Adjuvant active specific immunotherapy for stage II and III colon cancer with an autologous tumor cell vaccine: Eastern Cooperative Oncology Group study E5283

Purpose: A randomized phase III clinical trial of adjuvant active specific immunotherapy (ASI) with an autologous tumor cell-bacillus Calmette-Guerin (BCG) vaccine wets conducted to determine whether surgical resection plus A SI was more beneficial than resection alone in stage II and III colon cance r patients. Patients and Methods: Patients(n = 412) with colon cancer (297 with stage I I disease, 115 with stage III disease) were randomly allocated to an observ ation arm or to a treatment arm in which they received three weekly intrade rmal vaccine injections of 10(7) irradiated autologous tumor cells beginnin g approximately 4 weeks after surgery. The first two weekly injections also contained 10(7) BCG organisms. Patients were observed for determination of time to recurrence and disease-free and overall survival. Results: This was a negative study in that after a 7.6-year median follow-u p period, there were no statistically significant differences in clinical o utcomes between the treatment arms. However, there were disease-free surviv al (P = .078) and overall survival (P = .12) trends in fervor of ASI when t reatment compliance was evaluated, ie, patients who received the intended t reatment had a delayed cutaneous hypersensitivity (DCH) response to the thi rd vaccination (induration greater than or equal to 5 mm). Also, the magnit ude of the DCH response correlated with improved prognosis. The 5-year surv ival proportion was 84.6% for those with indurations greater than 10 mm, co mpared with 45.0% for those with indurations less than 5 mm. Conclusions: When all randomized patients were evaluated, no significant cl inical benefit was seen with ASI in surgically resected colon cancer patien ts with stage II or III colon cancer. However, there was an indication that treatment compliance with effective immunization results in disease-free a nd overall survival benefits. (C) 2000 by American Society of Clinical Onco logy.