Abstract
BACKGROUND: Breast cancer has both aggressive clinicopathological characteristics and a poor prognosis in young females. However, limited information is available for breast cancer in Chinese females aged ≤25 years. Therefore, we aimed to explore prognostic factors for invasive disease-free (iDFS) and overall survival (OS) among breast cancer patients aged ≤25 years. METHODS: We retrospectively analyzed data from 174 Chinese females aged ≤25 years with invasive breast cancer treated in the Cancer Hospital of the Chinese Academy of Medical Sciences from January 1, 1999, to December 31, 2018. Univariate and multivariate Cox regression analyses were performed to identify independent prognostic factors. RESULTS: The median follow-up time was 75 months (ranging from 1 to 236 months). Breast cancer patients aged ≤25 years exhibited aggressive clinicopathological characteristics, including advanced tumor stage (21.8%), lymph node metastasis (47.1%), lymphovascular invasion (24.1%), estrogen receptor negativity (44.3%), progesterone receptor (PR) negativity (42.5%), and triple-negative breast cancer (25.3%). Among them, 50 cases had locoregional recurrence and metastasis, 20 had bilateral invasiveness, and 33 had breast cancer-specific deaths. Cox multivariate analysis identified that diagnosis delay, PR status, and radiotherapy were significant prognostic factors for both iDFS and OS (P < 0.05). The risk of recurrence and metastasis was five times higher in N3 than in N0 (HR: 6.778, 95% CI: 2.268-17.141, P < 0.001). Patients with lymphovascular invasion had a threefold increase in the risk of breast cancer-specific death (HR: 4.217, 95% CI: 1.956-9.090, P < 0.001). No differences were observed between mastectomy and breast-conserving surgery (BCS) plus radiotherapy for iDFS or OS (iDFS: χ (2) = 0.678, P=0.410; OS: χ (2) = 0.165, P=0.685). CONCLUSIONS: Breast cancer in females ≤25 years old was associated with aggressive clinical features and a worse prognosis. Young females with breast lumps should receive timely diagnosis and treatment. Young breast cancer patients with lymphovascular invasion, PR-negative status, and lymph node metastasis have an increased risk of experiencing recurrence and metastasis and should hence be closely monitored. Age at diagnosis should not be the sole deciding factor for surgical treatment methods.