The Prognosis In Breast Cancer: Is Young Age By Subtype Always An Independent Risk Factor?

Purpose Young age(≤40 years)use to be considered an independent risk factor for prognosis in women with early-stage breast cancer.We conducted a retrospective analysis to investigate this claim in a population of young patients who were stratified by molecular subtype.Methods We identified 2,125 women with stage I to III breast cancer from the Union Hospital Affiliated with Fujian Medical University who were seen between2004 and 2011.Multivariable Cox proportional hazards models were used to analyze the relationship between age groups stratified by molecular subtype and 5-year disease-free survival(DFS),5-year distant metastasis-free survival(DMFS),and5-year breast cancer–specific survival(BCSS).Results Median follow-up time was 77 months.Patients ≤ 40 years(542,25%)presented a significantly worse 5-year DFS and 5-year DMFS(hazards ratio(HR)=1.37,95% confidence interval(CI)1.12–1.67 and HR = 1.38,95% CI 1.12–1.69,respectively),and were associated with borderline risk for 5-year BCSS(HR = 1.37,95% CI 1.00–1.89).In stratified analyses,the effect of age on the prognosis of breast cancer varied with molecular subtype.Young women with luminal A subtype were associated with a worse 5-year DFS,5-year DMFS,and 5-year BCSS(HR=2.06,95%CI 1.15 to 3.69,HR=1.88,95% CI 1.04 to 3.41,and HR=5.85,95% CI 1.22 to 28.01,respectively).Women with luminal B(Her2-)showed a 1.47-fold and a 1.51-fold decrease in 5-year DFS and 5-year DMFS.There was no significant difference in5-year BCSS with luminal B(Her2-)(HR=1.73,95% CI,0.87 to 3.44).Young age was not associated with significantly inferior survival(including 5-year DFS,5-year DMFS and 5-year BCSS)among women with luminal B(Her2+),Her2over-expression and triple-negative subtypes.Conclusion The effect of age on the prognosis at early-stage breast cancer is vary with molecular subtype.Young age seems to be an independent risk factor for prognosis for breast cancer patients with the luminal A and luminal B(Her2-)subtypes but not in those with luminal B(Her2+),Her2 over-expression,and triple-negative disease.