Imaging of Small Renal Masses before and after Thermal Ablation

The incidence of kidney cancer has been rising over the last two decades, especially in cases where the disease is localized. Although rates of renal surgery parallel this trend, mortality rates have continued to rise. To investigate the basis of this "treatment disconnect" (i.e., increased rates of treatment accompanied by increased mortality rates), we analyzed patient data from nine registries of the National Cancer Institute's Surveillance, Epidemiology, and End Results Program. We assembled a cohort of 34,503 kidney cancer patients and derived incidence, treatment, and mortality trends for kidney cancer, overall and as a function of tumor size. From 1983 to 2002, the overall age-adjusted incidence rate for kidney cancer rose from 7.1 to 10.8 cases per 100,000 US population; tumors 7 cm. Our results demonstrate that the rising incidence of kidney cancer is largely attributable to an increase in small renal masses that are presumably curable. The fact that increased detection and treatment of small tumors is not reducing mortality argues for a reassessment of the current treatment paradigm.

Evidence exists to suggest a pattern of increasing early diagnosis of renal cell carcinoma (RCC). The aim of the study was to analyze patterns of disease presentation and outcome of RCC by AJCC stage using data from the National Cancer Data Base (NCDB) over a 12-year period. The NCDB was queried for adults diagnosed between 1993 and 2004 presenting with ICD-O-2 of 3 renal cell tumors arising in the kidney. Cases were classified by demographics, 2002 AJCC stage (6th edition), and histology. The Cochran-Armitage Test for Trend was used to determine statistical significance of trends over time. Cox regression multivariate analysis was used to evaluate the impact of stage and histology on relative survival. SPSS 14.0 was used for analyses. Between 1993 and 2004 a total of 205,963 patients from the NCDB fit our case definition of RCC. Comparisons between 1993 and 2004 data show an increase in stage I disease and decrease in stage II, III, and IV disease (P < or = .001). The size of stage I tumors also decreased from a mean of 4.1 cm in 1993 to 3.6 cm in 2003. In multivariate analysis, stage, but not histology, predicted relative survival. A 3.3% increase in survival was found for patients diagnosed in 1998 compared with patients diagnosed in 1993. A greater proportion of newly diagnosed patients with RCC currently present with stage I disease compared with earlier years. Stage predicts relative survival for patients with kidney cancer. More recently diagnosed patients have improved relative survival. (Copyright) 2008 American Cancer Society.