Incidental renal cell carcinoma-age and stage characterization and clinical implications: study of 1092 patients (1982-1997).

OBJECTIVES: To compare the epidemiologic, clinical, and pathologic characteristics of incidental and symptomatic renal cell carcinoma in a large series of patients, with emphasis on age distribution and its potential impact in defining groups of patients that may benefit from early detection programs.

METHODS: Records of 1092 patients with renal tumors from 1982 to 1997 were reviewed. Age, clinical presentation, and pathologic stage and grade were analyzed. Special attention was given to the age distribution and its relationship to the incidental or symptomatic diagnosis.

RESULTS: The overall mean age and proportion of patients older than 65 gradually increased (from 57 to 62.6 years and from 24.7% to 48.7%, respectively) from 1982 to 1997. The mean age in the incidental group rose steadily higher than in the symptomatic group. A progressive increase of incidental tumors from 13.0% in 1982 to 1983 to 59.2% in 1996 to 1997 was observed. A lower stage (74.3% versus 49.1%), grade (75.5% versus 56.9%), and percentage of metastases at presentation (10.4% versus 19.6%) were registered in the incidentally found neoplasms than in the symptomatic neoplasms. Eighty-two (80.4%) of 102 patients who underwent conservative surgery had incidental renal cell carcinoma.

CONCLUSIONS: Our data confirm a rapid and dramatic change in the epidemiologic and clinical characteristics of renal cancer, with an increasing number of incidentally found tumors presenting with lower stage, grade, and percentage of metastases. An unexpected but significantly higher rate of renal neoplasms was observed in older patients. The stage, grade, and patient age observed in our series of incidentally found tumors raises the question of whether to leave the current diagnostic approach unaltered, thus benefiting a subgroup of patients with clinically unrecognized and possibly indolent renal cell carcinoma, or to extend early detection programs to younger patients with potentially more aggressive tumors.