TOPIC Discussion: Hypertension as risk factor for Renal Cell Cancer

We know that smoking increases risk of renal cell cancer. It is interesting to note that a study published more than 10 years ago in NEJM showed the risk of Obesity and HTN as a risk factor for renal cell cancer.

The study had looked at over 300,000 Swedish men who had physical exams done in 1970s and 1990s and followed till 1995.  Renal cell cancer patients were identified and risks were analyzed. Higher body-mass index and elevated blood pressure independently increase the long-term risk of renal-cell cancer in men. A reduction in blood pressure lowers the risk.

While obesity and lot of things are an enigma, the association with HTN is concerning.  Most of the anti cancer agents in RCC are anti VEGF or Tyrosine kinase inhibitors and it is possible that the HTN in this case is might be associated elevations of such factors and leading to renal cancer.  Does HTN leading to CKD then predispose one to getting renal cancer? These are some interesting findings. Nevertheless, it’s an observational study with only Swedish Men and cannot be generalized at all. 

What else is out there regarding this association of HTN and renal cell cancer?

A Japanese study called the JACC study found nine risk factors (i.e., smoking, obesity, low physical activity, hypertension, diabetes mellitus, kidney diseases, beef intake, fondness for fatty food and black tea) in a Japanese population.

Another study done in the US looked at risk factors for RCC. Hypertension, high BMI, and smoking were associated with renal cell carcinoma, but findings generally did not differ by race. Relative to other racial/ethnic groups, blacks had the highest proportion of renal cell carcinoma incidence attributable to hypertension and chronic kidney disease in their study.  Another study published in the Urology journals puts HTN as a risk factor. VITAL study found a significant association of renal cell carcinoma with obesity, smoking, hypertension, renal disease and viral hepatitis.

Now here is a study that doesn’t feel that HTN is a risk factor for RCC.

 It is quite possible that is the constellation of metabolic syndrome that leads to this RCC risk. Given the risk factors that are consistently being similar to risk factors for cardiac disease, it is more likely that the metabolic syndrome might be the major culprit. The rise of incidence in RCC that we have seen in the last 2 decades goes in line with the rise of the metabolic syndrome and obesity.