In the US, many cancer patients in advanced stages of the disease and a life expectancy of only a few years still undergo common cancer screening tests that are unlikely to benefit them, said researchers, who suggested policymakers and health professionals should consider ways to stop such patients being summoned unnecessarily for cancer screening.

A paper on the findings was published online in the 13 October issue of JAMA, the Journal of the American Medical Association. The lead author was Dr Camelia S. Sima, of Memorial Sloan-Kettering Cancer Center in New York.

Cancer screening programs such as colonoscopy, mammography, Pap test and PSA (prostate-specific antigen), have made a significant contribution to reducing cancer deaths, and while the benefits of such programs to most people are compelling, their value is less clear for patients who are already ill and have severely limited life expectancy.

In the US, the current guidelines do not directly address whether patients in advanced stages of cancer should still be offered or undergo screening.

“In the extreme situation of patients with advanced cancer, screening will lead to over diagnosis (detection of a cancer which, if not found by active search, would not affect survival) in virtually all cases when a new malignancy is found,” wrote the authors.

Plus, patients may be subject to unnecessary risks from further invasive testing such as biopsies, and may experience unnecessary psychological distress, they added.

For the study, Sima and colleagues examined data on 87,736 fee-for-service Medicare enrollees aged 65 and older diagnosed with advanced breast, lung, colorectal, pancreatic and gastroesophageal cancer between 1998 and 2005 whose cancer was reported to one of the SEER (Surveillance, Epidemiology, and End Results) registries.

SEER collects information on cancer from specific geographic areas representing 28 percent of the US population.

The study followed patients until December 2007 or death, whichever came first, in order to count Medicare charges and screening rates.

For comparison, the researchers created a control group from another 87,307 Medicare enrollees without cancer and matched them individually to the cancer group by age, sex, race, and area of residence.

The control group was also followed over the same period so that rates of screening were obtained in context.

The researchers found that:

  • 8.9 per cent of the women with advanced cancer received at least 1 screening mammogram compared to 22.0 per cent of women without cancer (the controls).
  • For the Pap test, these figures were 5.8 per cent of women with advanced cancer compared to 12.5 per cent of women without cancer.
  • 15.0 per cent of the men with advanced cancer received PSA testing compared with 27.2 per cent without cancer.
  • 1.7 per cent of male and female patients with advanced cancer received lower gastrointestinal endoscopy compared with 4.7 per cent of controls.
  • Screening was also more frequent among patients with a recent history of screening and the strongest predictor of screening among advanced cancer patients was having had a screening test before diagnosis.
  • For each type of test, being married and having a higher socioeconomic status increased the likelihood of being screened.

The researchers concluded that:

“A sizeable proportion of patients with advanced cancer continue to undergo cancer screening tests that do not have a meaningful likelihood of providing benefit.”

They suggest that the most plausible explanation is that efforts to persuade people to undergo cancer screening “have led to deeply ingrained habits”.

“Patients and their health care practitioners accustomed to obtaining screening tests at regular intervals continue to do so even when the benefits have been rendered futile in the face of competing risk from advanced cancer,” they wrote.

They said their findings have several implications for health policymakers.

First, making people more aware of the questionable benefits of undergoing screening when a person is already in an advanced state of a disease and facing limited life expectancy “may in and of itself limit use”.

Second, as more and more sophisticated computer systems are used to keep track of what is happening with each person’s health and illnesses, then it should not be difficult to adjust screening reminder systems to flag up a need to re-evaluate or cease sending reminders to people who are unlikely to benefit from testing.

Another way would be for Medicare not to provide insurance cover for cancer screening for advanced cancer patients with less than 2 years of life expectancy.

Dr Therese Bevers, who is medical director of the Cancer Prevention Center at MD Anderson Cancer Center in Houston, Texas, said in a telephone interview reported by Reuters press agency that cancer patients who are facing less than 10 years life expectancy are not likely to benefit from this kind of screening.

Bevers, who was not involved in the study, said it was not just about saving money, she was also concerned for the patients:

“Do we need to be putting them through this if they are not going to benefit from it?” she asked.

“Cancer Screening Among Patients With Advanced Cancer.”
Camelia S. Sima; Katherine S. Panageas; Deborah Schrag.
JAMA, Vol 304, No 14, pp 1584-1591, Published online 13 October 2010.
DOI:10.1001/jama.2010.1449

Sources: JAMA and Archives Journals, Reuters.

Written by: Catharine Paddock, PhD