Metformin ( Glucophage ), the common first-line drug for type 2 diabetes, may be effective in increasing pathologic complete response rates in diabetic women with early stage breast cancer who took the drug during chemotherapy prior to having surgery, paving the way for further research of the drug as a potential cancer therapy, according to researchers at The University of Texas M. D. Anderson Cancer Center.
The authors decided to conduct the research after a large, intriguing epidemiologic study published last year showed that patients with diabetes who took Metformin had lower incidences of cancer as well as better outcomes.
" Metformin works by decreasing the amount of insulin-resistance in diabetics and insulin seems to be a growth factor for cancer," said Gonzalez-Angulo.
Using the M. D. Anderson Breast Medical Oncology database, Gonzalez-Angulo, Jiralerspong and their team identified 2,529 women with early-stage breast cancer who received chemotherapy in the neoadjuvant setting, before surgery. Of the patients, 2,374 were non-diabetic, 68 were diabetic but not taking Metformin and 87 were diabetic and taking the drug.
The study's endpoint was pathologic complete response, or the absence of cancer at the time of surgery.
The researchers found that the pathologic complete response rates in the diabetic breast cancer patients taking Metformin was 24 percent, three times higher than the rates in diabetic patients not taking the drug, 8 percent. In the non-diabetic women, the pathologic complete response rate was 16 percent. After adjusting for other factors, the researchers found that Metformin was an independent predictor of pathologic complete response in diabetic patients.
While very exciting, the findings are still very early, cautioned Jiralerspong and Gonzalez-Angulo, and further investigation with Metformin is needed.
Source: ASCO Meeting, 2008
Link: Xapedia - Medical Encyclopedia