The association of metformin use with prostate cancer aggressiveness among Black Americans and White Americans in a population-based study

Examining the relationship between metformin dose and cancer survival: A SEER-Medicare analysis

Cancer is a major health problem in the U.S and type 2 diabetes mellitus (T2DM) is known to increase the risk for the development of many cancers. Metformin, a first-line therapy for treating T2DM, is increasingly being used for its anticancer effects; however, the literature is limited on the effect of metformin dose on overall survival in patients with stage IV cancer. Overall survival was defined as the time interval from the date of diagnosis to the last known follow-up or death from any cause. Subjects who were alive on December 31, 2016 were censored. In this cohort study we examined the relationship between metformin dose and overall survival in persons with both T2DM and stage IV lung, breast, colorectal, prostate, or pancreas cancers. We used a retrospective study design with Cox proportional hazards regression analysis of the 2007-2016 of the Surveillance Epidemiology and End Results-Medicare (SEER) dataset. Of the 7,725 patients, 2,981(38.5%) had been prescribed metformin. Patients who used metformin had significantly better overall survival in both unadjusted (Unadjusted HR, 0.73; 95% CI, 0.69-0.76; p < 0.001) and adjusted models (adjusted HR, 0.77; 95% CI, 0.73-0.81; p < 0.001). The overall survival between patients who took metformin with average daily dose ≥ 1000mg or < 1000mg were not statistically significant (aHR, 1.00; 95% CI, 0.93-1.08; p = 0.90). Metformin use regardless of dose is associated with increased overall survival in older adults with stage IV cancer.

The Effect of Metformin on Male Reproductive Function and Prostate: An Updated Review

Metformin is the first-line oral antidiabetic drug that shows multiple pleiotropic effects of anti-inflamation, anti-cancer, anti-aging, anti-microbia, anti-atherosclerosis, and immune modulation. Metformin's effects on men's related health are reviewed here, focusing on reproductive health under subtitles of erectile dysfunction (ED), steroidogenesis and spermatogenesis; and on prostate-related health under subtitles of prostate specific antigen (PSA), prostatitis, benign prostate hyperplasia (BPH), and prostate cancer (PCa). Updated literature suggests a potential role of metformin on arteriogenic ED but controversial and contradictory effects (either protective or harmful) on testicular functions of testosterone synthesis and spermatogenesis. With regards to prostate-related health, metformin use may be associated with lower levels of PSA in humans, but its clinical implications require more research. Although there is a lack of research on metform's effect on prostatitis, it may have potential benefits through its anti-microbial and anti-inflammatory properties. Metformin may reduce the risk of BPH by inhibiting the insulin-like growth factor 1 pathway and some but not all studies suggest a protective role of metformin on the risk of PCa. Many clinical trials are being conducted to investigate the use of metformin as an adjuvant therapy for PCa but results currently available are not conclusive. While some trials suggest a benefit in reducing the metastasis and recurrence of PCa, others do not show any benefit. More research works are warranted to illuminate the potential usefulness of metformin in the promotion of men's health.

Clinical association of metabolic syndrome, C-reactive protein and testosterone levels with clinically significant prostate cancer

Recently, the influence that metabolic syndrome (MetS), hormonal alterations and inflammation might have on prostate cancer (PCa) risk has been a subject of controversial debate. Herein, we aimed to investigate the association between MetS‐components, C‐reactive protein (CRP) and testosterone levels, and the risk of clinically significant PCa (Sig‐PCa) at the time of prostate biopsy. For that, men scheduled for transrectal ultrasound guided biopsy of the prostate were studied. Clinical, laboratory parameters and criteria for MetS characterization just before the biopsy were collected. A total of 524 patients were analysed, being 195 (37.2%) subsequently diagnosed with PCa and 240 (45.8%) meet the diagnostic criteria for MetS. Among patients with PCa, MetS‐diagnosis was present in 94 (48.2%). Remarkably, a higher risk of Sig‐PCa was associated to MetS, greater number of MetS‐components and higher CRP levels (odds‐ratio: 1.83, 1.30 and 2.00, respectively; P < 0.05). Moreover, higher circulating CRP levels were also associated with a more aggressive Gleason score in PCa patients. Altogether, our data reveal a clear association between the presence of MetS, a greater number of MetS‐components or CRP levels >2.5 mg/L with an increased Sig‐PCa diagnosis and/or with aggressive features, suggesting that MetS and/or CRP levels might influence PCa pathophysiology.