Differences in clinicopathologic features and subtype distribution of invasive breast cancer between women older and younger than 40 years

OBJECTIVES: We investigated and compared clinicopathologic features and subtype distribution of invasive breast cancer among women <40 and ≥40 years of age. METHODS: We retrospectively compared clinicopathologic characteristics and subtype distribution of invasive breast cancer in women <40 and ≥40 years of age, in a cohort of 1,130 patients. Subtypes included luminal A (positive for hormone receptors [HR]—estrogen receptor [ER] and/or progesterone receptor [PR]—and negative for human epidermal growth factor receptor 2 [HER2] with low Ki67), luminal B (HER2(–)) (HR(+)/HER2(–)/Ki67(High)), luminal B (HER2(+)) (HR(+)/HER2(+)), HER2-overexpressing (HR(–)/HER2(+)), and triple negative (ER(–)/PR(–)/HER2(–)). RESULTS: Breast cancers in younger women had unfavorable clinicopathologic characteristics, including larger tumors and more frequent node involvement. Subtypes among the 1,130 tumors were luminal A: 36.4%, luminal B (HER2(–)): 35.0%, luminal B (HER2(+)): 7.5%, HER2-overexpressing: 7.1%, and triple negative: 14.0%. The age groups significantly differed in subtype distribution (P<0.001). Luminal A subtype was more common in the older group (38.5%) than the younger group (16.2%), and luminal B (HER2(–)) was more common in the younger group (52.2%) than in the older group (33.2%; P<0.001). CONCLUSIONS: Breast cancers in women younger than 40 years have unfavorable clinicopathologic characteristics and are more likely to be luminal B (HER2(–)) and less likely to be luminal A than breast cancers in older women

Risk factors for late recurrence and postrelapse survival in estrogen receptor (ER)-positive, human epidermal growth factor receptor (HER) 2-negative breast cancer after 5 years of endocrine therapy

It is unclear which patients with ER-positive, HER2-negative breast cancer benefit from extended endocrine therapy beyond 5 years. Prognostic factors for late-recurring breast cancer postrelapse survival have been reported. We retrospectively analyzed data from 892 patients with ER-positive and HER2-negative invasive breast cancer who were disease-free after completing a 5-year adjuvant endocrine therapy. Patients were then classified as high-risk (positive lymph nodes, large tumor size, high tumor grade) or low-risk. High-risk patients were divided into extended endocrine therapy and stop groups. Comparisons were made using propensity score matching, and the benefits of extended endocrine therapy for high-risk patients and prognostic factors for postrelapse survival were assessed. The high- and low-risk groups comprised 444 and 448 patients, respectively. The 10-year distant disease-free survival (DDFS) rates were 96.3 % (95 % confidence interval [CI] 0.912–0.985) and 86.5 % (95 % CI 0.798–0911) in the extended and stop groups, respectively (P = 0.00382). Cox proportional hazards model revealed that extended endocrine therapy promoted greater reduction in distant metastasis risk than 5-year endocrine therapy in high-risk populations (hazard ratio [HR] 0.27; 95 % CI 0.11–0.68; P = 0.0054). Postrelapse survival was significantly different in patients with DDFS ≥7 years (HR 0.24; 95 % CI 0.072–0.81; P = 0.021) and those with better response to first-line treatment (HR 0.072; 95 % CI, 0.058–0.90; P = 0.041). Patients with risk factors for late recurrence should be considered for extended endocrine therapy. Longer DDFS and response to first-line treatment may be a prognostic factor for postrelapse survival after late recurrence

Negative progesterone receptor status correlates with increased risk of breast cancer recurrence in luminal B HER2-positive and -negative subtypes

Objectives: The prognostic significance of the progesterone receptor (PR) has been widely investigated in luminal A and luminal B [human epidermal growth factor receptor 2 (HER2)–] breast cancer subtypes, both of which are estrogen receptor (ER)-positive and HER2-negative. In contrast, few studies have focused on PR status in luminal B (HER2+) tumors. The aim of this study was to evaluate the impact of positive PR status on outcomes in patients with luminal B (HER2–) or luminal B (HER2+) breast cancer. Methods: Survival analysis was performed to estimate the likelihood of distant recurrence and death in 469 breast cancer patients with the luminal B (HER2–) or luminal B (HER2+) subtype. The relationship between PR and HER2 status was also assessed. Results: Of 387 luminal B (HER2–) and 82 luminal B (HER2+) cancers, PR+ was significantly more frequent in the former than the latter (86.3% vs. 61.0%, respectively; P<0.001). In univariate analysis, PR was identified as a significant favorable prognostic factor for distant disease–free survival and overall survival in both subtypes, but in multivariate analysis PR was not an independent prognostic factor. Conclusions: After patients with luminal B subtype were divided into two subgroups according to HER2 status, there was evidence of a relatively good prognosis in the PR+ subgroup. Further studies with a larger number of patients are recommended to validate these findings