TUESDAY, May 25, 2004 (HealthDayNews) -- It might seem obvious that the outlook for someone with cancer will be influenced by other medical problems the patient may have, but a new study says most cancer doctors don't pay attention to that possibility.
"As simple and as straightforward as it sounds, a number of my colleagues have never heard of this concept of comorbidity," said Dr. Jay F. Piccirillo, an associate professor of otolaryngology and medicine at the Washington University School of Medicine in St. Louis.
Piccirillo is one of a relatively small number of researchers who are working to have doctors make a routine assessment of comorbidity -- the medical term for an illness found in a patient already diagnosed with another illness.
Piccirillo's work focuses on cancer patients.
His latest effort is a report in the May 26 issue of the Journal of the American Medical Association, in which he and some colleagues show comorbidity can have a significant effect on many different kinds of cancer.
The study included more than 17,700 patients with a wide range of cancers, including prostate, breast, lung, head and neck, and gynecological tumors.
"Severity of comorbidity strongly influenced survival in a dose-dependent fashion, and the impact of comorbidity was independent of cancer stage," the study said. It included data on 27 serious illnesses, such as heart failure, diabetes and kidney disease.
In general, the impact of other illnesses was greatest in "those cancers that are least lethal," Piccirillo said. For example, comorbidity was an important predictor of outcome for men with prostate cancer, where the survival rate is high. But lung cancer, where the median survival time is six months, "is so lethal that comorbidity doesn't make a difference," he said.
For some cancers, comorbidity can influence treatment, Piccirillo said. For example, a doctor may choose radiation therapy rather than surgery for a patient with a severe illness, such as heart failure.
William A. Satariano is a professor of epidemiology at the University of California, Berkeley, School of Public Health. "The report makes a convincing case that information on comorbidity should be collected as part of regular cancer surveillance," he said.
One problem is that different illnesses can affect the health of different patients in different ways. "There is no opinion about the best way to summarize the situation. We certainly need some standardization in this area," said Satariano, who is also a member of a group recently created by the National Institute on Aging to examine the issue of comorbidity.
Steps to have cancer specialists consider comorbidity are being taken in the United States and abroad, he said. The British National Health Service has told doctors to consider the issue patient by patient. In the United States, the Commission on Cancer, a consortium of 40 medical organizations organized by the American College of Surgeons, has mandated that information on comorbidity be included in all hospitalizations.
Still, standard reference books on cancer list projected survival times only on the basis of the size and site of a tumor, with no reference to comorbidity, Piccirillo said.
"We are working on a computer program that will incorporate comorbidity" into treatment regimens, Piccirillo said. The hope is the program will be available to all physicians within nine months.
For more on comorbidity and cancer, visit Washington University School of Medicine.