Tumor cells are clearly different from healthy tissue cells. Researchers expect to find characteristic proteins called tumor specific antigens on the surface of cancer cells, where the immune system can identify them. This is the basis for development of cancer vaccines. It's a different concept from ordinary vaccines, which are used to prevent infectious disease. Flu shots, for example, are given before the recipient encounters the particular strain of flu virus, and give the immune system a head start on producing antibodies.
Cancer vaccines are intended to be therapeutic for patients who already have tumors. This may sound contradictory, but here's how it works. After surgical treatment, patients need some way to kill off individual cancer cells that are still hiding in otherwise healthy tissue. The immune system is ideally suited to such a job. Researchers hope vaccines can boost the effectiveness of the immune attack. If appropriate antibodies can be produced faster than tumor cells multiply, then the immune system has a chance to win the race and eradicate the cancer.
Preventive cancer vaccines are also part of the picture. Hepatitis B and certain strains of human papillomavirus are known to cause cancer, and vaccines are available to prevent these infections. Viruses are also suspected as causative agents in more types of cancer. In principle, vaccines can eradicate these viruses (remember smallpox) and prevent the cancers they cause. Research continues into developing more numerous and more effective preventive vaccines.
Therapeutic cancer vaccines are an active area of research. I found 1,074 clinical trials with the search terms “cancer vaccine” at the registry site, http://clinicaltrials.gov. A similar search on the National Library of Medicine site (PubMed) showed 621 articles published in the medical literature over the last 10 years. Ask your doctor whether you qualify to be a participant in ongoing studies.
1. Tan A et al, “The application of exosomes as a nanoscale cancer vaccine”, Int J Nanomedicine. 2010 Nov 10; 5: 889-900.
2. Vergati M et al, “Strategies for cancer vaccine development”, J Biomed Biotechnol.