Should Older Adults be Screened for Cancer?

Right about now, you might be thinking you've heard enough of cancer screening. From mammography to prostate cancer, cancer screening tests have been much debated this fall. Should a 40 year old woman get a mammogram or not? Should men abandon the PSA test? Yet another study released this week looks at a surprisingly unexplored group--older Americans.

Researchers wanted to look at this group because of an "ambiguity of recommendations" for them. While it seems like there's some ambiguity for the rest of us, the ambiguity here is particularly surprising since age is perhaps the most significant risk factor for many cancers.

The study, "Prevalence of Cancer Screening in Older, Racially Diverse Adults," appears in the Archives of Internal Medicine and found that, among adults aged 75 to 79, the screening rates for colorectal, breast, cervical and prostate cancer were between 56 and 62 percent. Screening rates are lower for older adults who are not white.

But are these rates good or bad? Too high or too low? The major organizations that issue guidelines on screening are divided on age cutoffs, as are many doctors. Dr. Louise Walter of UC San Francisco's Division of Geriatrics, captures that divide in a commentary that accompanies the published study:

"Some had advocated for high breast and colorectal cancer screening rates in healthy older adults because the incidence and mortality of these cancers increase with age. ... Others have advocated for low cancer screening rates in persons older than 75 years because the benefit of continuing screening is uncertain and screening can cause substantial harm, especially in frail, older adults."

In an interview, Walter spoke of experiences from her own practice. "I have 80-year-olds hiking in mountains ... and likely to live a long time, and I have people who have serious medical issues, dementia and life limiting disease." The types of preventive care she would recommend for these two patients, she says, is very different and not based on age, but on their overall health status.

The study also found that nearly one in ten patients with terminal cancer still received screening tests for breast, cervical or prostate cancer. Walter described cases of older women who have had a hysterectomy, including removal of the cervix, yet still receive Pap smears to test for cervical cancer.

"The thing I try to emphasis is let's do thoughtful cancer screening. Let's avoid cancer screening in someone without a cervix, someone who is in a nursing home, very frail." While people often think of screening tests as fairly benign, a positive result can lead to more and more invasive procedures to confirm a diagnosis, invasive procedures that can be very difficult for frail patients to withstand.

This study underscores the need for doctors to talk with older patients about their overall prognosis. Walter pointed out that screening tests can become a "distraction" from someone's overall health concerns. "If you had a recent heart attack, that's your major problem. Any major problem should make you rethink, 'Why am I looking for an asymptomatic problem that I probably don't have?'"