A study has found a lower mortality rate (death following an operation) for cancer patients having surgery at facilities designated by the US government as "centers of excellence" than patients who are treated elsewhere. However, the study did not find any difference in survival at five years. The research is the first to provide a comparison of these variables.
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 the NCI's designation.
According to the study, these centers are well-staffed with specialists and perform 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.
Researchers at the University of Michigan Medical School in Ann Arbor compared the outcomes of Medicare patients who were 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 had one of the procedures at 51 NCI cancer centers, while 36,839 people had one of the procedures at 51 control hospitals. The control hospitals were chosen because they performed the greatest number of each procedure.
Surgical mortality rates were lower at the NCI centers of excellence compared with the control hospitals for four of the six procedures-colon (5.4% vs. 6.7%), lung (6.3% vs. 7.9%), gastric (8% vs. 12.2% and esophageal (7.9% vs. 10.9%). These rates were also lower at NCI centers for bladder and pancreatic cancer but not significantly.
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.
"'We were very surprised," says lead author of the study, Nancy J.O. Birkmeyer, associate professor of surgery at the University of Michigan Medical School. "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."
"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 speculates.
The study authors say patients should not be overly concerned with a center's designation. Instead, they should pay attention to other issues, such as hospital volume, surgeon volume and subspecialty training.
The NCI acknowledges that there had been no head-to-head comparisons of cancer centers and high-volume hospitals, but it also points out some limitations of the new study.
"This is a great first look, but there are clearly some problems," states Linda Harlan, an epidemiologist working with the NCI's applied research program.
One problem, she says, is that the study did not factor in the stage of the cancer, which can affect survival rates. More research is needed, Harlan adds.