Prostate cancer is the second leading killer of men, according to the American Cancer Society (ACS). And while there are many effective procedures and treatments for prostate cancer, still more than 27,000 men will die this year from their disease. Fortunately, a novel treatment under development – a prostate cancer vaccine – might help prolong the life of people with advanced or metastatic disease who have no further treatment options.
How Does the Vaccine Work?
One such vaccine under development, known as Provenge acts by enhancing the body's immune system (the system that helps fight disease), which then goes after the prostate cancer cells or tumors that are present in the body. According to the ACS, the vaccine is designed to treat existing cancer rather than prevent disease from occurring. The studies to date have shown that the vaccine may prolong the life of a person with advanced prostate cancer, but the vaccine does not “cure” the disease because the tumors do eventually grow again according to the studies. In a study conducted in 2005, about 18 percent of the men who received the vaccine experienced an increase in survival time. On average, the men who received the vaccine lived about 4.5 months longer than the men who did not receive the vaccine. Further studies are underway to confirm the effectiveness and safety of the vaccine.
A panel for the FDA voted at the end of March 2007 to support approval of Provenge, which for the time being is only being used in clinical trials. The panel voted that the treatment was “reasonably safe.” According to the ACS common side effects included chills, fatigue, fever, and back pain. A small percentage (about 5 percent) of men who received the vaccine had a stroke. Final approval for the drug, however, has not been issued as the FDA states that more data is needed at this point to support the vaccine’s effectiveness.
Men who might be eligible to receive such a vaccine are patients with advanced or metastatic disease who are no longer responding to traditional hormonal treatments. In other words, their cancer has become resistant to those treatments. But these same men may have a positive response with Provenge or other similar vaccines under development.
How Common is Prostate Cancer?
Prostate cancer is the most common cancer in men after skin cancer, according to the ACS. Men should talk with their doctor about screening for prostate cancer because early detection improves the chances for survival. Men with advanced prostate cancer should talk with their doctor about important new options that may exist for them. The good news is that there are other novel treatments, such as Provenge, that are in the development phase and could become available in the near future. |
