High Ki67 predicts unfavourable outcomes in early breast cancer patients with a clinically clear axilla who do not receive axillary dissection or axillary radiotherapy.

AIM: Axillary dissection is increasingly forgone in early breast cancer patients with a clinically negative axilla. The GRISO 053 randomised trial recruited 435 patients of age over 45 years, tumour ≤1.4 cm and clinically negative axilla, to assess the importance of axillary radiotherapy versus no axillary radiotherapy in patients not given axillary dissection. In the present study on a subgroup GRISO cases our aim was to assess the prognostic importance of tumour biological factors after more than 10 years of follow-up. METHODS: We retrospectively assessed biological factors in a subgroup of 285 GRISO cases (145 given axillary radiotherapy; 140 not given axillary radiotherapy) with complete biologic, therapeutic and follow-up information, using multivariable Cox proportional hazards regression modelling. RESULTS: Only 10-year cumulative incidence of distant metastasis was lower in the axillary radiotherapy (1%) than no axillary radiotherapy arm (7%) (p=0.037). Irrespective of study arm, hormone receptor positivity had significantly favourable effects on 10-year disease-free survival (DFS) and overall survival. human epidermal growth factor receptor 2 (HER2)-positive and triple-negative subtypes were associated with lower 10-year DFS (60% and 76%, respectively) than luminal A (96%) and B (91%) (p=0.001). Ten-year DFS for high (≥14%) Ki67 cancers was lower than for low Ki67 cancers (p=0.027); however, this effect was mainly confined to the no axillary radiotherapy arm. CONCLUDING STATEMENT: For patients with clinically node-negative small breast cancer not given axillary dissection, 10-year DFS is worsened by HER2 positivity, triple-negative phenotype and high Ki67. Axillary radiotherapy counteracts the negative prognostic effect of high Ki67 in patients not receiving axillary dissection.

Adverse prognostic value of peritumoral vascular invasion: is it abrogated by adequate endocrine adjuvant therapy? Results from two International Breast Cancer Study Group randomized trials of chemoendocrine adjuvant therapy for early breast cancer.

BACKGROUND: Peritumoral vascular invasion (PVI) may assist in assigning optimal adjuvant systemic therapy for women with early breast cancer. PATIENTS AND METHODS: Patients participated in two International Breast Cancer Study Group randomized trials testing chemoendocrine adjuvant therapies in premenopausal (trial VIII) or postmenopausal (trial IX) node-negative breast cancer. PVI was assessed by institutional pathologists and/or central review on hematoxylin-eosin-stained slides in 99% of patients (analysis cohort 2754 patients, median follow-up >9 years). RESULTS: PVI, present in 23% of the tumors, was associated with higher grade tumors and larger tumor size (trial IX only). Presence of PVI increased locoregional and distant recurrence and was significantly associated with poorer disease-free survival. The adverse prognostic impact of PVI in trial VIII was limited to premenopausal patients with endocrine-responsive tumors randomized to therapies not containing goserelin, and conversely the beneficial effect of goserelin was limited to patients whose tumors showed PVI. In trial IX, all patients received tamoxifen: the adverse prognostic impact of PVI was limited to patients with receptor-negative tumors regardless of chemotherapy. CONCLUSION: Adequate endocrine adjuvant therapy appears to abrogate the adverse impact of PVI in node-negative disease, while PVI may identify patients who will benefit particularly from adjuvant therapy.