectively. Significant difference in survival among four subtypes was observed (Log-rank test, P<0.01). Multivariate Cox regression indicated that hormonal therapy can significantly reduce the long-term risk of total mortality and recurrence breast cancer specific mortality among Luminal A subtype patients. Adjuvant chemotherapy could improve the long-term prognosis of triple-negative breast cancer. No benefit from radiotherapy was observed for four subtypes of breast cancer in terms of long-term prognosis. CONCLUSIONS: Molecular subtypes based on ER/PR/HER2 could provide important information to predict breast cancer prognosis. The hormonal status was an important basis for individualized therapy and precision medicine.