Impact of immune parameters on long-term survival in metastatic renal cell carcinoma

Purpose The purpose of this study was to evaluate the impact of immunologic prognostic factors in combination with established clinical prognostic factors in patients with metastatic renal cell carcinoma (mRCC). Patients and Methods A total of 120 consecutive patients with mRCC received interleukin-2 (IL-2)-based immunotherapy. Baseline tumor biopsies were available from 85 of these patients. Potential prognostic factors were analyzed by univariate and multivariate analyses. Results Multivariate analysis (N=120) identified high lactate dehydrogenase, lymph node metastases, low hemoglobin, low Karnofsky performance status, and bone metastases as independent poor prognostic clinical factors. The impact of these clinical factors has been demonstrated by others. Multivariate analysis (n=85) also identified a high blood neutrophil count (>6.0x10(9)/L; hazard ratio, 2.0; P=.015), the presence of intratumoral neutrophils (>0 cells/mm(2) tumor tissue; hazard ratio, 2.3; P=.001), and low intratumoral CD57(+) natural killer cell count (<50 cells/mm(2) tumor tissue; hazard ratio, 2.1; P=.01) as independent poor prognostic immunologic factors. These three independent immunologic parameters had significant discriminatory power as supplemental risk factors in prognostic models based on the clinical risk factors, identifying subgroups within the favorable clinical group with estimated 5-year survival rates of 60%, 25%, and 0%, respectively. These findings were apparent in both our own prognostic model and in an extended Memorial Sloan-Kettering Cancer Center (New York, NY) prognostic model. Conclusion This study points on five clinical and three supplemental immunologic independent prognostic factors of survival in patients with mRCC receiving IL-2.