Health
Screening, tobacco control drive cancer declines
■ Referrals for mammograms and colonoscopies from a patient's medical home are found to boost follow-through.
By Susan J. Landers — Posted Dec. 29, 2008
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Washington -- Declining incidence and death rates for some of the nation's most common cancers mean physicians can take a deep breath, pat themselves on the back and keep up the good work.
It looks like increasing screening rates and encouraging patients to toss out the cigarettes are effective strategies, but more patients should be following through on both, according to the "Annual Report to the Nation on the Status of Cancer, 1975-2005."
The report, published online Nov. 25, 2008, and printed a week later in the Journal of the National Cancer Institute, found that, for the first time since the report was issued in 1998, trend lines went down for all cancers combined. These declines were driven by drops in some of the most common types of cancers -- including breast and colorectal, for which there are effective screening tests.
The report shows that incidence rates for all cancers decreased 0.8% per year from 1999 through 2005 for both sexes. Incidence rates decreased 1.8% per year for men from 2001 through 2005, and 0.6% per year for women from 1998 through 2005.
Death rates for all cancers also decreased an average of 1.8% per year from 2002 through 2005.
Celebration surrounded this good news, but so did a degree of wariness. "The drop in incidence seen in this year's annual report is something we've been waiting to see for a long time," said Otis W. Brawley, MD, chief medical officer of the American Cancer Society, one of the groups responsible for the report. The others were the Centers for Disease Control and Prevention, the National Cancer Institute and the North American Assn. of Central Cancer Registries. "[But] we have to be somewhat cautious about how we interpret it because changes in incidence can be caused not only by reductions in risk factors for cancer, but also by changes in screening practices."
For example, the reasons behind the 2.2% decline per year in breast cancer incidence rates from 1999 through 2005 could be good or bad. On the positive side, some speculate the drop is due to the rapid discontinuation of hormone replacement therapy. Conversely, though, that reduction could be an offshoot of the recent drop in the number of screening mammograms, meaning the cancer may be evading detection. Time and a watch over the breast cancer death rate will tell which it is. "We need to keep an eye on this," said Therese Bevers, MD, medical director for Clinical Cancer Prevention at the University of Texas M.D. Anderson Cancer Center in Houston.
"The bad news is that after going up for many years and then leveling off, mammogram screening has dropped since 2003," said Elizabeth Fontham, MPH, DrPH, president of the American Cancer Society.
The importance of a medical home
She urged physicians to continue to refer women for mammograms. These referrals play a crucial role. While 61% of women older than 40 receive them, that rate drops to 32% among those without a usual source of medical care, said Fontham, who also is dean of the Louisiana State University Health Sciences Center's School of Public Health. "That to me is a huge red flag about the importance of a medical home and continuity of care. The primary care physician is key to getting appropriate screening."
In addition, physicians should make sure patients are following through on these tests, said Dr. Bevers. Many radiology facilities no longer offer mammograms because of low or nonexistent profit margins and high liability risks. "Women may call, find that the facility isn't doing it anymore, may not find another facility and miss their mammogram."
Physicians also should continue to encourage patients to receive screening colonoscopies, added Dr. Bevers. Their benefit may be seen in the dropping incidence rate for colorectal cancer -- a decline of 2.8% per year among men and 2.2% per year among women from 1998 to 2005.
"This report demonstrates the importance of colorectal cancer screening beginning at age 50," said John L. Petrini, MD, president of the American Society for Gastrointestinal Endoscopy. "While we are encouraged by this excellent news, far too few people are getting screened."
As is the case for mammograms, a medical home is an important driver for colonoscopies, said Fontham. Only about 26% of people without a medical home receive them, compared with 56% of those referred by their primary care physicians, she added.
The report, which also includes a section on tobacco use and lung cancer, found substantial differences in death rates by state and geographic region. Lung cancer deaths among men declined an average of 2.8% per year from 1996 through 2005 in California, which enacted a smoking ban in 1998. This amount was more than twice the drop seen in Midwest and Southern states that have no bans, according to the report.
Tobacco control remains the only way to continue to achieve these reductions, noted Dr. Bevers. Although no lung cancer screening tests currently exist, results from ongoing trials are expected in about a year.
Meanwhile, counseling patients to quit smoking and offering them assistance has been found to work, said Dr. Bevers. Many medical groups, including the American Medical Association, favor aggressively pursuing all avenues of educating patients and the general public on tobacco's harms and offering patients counseling and medications to help.
Dr. Bevers suggested doctors get involved in efforts to enact smoking bans. "In Texas, we tried it in the last legislative session." Although that effort failed, "we will try again."