Differences in organ system of distant metastasis by renal cell carcinoma subtype

Purpose; The majority of the published data regarding the rates of renal cell carcinoma metastasis to specific locations has examined renal cell carcinoma as a whole. We evaluated site of distant metastasis by renal cell carcinoma histological subtype. Materials and Methods; We studied 910 patients treated with radical nephrectomy for clear cell, papillary or chromophobe renal cell carcinoma at the Mayo Clinic between 1970 and 2000 who had distant metastasis at nephrectomy or who had metastasis during followup. The sites of metastases were compared by histological subtype using the chi-square and Fisher exact tests. Results; There were 853 (94%) patients with clear cell, 39 (4%) with papillary and 18 (2%) with chromophobe renal cell carcinoma. Median followup for the 65 patients who were still alive at last followup was 11.6 years. Patients with clear cell renal cell carcinoma were more likely to have metastasis to the lungs (53.6%) compared to those with papillary (33.3%) and chromophobe (33.3%) renal cell carcinoma (p = 0.012). Patients with chromophobe renal cell carcinoma were more likely to have metastasis to the liver compared to those with clear cell renal cell carcinoma (33.3% vs 9.7%, p = 0.007), but there was not a statistically significantly difference in the incidence of liver metastases between patients with chromophobe and papillary renal cell carcinoma (33.3% vs 18.0%, p = 0.308). Conclusions; Site of distant metastasis varies significantly by renal cell carcinoma histological subtype. Patients with clear cell renal cell carcinoma are more likely to have metastasis to the lungs while patients with chromophobe renal cell carcinoma are more likely to experience liver metastasis.