No link seen between bone drugs, colon cancer

Women who use certain bone-building drugs may not have a decreased risk of colon cancer, a new study finds - despite prior evidence suggesting the drugs might offer some protection.

The drugs, called bisphosphonates, include brands like Fosamax, Boniva, Reclast and Actonel, along with generic versions.

They are used to prevent and treat the bone-thinning disease osteoporosis, which mainly strikes older women. The drugs can also be used to help treat cancer that has spread to the bone from other sites in the body.

Bisphosphonates have been tied to both good and bad side effects.

Research has found after years of use, the drug may, in rare cases, actually weaken the bones and lead to thighbone fractures or a painful breakdown of the jaw bone.

On the other hand, several studies have suggested women who use bisphosphonates may have a decreased risk of developing breast or colon cancer.

But this latest study, reported in the Journal of Clinical Oncology, found no evidence that women on the medications had lower odds of colon cancer.

Of more than 86,000 U.S. nurses followed for over a decade as part of a large health study, 801 developed colon cancer. The risk was no different among women who didn't use bisphosphonates, versus users - regardless of how many years they had been on the medications.

FDA Drug Safety Communication: Ongoing safety review of oral osteoporosis drugs (bisphosphonates) and potential increased risk of esophageal cancer

Commonly used for the prevention and treatment of osteoporosis as well as to treat other bone diseases such as Paget's disease. Osteoporosis is a disease that makes bones weak and more likely to break.

Include: Fosamax (alendronate), Actonel (risedronate), Boniva (ibandronate), Atelvia (risedronate delayed release), Didronel (etidronate), and Skelid (tiludronate).

May cause irritation of the esophagus. Irritation of the esophagus can lead to esophagitis (inflammation) or esophageal ulcers (sores), which may bleed. The risk of these esophageal events is low when oral bisphosphonates are prescribed appropriately and the specific directions for use are followed by patients.

"It is not clear whether bisphosphonates have any role in treatment of colorectal cancer, and our data does not support its routine use as a (prevention) agent for colorectal cancer," lead researcher Dr. Hamed Khalili, a gastroenterologist at Massachusetts General Hospital in Boston, said in an email.

Since evidence suggests bisphosphonate users have a lower risk of certain cancers, researchers have been interested in whether the drugs might help prevent those tumors in people who are particularly at risk.