Oral bisphosphonates may confer a protective effect against lung cancer, according to an observational study.
However, this effect was only observed among never-smokers, as there was no significant difference in lung cancer incidence between oral bisphosphonate use and nonuse in the overall study cohort, Meng-Hua Tao, PhD, of the University of North Texas Health Science Center, Fort Worth, and associates reported in Annals of Oncology.
While bisphosphonates are commonly prescribed to prevent and treat osteoporosis, research suggests that they may have a range of other benefits, such as inhibition of tumor angiogenesis and cellular proliferation, prevention of tumor-cell adhesion and invasion, and induction of tumor-cell apoptosis. Recent studies have also investigated the association between bisphosphonate use and the risk of several cancers including breast, gastrointestinal tract, endometrial, and ovarian. Additionally, a few studies have looked at the relationship between oral bisphosphonates and lung cancer risk, but results have been inconsistent.
However, previous studies had very limited information on lung cancer risk factors, such as tobacco use, and none had analyzed the potential associations between bisphosphonate use and lung cancer and how it might vary by smoking status, the authors noted.
In the current study, the relationship between oral bisphosphonates use and lung cancer risk, and its potential interaction with smoking status on lung cancer risk, was examined using a prospective cohort of 151,432 postmenopausal women enrolled in the Women’s Health Initiative during 1993-1998. At baseline and follow-up, an inventory of regularly used medications including bisphosphonates was completed.
After a mean cumulative follow-up of 13.3 years, there were 2,257 nonusers and 254 ever-users of oral bisphosphonates, and 2,511 women were diagnosed with incident lung cancer. On multivariable-adjusted analysis, the hazard ratio for lung cancer incidence after use of any type of oral bisphosphonate, compared with never-use, was not significantly different (HR = 0.91; 95% confidence interval, 0.80-1.04; P = .16).
In a subgroup analysis, the authors found that the association patterns differed between never-smokers and ever-smokers (P = .02). Among women who never smoked, oral bisphosphonate use was inversely associated with lung cancer risk in the multivariate adjusted models (HR = 0.57; 95% CI, 0.39-0.84; P less than .01), and this association was stronger when the duration of bisphosphonate usage was 1.5 years or longer (HR, 0.36; 95% CI, 0.18-0.73).