Survival benefits in colorectal adenocarcinoma with the use of metformin among a black diabetic inner city population

Abstract

We assessed the association of metformin use with survival in colorectal cancer in a population consists mostly of African-American and Afro-Caribbean patients. We identified 585 colorectal cancer patients, 167 (28.6%) and 418 (71.5%) were as diabetic (DM) and nondiabetic, respectively. The diagnosis of diabetes did not impact cancer survival or extent of disease. Overall, DMs with metformin use (D+M+) have better overall survival than both DMs without metformin use (D+M∼) and nondiabetics (D∼M∼), with a mean survival of 109.9 months compared with 95.7 and 106.1 months, respectively (log-rank p < 0.05). The use of metformin shows significant reduction of risk of mortality compared with nonusers (hazard ratio: 0.34; 95% CI: 0.15–0.81; p = 0.01). Use of insulin and status of diabetes did not have a significant impact on overall cancer survival.

ERR1- and PGC1α-associated mitochondrial alterations correlate with pan-cancer disparity in African Americans

“…Interestingly, clinical trial data for metformin, a mitochondrial inhibitor, has shown that African American patients, in general, respond better to this drug than European American patients (20). Metformin was also more effective in reducing the incidence of PCa and the risk of colorectal cancer death in African American patients compared with European American patients (21,22). These findings provide a rationale for evaluating existing mitochondrial drugs to treat tumors from African American patients.…”

Metformin and Colorectal Cancer – A Systematic Review.

“…The study by Zhu et al was conducted on 167 patients with diabetes and CRC treated with metformin. The results have shown that metformin lowered mortality (hazard ratio: 0.34; 95 % CI: 0.15-0.81; p = 0.01) but had no impact on OS (overall survival) [68]. In a study on 202 patients with CRC metformin treatment was associated with lower mortality (48 % versus 76 %, p < 0.001), fewer recurrences (4 % versus 19 %, p = 0.002), less metastases (23 % versus 46 %, p = 0.001).…”

Obesity, Diabetes and Gastrointestinal Malignancy: The role of Metformin and other Anti-diabetic Therapy

“…The landmark UK Prospective Diabetes Study (UKPDS) showed that metformin significantly reduced diabetes-related mortality by 42%, all-cause mortality by 36%, myocardial infarction by 39%, and any diabetes related endpoint by 32% [40]. In a prospective study performed by our authors, the use of metformin showed significant risk reduction in mortality, and improved overall survival, in patients with colorectal carcinoma [59]. Additionally, a study of 30,493 patients with colorectal cancer, of which 3,391 were diabetic, and 1962 were treated with metformin, found an increased HR for all-cause mortality in the diabetes group, and a reduction in mortality by 15% in the metformin treated group [60].…”