A combination of both radiation and “suicide gene therapy” is highly effective in treating prostate cancer, as a new study suggests. Researchers with the Houston Methodist Hospital explained that in this specific type of gene therapy, a patient’s cancer cells are genetically modified so that they prompt the person’s immune system to attack the cells. In a hospital news release, chair of the department of radiation oncology, Dr. E. Brian Butler stated,
“We have created a vaccine with the patient’s own cancer cells, a treatment that complements, and may even enhance, what we can achieve with traditional radiation and hormonal therapies.”
The study was comprised of total of 62 participants all of whom were then divided into two separate test groups. Prostate cancer patients in the first group, with cancerous cells confined to their prostate gland, only received radiation treatment. While patients in the second group however, with a more aggressive form of prostate cancer, received a combination of both radiation and hormone treatments. The experimental gene therapy was administered twice to the first group of patients, and the gene therapy was given a total of three times to the second group during the second phase of the clinical trial which was conducted between 1999 and 2003 respectively.
Two years following treatment, prostate biopsies were found negative in about 83 percent of patients within the first test group and 79 percent of patients within the second group. After five years, the study’s findings showed that 94 percent of patients in the first group showed no signs of cancer recurrence and 91 percent in the second group. The five year survival rates among the two test groups were 97 and 94 percent.
“The results are extremely pleasing to us, considering we had patients enrolled in our protocol after other physicians deemed them incurable. We firmly believe this will be a viable treatment strategy.”
Lead author Dr. Bin Teh, vice chair of the department of radiation oncology, stated in the news release.
A phase 3 clinical trial is currently underway for a final evaluation of to determine the gene therapy’s safety and efficiency before it can be submitted for approval to the U.S. Food and Drug Administration (FDA). The study was published online Dec. 12 in the Journal of Radiation Oncology.