Adjuvant interferon alpha therapy in renal cell carcinoma (RCC): prognostic value of DNA cytophotometry.

BACKGROUND: Adjuvant immunotherapy with interferon alpha in non-metastatic RCC is still controversial. It was the aim of the present study to investigate whether tumor ploidy can help to isolate a group of patients profitting from this treatment. MATERIALS AND METHODS: Survival data of 119 patients undergoing tumor nephrectomy because of a non-metastatic RCC were analyzed retrospectively. Ploidy was measured in every tumor by means of DNA-cytophotometry. 24 patients received an adjuvant therapy with interferon alpha for one year. Statistical evaluation was performed by the Kaplan-Meier-Method with the logrank-test. RESULTS: Ploidy could be measured in all tumors. 56 (47%) tumors showed a diploid, 63 (53%) an aneuploid DNA-distribution. Ploidy was seen to be a good prognostic factor in RCC with significantly better survival in patients with diploid than those with aneuploid tumors. The adjuvant interferon therapy provided a marginal however not significant better survival in diploid tumors. Patients with aneuploid RCC had no benefit from this treatment. CONCLUSIONS: The data show that an interferon treatment in non-metastatic RCC might improve survival in patients with the prognostic better diploid tumors. However further investigations are necessary to give a general recommendation for this therapy in this group of patients. Additional molecular tumor factors like S-phase analysis and others might also improve patient selection.