ENDOMETRIAL CANCER SURVIVAL BETTER UNDER SPECIAL CARE

Women with high-risk endometrial cancer who were treated by gynecological oncologists had significantly better survival than patients not receiving such care, but the same study found that in the United States, only about 20% of women with endometrial cancer are treated by these specialists.
The findings are published online in the Journal of Clinical Oncology.
"The survival benefit associated with care by a gynecologic oncologist may be explained by their better understanding of the disease process, resulting in more accurate staging, followed by adjuvant treatment if indicated," the authors explain. However, they and an outside commentator point out that the superior survival could be attributed to a "stage migration" effect.
Deaths Are Increasing
The study is important, say the researchers, because the number of annual deaths from endometrial cancer has doubled over the past 20 years.
As far as they are aware, it is the first large population-based study to evaluate the influence of subspecialty care on patients with endometrial cancer.
The team, led by John Chan, MD, from the University of California San Francisco, analyzed data on 18,338 women with endometrial cancer from 1988 to 2005, obtained from the Medicare and Surveillance, Epidemiology and End Results (SEER) database.
They found that 21.4% of these women received care from gynecologic oncologists.
Compared with the remaining women, the women who received care from gynecologic oncologists were older, had more lymph nodes removed, presented with more advanced cancer (stages III to IV), had higher-grade tumors, and were more likely to receive chemotherapy for advanced disease.
They were also more likely to undergo staging procedures with lymph node assessment and to receive chemotherapy.
They showed significantly better survival rates for high-risk disease.
For women with stage II to IV disease who received care from a gynecologic oncologist, 5-year disease-specific survival was 79%, compared with 73% for women who didn't receive such care (P = .001). The difference was even greater for women with advanced-stage disease (stage III to IV), where the 5-year disease-specific survival was 72%, compared with 64% (P < .001).
However, there was no difference in survival rates for women with early, stage I and grade 1 cancers. All of them had "excellent" overall survival, the researchers note, with a 5-year disease-specific survival of 95%.
"This is an important paper, as it suggests that patients with more advanced endometrial cancer who are managed by gynecologic oncologists experience a superior outcome," said Maurie Markman MD, vice president of patient care services and national director for medical oncology at Cancer Treatment Centers for America, in Philadelphia, Pennsylvania.
"However, one must be cautious in the interpretation of the data, as 'stage migration' may be playing an important role," Dr. Markman added. This would have the effect of making it appear that patients with more advanced disease have a superior outcome when managed by a gynecologic oncologist, when in fact it is possible that the process of being seen by a gynecologic oncologist and undergoing a more extensive staging procedure results in patients being upstaged (e.g., from stage I to stage II or stage II to stage III), he explained.
The authors concur. In a subset analysis, they found that after adjusting for the effect of surgical staging in women with stage III disease, care by a gynecologic oncologist was no longer associated with an improvement in survival (84.6% vs 84.4%; P = .6).
"The result of this subset analysis suggests that the effect of gynecologic oncologist care may be partially attributed to the comprehensive staging procedures and subsequent guidance to appropriate therapy for improving survival," they write.
However, for women with stage III to IV disease, the benefit of gynecologic oncologist care might be associated not only with comprehensive surgical staging, but also with cytoreduction of metastatic disease, Dr. Chan and colleagues note. They found that, in a subset of 1689 stage IV patients, care from a gynecologic oncologist improved survival from 52% to 63%, suggesting that cytoreductive surgery might play a role in the survival advantage.
Another factor that might be at play is that care by a gynecologic oncologist might be associated with better screening and early detection of other malignancies, the authors suggest. They cite a previous study (Am J Obstet Gynecol. 2008;198:86.e1-86.e8), which found that patients with endometrial cancer who were cared for by gynecologic oncologists were more likely to receive mammography and colorectal cancer screening, compared with a matched group of women with no history of cancer cared for by primary care providers.
The authors have disclosed no relevant financial relationships. Dr. Markman reports serving as a director, officer, partner, employee, advisor, consultant, or trustee for Boehringer Ingelheim Pharmaceuticals, Genentech, Amgen, Celgene, and Hana Biosciences; and a as speaker or a member of a speakers bureau for Eli Lilly.