Prognostic factors for biologic therapy in kidney cancer.

Renal cell cancer is resistant to most forms of therapy. Cytokine therapy with either interleukin-2 or interferon-alpha yields the best results, with response rates from 10% to 20%. Therapy is not without toxicity, which means that the majority of patients treated with cytokines suffer toxicity without any therapeutic benefit. Recent endeavors have tried to find new ways to identify responders to cytokine therapy. Prognostic factors, such as good performance status, lack of anemia, normal calcium, normal lactate dehydrogenase, and prior nephrectomy, correlate with an increased likelihood of responding to cytokine therapy. Recent studies have examined whether altered subpopulations of lymphocytes, the presence of eosinophils, or altered levels of cytokines can predict response to cytokine therapy. Although prior nephrectomy does correlate with improved survival while the patient is receiving cytokine therapy, it is unclear if this is due to a significant alteration in the tumor's response to cytokine or some unrelated benefit from surgery. Further studies are needed to confirm the current immune parameters and disease characteristics that suggest a better response to cytokine therapy.