Metformin in early breast cancer: a prospective window of opportunity neoadjuvant study
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Metformin may exert anti-cancer effects through indirect (insulin-mediated) or direct (insulin-independent) mechanisms. We report results of a neoadjuvant “window of opportunity” study of metformin in women with operable breast cancer. Newly diagnosed, untreated, non-diabetic breast cancer patients received metformin 500 mg tid after diagnostic core biopsy until definitive surgery. Clinical (weight, symptoms, and quality of life) and blood [fasting serum insulin, glucose, homeostasis model assessment (HOMA), C-reactive protein (CRP), and leptin] attributes were compared pre- and post-metformin as were terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) and Ki67 scores (our primary endpoint) in tumor tissue. Thirty-nine patients completed the study. Mean age was 51 years, and metformin was administered for a median of 18 days (range 13–40) up to the evening prior to surgery. 51 % had T1 cancers, 38 % had positive nodes, 85 % had ER and/or PgR positive tumors, and 13 % had HER2 overexpressing or amplified tumors. Mild, self-limiting nausea, diarrhea, anorexia, and abdominal bloating were present in 50, 50, 41, and 32 % of patients, respectively, but no significant decreases were seen on the EORTC30-QLQ function scales. Body mass index (BMI) (−0.5 kg/m2, p < 0.0001), weight (−1.2 kg, p < 0.0001), and HOMA (−0.21, p = 0.047) decreased significantly while non-significant decreases were seen in insulin (−4.7 pmol/L, p = 0.07), leptin (−1.3 ng/mL, p = 0.15) and CRP (−0.2 mg/L, p = 0.35). Ki67 staining in invasive tumor tissue decreased (from 36.5 to 33.5 %, p = 0.016) and TUNEL staining increased (from 0.56 to 1.05, p = 0.004). Short-term preoperative metformin was well tolerated and resulted in clinical and cellular changes consistent with beneficial anti-cancer effects; evaluation of the clinical relevance of these findings in adequately powered clinical trials using clinical endpoints such as survival is needed.
KeywordsBreast cancer Metformin Neoadjuvant Ki67 TUNEL Insulin
This research was supported by a Grant from Susan G. Komen for the Cure. Dr. Dowling is supported by a Banting Postdoctoral Fellowship from the Canadian Institutes of Health Research.
Conflict of interest
Dr. Chang acknowledges funding from Hoffmann-LaRoche. The remaining authors declare that they have no conflicts of interest.
Conduct of this study at Mount Sinai and Princess Margaret Hospitals was performed in compliance with the standards of the Ontario Cancer Research Ethics Board.
- 3.Chlebowski RT, McTiernan A, Wactawski-Wende J, Manson JE, Aragaki AK, Rohan T, Ipp E, Kaklamani VG, Vitolins M, Wallace R, Gunter M, Phillips LS, Strickler H, Margolis K, Euhus DM (2012) Diabetes, metformin, and breast cancer in postmenopausal women. J Clin Oncol 30:2844–2852PubMedCrossRefGoogle Scholar
- 5.Jiralerspong S, Palla SL, Giordano SH, Meric-Bernstam F, Liedtke C, Barnett CM, Hsu L, Hung MC, Hortobagyi GN, Gonzalez-Angulo AM (2009) Metformin and pathologic complete responses to neoadjuvant chemotherapy in diabetic patients with breast cancer. J Clin Oncol 27:3297–3302PubMedCrossRefGoogle Scholar
- 9.Irwin ML, Duggan C, Wang CY, Smith AW, McTiernan A, Baumgartner RN, Baumgartner KB, Bernstein L, Ballard-Barbash R (2011) Fasting C-peptide levels and death resulting from all causes and breast cancer: the health, eating, activity, and lifestyle study. J Clin Oncol 29:47–53PubMedCrossRefGoogle Scholar
- 16.Cancer Therapy Evaluation Program, Common Terminology Criteria for Adverse Events, Version 3.0, DCTD, NCI, NIH, DHHS March 31, 2003. http://ctep.cancer.gov. Publish Date: 9 August 2006
- 18.Hammond ME, Hayes DF, Dowsett M, Allred DC, Hagerty KL, Badve S, Fitzgibbons PL, Francis G, Goldstein NS, Hayes M et al (2010) American Society of Clinical Oncology/College of American Pathologists guideline recommendations for immunohistochemical testing of estrogen and progesterone receptors in breast cancer. J Clin Oncol 28:2784–2795PubMedCrossRefGoogle Scholar
- 19.Wolff AC, Hammond ME, Schwartz JN, Hagerty KL, Allred DC, Cote RJ, Dowsett M, Fitzgibbons PL, Hanna WM, Langer A et al (2007) American Society of Clinical Oncology/College of American Pathologists guideline recommendations for human epidermal growth factor receptor 2 testing in breast cancer. J Clin Oncol 25:118–145PubMedCrossRefGoogle Scholar
- 35.Bonanni B, Puntoni M, Cazzaniga M, Pruneri G, Serrano D, Guerrieri-Gonzaga A, Gennari A, Trabacca MS, Galimberti V, Veronesi P, Johansson H, Aristarco V, Bassi F, Luini A, Lazzeroni M, Varricchio C, Viale G, Bruzzi P, Decensi A (2012) Dual effect of metformin on breast cancer proliferation in a randomized presurgical trial. J Clin Oncol 30:2593–2600PubMedCrossRefGoogle Scholar