Clinical and Pathological Characteristics of Young Female Breast Cancer

Abstract BackgroundWith the increase in socioeconomic status and development of early screening technologies, the proportion of young breast cancer has gradually increased. However, epidemiological research on breast cancer in young women is lagging. There is a lack of diagnosis and treatment guidelines specifically for young breast cancer patients. MethodsThis is an single-center, retrospective cohort study which adopted 2,142 women ≤ 41 years who were diagnosed with stage I-III invasive breast cancer. Patients were grouped into hormone receptor-positive and -negative groups. Variance of common characteristics between the two groups were compared using Chi-square test, Fisher-exact test and Wilcoxon rank sum test. Cox proportional hazards regression was employed for survival estimation and Kaplan–Meier curves were used to graphically present the survival data. Propensity score matching was used to balanced covariates between patients who received or not received the same treatment. ResultsThe median age of the whole cohort was 37 (16-40), and 75.0% suffered from hormone receptor (HR) positive tumors. Modified radical mastectomy was the most frequent surgery (77.7%), and 78.7% women received adjuvant chemotherapy. Adjuvant radiotherapy was implemented in 39.0% of patients, and 58.3% women did not receive radiotherapy. The HR-positive status independently predicted unfavorable overall survival (OS, HR = 1.50, 95% CI 1.03-2.21, P = 0.04) and invasive disease-free survival (iDFS, HR = 1.47, 95% CI 1.05-2.05, P = 0.02). After propensity score matching (PSM), adjuvant chemotherapy (HR = 0.47, 95% CI 0.26-0.87, P = 0.02), and adjuvant radiotherapy (HR = 0.54, 95% CI 0.37-0.78, P = 0.001) improved OS significantly. Adjuvant chemotherapy predicted favorable iDFS (HR = 0.60, 95% CI 0.38-0.94, P = 0.03). Endocrine therapy improved both OS and iDFS in patients with HR-positive disease. ConclusionThe number of young women with breast cancer is gradually increasing, and these women have worse survival outcomes than their elder counterparts. HR-positive disease predicted worse long-term survival outcomes. Adjuvant chemotherapy and adjuvant radiotherapy were required for all of the young patients. Young women with HR-positive disease can benefit from endocrine therapy. No clear benefit was seen from neoadjuvant chemotherapy in young women with early-stage breast cancer.