Clinicopathologic features and prognosis of triple-negative breast cancer in China: a retrospective cohort study of patients under 35 years old

To analyze factors that affect the prognosis of triple-negative breast cancer patients under 35 years old. We retrospectively analyzed confirmed triple-negative breast cancer cases from 2000 to 2016 in multiple institutions. A total of 105 patients were included in the study, Nineteen of them were diagnosed with age ≤ 25, and 86 of them were aged between 26 to 35. There were no statistically significant differences in clinicopathologic features and treatment choices between patients aged ≤ 25 years and those aged 26-35 years (P > 0.05). Survival analysis showed no statistically significant differences in DFS and OS between the two groups (P > 0.05). Multiple factor analysis showed that age of menarche (HR 0.697, 95% CI [0.5634, 0.8631]), pregnancy correlation (HR 2.673, 95% CI [1.1581, 6.1741]), and lymph node positivity (HR 4.915, 95% CI [2.3774, 10.1627]) were independent prognostic factors that affected patients' DFS. Independent prognostic factors that influenced OS were age of menarche (HR 0.598, 95% CI [0.462 6, 0.775]) and lymph node positivity (HR 7.751, 95% CI [2.923, 20.559]). There was no difference in the clinicopathological features and prognosis between women ≤ 25 and women aged 26-35 years with triple-negative breast cancer. Age of menarche, pregnancy correlation, and positive lymph nodes were independent factors affecting prognosis. The relationship between reproductive factors and prognosis in young patients with triple-negative breast cancer needs further discussion.