Healthwatch: Colorectal Cancer

A common virus might be causing some cases of colorectal cancer, which according to Dr. Ekaterina Dadakova from Albert Einstein University, is not at all unusual.

"According to the health statistics, approximately 1.3 million cases of cancer  worldwide are caused by pre-existing viral infections," explained Dr. Dadakova. 

But this virus is the human papilloma virus, or HPV, the same virus well-known to cause cervical cancer in women.

It's believed when HPV infects a cell, and the viral DNA changes the cell's DNA causing it to start dividing irregularly and aggressively. In the early stages, it's called atypia.

But Dr. Henry Wodnicki from Mount Sinai Medical Center says that atypia is how tumors start to grow. 

"With each mutation, the cells tend to become more unusual, more bizarre-looking, and as we were talking about with atypia, it approaches cancer, and eventually it becomes a cancer," said Dr. Wodnicki.

A recent study conducted by the National Cancer Institute found 51% of the colorectal tumors they tested were positive for HPV in both men and women. Other studies have found similar results. And since the virus is sometimes transmitted sexually, particularly in gay men, doctors are beginning to test for it just like they do for cervical cancer.

"What we've been doing is Pap smears on all males who have been exposed, or potentially exposed to HPV," Dr. Wodnicki added.

The good news is if the HPV virus is causing some colon cancers, a vaccine might one-day protect against it.