Serendipitous renal cell carcinoma in the post-CT era: Continued evidence in improved outcomes

Purpose: To compare patient and tumor characteristics, including survival data, between serendipitous and non-serendipitously discovered renal cell carcinoma (RCCA) in an era of more frequent use of CT scanning and ultrasonography. Materials and methods: The Tumor Registry of the Audie L. Murphy VA Hospital in San Antonio, TX, was reviewed for new diagnoses or initial treatment of RCCA from January 1985 through December 1999. Records were evaluated as to whether the initial diagnosis of RCCA was made serendipitously. Prognostic and epidemiological variables, were collected and disease-specific and overall survival data were computed. Results: Of 257 patients with RCCA, 93 (36.2%) presented with serendipitously discovered tumors and 100 presented with metastases at diagnosis. Mean tumor size was smaller in the serendipitous group, compared both pathologically (6.74 cm vs. 4.49 cm, P < 0.0001) and by radiographic measurement (8.04 cm vs. 4.87 cm, P < 0.0001). Sixty-six (71%) of 93 serendipitously discovered tumors were Stage I at diagnosis, vs. only 30 (18.4%) of 163 non-serendipitous tumors (P < 0.0001). When non-serendipitous tumors with metastatic disease at presentation were excluded, the percentage of patients with Stage I disease was lower than for serendipitous tumors (46.8% vs. 71%, P = 0.004). Pathologically confirmed tumor stage was more favorable for serendipitously discovered tumors: 40 of 77 (60%) non-serendipitous tumors were < pT3, vs. 70 of 86 (81.4%) serendipitous tumors (P < 0.0001). Overall and disease-specific survival was better in the serendipitous group as well, with a 5-year disease-specific survival of 94%, contrasted with 35% in the non-serendipitous group (P < 0.0001). Conclusions: The widespread use of CT scanning and ultrasonography has led to a continued increase in the serendipitous diagnosis of a significant number of all RCCA which are associated with significantly lower stage at diagnosis, and thus with significantly improved survival.