A vaccine against lung cancer?

A potential link between lung cancer and human papilloma virus may make parents even more glad about vaccinating their children with Gardasil®. Not only are the children protected against viruses that commonly cause cervical cancer, they may be protected against some forms of lung cancer as well. The April 25th version of Nature News reports (1) that two viruses, HPV (Human papilloma virus) and measles virus, have been found in lung tumors. From Nature News:

Samuel Ariad of the Soroka Medical Center in Beer Sheva, Israel, and his colleagues began by analyzing tumours taken from 65 lung cancer patients. They found evidence of measles virus proteins in about half of their samples. The work provides the first hint that the measles virus may contribute to lung cancer, and follows on Ariad's previous studies showing a possible association between the measles virus and a cancer of the lymph tissue called Hodgkin's disease3. In addition, Arash Rezazadeh of the University of Louisville in Kentucky and his colleagues tested 23 lung cancer tumours for HPVs. In five cases, the samples tested positive for the virus's DNA. Others have previously shown a possible link between the virus and lung cancer, but, as in this case, have relied on small sample sizes.

It's not known if the viruses caused the tumors; however, many kinds of cancer are associated with viral infections and HPV, at least, is a well-established cause of both cervical cancer and warts. The connection between measles virus and cancer isn't as clear, but there is one recent study that shows a link between measles virus and Hodgkins disease. From Nature News:

As much as 20% of the world's cancers have been linked to infections. In addition to the connection between HPVs and cervical cancer, chronic infections by hepatitis-B and -C viruses contribute to liver cancer, and the bacterium Helicobacter pylori has been associated with stomach cancer. In February, researchers reported viral genome sequences found in an aggressive form of skin cancer called Merkel cell carcinoma, although it remains to be seen precisely how the virus contributes to skin cancer, if at all. And some have proposed that a virus similar to the 'mouse mammary tumor virus' -- which causes breast cancer in mice -- could also be associated with breast cancer in humans.

Our ability to uncover hidden viruses is improving greatly due to Next Generation DNA sequencing technologies (2). It is likely that further research will find viruses involved in many more health problems. In this case, more research is needed to prove a link between these viruses and lung cancer. If these early results are confirmed, many of us will doubly glad that we had our children vaccinated against HPV. NOTE: I should add that lung cancer can be caused by multiple things - smoking, asbestos, maybe measles?, - a vaccine against HPV would only protect against lung cancer if that cancer was caused by the same strain HPV used in the vaccine. References: 1. Heidi Ledford "Viruses found in lung tumours" Nature News, April 25, 2008. 2. Feng, H. , Shuda, M. , Chang, Y. & Moore, P. S. "Clonal Integration of a Polyomavirus in Human Merkel Cell Carcinoma" Science 319, 1096-1100 (2008).