Patients diagnosed with terminal cancer continue screenings for common cancers even though there is no benefit likely to be gained from these tests.

Researchers from the Memorial Sloan-Kettering Cancer Center in New York City found these screen tests, which include mammograms or blood tests for prostate cancer, do more harm than good by exposing patients to the fear of being diagnosed with a new type of cancer and expose them to unnecessary risks.

"For patients living with advanced cancer, cancer screening should not be a routine procedure," lead researcher and assistant attending biostatistician, Dr. Camelia S. Sima, said.

"Patients living with advanced malignancies and their doctors should engage in a realistic conversation about the risks and benefits associated with cancer screening in [the] face of a severely limited life expectancy," she added.

The team of researchers analyzed data of people of 65 years and older who were enrolled in the federal health insurance program for the elderly, Medicare, and were diagnosed with advanced lung, colorectal, pancreatic and other cancers.

Results of the control group were compared to Medicare patients of the same age, sex and race who did not have cancer to determine the usefulness of screening tests, which included mammograms, Pap tests for cervical cancer, prostate-specific antigen, or PSA tests, and colonoscopies.

The scientists concluded that 8.9 percent of women with advanced cancer had a mammogram, compared with 22 percent of those without cancer; and 5.8 percent of the cancer patients had a Pap test, compared with 12.5 percent of those without cancer.

Among men, 15 percent of those with advanced cancer had a PSA test for prostate cancer, compared with 27.2 percent of those without cancer.

Many cancer patients do screening tests automatically without considering whether they will actually dothem any good.

According to Sima, "Screening guidelines could be reassessed to address the appropriateness of screening for patients whose very limited life expectancy due to advanced cancer negates any potential benefit that may be derived."