A melanoma vaccine developed at the University has shown a positive correlation to tumor regression in a recent study conducted by the University of Virginia Health System.
Of patients injected with the vaccine, 75 percent showed response by the killer t-cells in the lymph nodes. Killer t-cells are leukocytes, or white blood cells, which recognize and destroy abnormal or infected cells.
Research on melanoma at the University has been on-going for a number of years, and the current study stems from earlier efforts. The most recent study took place over seven weeks in the past year, according to Hospital spokesperson Robert Beard.
Beard said that the next stages in the study will include more research.
"There will be further study," Beard said. "We are continuing to give vaccine boosters to patients who responded positively."
Beard said he did not plan for results to come so soon for such a long-term study.
"Success is never expected this quickly," Beard said. "The hope is that these vaccines will be useful to patients with advanced melanoma."
The study is exclusively a University effort and 19 researchers contributed.
The research was headed by Craig L. Slingluff, Jr., professor of surgery and director of the Human Immune Therapy Center.
James W. Patterson, professor of pathology and dermatology and director of dermatopathology, explained that multiple departments collaborated on the study. Patterson performed biopsies and examined tissue samples, contributing to the compilation of data that will be used in future study at the University and beyond.
Patterson said the vaccine showed important successful results.
"The hope is that this vaccine therapy will cause patients to get rid of their melanoma," Patterson said. "And you can actually see shrinkage and sometimes the removal of tumors through this treatment."
He explained that the next stage of the study will involve efforts to understand why the treatment was not successful in all cases.
"What we're trying to find out is why some patients get better and why others do not," Patterson said. "The vaccine is expressed toward the antigen on the melanoma cells. Melanoma cells are very smart, and sometimes they can figure out you're attacking, and they can change their antigen, which is why some patients don't respond to the therapy as well as others."
When the vaccine was applied directly to skin cells, patients showed 85 percent less response, indicating little to no correlation, according to the report, which was published in the Journal of Clinical Oncology.
Melanoma was the cause, according to the American Cancer Society, of about 7,400 deaths and 53,600 new cases of cancer in 2002. No other form of skin cancer killed more people in the past year, despite the fact that melanoma accounts for only 4 percent of all skin cancer cases. However, melanoma can be completely treated with early detection, hence the interest in investigating a vaccine.