Data from the California Cancer Registry (CCR), a population-based cancer surveillance system, was used to retrospectively analyze 28,252 patients with RCC diagnosed between 1998 and 2007. Inter-era differences in clinical variables鈥攊ncluding year of diagnosis, histologic characteristics, age, sex, race, stage, nephrectomy status, overall survival (OS), and cause-specific survival (CSS)鈥攚ere assessed. Univariate and multivariate Cox models were used.
Crude 3-year OS (68.2%vs. 74.6%; 2P < .001) and CSS (78.1%vs. 82.3%; 2P < .001) were significantly higher in the post-cytokine era. In multivariate analysis, the 3 strongest predictors for improved survival were localized disease (hazard ratio [HR], 18.1; 95%confidence interval [CI], 16.6-19.6), nephrectomy (HR, 2.87; 95%CI, 2.68-3.08), and clear cell histologic type (HR, 1.33; 95%CI, 1.22-1.44).
In this analysis of a large RCC registry, there was an apparent increase in crude OS and CSS in the post-cytokine era compared with the cytokine era. Insufficient follow-up time in the post-cytokine era and a higher proportion of localized disease in that era confound the possibility of benefit derived from targeted therapies. Longer follow-up for patients treated in the post-cytokine era is necessary for a more robust comparison of long-term OS.