Promising Results in First Randomized Trial of a Colon Cancer Vaccine

CHICAGO—Using a patient’s own tumor cells to produce immunity against further cancer growth may improve survival in some patients, researchers have found in the first randomized multicenter test of immunotherapy in colon cancer. The 7-year, 412-patient trial, conducted by the Eastern Cooperative Oncology Group, shows the promise of adjuvant active specific immunotherapy in stage II/ III colon cancer, said lead author Jules E. Harris, MD, of Rush-Presbyterian-St. Luke’s Medical Center.

The study compared surgery alone vs surgery followed by immunotherapy. Although there was no overall survival benefit, patients who were sensitive to the vaccine, as measured by a skin test, did well. Overall 5-year survival was approximately 63%, but was 84.6% among patients most sensitive to the vaccine, and as low as 45% in patients who were only somewhat sensitive ( J Clin Oncol 18:148-157, 1999).

The vaccine was made using cells obtained from the patient’s own tumor tissue, which were then irradiated and mixed with Bacillus Calmette Guerin (BCG). Patients received two injections of the vaccine and a final dose of irradiated tumor cells alone.