CAVEATS: Study sample and HRT use could affect outcome
The average age of patients in the treatment (oophorectomy) arm was higher than that of patients in the control group; the women in the treatment group were older at the time of hysterectomy (46.8 vs 43.3 years), as well. This should not bias the results, which were adjusted by age and many other variables.
Nonrepresentative sample. This group of nurses is not representative of the general population in several important aspects, including socioeconomic status, educational level, and race (94% Caucasian). This may limit the generalizability of the findings.
Study design. The observational design and the fact that the patients themselves decided whether or not to undergo oophorectomy also raise the possibility of unmeasured confounding factors.
Cancer risk. Women with known BRCA mutations were not studied separately, but the results were adjusted for family history of breast or ovarian cancer. The authors stated that a subgroup analysis of women with a family history of ovarian cancer had similar outcomes, although the data were not included
HRT use. As might be expected, patients in the oophorectomy arm of the study were more likely to use HRT. Since the completion of the study in 2000, practice recommendations have shifted against combined HRT use. Unopposed estrogen, which is not thought to increase the incidence of cardiovascular disease, remains a treatment option for women who have undergone hysterectomy and oophorectomy. But the overall effect of unopposed estrogen on survival is still uncertain.4 It is unclear how the recent decline in the use of exogenous hormones would affect these results.
BARRIERS TO IMPLEMENTATION: FP-GYN communication can be difficult
This study provides important information for primary care physicians to discuss with female patients and their gynecologists. However, some doctors may not have relationships with the gynecologists in their community, or have limited (or no) influence or input into which specialists their patients see. In addition, some gynecologists may hesitate to perform hysterectomy without oophorectomy in some cases for technical reasons.10
Concern about prevention of ovarian cancer must be balanced with increased risk of mortality and CHD events. It may be helpful to tell patients who are about to undergo hysterectomy for a benign condition that women are nearly 30 times more likely to die of cardiovascular disease (CHD or stroke) than ovarian cancer (413,800/year vs 14,700/year).11
Acknowledgement
The PURLs Surveillance System is supported in part by Grant Number UL1RR024999 from the National Center for Research Resources, a Clinical Translational Science Award to the University of Chicago. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Center for Research Resources or the National Institutes of Health.
The authors wish to acknowledge Sofia Medvedev, PhD, of the University HealthSystem Consortium in Oak Brook, Ill, for analysis of the National Ambulatory Medical Care Survey data and the UHC Clinical Database.
PURLs methodology
This study was selected and evaluated using FPIN’s Priority Updates from the Research Literature (PURL) Surveillance System methodology. The criteria and findings leading to the selection of this study as a PURL can be accessed at www.jfponline.com/purls.