MONDAY, Dec. 27, 2004 (HealthDayNews) -- People who have cancer surgery at facilities designated by the U.S. government as "centers of excellence" are less likely to die soon after the operation. But their long-term survival rates are no better than patients who are treated at hospitals without the designation, a new study finds.
The study, appearing in the Feb. 1, 2005, issue of the journal Cancer, found a lower rate of mortality associated with the surgery at these centers, but no difference in survival at five years. The research is the first to provide a comparison of these variables.
"We were very surprised," said study lead author Nancy J.O. Birkmeyer, associate professor of surgery at the University of Michigan Medical School in Ann Arbor. "Our hypothesis had been that the centers of excellence would do better because they have a greater concentration of specialists, and that this would show up in long-term mortality. But all of the action was in postoperative mortality, indicating that the safety of procedures was better but not really the effectiveness."
The National Cancer Institute (NCI) started awarding regional "center of excellence" designations in 1971 to facilities that demonstrated superiority in research, cancer prevention and clinical services. Many of these hospitals promote this designation, not unlike products that boast a Good Housekeeping seal of approval.
According to the study, these centers are well-staffed with specialists and do a high volume of procedures, factors that are usually associated with better outcomes. The centers may also be on the cutting edge of new therapies.
Birkmeyer and her colleagues compared the outcomes of Medicare patients undergoing surgery for lung, esophageal, gastric, pancreatic, bladder, or colon cancer. All of these procedures are relatively complex and have high surgical mortality rates.
Between 1994 and 1999, 27,021 patients underwent one of the procedures at 51 NCI cancer centers, while 36,839 people had the procedures at 51 control hospitals with the highest volumes for each procedure. This represented 12.8 percent of the Medicare population undergoing these procedures during that time frame, the study authors said.
Surgical mortality rates were significantly lower at the NCI centers of excellence for four of the six procedures -- colon (5.4 vs. 6.7 percent), lung (6.3 vs. 7.9 percent), gastric (8 vs. 12.2 percent), and esophageal (7.9 vs. 10.9 percent). Death rates were also lower at NCI centers for bladder and pancreatic cancer, but not significantly so.
"For some reason, the procedures are done more safely, and it probably is related not to hospital volume but to surgeon volume and specialization," Birkmeyer speculated.
Five-year mortality rates, on the other hand, were no different between the two types of institutions for any of the procedures, the study found.
The bottom line, said the authors, is that patients should be less concerned with a center's "excellence" designation than with other issues like hospital volume, surgeon volume, and subspecialty training.
The NCI acknowledged that there had been no head-to-head comparisons of cancer centers and high volume hospitals, but also pointed out some limitations to the new study.
"This is a great first look, but there are clearly some problems," said Linda Harlan, an epidemiologist with the NCI's applied research program.
For one thing, she said, the study didn't factor in the stage of the cancer, which can affect survival rates. Racial differences also were not taken into account. "The proportion of blacks is higher in the cancer centers," she said. "And we also know, unfortunately, when we look at five-year survival it's worse, stage-for-stage, in non-Hispanic blacks," Harlan said.
Harlan said the next step is to do an analysis with more specific information. "We have a lot of information that is patient-level and linked to Medicare data," she said. "We're going to look at that."
For more on the centers of excellence program, visit the National Cancer Institute.