Painkillers (Ibuprofen And Naproxen) Linked To Kidney Cancer

Statistics Cited in Headline Stories, However, Are Deceptive

Previous studies have suggested that these common over-the-counter pain relievers might even be helpful in the treatment of kidney cancer. Researchers at the US National Cancer Institute found that ibuprofen makes cancerous cells in the kidney more susceptible to radiation treatment. But is it possible that taking medications like Aleve and Advil could really cause cancer?

Common Risk Factors for Kidney Cancer

About 1 of every 30 persons who gets cancer gets kidney cancer. There are few early warning signs, and symptoms of kidney cancer are often misdiagnosed as symptoms of other diseases. But about 40% of people who develop kidney cancer have other genetic conditions.

Specific genes have been identified that seem to trigger hereditary papillary renal carcinoma, hereditary renal carcinoma, familial renal oncocytoma, Birt-Hogg-Dube syndrome, and von Hippel-Lindau syndrome. If someone in your family has had kidney cancer after developing on of these diseases, then there is an elevated risk that you will develop kidney cancer, too (although it's not a sure thing).

In Europe, Scandinavians are at greater risk of the disease, but in the United States, the greatest number of deaths from kidney disease occurs among African-Americans. Far more men die of kidney cancer than women. But there are also causes of kidney cancer that can be controlled:

• Smoking doubles the risk of kidney cancer, and about 1/3 of Americans who develop kidney cancer smoke. The  more you smoke, the greater your risk of kidney cancer.
• Uncontrolled high blood pressure is associated both with increased risk of both kidney cancer and kidney failure.
• Occupational exposure to cadmium, used in electroplating and the making of batteries, increases the risk of kidney cancer.
• Phenacetin, which is used to cut cocaine, greatly increases the risk of kidney cancer.

Women who have had hysterectomies are at greater risk for kidney cancer, especially if there are problems with the placement of the catheter to facilitate urination while tissues heal.

Also, people on dialysis tend to develop acquired cystic kidney disease, which often leads to kidney cancer. People who develop cystic kidney disease of the kidneys while on dialysis are 30 times more likely to develop kidney cancer.

All of these risk factors, however, do not result in a very high rate of kidney cancer. Only one in every 4800 people develops kidney cancer in any given year. If there are no special risk factors, the lifetime risk of developing kidney cancer is about 1 in 70. About 1 in every 24,000 people dies of kidney cancer in any given year, and about 1 in 350 deaths is due to the disease. Even if you develop cystic kidney disease while you are on dialysis, you have less than a 1 in 2 risk of developing kidney cancer. So how big a risk factor is using ibuprofen and naproxen sodium?

Should You Stop Use Pain Relievers So You Won't Get Kidney Cancer?

If you don't have other risk factors for kidney cancer and you don't use pain relievers like Aleve and Advil, you have about a 0.004% risk of developing kidney cancer in any given year. If you don't have other risk factors for kidney cancer and you do use pain relievers like Aleve and Advil, and you participated in the Nurses Health Study, from which the headlines-making data were taken, you have about a 0.002% risk of developing cancer. That isn't a typo, and, yes, 0.002% is less than 0.004%.
 

The scary headlines come from a study that found that nurses who take NSAID pain relievers such as ibuprofen and naproxen sodium actually have lower risk of kidney cancer than the general public, although they had a higher risk of kidney cancer than nurses who did not take these medications. Nurses who took these medications were 50% more likely to get kidney cancer than nurses who did not, but still 50% less likely to get kidney cancer than people who did not participate in the study.

Moreover, the study found that Aleve and Advil seemed to be associated with higher kidney cancer rates in nurses, but Aspirin was not. Researchers have no clear understanding of why one kind of NSAID pain reliever would be associated with kidney cancer and another NSAID pain reliever would not.

The answer might be that Aleve and Advil usually come in plastic-coated capsules, while Aspirin does not. Maybe plastic coatings cause cancer. Or maybe they prevent cancer. After all, nurses in the study were still far less likely than the general public to get this or any other kind of cancer. But there is no way to tell from this kind of study.

It's never a good idea to turn your life upside down because some new study has found some new link to a horrible disease. Here are the things to remember about scary health headlines:

• Epidemiology does not uncover the causes of diseases. It just finds things that seem to happen together, in this case, taking otherwise harmless pain relievers and higher cancer rates. Correlation does not prove causation. Just because two things both happen doesn't mean that one causes the other—or doesn't.
• A huge increase in a rate may mean a tiny increase in risk. If you would have a 0.001% chance of getting a disease and a certain substance would raise your risk by 100%, you would still only have a 0.002% risk of the disease. If another substance increased your risk 100-fold, your risk would still be just 0.1%.
• As a general principle, any headline designed to scare you isn't designed to help you.

If a family member has been diagnosed with one of the hereditary conditions mentioned earlier in this article, you need to be alert to the symptoms of kidney cancer. Blood in urine, pain on just one side of the waist,  and the appearance of a lump or mass on the side of the body are sure signs a trip to the doctor is urgent.

Otherwise, simply have regular checkups with a doctor who examines all your lab results carefully. Kidney cancer is still most often diagnosed on a "hunch." You need a doctor who takes enough time to know your needs that hunches can occur.