Interferon-alpha and survival in renal cell cancer

To establish whether the use of interferon-alpha might result in improved survival, using two large series of patients with advanced renal cell cancer treated during studies of chemotherapy and biological therapy, respectively.

Patients treated either in the Eastern Cooperative Oncology Group (ECOG) chemotherapy protocols (327 patients) or in protocols employing interferon as part of a European randomized study or phase II studies at the Norwegian Radium Hospital (231 patients) were retrospectively analysed. Groups for comparison were matched by exclusion of those with an ECOG performance status > 2, no prior nephrectomy, brain metastases or prior chemotherapy. Univariate analysis of prognostic factors for survival was performed by the log rank method and multivariate analysis by Cox regression.

Univariate analysis of the whole population showed that performance status, time from diagnosis to treatment, sites of metastases and the use of interferon carried the greatest prognostic significance. In multivariate analysis, the use of interferon remained a significant predictor of survival (P < 0.001). Subgroup analysis suggested that the impact of interferon treatment was greatest in those patients with two of the following characteristics: good performance status, an interval of > 2 years from diagnosis to treatment and no more than one site of metastasis.

Although a prospective randomized trial is needed to establish definite benefit from the use of interferon in advanced renal cell cancer, this analysis supports the rationale for performing such a trial, particularly in patients with relatively good prognostic features. Patients should be entered into the Medical Research Council study comparing interferon with medroxyprogesterone acetate.