Cancer is one of the last great scourges of humanity, and modern medicine has designed many tests that can screen for cancers. The most popular are mammograms for women, and prostate checks for men. The whole point of a screening test is to do as little harm as possible, to detect something that can be treated, and overall society would benefit from less of this disease. Cervical cancer screening is a huge success; but now there is growing evidence that prostate cancer screening may not be too effective; and mammograms are not 100% effective, either. The latest debate is swirling around a new review in JAMA which showed how mammograms and PSA tests haven’t made much of a dent in overall decrease in severe cancers:

…screening may be increasing the burden of low-risk cancers without significantly reducing the burden of more aggressively growing cancers and therefore not resulting in the anticipated reduction in cancer mortality. To reduce morbidity and mortality from prostate cancer and breast cancer, new approaches for screening, early detection, and prevention for both diseases should be considered.

This was followed by a New York Times mention that the American Cancer Society is taking such reviews seriously and is preparing a careful revision of their recommendations for screening. Here’s a great quote from that article, as well as a revealing graph from the article:

“We don’t want people to panic,” said Dr. Otis Brawley, chief medical officer of the American Cancer Society. “But I’m admitting that American medicine has overpromised when it comes to screening. The advantages to screening have been exaggerated.”

Now, the New York times has a good follow up article focusing on mammograms. The main concern is that mammogram’s risk/benefit ratio is very strong for women 50-60 but less clear for women 40-50 and especially over 70. This is a fascinating and informative review that many women will find useful. Here’s a good quote:

“In a certain sense, I have to confess that I’m happy if the public gets offended or infuriated” by the debate, Dr. Formenti said. “I want taxpayers to say: ‘You have no clarity. Study it. Stop telling us you are a good girl if you get a mammogram.’ ”

By the time I finished the interviews I decided that, because I’m between 50 and 60, I’ll keep having mammograms. But I’ve requested the report from my last one to find out about my tissue density, and if it’s low, I might stretch the interval to 18 months or even 2 years. And I’ll hope that in the meantime research does find a way to tell which tumors will kill you, and which will just sit there and mind their own business until you die of something else.

The Bottom Line?

The truth is that some cancer screening tests are not fail-safe, and patients should be having more discussions with their doctors about risks and benefits of screening. Over the last couple years I have changed my practice and am much less enthusiastic than before about PSA testing. I still think that mammograms are a good idea for women in those discussed high-risk age groups, but women need to be aware of its limitations.