Efficacy of continuous subcutaneous infusion therapy using interferon alpha and the possible prognostic indicator of TNF-alpha in renal cell carcinoma.

BACKGROUND

In an attempt to improve efficacy by escalating the dose and maintaining higher serum concentrations over a long period of time, this study examines continuous interferon alpha (IFN alpha) subcutaneous infusion therapy in patients with renal cell carcinoma (RCC).

METHODS

Seven of 11 patients with RCC had evaluable metastatic lesions. A highly purified natural human IFN alpha was injected subcutaneously via an infuser pump for 5 consecutive days, followed by a 2-day rest period (25 million IU/week). The treatment was continued for a period of 15 weeks. Serum concentrations of IFN alpha, IL-1 alpha, IL-1 beta, TNF-alpha, and IFN gamma were measured at intervals throughout the study period.

RESULTS

Two of the 7 patients with evaluable lesions achieved a partial response (overall response rate, 29%), while 1 achieved a partial response only to lung metastasis. These 3 cases were defined as responders. No difference was found in the concentration of serum IFN alpha between responders and nonresponders, however, a significantly higher concentration of serum TNF-alpha was observed in responders (P < 0.05, Mann-Whitney U test). Five cases (45%) had moderate to severe adverse effects, including depression (n = 1), eyeground hemorrhage (n = 2), and general fatigue (n = 2).

CONCLUSION

Appropriate patient selection may be necessary for subcutaneous continuous infusion therapy for the treatment of metastatic RCC. Also, the serum concentration of TNF-alpha measured during the course of treatment reflected well on the outcome of IFN alpha therapy.