The controversial cancer treatment drug Avastin (bevacizumab) has one more warning attached to it – the drug has been associated with two deaths and 52 cases of flesh-eating disease.

The drug’s maker, Hoffman-LaRoche Ltd., identified the cases of necrotizing fasciitis (flesh-eating bacteria) occurring worldwide from 1997 to 2012.  Both the FDA and Health Canada are warning about this latest turn for Avastin, which remains on the market.

Those most at risk are patients who have a lowered immune system or have fistulas, gastrointestinal perforation or problems with wound-healing. Roche says the bulk of the cases have been found in patients who are suffering from colorectal cancer. The patients with the flesh-eating bacteria were also receiving other chemotherapies.

Necrotizing fasciitis can advance swiftly and may be accompanies by pain, fever and irritation at the site of a wound such as a cut or bruise.

Avastin was first approved in 2004 to treat cancers that had spread or metastasized. In October 2006, the FDA approved it as a first-line treatment for non-small cell lung cancers.

The drug works by slowing the growth of blood vessels that feed the cancer but Avastin has long been associated with serious side effects such as gastrointestinal perforation and complications with wound healing, hemorrhage, congestive heart failure and nephritic syndrome (kidney damage).

In November 2011, both the U.S. FDA and Health Canada revoked approval of the drug as a treatment for metastatic breast cancer because of a lack of evidence whether the benefits outweighed the risks.

The drug has long been criticized for its cost – about $88,000 a year in the U.S. while delivering a questionable benefit of several more months of life.