Penn participating in study of brain cancer 'vaccine'

Over the past few years, we've been increasingly interested in the ways in which the definition of 'vaccine' has been broadened by researchers to describe a variety of new treatments that differ in form and function from vaccines of the past or present.

Tracing the evolution of the term 'vaccine' from the time of Edward Jenner to the present would be a great project for a historian or sociologist, as would attempting to understand why developers of new immunotherapies are eager to describe them as 'vaccines.' (One hypothesis -- unlikely to be palatable to critics of vaccination -- is that vaccines have a long-established record of safety and effectiveness, and classifying a new product as a 'vaccine' hopes to share in this positive connotation.)

Regardless, the latest example of this phenomenon comes from our own university, with a press release announcing, "Study Investigating Vaccine to Treat Brain Tumors Underway at Penn." As the press release and the web site of Celldex Therapeutics (the company testing the product) explain, the 'vaccine' (called CDX-110) is intended to target a particular molecule present in a significant portion of brain cancers (and other types of cancer, for that matter). The researchers' hypothesis is that administering CDX-110 to patients diagnosed with glioblastoma multiforme, the most serious form of brain cancer, will train the immune system to kill the cancer cells containing the specific target molecule.

Regardless of the branding issue, it's a very interesting and promising strategy worth following as research continues.

The future of 'cancer vaccines'

Even though the phrase 'cancer vaccine' is a bit misleading, the HPV vaccines on the horizon will likely call attention to other cancers linked closely with viruses and bacteria. In theory, vaccines could be able to reduce the incidence of these cancers just as HPV vaccines appear to prevent most cervical cancers.

Today's Telegraph reports that Cancer Research UK has recently explored the topic. Their key findings:

"One in 10 cancers could be prevented by vaccines and they estimate that a quarter of cancers in the developing world are triggered by a handful of infections."

"The global number of virus-associated cancer accounts for more than 1.8 million cases of cancer each year - which is around 18 per cent of all new cancer cases worldwide."

The key contributors to this number are cervical cancer and some types of liver cancer (for which HPV and Hepatitis B vaccines are already available or will be soon). Less prevalent viral or bacterial-related cancers include cancer of nasal passages, some lymphomas, rare forms of leukemia, and many cases of stomach cancer, the story notes.