Researchers Say More Cancers Are Being Detected Early or Prevented Through Screening
WebMD Health News
Reviewed By Louise Chang, MD
Dec. 7, 2009 -- New cancer cases and the cancer death rate continue to fall in the U.S., driven largely by declines in lung, prostate, and colorectal cancers in men and breast and colorectal cancers in women.
For all types of cancer, new cases declined by nearly 1% a year between 1999 and 2006. During much of the 1990s cancer incidence rates were stable, after increasing steadily from the mid-1970s.
The cancer death rate -- the best predictor of progress against the disease -- has been falling for more than a decade and a half. Deaths from cancer declined by about 1% annually between 1993 and 2001 and 1.6% annually from 2002 to 2006.
Fewer Americans are smoking and more cancers are being detected early or prevented entirely through screening.
These two trends have played a big part in reducing cancer deaths in the U. S., experts say.
"We continue to make progress in the battle against cancer, and this progress is reflected in the continued decline in deaths," Elizabeth Ward, PhD, of the American Cancer Society tells WebMD.
Breast, Colon, and Prostate Cancer Deaths Fall
The annual report examining cancer incidence and cancer death trends in the U.S. is a joint effort by the CDC, the National Cancer Institute, the American Cancer Society, and the North American Association of Central Cancer Registries.
Among the major findings:
- The overall cancer incidence continues to be higher for men than for women, but men experienced the greatest declines in new cases and deaths.
- New cases declined for the three leading cancers in men -- prostate, lung, and colorectal cancer -- as well as for brain cancer, stomach cancer, and cancer of the oral cavity. No change was seen in the rate of pancreatic cancer and non-Hodgkin's lymphoma and increases were reported for cancers of the brain, esophagus, kidney, and liver and for melanoma and myeloma.
- Among women, declines were reported for two of the three most widely diagnosed cancers: breast and colorectal. New cases of lung cancer rose slightly.
- For men and women, death rates declined for colorectal, stomach, kidney, and brain cancers, as well as for leukemia, non-Hodgkin's lymphoma, and myeloma. Lung cancer death rates dropped by 2% annually among men and remained unchanged for women.
- Deaths from prostate cancer fell by about 4% annually between 2001 and 2006 and deaths from breast cancer fell by almost 2% a year during the same period.
"The continued decline in death rates from all cancers combined for men and women reflects the impact of increased screening, reduction of risk factors, and improved treatment," the report notes.
While the death rate from cancer continues to fall, the actual number of Americans who die from the disease is projected to rise in coming years as the population increases and baby boomers reach the high-risk age for cancer.
Screening Spurs Decline in Colorectal Cancer
The report included a special section on colorectal cancer, which is the third most frequently diagnosed malignancy in both men and women in the U.S. Deaths from colorectal cancer have been declining since the mid-1980s in men and the mid-1970s in women. For both sexes, the rate of decline accelerated beginning early in the current decade.
Improved screening is largely responsible for the decline, Brenda K. Edwards, PhD, of the National Cancer Institute tells WebMD.
Based on a model they developed, Edwards and colleagues predicted that colorectal cancer deaths could drop by another 50% over the next decade.
The projection assumes lifestyle factors like smoking rates will continue to decline and more Americans will be screened for colorectal cancer, and better results from cancer treatment.
"The model is a bit ambitious, but we think this rate of decline is achievable," she says.
Smoking, exercising, and a diet high in red meat are all believed to be risk factors for colorectal cancer.
Cleveland Clinic colorectal cancer surgeon James Church, MD, agrees that increased screening would result in dramatic further reductions in colorectal cancer deaths.
"Colorectal cancer is preventable," he tells WebMD. "Every colorectal cancer starts off as a polyp, so if we find polyps early and take them out we prevent cancer from happening."
Church says as many as 85% of colorectal cancers could be prevented if everyone who was eligible for screening actually got screened.
Screening is recommended beginning at age 50 for most people. Those with risk factors for the cancer or a family history of the disease may need to be screened earlier.
"The average lifetime risk for colorectal cancer in the U.S. is about 6%," Church says. "The risk doubles for someone with a mom or dad who had the disease and it is four times higher when a parent is diagnosed at a young age."
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SOURCES: "Annual Report to the Nation on the Status of Cancer, 1975-2006," CDC, NCI, ACS and the NAACCR, Cancer, Dec. 7, 2009; online edition.
Brenda K. Edwards, PhD, associate director of surveillance research program, National Cancer Institute, Bethesda, Md.
Elizabeth Ward, PhD, vice president for surveillance and health policy research, American Cancer Institute, Atlanta.
James Church, MD, colorectal cancer surgeon, Cleveland Clinic, Ohio.
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