Cancer screening unlikely to benefit patients with a short life expectancy

January 8, 2013, British Medical Journal

Breast and colorectal cancer screening should be targeted towards patients with a life expectancy greater than 10 years: for any shorter life expectancy the harms are likely to outweigh the benefits, concludes a study published in BMJ today.

The authors that their results "should not be used to deny screening for with limited life expectancy" but "should inform which aims to account for patient preferences and values while maximising benefits and minimising risks."

Guidelines recommend screening healthy older patients because complications from screening can harm patients immediately while the benefits of screening are not seen for many years.

What still remains unclear, however, is how long a patient needs to live to benefit from . Previous trials have focused on the size of benefit rather than when those benefits occur.

Researchers from the University of California in San Francisco therefore analysed the results of five breast and four colorectal cancer screening trials focusing on patients aged over 50.

Their goal was to estimate the time-lag to benefit (the time between screening and when the benefits of screening are seen) to determine whether an individual patient is likely to benefit from screening.

The trials were published between 1986 and 2008 and ranged in size from just under 40,000 people to just over 150,000 people. Follow-up ranged from 8-20 years.

Results showed that at five years, an average 2.8 colorectal cancer deaths were prevented for every 10,000 people screened. This benefit steadily increased with longer follow-up, reaching 23 colorectal cancer deaths prevented for every 10,000 people screened at 15 years.

In absolute terms, it took an average of 4.8 years to prevent one colorectal cancer death for 5,000 people screened and 10.3 years to prevent one death for 1,000 people screened.

For breast cancer, at five years an average of 5.1 deaths were prevented for every 10,000 women screened. By 15 years, this mortality benefit had increased to 19 breast cancer deaths prevented for every 10,000 women screened.

In absolute terms, it took an average of three years to prevent one breast for 5.000 women screened and 10.7 years to prevent one death for 1,000 women screened.

However, the researchers say that in both colorectal and breast cancer, approximately one in ten people screened will have a false positive result and many more will be subject to possibly unnecessary treatment.

Based on these results, they suggest that patients with a life expectancy greater than ten years "should be encouraged to undergo colorectal and screening" but patients whose is 3-5 years "probably should be discouraged from screening since the potential risks likely outweigh the very small probability of benefit."

They conclude that incorporating time lag estimates into screening guidelines "would encourage a more explicit consideration of the risks and benefits of breast and screening, likely resulting in a more individualised decision making process for the heterogeneous population of older adults."

Explore further: Study finds mammography screening reduces breast cancer mortality

More information: Time-lag to benefit after screening for breast and colorectal cancer: meta-analysis of survival data from the United States, Sweden, United Kingdom and Denmark, BMJ, 2013.

Related Stories

Study finds mammography screening reduces breast cancer mortality

June 28, 2011
Breast cancer screening with mammography results in a significant reduction in breast cancer mortality, according to long-term follow-up results of a large-scale Swedish trial. The results are published online in the journal ...

ACP releases new colorectal cancer screening guidance statement

March 5, 2012
The American College of Physicians (ACP) today issued a new guidance statement for colorectal cancer screening. Colorectal cancer is the second leading cause of cancer-related deaths for men and women in the United States. ...

Depression affected preventive health screening among Latina breast cancer survivors

September 19, 2011
Depression, in addition to other barriers, may prevent Latina breast cancer survivors from undergoing preventive health screening for colorectal and ovarian cancer, according to data presented at the Fourth AACR Conference ...

New study supports claim that breast screening may be causing more harm than good

December 9, 2011
A new study published on bmj.com today supports the claim that the introduction of breast cancer screening in the UK may have caused more harm than good.

Too many americans skipping colon cancer screening

March 2, 2012
(HealthDay) -- Approximately one in three U.S. adults between the ages of 50 and 75 who should be screened for colorectal cancer have not been, according to the American Society for Gastrointestinal Endoscopy.

Recommended for you

How cancer metastasis happens: Researchers reveal a key mechanism

January 18, 2018
Cancer metastasis, the migration of cells from a primary tumor to form distant tumors in the body, can be triggered by a chronic leakage of DNA within tumor cells, according to a team led by Weill Cornell Medicine and Memorial ...

Modular gene enhancer promotes leukemia and regulates effectiveness of chemotherapy

January 18, 2018
Every day, billions of new blood cells are generated in the bone marrow. The gene Myc is known to play an important role in this process, and is also known to play a role in cancer. Scientists from the German Cancer Research ...

These foods may up your odds for colon cancer

January 18, 2018
(HealthDay)—Chowing down on red meat, white bread and sugar-laden drinks might increase your long-term risk of colon cancer, a new study suggests.

The pill lowers ovarian cancer risk, even for smokers

January 18, 2018
(HealthDay)—It's known that use of the birth control pill is tied to lower odds for ovarian cancer, but new research shows the benefit extends to smokers or women who are obese.

Researchers develop swallowable test to detect pre-cancerous Barrett's esophagus

January 17, 2018
Investigators at Case Western Reserve University School of Medicine and University Hospitals Cleveland Medical Center have developed a simple, swallowable test for early detection of Barrett's esophagus that offers promise ...

Scientists zoom in to watch DNA code being read

January 17, 2018
Scientists have unveiled incredible images of how the DNA code is read and interpreted—revealing new detail about one of the fundamental processes of life.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.