204P Metformin with neoadjuvant chemotherapy in stage II-III breast cancer: A phase II clinical trial

Abstract

Results: Fifty-one patients were included with a median age of 53 (37-77), of which 24 (45%) were premenopausal. The median tumour size was 29 mm (17-48). Ten patients had lymph node-positive disease. Based on the St. Gallen criteria. 30 patients were classified as luminal A and 21 as luminal B. Tamoxifen was started in pre-and an aromatase inhibitor in postmenopausal patients, with a median duration of 8 months (4-14) until surgery. Four patients switched therapy because of stable or progressive disease at 3-month evaluation. Radiological complete response was observed in seven patients (14%), partial response in 32 (64%) and stable disease in 10 (20%) patients. Major pathological response was observed in 12.5% of the cases. Of the eleven patients in whom mastectomy had been indicated initially, seven (7/11; 64%) were eligible for BCS after NET. Because of lymph node-positive disease or a second progressive lesion found post-operatively, five (10%) patients received adjuvant chemotherapy.Conclusions: Based on this relatively small series, treating patients with a low-risk 70gene signature with neoadjuvant endocrine therapy seems feasible. The pathological response rate and conversion to breast-conserving surgery are of clinical relevance and deserve validation in a larger study.Legal entity responsible for the study: Netherlands Cancer Institute/Antoni van Leeuwenhoek hospital (NKI-AVL).

Ianus Bifrons: The Two Faces of Metformin

“…Similarly, Azazy et al performed a phase II randomized and placebo-controlled trial in 60 non-diabetic patients with stage II-III BC and documented a higher pCR in the group receiving metformin (850 mg b.i.d.) and neoadjuvant chemotherapy without reaching any significance (p = 0.09) [148]. It is also documented that metformin has a positive impact when combined with neoadjuvant chemotherapy on the pCR rate, particularly in individuals with stage II-III triple-positive BC without diabetes and with a BMI ≥ 25 kg/m 2 [149].…”