Prostate, Colorectal Screening Rates Affected by Numerous Factors
It's been more than 4 years since Today Show co-host Katie Couric attempted to stamp the importance of colorectal cancer screening onto the national psyche by undergoing a colonoscopy live on the air. In the weeks and months that followed, colon cancer screenings increased dramatically, at least according to one study of the "Katie Couric Effect" published in the Archives of Internal Medicine.
Four years later, although screening rates in people 50 and over (the recommended age for screening) have shown measured improvement, there still is a significant shortfall in the number of men and women who should be screened but haven't been. That trend comes in perplexing contrast to prostate-specific antigen (PSA) screening for prostate cancer, which has seen substantial growth despite a lack of evidence from controlled clinical trials that screening saves lives and concerns about adverse consequences of treatment for a disease that may never have manifested in the absence of screening, nor become life-threatening. Last week at the fourth annual Translating Research into Practice conference in Washington, D.C., experts came together to discuss why there is this curious contradiction of PSA and colorectal cancer screening practices in the United States.
In a study published in the March 2003 Journal of the American Medical Association, for example, researchers from the VA Outcomes Group in Vermont assessed the results of a 2001 Centers for Disease Control and Prevention survey and found that 75 percent of men 50 and over reported having had a PSA test, while only 63 percent reported having ever been screened for colorectal cancer by any of the five available modalities. Up-to-date prostate cancer screening was also higher than for colorectal cancer screening, including men over 80 years old, for whom screening is considered to be of little if any benefit. Meanwhile, Dr. Michael Barry of Massachusetts General Hospital presented a recent unpublished survey that found that 95 percent of urologists and 87 percent of general and family practitioners supported PSA testing for asymptomatic men, and 95 percent of urologists and 78 percent of general and family practitioners had a PSA test themselves.
These results reinforce another important point, says Dr. Jon Kerner, deputy director for Research Dissemination and Diffusion in the NCI Division of Cancer Control and Population Sciences: What practitioners do for themselves often indicates what they'll recommend to their patients. "It's understandable that practitioners who practice a behavior themselves are more likely to believe in it and will translate that practice into their recommendations to patients," Dr. Kerner says.
A communication gap between physicians and patients may explain part of the problem, said Dr. Michael Pignone, of the University of North Carolina. For example, in a 2002 survey of nearly 1,100 people conducted by the Cancer Research Foundation of America, only 52 percent of respondents 50 or older reported having been advised by their physicians to get an endoscopic exam for colorectal cancer screening. Other factors such as a lack of an appropriate information system infrastructure and inadequate access to care may also play a role.
Patients' role in this phenomenon - including their fear of the more invasive colorectal cancer screening modalities - cannot be discounted, argued Dr. Steven Woolf, of Virginia Commonwealth University. The male patients he sees typically do not hesitate to agree to PSA screening, a simple blood test. But it's often a different story with colorectal cancer screening. "I emphasize that all national guidelines recommend screening starting at 50 and that they can choose which tests they prefer," Dr. Woolf recounted. "And they say, 'I'll think about it.' I think that reflects where patients are right now.
"The contrast between patient uptake of prostate and colorectal cancer screening, Dr. Kerner explains, also highlights the importance of implementing a better "wholesale approach" to educating health care providers and patients. The CEO Cancer Gold Standard initiative recently launched by C-Change (see June 1 NCI Cancer Bulletin), in which leaders from some of the nation's largest corporations pledged to add cancer screening and prevention measures to their employees' health benefits, is a good example. "When you get companies to adopt those types of benefits, that's a 'wholesale' approach, because it addresses system barriers to appropriate screening and creates a supportive environment to get it done," Dr. Kerner says. "We need to better understand how to affect these wholesale systems to complement what we're trying to accomplish at the individual ('retail') patient level."