Hormone Receptor Positive Malignant Neoplasm of Breast | Neoadjuvant Letrozole Plus Metformin vs Letrozole Plus Placebo for ER-positive Postmenopausal Breast Cancer

Hormone Receptor Positive Malignant Neoplasm of Breast research study

What is the primary objective of this study?

Preoperative letrozole versus letrozole with metformin in postmenopausal Estrogen receptor positive breast cancer patients Phase II multicenter 1:1 randomized clinical trial Total 208 patients Primary endpoint Clinical response rate Secondary endpoint Pathologic complete response rate Breast conserving surgery rate Percent mammographic density change Ki67(%) change after 4week medication of 2nd core needle biopsy Toxicity profile of neoadjuvant letrozole, metformin

Who is eligible to participate?

Inclusion Criteria: - Estrogen receptor positive breast cancer - Clinically measurable tumor size(stage II/III) - No evidence of distant metastasis - Postmenopause women 'Age≥60yr' OR 'previous bilateral oophorectomy' OR 'FSH>30 with no bleeding history within 1yr' - ECOG 0-2 - Adequate hepatorenal, bone marrow function 'serum Cr<1.4mg/dL' AND 'Bilirubin< upper limit of normal x 1.5 AND 'AST/ALT < upper limit of normal x 1.8 AND 'ALP < upper limit of normal x 1.8 AND 'Hemoglobin >10 g/dL' AND 'ANC >1,500/mm3' AND 'Platelet >100,000/mm3' - Spontaneous signed into the written informed consent Exclusion Criteria: - Who does not meet the above inclusion criteria - History of other carcinoma - Uncontrolled infection - History of psychiatric, epileptic disease - Male breast cancer - Diabetes 'HbA1c≥6.5' OR 'FBS≥126mg/dL' - Hypersensitivity or intolerance to metformin - Risk of metformin associated lactic acidosis 'Congestive heart disease of NYHA Class llll/IV' OR 'History of other acidosis' OR 'Alcohol intake more than either 3 bottles beer OR 1 bottle Soju' - During medication of metformin, sulfonylureas, thiazolidinediones, insulin - Diffuse microcalcification in mammogram - Multiple OR bilateral OR inflammatory breast cancer - Chemotherapy or endocrine therapy within 2yr due to history of breast cancer

Which medical condition, disease, disorder, syndrome, illness, or injury is researched?

Hormone Receptor Positive Malignant Neoplasm of Breast

Study Interventions

Interventions can include giving participants drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available or noninvasive approaches such as surveys, education, and interviews.

Drug:MetforminMetformin HCl 500mg(morning/evening) PO daily x 1week Metformin HCl 1000mg(morning)and 500mg(evening)PO daily x 1week Metformin HCl 1000mg(morning/evening) PO daily x 22weeks

Drug:PlaceboLetrozole 2.5mg PO daily + Placebo 1 tablet PO 2/day x 1week Letrozole 2.5mg PO daily + Placebo 2 tablet+ 1 tablet PO x 1 week Letrozole 2.5mg PO daily + Placebo 2 tablet PO 2/day x 22 weeks

Study Arms

Research studies and clinical trials typically have two or more research arms. An arm is a group of people who receive the same treatment in the study.

Arm1_ MetforminLetrozole with concurrent metformin

Arm 2_ Letrole aloneLetrozole with placebo

Study Status


Start Date: May 2012

Completed Date: August 2018

Phase: Phase 2

Type: Interventional


Primary Outcome: Clinical response rate

Secondary Outcome: Pathologic complete response rate

Study sponsors, principal investigator, and references

Principal Investigator: Wonshik Han, MD PhD

Lead Sponsor: Seoul National University Hospital


More information:

Fisher B, Bryant J, Wolmark N, Mamounas E, Brown A, Fisher ER, Wickerham DL, Begovic M, DeCillis A, Robidoux A, Margolese RG, Cruz AB Jr, Hoehn JL, Lees AW, Dimitrov NV, Bear HD. Effect of preoperative chemotherapy on the outcome of women with operable breast cancer. J Clin Oncol. 1998 Aug;16(8):2672-85.

Discuss Metformin