{'fraction_non_alphanumeric': 0.0630841121495327, 'fraction_numerical': 0.059813084112149535, 'mean_word_length': 4.786486486486487, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Abstract PD03-06: Clinical and Biologic Effects of Metformin in Early Stage Breast Cancer

Background: Numerous epidemiological and pre-clinical studies have associated potential antineoplastic activity with the antidiabetic drug metformin in various tumor types including breast cancer (BC). We are conducting a neoadjuvant “window of opportunity” study to examine biologic and clinical effects of metformin in early stage BC. Data from a planned interim analysis are presented here. Materials and methods: 15 of planned 40 non-diabetic women Results: Mean age was 51.7 years. 73.3% (11/15) and 26.7% (4/15) had T1 and T2 BC respectively; 40% (6/15) were node positive, 86.7% (13/15) were ER and PR positive and 26.6% (4/15) were HER-2 +. Metformin was administered for a median of 21 days (range 14 - 40). Gastrointestinal (GI) side effects were most frequent and usually self-limiting — mild diarrhoea 60% (9/15), anorexia 53% (8/15) and nausea 46% (7/15). EORTC30 QLQ scores were stable. Weight decreased (mean change -0.81 kg; Mann-Whitney U p-value 0.057). HOMA (a marker of insulin sensitivity) and C-reactive protein improved, mean change -0.32 and -0.21mg/L respectively. Ki67 decreased significantly after metformin treatment (from 27.6 to 22.7, Wilcoxon signed-rank test p-value = 0.043); TUNEL staining increased significantly (from 0.43 to 1.48, p=0.03) and cleaved Caspase 3 increased non-significantly (from 1.01 to 3.96, p=0.31). Conclusion: Preoperative metformin was well tolerated with mild GI toxicities, but no significant QOL effects; it was associated with improved insulin resistance. A short term administration of metformin significantly reduced breast cancer cell proliferation (as measured by change in Ki67 index) and induced apoptosis (reflected by TUNEL). Metformin administration elicited potential physiologic and cellular effects in breast cancer that are in keeping with beneficial anti-cancer effects. Updated results and the impact of metformin on IR/IGF1R/PI3K and AMPK/mTOR signaling pathways within the cancers will be reported. Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr PD03-06.