LISBON, Portugal--Adjuvant immunotherapy with low-dose interferon (IFN)-alfa-2a (Roferon-A) boosts disease-free survival by a significant 40% in melanoma patients with regional lymph node metastasis, according to the findings of the latest multicenter World Health Organization (WHO) Melanoma Programme trial.
After undergoing radical surgery, 218 participants in this study were randomized to receive IFN-alfa-2a, 3 million units subcutaneously, thrice weekly for 3 years, while 209 received no further treatment. At a mean follow-up of 22 months, 45% of IFN-treated patients were alive and disease-free, compared with only 32% of controls, said Dr. Natale Cascinelli, of the National Cancer Institute, Milan, who is president of the WHO Melanoma Programme.
Speaking at the congress of the European Society of Medical Oncology, Dr. Cascinelli also noted a trend toward improved overall survival, pointing out, however, that definitive evidence of a statistically significant overall survival advantage must await longer follow-up.
Dr. Cascinelli called the results highly encouraging, particularly in light of the fact that in patients with stage II melanoma, most adverse events tend to occur during the first 24 months.
The WHO investigators found that the response to adjuvant immunotherapy hinged not only on the number of positive nodes but also on the patient's age and gender. They observed that disease-free survival increased with increasing age in men who received IFN-alfa-2a but, conversely, declined with increasing age in IFN-treated women.
Dr. Cascinelli speculated that the lesser benefit of IFN treatment in women over the age of 50 might mean that the effect of the immune stimulant is mediated by sex hormones.
"We are now conducting experiments in the laboratory to determine whether the actions of IFN are potentiated by estrogens(Drug information on estrogens)," he said.