The following is a guest blog post by Dr. Richard Hoffman, who has been reviewing health care news stories for us for years. He recently became the Director of the Division of General Internal Medicine for the University of Iowa Carver College of Medicine/Iowa City VA Medical Center.
I was recently invited to attend an “80% by 2018” kickoff event. This program, announced with considerable fanfare by the National Colorectal Cancer Roundtable during Colorectal Cancer (CRC) awareness month in March, aims to increase the proportion of U.S. adults who are current with CRC screening from about 65% to 80%.
Colorectal cancer is an important public health problem—it’s the 4th most frequently diagnosed cancer in the US and the 2nd leading cause of cancer death—and screening is effective. Clinical trials of screening programs based on fecal blood testing and flexible sigmoidoscopy have shown significant albeit small absolute risk reductions for being diagnosed with and dying from CRC—though no overall mortality benefit. The good news is that CRC incidence and mortality have been steadily declining for decades. Interestingly, these trends were first observed before screening became widespread—suggesting the concomitant importance of improved treatment and reducing population risk factors.
The alliterative effort to boost CRC screening, though, could be problematic. Most gastroenterologists and primary care clinicians consider colonoscopy to be the best screening test and efforts to achieve the screening target will likely focus on colonoscopy. However, there is no direct evidence for the efficacy of colonoscopy and there is evidence that many people prefer to be screened with fecal blood tests. Furthermore, colonoscopies are expensive, require an onerous bowel preparation, and can cause complications such as bowel perforation and bleeding.
There are also important opportunity costs associated with colonoscopy and CRC screening. The lifetime risk of being diagnosed with CRC is only about 5%, meaning that screening for the remaining 95% of the population will not offer any benefit—just potential harms and costs. Efforts to increase CRC screening could divert limited health care resources that might be better allocated to more burdensome public health problems—smoking, obesity, or diabetes.
None of this nuance came through in stories and web articles such as these:
Rather than just promoting a message of more screening, media messages could help people think about screening smarter—a goal for health care to identify high-risk patients (those with a family history) who would have most to gain from screening. We should also ensure that patients with a previous history of pre-cancerous polyps get timely surveillance colonoscopies–polypectomy is associated with reducing the risks of CRC incidence and mortality.
Working towards a screening target also obscures the fact that cancer screening is a preference-sensitive decision. A well-informed patient, aware of the potential benefits and harms, could reasonably decline CRC screening. A more appropriate target for 2018 might be that 80% of US adults have had the opportunity to make an informed decision about CRC screening.
That would make a terrific public health and media campaign.
On a related topic, Dr. Richard Lehman recently wrote on his BMJ journal review blog:
“I am hardly the most ardent advocate of cancer screening, but I had come to think there might be a place for some kind of screening for colorectal neoplasia. Now I’m not so sure. Flexible sigmoidoscopy appears to have the best effectiveness, but this survival meta-analysis states that it took 9.4 years (7.6 to 11.3) to observe an absolute risk reduction of 0.001 (one colorectal cancer related death prevented for every 1000 flexible sigmoidoscopy screenings). Have a think whether that would persuade you to go and have one.”