Number of metastatic sites rather than location dictates overall survival of patients with node-negative metastatic renal cell carcinoma

Objectives. To perform a retrospective study to determine whether survival and immunotherapy response are related to the site of metastases (lung versus bone) and to the number of organ sites involved (one versus multiple). The most common sites of metastatic renal cell carcinoma (mRCC) are the lung and bone. Methods. The records of 434 patients with mRCC were reviewed. Patients with pathologic evidence of nodal involvement were excluded, leaving 120 patients with mRCC to lung only, 33 patients to bone only, and 144 patients with multiple organ involvement. The response rates to immunotherapy and overall survival were compared. The variables evaluated in statistical analyses included Eastern Cooperative Oncology Group score, grade, 1997 tumor stage, and multiple organ involvement. Results. The median survival for patients with lung only and bone only mRCC was 27 months; patients with multiple organ involvement had a median survival of 11 months. In patients who underwent nephrectomy followed by immunotherapy, the median survival time was 31, 31, and 13 months in the lung, bone, and multiple sites groups, respectively. The response rate to immunotherapy after nephrectomy was 44%, 20%, and 14% in the lung, bone, and multiple organ groups, respectively. Multivariate analysis confirmed that metastatic disease to more than one organ site was associated with poor prognosis (2.05 risk ratio, P <0.001). Conclusions. Patients with mRCC to only one organ site fared significantly better than patients who had evidence of disease in multiple organs. Survival in patients with disease limited to the lung was similar to that of patients whose disease was limited to bone.