Interferon-α as the only adjuvant treatment in high-grade osteosarcoma:: Long term results of the Karolinska Hospital series

This experience of single agent interferon-alpha treatment in high- grade osteosarcoma was based on observed anti- osteosarcoma activity in laboratory models and was started before introduction of aggressive combination chemotherapy. From 1971 to 1990, 89 consecutive patients with non- metastatic high- grade osteosarcoma received semi- purified, leukocyte interferon-alpha as adjuvant treatment. From 1971 to 1984, 70 patients were given a dose of 3 MIU daily for one month followed by 3 times weekly for an additional 17 months. For 19 patients treated from 1985 to 1990 the dose was increased to 3 MIU daily and the treatment duration extended to 3 - 5 years. All patients underwent surgery prior to interferon treatment. The toxicity was mainly constitutional and long- term toxicity was virtually absent. With a median follow- up of 12 years the observed 10- year metastases- free and sarcoma specific survival rates were 39% and 43%, respectively. Only one of seven survivors after relapse received chemotherapy. This work suggests activity of interferon-alpha as adjuvant treatment in high- grade osteosarcoma. The efficacy of interferon in combination with standard therapy should be explored in randomized trials.