These findings were reported in the Journal of Clinical Oncology.
Bisphosphonates are a class of drugs used to prevent and treat osteoporosis and to reduce the risk of bone complications from bone metastases or multiple myeloma. Studies have suggested that in addition to their effects on bone, bisphosphonates may also have certain anticancer effects. Recent research has indicated that use of bisphosphonates may help reduce the risk of breast cancer; it is not known, however, whether these drugs may protect again other cancers.
To investigate whether bisphosphonates may help reduce the risk of colorectal cancer, researchers in northern Israel conducted a study including 933 patients diagnosed with colorectal cancer (cases). Cases were matched with and compared to individuals who had not been diagnosed with cancer (controls). Cases and controls were paired according to age, place of treatment, and ethnic group. All participants were postmenopausal females.
Patients who had used bisphosphonates for more than one year had a statistically significant 59% reduction in the risk of colorectal cancer. Use of bisphosphonates for less than one year, however, was not associated with this reduction in risk. The researchers accounted for other factors that may affect colorectal cancer risk (vegetable consumption; physical activity; body mass index; and the use of low-dose aspirin, statins, vitamin D, and postmenopausal hormones) and found that bisphosphonates were still associated with a statistically significant reduction in colorectal cancer risk. Use of bisphosphonates together with statins (cholesterol-lowering drugs associated with a reduced risk of colorectal cancer) did not appear to further lower risk.
It appears that use of bisphosphonates for more than one year may reduce the risk of colorectal cancer.
Reference: Rennert G, Pinchev M, Rennert HS, et al. Use of bisphosphonates and reduced risk of colorectal cancer. Journal of Clinical Oncology [early online publication]. February 14, 2011.