August 19, 2014
News Review From Harvard Medical School -- Many Get Cancer Screening at Advanced Ages
Many older adults who are unlikely to live more than 10 years still are given routine screening tests for cancer, new studies show. But those tests are unlikely to help them and may have risks, the authors say. One study used 10 years of data from a U.S. government health survey. It included 27,000 men and women ages 65 and older. Based on their health history, the authors estimated their risk of dying in less than 10 years. Among men at the highest risk of near-term death, 31% to 55% received screening tests for various types of cancer. A second story focused on screening for colon cancer in adults 65 or older. It was based on Medicare records. About 1 in 5 of those who had a colonoscopy that found no problems ended up having another colonoscopy 5 years later. This test is recommended every 10 years. About 1 in 4 older adults who had a screening colonoscopy at age 75 or older was given a repeat test years later. Current guidelines say screening colonoscopy is not needed after age 75. The journal JAMA Internal Medicine published the studies. HealthDay News wrote about them August 18.
By Howard LeWine, M.D.
Harvard Medical School
What Is the Doctor's Reaction?
Screening for cancer has been heavily promoted as an important part of staying healthy. The public health messages never state the risks or costs of screening. So it's widely believed that cancer screening is always a good thing.
Two new articles add to the growing evidence that cancer screening should not be routine for everyone. And it can be harmful, especially in older folks. The articles appear in this week's journal JAMA Internal Medicine.
Guidelines from well-respected health organizations often include ages when screening should stop. Despite the evidence, that advice has often been ignored.
Besides the potential risks of further tests and treatments, the costs of cancer screening can be misleading. For example, the PSA (prostate-specific antigen) blood test to detect early prostate cancer is indeed low-cost. But an abnormally high PSA often means that men have expensive biopsies. If prostate cancer is found, many may have even more costly cancer treatment. Quite often, the cancer treated would not have shortened their lives.
Even the value of breast cancer screening for women at average risk of the disease is being questioned. A mammogram costs a bit more than PSA screening in men. But, similar to PSA testing, it's the large number of further tests, biopsies and surgeries that really run up the cost.
One of these new studies showed that screenings for breast, cervical, prostate and colorectal cancer were often done in people with life expectancy of fewer than 10 years. Cancer screening in people with limited life expectancy rarely translates into improved survival. And those extra months or years almost never lead to better quality of life.
The other study focused on the large number of colonoscopies that did not follow current guidelines. The data included:
- Colonoscopies ordered on people over age 75
- Repeat colonoscopies sooner than every 10 years, the recommended interval for people with a previous normal test
What Changes Can I Make Now?
Current guidelines suggest the following:
- Stop routine Pap smears to screen for cervical cancer at age 65 if Pap smears have been negative in the past.
- Stop routine screening mammography for women at average risk of breast cancer after age 75.
- Stop screening colonoscopies for adults at average risk of colorectal cancer at age 75.
- Stop all routine screening with PSA for men at average risk of prostate cancer.
Experts realize that cancer screening advice based on age alone is too arbitrary. That is why many experts suggest doctors consider a person's life expectancy. If it is less than 10 years, screening is unlikely to improve survival and quality of life. And usually the risks are greater than the benefits.
But estimating life expectancy is very difficult. Therefore, doctors are reluctant to make what amounts to a guess for many patients.
Instead, cancer screening should be a mutually shared decision, with the patient well informed of the risks. That includes the risks of the test. But it also should include the risks of what may happen if a test does suggest there may be a cancer -- one that won't shorten the patient's life.
What Can I Expect Looking to the Future?
We should focus less on cancer screening. What's more important is cancer prevention. Here's what you can do:
- Stay physically active and spend at least 150 minutes per week on moderate-intensity exercise.
- Maintain a healthy weight.
- Don't smoke or use other tobacco products.
- Either avoid alcohol or drink moderately. This means an average of no more than one alcoholic drink per day for women or no more than two per day for men.
- Eat a diet rich in fruits, vegetables and whole grains.