It’s not exactly logical, but that doesn’t stop it from being true: though we are diagnosing and treating more cases of kidney cancers earlier, the number of people dying from the disease is escalating. Researchers from the University of Michigan have reported that the number of kidney cancer cases is growing because doctors are getting much better at detecting smaller tumors — but these tumors can usually be cured, so the fact that people are dying more regularly from the illness is a bit of a mystery.
Each year in the U.S. there will be nearly 40,000 new cases of kidney cancer. And each year nearly 13,000 people will die from the disease, according to the American Cancer Society. When it comes to tumors in the urinary and reproductive systems, kidney cancer is ranked as being the third most common. Heading into the study, researchers expected to witness a decrease in kidney cancer deaths, but were surprised to discover that this wasn’t the case at all.
The study included information on 34,500 patients with kidney cancer. Over a span of two decades (wrapping up in 2002), the number of diagnosed cases rose 52%. (It is, thankfully, still pretty rare in the whole scheme of things: About 11 out of every 100,000 people will get it.) The most notable increase happened in people with tumors of a small stature, somewhere around 3 cm in size.
That much is not surprising, as with better diagnostic techniques we can spot more tumors that otherwise would remain hidden. That alone would suggest that more deaths could be prevented than before. Yet the study found that death rates rose throughout those two decades, particularly among those patients with tumors greater than 7 cm in size. The death rates nearly tripled over the 20 years to 3.2 per 100,000 people.
One of the reasons for this may be that more and more larger, dangerous tumors are developing. While more people with small, detectable kidney tumors are being treated, the number of patients with larger tumors has not decreased. It is the larger ones that are linked with mortality. Another idea put forth is that the high death rate could be in part caused by a lack of chemotherapy drugs after surgery.
Some experts believe there aren’t very many good drugs available for kidney cancer and the tumor is often not responsive. To stop the cancer from spreading, better drugs need to be developed.