Pre‐clinical studies have suggested that Metformin and statins may delay prostate cancer metastases; however, data in humans are limited.
This is the first human study aimed to quantify the individual and joint effects of statin and Metformin use among patients with high‐risk prostate cancer.
. A population‐based retrospective cohort study identified patients from the Surveillance, Epidemiology, and End Results ( SEER )‐Medicare linked database.
Exposure to Metformin and statins was ascertained from Medicare Prescription Drug Event files. The association with all‐cause and prostate cancer mortality were evaluated using Cox proportional hazard model with competing causes of death, where propensity scores were used to adjusted imbalances in covariates across groups.
Based on 12 700 patients with high‐risk prostate cancer, statin alone or in combination with Metformin was significantly associated with reduced all‐cause mortality ( hazard ratio [ HR ]: 0.89; 95% confidence interval [ CI ]: 0.83, 0.96; and HR: 0.75; 95% CI, 0.67‐0.83, respectively ) and prostate cancer mortality ( HR, 0.80; 95% CI: 0.69, 0.92 and 0.64; 95% CI, 0.51‐0.81, respectively ).
The effects were more pronounced in post‐diagnostic users: combination use of Metformin / statins was associated with a 32% reduction in all‐cause mortality ( 95% CI, 0.57‐0.80 ), and 54% reduction in prostate cancer mortality ( 95% CI, 0.30‐0.69 ).
No significant association of Metformin alone was observed with either all‐cause mortality or prostate cancer mortality.
In conclusion, statin use alone or in combination with Metformin was associated with lower all‐cause and prostate cancer mortality among high‐risk patients, particularly in post‐diagnostic settings; further studies are warranted. ( Xagena )
Source: Cancer Medicine, 2020