UroToday.com - Renal cell cancer is the third most common urologic malignancy and the seventh most common cancer overall. Incidence rates have been increasing steadily each year in the United States (U.S.) and Europe during the last 3 decades1. There are projected to be 54,390 new cases and 13,010 deaths from renal cell cancer in 2008 in this country2.
Renal cell cancer imposes a significant burden on the U.S. healthcare system, as its diagnosis involves advanced radiological testing and its treatment often involves surgery, hospitalization, and regular surveillance visits to assess for recurrence. Costs associated with the diagnosis and treatment totaled approximately $400 million in 20003.
Risk factors associated with renal cell carcinoma rates have been investigated and reported in the literature. Cigarette smoking, obesity, physical inactivity and diabetes have been found to increase risk in past studies. Hypertension appears to independently influence renal cell cancer risk. A protective effect of fruit/vegetable consumption has been reported while excessive alcohol consumption has been found to be a risk factor in some studies1.
In this study, we compare renal cell carcinoma incidence and mortality rates among states to factors suspected of influencing kidney cancer risks. Family income, lack of health insurance, urbanization and the population density of urologists among states were included to adjust for access to health care and socioeconomic status. Urbanization was selected as a factor for consideration in this study because hospitals and physicians are more likely to be located in urban areas. The prevalence of urologists in the population may be related to renal cancer screening and treatment.
In this study we found that smoking, obesity and physical inactivity correlate directly with renal cell carcinoma incidence and mortality rates while hypertension correlates directly with incidence rates solely. High fruit/vegetable diet, family income and urbanization correlate inversely with renal cell carcinoma mortality rates. The prevalence of urologists correlates directly with incidence rates for males but not females.
There are limitations in the ecologic approach taken in this study that may cause uncertainties in the results. The analyses are not based on individual data but on data representing an entire state - which does not take into consideration the range of values within the state. The results of this study, suggesting that cigarette smoking, obesity and physical inactivity may be associated with increased renal cell cancer risk, while a high fruit/vegetable diet are may be associated with decreased renal cancer risks, are consistent with studies in the literature.