Oral Bisphosphonates Linked to Esophageal Cancer: New Worries about Fosamax and Actonel

Posted Fri, 09/03/2010 - 09:24 by Tom

A new study finds that long-term usage of oral bisphosphonates to treat osteoporosis — drugs such as Fosamax, Actonel and Boniva — may double the risk of esophageal cancer. This follows on a report from a year and half ago from the FDA that raised concern about cancer in bisphosphonate users.

The study looked at 3,000 patients with esophageal cancer, 2,00 stomach cancer patients and 10,600 people with colorectal cancer. For each cancer patient, the researchers compared the cancer patients with five people without cancer, of the same age and gender. In this analysis, the team found no increased risk of stomach or colorectal cancer, but a near doubling of the risk of esophageal cancer in patients who had used one of the studied drugs for five or more years.

This contradicts an earlier study based on the registry — the General Practice Research Database of patients in Great Britain. While the earlier study found no increased risk of cancer, the current study followed patients for nearly twice as long and matched each patient with five, rather than just one, non-bisphosphonate user. In short, the new results would be considered stronger evidence.

In terms of actual risk, it must be stated that the risk of esophageal cancer remains quite low in absolute terms. The risk for bisphosphonate users is roughly 2 in 1000 compared to 1 in 1000 for non-users. Specifically, the researchers estimated the risk to those having 10 or more prescriptions of bisphosphonates at 1.93 times those having only had one to nine, and those who had been on bisphosphonates for 5 years or more to be 2.24 times the risk of those who had not taken bisphosphonates.

It known that bisphosphonates are associated with acid reflux and that aicd reflux is a risk factor for esophageal cancer. That said, the researcher of the current study did not see a correlation between cancer and prescriptions for acid suppressants. The study, in fact, controlled for many factors and the authors conclude that

The association [between bisphosphonates and cancer] did not vary materially within subgroups defined by age, sex, smoking status, alcohol drinking, or body mass index; diagnosis of osteoporosis, previous fracture, or previous upper gastrointestinal disease; or prescription of non-steroidal anti-inflammatory drugs, corticosteroids, or acid suppressant
drugs. (Green, p. 4)

Nevertheless, Diane Wysowski, the FDA epidemiologist who has led the FDA work on this issue, noted that it is important that patients carefully follow the instructions on these drugs, meaning to take them on an empty stomach, with a full glass of water, at least 30-60 minutes before eating or lying down. Any patients who have heartburn, chest pain or difficulty swallowing after taking their pills should see medical attention.

Clearly, each patient in consultation with his or her doctor needs to assess this information in the context of overall risk. It should be a warning to younger patients, who could potentially be on these drugs very long term, that anything they can do in terms of diet and exercise is of course advised (See the WEBMD article on 12 Foods to Boost Bone Health). In the end, though, patients have to balance the increased risk of a life-altering event like breaking a hip with the increased risk of cancer or osteonecrosis of the jaw.

As my mom loves to say (quoting Bette Davis I think), "getting old is not for sissies."

Disclaimer: I'm not a medical professional. I simply have a family history of osteoporosis and like to keep track of what's happening. Never, ever change yoru medication based on what you read on some random site on the internet!

Sources:

  • Jane Green, Gabriela Czanner, Gillian Reeves, Joanna Watson, Lesley Wise, Valerie Beral, "Oral bisphosphonates and risk of cancer of oesophagus,stomach, and colorectum: case-control analysis within a UK primary care cohort," BMJ 2010;341:c4444. Download the full PDF online. If you don't mind reading scientific papers, this is a really good read. Very interesting on many accounts and better-written than most scientific papers.
  • Salynn Boyles, "Osteoporosis Drugs May Be Linked to Cancer Risk Study Shows Some Increased Risk of Esophageal Cancer From Oral Bisphosphonates", medical review by Laura J. Martin, MD, WebMD Health News, Sept. 2, 2010. full article online
  • John Gever, "Bisphosphonates Tied to Esophageal Cancer," MedPage Today, September 02, 2010. Read the full article
  • Charles Bankhead, "No Cancer Risk with Bisphosphonates," MedPage Today, August 11, 2010. Read the full article online