Seo HR, et al. J Breast Cancer. 2012 Mar;15(1):111-118. http://dx.doi.org/10.4048/jbc.2012.15.1.111

Background: Neoadjuvant endocrine therapy with an aromatase inhibitor has shown efficacy comparable to that of neoadjuvant chemotherapy in patients with postmenopausal breast cancer. Preclinical and clinical studies have shown that the antidiabetic drug metformin has anti-tumor activity. This prospective, multicenter, phase II randomized, placebo controlled trial was designed to evaluate the direct anti-tumor effect of metformin in non-diabetic postmenopausal women with estrogen-receptor (ER) positive breast cancer. Methods/Design: Patients meeting the inclusion criteria and providing written informed consent will be randomized to 24 weeks of neoadjuvant treatment with letrozole (2.5 mg/day) and either metformin (2000 mg/day) or placebo. Target accrual number is 104 patients per arm. The primary endpoint will be clinical response rate, as measured by calipers. Secondary endpoints include pathologic complete response rate, breast conserving rate, change in Ki67 expression, breast density change, and toxicity profile. Molecular assays will be performed using samples obtained before treatment, at week 4, and postoperatively. Discussion: This study will provide direct evidence of the anti-tumor effect of metformin in non-diabetic, postmenopausal patients with ER-positive breast cancer. Trial registration: ClinicalTrials.gov Identifier NCT01589367

Jung JJ, et al. J Breast Cancer. 2024 Feb;27:e8. https://doi.org/10.4048/jbc.2023.0265

Na KY, et al. J Breast Cancer. 2011 Mar;14(1):33-38. http://dx.doi.org/10.4048/jbc.2011.14.1.33

Kim KS. J Korean Med Assoc. 2017 Mar;60(3):223-227. https://doi.org/10.5124/jkma.2017.60.3.223

Granulocytic sarcoma is a localized extramedullary solid tumor composed of immature myeloid cell and is usually associated with acute myeloid leukemia or myelodysplastic syndrome. Although it can involve any site, commonly in lymph nodes, skin, bone and soft tissue, the involvement of breast is unusual. Especially, the involvement of the breast as a pattern of relapse after bone marrow transplantation is extremely rare. We have experienced 2 cases of granulocytic sarcoma after bone marrow transplantation. One case was a 39-year-old woman with right breast mass diagnosed with granulocytic sarcoma. She had received an unrelated bone marrow transplantation due to biphenotype acute leukemia 3 years before our presentation. Another case was a 48-year-old woman with acute myeloid leukemia, who was diagnosed with granulocytic sarcoma on both breasts 8 months after allogenic bone marrow transplantation. We also discuss the clinicopathologic features of granulocytic sarcoma in breast after bone marrow transplantation.