HPV Vaccine May Prevent Breast Cancers

One of Australia's proudest scientific achievements of recent years, the vaccine against cervical cancer, may turn out to even more important than anyone Research published in the British Journal or" Cancer suggests that the vaccine may also prevent some breast cancers.

Most cases of cervical cancer are caused by the human papillomavirus strains 16 and 18. The vaccines Gardasil and Cervarix, based on the work of the University of Queensland's Prof Ian AS, Jan/Feb 2006, p.9), operate against these strains. HPV has also been implicated in penile, anal and vaginal cancers, but these are much rarer than cervical cancer and have been treated as an afterthought.

Now, however, a research team at the University of NSW has found HPV-18 in nuclei of around 20% of invasive ductal breast cancer specimens, as well as 40% of non-invasive ductal carcinoma cells. sample sizes were small, and the actual frequency of HPV could turn out to be substantially different.

The presence of HPV in cancer cell nuclei does not, of itself, prove that the virus is causing the cancers, but Em/Prof James Lawson believes a case is building that HPV is responsible. Other researchers have reported HPV in breast cancer cells, but rates have varied widely, and the reports relied on techniques that are vulnerable to contamination.

"We've identified a cancer-causing protein, E6, from HPV-18 in breast cancer cells," Lawson says. "It's all based on work done on cervical cancer." The researchers also found enlarged nuclei surrounded by a "halo" when HPV starts the process of forming cancers in the cervix.

The team is attempting to use RNA to block the E6 protein and see if the cancer cells start to die normally. "If we can do that it's conclusive of causation," Lawson says.

With twice as many women dying globally from breast cancer as cervical cancer, and the ratio even higher in developed nations, even a small contribution to breast cancer reduction could greatly boost the demand for HPV vaccines. Lawson says there is strong evidence for HPV involvement in tonsil, mouth and throat cancers, and a possibility it is a factor in lung cancer.

"If this is found to be true, it will completely revolutionise our concepts about cancer," Lawson says. "These are the big cancers that are most common and lethal. HPV has also been found in bowel cancer, but that's not widely believed."

Copyright 2009