Second primary malignancies associated with renal cell carcinoma histological subtypes.

PURPOSE: Renal cell carcinoma has been linked to numerous secondary malignancies. We evaluated the risk of secondary malignancies by renal cell carcinoma histological subtype in patients with clear cell, papillary and chromophobe renal cell carcinoma.
MATERIALS AND METHODS: We studied 2,722 patients who underwent nephrectomy for sporadic renal cell carcinoma at our institution between 1970 and 2000. All specimens were reviewed by a single urological pathologist for histological subtype. Associations of second primary malignancies by histological subtype were evaluated using the chi-square and Fisher exact tests.
RESULTS: Of the patients studied 2,188 (80.4%) had clear cell, 378 (13.9%) had papillary and 128 (4.7%) had chromophobe renal cell carcinoma. Patients with papillary renal cell carcinoma were significantly more likely to have colon cancer (p = 0.041), prostate cancer (p = 0.003), any second malignancy (p <0.001) and multiple malignancies (p <0.001) compared with patients with clear cell renal cell carcinoma. In addition, patients with chromophobe renal cell carcinoma were significantly more likely to have colon cancer than patients with clear cell renal cell carcinoma (p = 0.020). Although patients with papillary renal cell carcinoma were more likely to have bladder cancer, the incidence did not differ significantly compared with that in patients harboring clear cell and chromophobe renal cell carcinoma (p = 0.193). We did not find a significant difference in the incidence of breast cancer, lung cancer, rectal cancer or lymphoma among histological subtypes.
CONCLUSIONS: Our data indicate that patients with papillary renal cell carcinoma are more likely to harbor secondary malignancies, including colon and prostate cancer, than patients with clear cell renal cell carcinoma. These results may have important implications for patient education and followup evaluation, and they should prompt mechanistic investigations.