When Colorectal Cancer Screening is Too Much, Too Frequent, or Not Enough

No other disease advocacy group has built as effective an awareness campaign as the cancer societies. It has helped to build support for prevention, research, and treatments, but I wonder whether excess awareness could be contributing to the overuse of colorectal cancer screening in older people. They have been exposed to this message for decades.

Earlier this week, Archives of Internal Medicine published two studies and an editorial pointing out problems with the lack of targeting in colorectal cancer screening (either fecal occult blood test (FOBT) and/or colonoscopy) to people most likely to benefit.

The fecal occult blood test checks for blood in your stool and is a noninvasive test that can be done easily as a first screen for colorectal cancer. Costs vary, depending on the laboratory, but $100 for the test is common. In the VA and among countries where costs are of concern, FOBT is often the initial cancer screening test of choice, offered to asymptomatic people in their fifties and sixties annually. If the test is suspicious, a colonoscopy is more definitive. Colonoscopy costs also vary, but it is not uncommon to cost $1000.

A study led by Christine Kistler, MD, raises questions about how well colorectal cancer screening is targeted. It’s a study of veterans age 70 and older at 4 VA facilities. The study revealed:

• Too many older people with significant health problems are getting screened; many are getting screened when their life expectancy is shorter than 5 years and they are likely die from other causes. Nearly half of the patients who had a fecal occult blood test (FOBT) didn’t have a follow-up colonoscopy in the 7-years of follow-up, and half of those died from other causes within 5 years

• Slightly more than 1/2  of  people who had a positive FOBT went on to have a follow-up colonoscopy in the 7 year follow-up period; at least a quarter of these had significant disease found, including 6 cases of cancer.

• Of those who had significant adenomas and cancer found on follow-up colonoscopy, some of these older individuals had serious complications from treatment, including time in the ICU, chronic ostomy leakage, or a hypoxic event.

“A colonoscopy clearly has risks,” explained Christine Kistler, MD, the study’s lead author, and assistant professor of Family Medicine at the University of North Carolina at Chapel Hill. “It’s not just a walk in the park for elderly patients with lots of health problems.”

A second study led by James Goodwin, MD, from the University of Texas Medical Branch, Galveston, TX, reviewed a 5 percent sample of Medicare enrollees to find average-risk people undergoing screening colonoscopy. Patients between age 75 and 79 or 80 years and older received a second colonoscopy examination 46 percentand 33 percent respectively within 7 years. Detailed analysis showed that higher rates of repeated colonoscopy was associated with being male, having more illnesses, and seeing a high volume colonoscopy provider. There was plenty of geographic variation, as low as 5 percent to 50 percent. The authors concluded that current Medicare policies that limit colonoscopy to once every ten years are not succeeding in slowing widespread use of colonoscopy.

The authors were both quick to point out that some groups are not getting the recommended cancer screenings that they need.

Colon Cancer Screening Recommendations

Current guidelines from the US Preventive Services Task Force and the American Cancer Society recommend regular colon cancer screenings begin at age 50 and continue until age 75. People with a higher risk should begin screening at a younger age, and they may need to be tested more frequently. Beyond age 75, USPSTF and ACS state that screening decisions should be individualized, factoring in life expectancy, other health problems, ability to tolerate a colonoscopy, and net expected benefit. In the UK, colorectal cancer screening is recommended for individuals until their 70s.

How do you get healthy people on the right track towards getting proven cancer screenings that can save lives at the recommended ages? And how do you get doctors on board to advise screening at those intervals.

A Patient POV and Her Daughter

I’ll tell you a story about my mother who died at age 92. Until the last 6 months of her life, she was in excellent shape. She religiously went for a Pap test and mammogram every year until shortly before she died. It didn’t make a lot of sense to me and I tried to convince her otherwise.

I knew that the US Preventive Services Task Force found no evidence for mammography over age 75. Some investigators say that it may be beneficial to continue mammography screening if life expectancy is 10 years. For Pap tests, for women who have previous normals and no other risk factors, you can stop at age 65.

So I couldn’t convince my mother to stop.  I assume she had regular colonoscopies as well. She had reason to go besides. She got reminders from her primary care doctor whose office was at an academic medical center. Her insurance covered it.

Dr. Kistler suggested that my mother might have had another reason for keeping these screenings up. “Sometimes if you suggest stopping, patients think that they are giving up.”  Sure enough, she didn’t stop getting screened for breast cancer and cervical cancer until she was declining in the last year of her life.

The astronomical dollars spent on end of life care are one thing that we have heard lots about, but what about the decades of cancer screenings in the golden years for no benefit, and possible harm. That needs to be examined too.

This entry was posted in American Cancer Society, colorectal cancer screening, complications, Medicare, USPSTF and tagged , , , , . Bookmark the permalink.