Are we really ready to inject vaccines in people to prevent cancer? Well it’s already happening. Three vaccines have hit the market in the past 6 years. These vaccines are Hepatitis B vaccine which can prevent liver cancer and the HPV vaccine which prevents about 70% of cervical cancers. The FDA has also recently approved a treatment vaccine for men with metastatic prostate cancer.
How do Vaccines Work?
Unlike certain viruses like hepatitis or polio, in which these cells are easily identified by the immune system as foreign, most cancer cells come off looking similar to molecules that are found in healthy cells. Vaccines boost the immune systems natural ability to protect the body against foreign invaders or threats by stimulating certain types of white blood cells to recognize and act against certain cancer cells.
The vaccines currently in clinical trials are “treatment” vaccines against breast cancer and pancreatic cancer. Treatment vaccines are intended to treat an existing cancer by strengthening the immune system to fight the cancer. Preventative vaccines prevent cancer from developing. Recent trials were done for women who completed treatment for HER-2 positive breast cancer. After 22 months of follow-up, the vaccine reduced the risk of cancer relapse by 43%. The recurrence rate was 10.3% among the vaccinated women vs 18% in controls.
Researchers are quick to say that this is not a “cure” for cancer as much as a different way of looking at cancer and living with it.
Cancer vaccination is in it’s infancy and is starting to take off. The goal of these immune-based treatments is to train the immune system to eradicate tumors as well as provide long-lasting memory against recurrence. This is bound to revolutionize cancer treatment.
Think about it. Many drugs and therapies available today to treat cancer are toxic and dangerous due to it’s side effects. This makes immunotherapy much more attractive in how it can prevent and in some cases treat cancer.
But immunotherapy will face its own hurdles, the main one being cost. The relative cost of 3-9 injections of immunotherapy may be low in comparison to many years of treatment with other therapies. Of course the cost up front for some of these drugs can be huge (some drugs costing $90,000!) vs $4000-$5000 in monthly payments for years. And then there’s the question on whether health insurance will cover any of these costs. We will be hearing more about cancer vaccines in the future. For now, we need to also take into consideration the economics, technology and politics involving the medicine of immunotherapy.
Reference: Wolchok, J. “Researchers, oncologists embrace the ‘concept of cure'”. HemOnc Today. Volume 13, Number 17. September 10, 2012.
NCI Cancer Vaccines Fact Sheet available at http://www.cancer.gov/cancertopics/factsheet/Therapy/cancer-vaccines