(HealthDay News) – Exposure to bisphosphonates (BPs) is associated with a reduction in the risk of colorectal cancer (CRC), a reduction that is significant only for risedronic acid, according to a study published in the March 1 issue of Cancer.
Harminder Singh, MD, MPH, from the University of Manitoba in Winnipeg, Canada, and colleagues identified 5,425 patients diagnosed with CRC from 2000–2009 who had been living in Manitoba for at least five years prior to diagnosis. Using incidence density sampling, each case was matched for age, sex, and duration of residence in Manitoba with 10 controls (54,242 controls). Exposure to BPs was determined, and its effect on CRC incidence was assessed, after adjusting for health care use, medical procedures, socioeconomic status, and pre-existing health conditions.
The researchers found that, on multivariate analysis, BP exposure correlated with a reduced risk of CRC (2–13 prescriptions over at least five years: odds ratio [OR], 0.84; 95% CI, 0.71–1; ≥14 prescriptions over at least five years: OR, 0.78; 95% CI, 0.65–0.94). The effect was significant only for risedronic acid (OR, 0.5) when the effect of specific BP agents was assessed. Increasing duration or cumulative dose of alendronic acid had no significant effect.
“Additional studies are needed to confirm these findings and to determine the cost-benefit ratio for the use of BPs, a class of agents commonly used in the elderly, which comprise a population at risk for both osteoporosis and CRC,” the authors write.
One of the authors disclosed financial ties to the pharmaceutical industry.