| Background & objective: Breast cancer is one of the most prevailing malignant diseases in women worldwide,and its incidence increases with age.As the aging population aggravates in our country,this medical problems of older breast cancer will become increasingly severe in the coming decades.Unfortunately,as older patients with breast cancer were excluded from most randomized controlled trials,inadequate clinical trial data are available to guide optimal treatment decisions.Second,there seems to be limited evidence for the association between molecular subtype and clinical outcomes in older breast cancer patients,and many contradictory findings have been reported.Therefore,The aim of this study was to compare the prognostic value of molecular subtypes in older women with breast cancer,to obtain a deeper understanding of the importance of molecular subtype in these patients and to provide more scientific and rationalized individual treatment among older breast cancer patients.Methods: The Surveillance,Epidemiology,and End Results Program(SEER)data were used to analyze the prognostic value of molecular subtypes in older women 65 years and older from 2010 to 2012.The cohort was divided into four molecular subtypes: Ho R+/ HER2-,Ho R+/HER2+,Ho R-/HER2+ and TNBC.Kaplan-Meier analysis was used to determine OS and BCSS based on molecular subtypes in the older patient cohort.By using Cox proportional hazards regression model,the univariate analysis and multivariate analysis were performed to investigate survival factors associated with overall survival(OS)and breast cancer-specific survival(BCSS).Results: A total of 30,357 older patients with breast cancer were enrolled in this study.Among the cohort,75.6%(n=23,236)were classified as Ho R+/HER2-,8.4%(n=2,554)as Ho R+/HER2+,4.0%(n=1,205)as Ho R-/HER2+,and 11.1%(n=3,362)as TNBC.Significant differences in survival were confirmed between the four groups,and molecular subtype was associated with OS and BCSS(OS:P<0.001;BCSS:P<0.001).Patients with Ho R+/HER2-exhibited the best survival outcome(3-OS: 91.2%;3-BCSS: 96.8%),whereas those with TNBC had the worst survival prognosis(3-OS: 78.4%;3-BCSS: 85.0%).The multivariate analysis showed that many factors were associated with OS and BCSS,including age at diagnosis,race,marital status,tumor grade,tumor stage,node status,molecular subtype,surgery,radiation,and chemotherapy.Compared with married patients,unmarried older patients were associated with poor survival(OS:HR= 1.235,95%CI:1.145-1.331,P<0.001;BCSS:HR= 1.233,95%CI:1.103-1.378,P<0.001).The multivariate analysis also revealed that molecular subtypes have a statistically significant prognostic effect on survival in older women.Compared with patients with the Ho R+/HER2-subtype,patients with the TNBC subtype exhibited shorter OS and BCSS(OS:HR=2.033,95%CI:1.857-2.226,P<0.001;BCSS:HR=2.792,95%CI:2.469-3.157,P<0.001)after adjustment for pivotal prognostic factors.In addition,further subgroup analyses,stratified by molecular subtypes,showed that patients with the Ho R-/HER2+ subtype could benefit from chemotherapy,but not patients with the Ho R+/HER2-subtype.Conclusion:(1)Molecular subtypes have a statistically significant prognostic effect on survival in older women,and that molecular subtype is an independent prognosis factor for OS.(2)Our study showed that many factors were associated with OS and BCSS,including age at diagnosis,race,marital status,tumor grade,tumor stage,node status,molecular subtype,surgery,radiation,and chemotherapy.Married older patients were associated with poor survival.(3)Further subgroup analyses,stratified by molecular subtypes,showed that patients with the Ho R-/HER2+ subtype could benefit from chemotherapy,but not patients with the Ho R+/HER2-subtype.Our findings may lead to a better understanding of molecular subtype,help to guide personalized therapy and improve survival outcomes among older breast cancer patients. |
PDF Full Text Request