Efficacy of extended aromatase inhibitors for hormone-receptor-positive breast cancer: A literature-based meta-analysis of randomized trials.

BACKGROUND: Endocrine treatment with Tamoxifen and aromatase inhibitors (AIs) is a staple in the management of hormone receptor positive breast cancer (HR + BC). It has become clear that HR + BC carries a consistent risk of relapse up to 15 years post-diagnosis. While increasing evidence supports the use of extended adjuvant Tamoxifen over 5 years, controversial data are available on the optimal duration of extended AIs adjuvant treatment. We performed a meta-analysis to assess the real impact of extended adjuvant therapy with AIs on disease-free survival (DFS). METHODS: A literature-based meta-analysis of randomized controlled trials (RCTs) was undertaken. Relevant publications from PubMed, the Cochrane Library, and abstracts from American Society of Clinical Oncology (ASCO) and San Antonio Breast Cancer (SABCS) symposia were searched. Primary and secondary endpoints were Disease Free Survival (DFS) and overall survival (OS) respectively. A subgroup analysis was also performed to elucidate the impact of nodal involvement. RESULTS: The pooled analysis revealed a significant increase in DFS in the extended AIs group (hazard ratio (HR): 0.78, 95% CI: 0.68-0.90; P = 0.0006). The subgroup analysis according to nodal status showed a greater DFS benefit with extended AIs in patients with positive nodes (HR = 0.67 versus 0.80). Our analysis also demonstrated no improvement in OS with extended AIs (HR = 0.99, 95%CI: 0.87-1.12; P = 0.84). CONCLUSION: This work confirmed the efficacy of extended adjuvant treatment with AIs for HR + early breast cancer, with a 22% increase in DFS, but no impact on OS. Greater efficacy was observed in women with positive nodal status.

Prospective neoadjuvant analysis of PET imaging and mechanisms of resistance to Trastuzumab shows role of HIF1 and autophagy.

BACKGROUND: Although Trastuzumab has improved survival of HER2+ breast cancer patients, resistance to the agent pre-exists or develops through the course of therapy. Here we show that a specific metabolism and autophagy-related cancer cell phenotype relates to resistance of HER2+ breast cancer to Trastuzumab and chemotherapy. METHODS: Twenty-eight patients with locally advanced primary breast cancer were prospectively scheduled to received one cycle of Trastuzumab followed by a new biopsy on day 21, followed by taxol/Trastuzumab chemotherapy for four cycles before surgery. FDG PET/CT scan was used to monitor tumour response. Tissue samples were immunohistochemically analysed for metabolism and autophagy markers. RESULTS: In pre-Trastuzumab biopsies, the LC3A+/HER2+ cell population was correlated with HIF1α expression (P=0.01), while GLUT1 and LC3B expression were correlated with Ki67 proliferation index (P=0.01 and P=0.01, respectively). FDG PET tumour dimensions before therapy were correlated with LC3B expression (P=0.005). Administration of Trastuzumab significantly reduced clinical and PET-detected tumour dimensions (P<0.01). An inverse association of tumour response with the percentage of cells expressing HIF1α at baseline was documented (P=0.01). Administration of Trastuzumab resulted in a decrease of the proliferation index (P=0.004), GLUT1 (P=0.04) and HER2 (P=0.01) expression. In contrast, the percentage of LC3A+/HER2+ cells was increased (P=0.01). High baseline HIF1α expression was the only parameter associated with poorer pathological response to preoperative chemotherapy (P=0.001). CONCLUSIONS: As the HER2+/LC3A+ phenotype, which often overexpresses HIF1α, is a major subpopulation increasing after therapy with Trastuzumab, LC3A- and HIF1α-targeting therapies should be investigated for the augmentation of anti-HER2 therapy efficacy.

Increased pathological complete response rate after a long-term neoadjuvant letrozole treatment in postmenopausal oestrogen and/or progesterone receptor-positive breast cancer.

BACKGROUND: The objective of this study was to determine the optimal scheduling of 2.5 mg daily letrozole in neoadjuvant breast cancer patients to obtain pathological complete response (pathCR) and assess Ki-67 expression as an early predictor of response. PATIENTS AND METHODS: This single institution study comprised 120 oestrogen receptor (ER)-positive postmenopausal women with primary breast cancer (clinical stage ≥ T2, N0-1), from three sequential cohorts (cohort A of 40, cohort B of 40 and cohort C of 40 patients, respectively) based on different duration of the neoadjuvant letrozole. Biological markers such as ER, progesterone receptor, HER2 and Ki-67 expression were tested at diagnosis and at definitive surgery. RESULTS: A total of 89 patients (75.4%) achieved an objective response with 44 (37.3%) clinical CRs and 45 (38.1%) partial responses. The clinical CRs were significantly observed in cohort C (23 out of 40 patients, 57.5%) and B (16 out of 38 patients, 42.1%) compared with cohort A (5 out of 40 patients, 12.5%) (P-value for trend <0.001). Letrozole induced a similar significant reduction in Ki-67 index after treatment in all cohorts. The pathCR rate was significantly more frequent in cohort C (7 out of 40 patients, 17.5%) than in cohort A (1 out of 40 patients, 2.5%) and B (2 out of 40 patients, 5.0%) (P-value for trend <0.04). CONCLUSION: One-year neoadjuvant letrozole therapy leads to a higher pathCR rate and may be the optimal length of drug exposure.