BOSTON. - Gynecologic oncologists delivered better care and achieved superior results than did general surgeons when treating ovarian cancer.
However, the volume of procedures performed at a particular hospital or by an individual surgeon did not affect outcomes of ovarian cancer surgery, according to a related study. Both were reported in the Feb. 1 issue of the Journal of the National Cancer Institute.
The latter finding contrasts with previous research suggesting that outcomes for other types of cancer are better with high-volume hospitals and surgeons, especially for high-risk operations such as pancreatectomy and esophagectomy, said Craig C. Earle, M.D., of the Dana-Farber Cancer Center here, and Deborah Schrag, M.D, of the Memorial Sloan-Kettering Cancer Center in New York, and colleagues.
Both studies focused on nearly 3,000 patients who had surgery for primary epithelial ovarian cancer from 1992 through 1999, as identified in the Surveillance, Epidemiology, and End Results (SEER) database. Five states and six metropolitan areas were represented in the data.
The first study, led by Dr. Earle, examined the relationship between surgery outcomes and the specialty or subspecialty training of the surgeons. The investigators reported:
* At 30 days post-surgery, the mortality rates were 2.1% for patients treated by gynecologic oncologists, 2.1% for patients treated by general gynecologic surgeons, and 4% for patients treated by general surgeons (P=.01).
* At 60 days post-surgery, the mortality rates were 5.4% for patients treated by gynecologic oncologists, 6.4% for patients treated by general gynecologic surgeons, and 12.3% for patients treated by general surgeons (P<0.001).
* Median survival time was about 32 months for patients treated by gynecologic oncologists, compared with about 35 months for patients treated by general gynecologic surgeons, and 24 months for patients treated by general surgeons (P<.001).
* Patients treated by gynecologic oncologists had a reduced risk of all-cause mortality compared with patients operated on by a general surgeon (hazard ratio=0.85; 95% CI=0.76-0.95). However, cancer stage was the strongest predictor of mortality.
Gynecologic oncologists provided superior quality of care, Dr. Earle and colleagues concluded. "Specifically, gynecologic oncologists were more likely than general gynecologists and general surgeons to perform appropriately aggressive surgery and to provide indicated postoperative chemotherapy and less likely to perform generally unnecessary procedures, such as second-look laparotomies," they wrote.
"Our data support professional societies' recommendations that it is preferable for ovarian cancer patients to be operated on by gynecologic oncologists when possible," they concluded.
The second study, led by Dr. Schrag, found little evidence to support a connection between volume of procedures performed and outcomes.
Initially, two-year mortality rates appeared to be better in patients treated by high-volume hospitals and surgeons, she reported For example, the rate was about 45% at low-volume hospitals compared with about 37% at high-volume hospitals (P=.011).
However, after adjusting for differences in case mix, "neither hospital volume (P=.031) nor surgeon volume (P=.062) was strongly associated with overall survival," Dr. Schrag and colleagues concluded.
In an editorial, Joseph Lipscomb, Ph.D., of Emory University in Atlanta, stopped short of concurring with the recommendation that ovarian cancer be treated by gynecologic oncologists whenever possible, but he said the data showed that "gynecologic oncologists appeared to be delivering a different brand of cancer care from that of other types of surgeons."
Further study is needed to tease out all the factors contributing to ovarian cancer surgery outcomes, Dr. Lipscomb said. "Building on the example set by these ovarian cancer analyses, there should be simultaneous consideration of institutional case volume, physician case volume, physician specialty, the processes of care selected, and the outcomes achieved, while controlling for case-mix and other exogenous factors," he concluded.