Interferon Plus Chemotherapy Is Better Than Chemotherapy Alone In Renal Cell Cancer
Seppo Pyrhönen, M.D., senior physician, chief, Outpatient Chemotherapy Unit, Helsinki University Central Hospital (Helsinki, Finland), presented the results of a multicenter trial which compared the effects of combination therapy with chemotherapy and interferon alfa-2a cersus chemotherapy alone on the overall survival of patients with advanced renal cell carcinoma.
Renal cell carcinoma is the most common type of kidney cancer. Each year in the U.S., 25,000 to 30,000 new cases are diagnosed, and 10,000 to 12,000 patients die of the disease. While a large proportion of patients can be cured if the disease is detected early, almost half of the patients do not know they have the disease until it is at an advanced stage.
The Phase III study consisted of 160 patients with advanced renal cell carcinoma (RCC) who were randomized to receive either combination therapy with the chemotherpeutic drug vinblastine plus interferon alfa-2a, or vinblastine alone. The two treatment arms were well balanced for all prognostic factors.
Interferon alfa-2a was injected subcutaneously three times a week. Vinblastine therapy was given intravenously once every three weeks to patients in both treatment arms. Treatment was continued for one year, unless disease progression or intolerable side effects occurred.
Median survival in the combination vinblastine and interferon alfa-2a arm was 15.8 months, versus 8.8 months in the vinblastine-only arm, a statistically significant increase of 80%. Median time to disease progression in the combination arm was three months versus 2.1 months in the vinblastine-only arm, and objective response rates (complete responses and partial responses) were 16% for the vinblastine-interferon group, versus 2.5% for the chemotherapy-only. Two patients in the combination therapy arm are still alive more than five years later.
Treatment with interferon was associated with higher incidences of constitutional symptoms (such as aches, fever, malaise) as well as gastrointestinal and nervous system complaints, which required dose reduction of interferon in almost half of the patients. The results of the study showed that patients who needed to reduce the interferon dose to manage side effects lived as long as the patients who continued at the highter dose.
"In comparison with conventional chemotherapy regimens, this study shows that combination therapy with interferon prolongs survival by seven months and delays disease progression," Lynn Mara Schuchter, M.D., assistant professor of medicine, Abramson Cancer Center of the University of Pennsylvania (Philadelphia, PA), said at a press briefing today. "While there was an increased incidence of side effects in the combination therapy group, the addition of interferon can be considered an important advance in prolonging the overall survival of patients with advanced renal cancer."