Population-Based Estimates of the Prevalence of Uterine Sarcoma Among Patients With Leiomyomata Undergoing Surgical Treatment

Uterine leiomyomata are one of the most common gynecologic problems among women in the United States, with an annual diagnosis range from 2.0 to 12.8 per 1000 reproductive-age women.¹ Intervention is a standard management for symptomatic patients, and various procedures include open and laparoscopic hysterectomy, myolysis, uterine artery embolization, and magnetic resonance–guided focused ultrasonographic surgery.

The practice of electric morcellation has been used by gynecologic surgeons during laparoscopic and robotic-assisted hysterectomies and myomectomies as a less invasive alternative to open surgery.² In April 2014, the US Food and Drug Administration (FDA) stated that they discouraged the use of this technique over concern that morcellation may spread unsuspected sarcoma tissue.^3,4 Based on the literature, the FDA reported that 1 in 352 women have unsuspected uterine sarcoma while undergoing surgery for presumed benign leiomyoma.⁵ A recent study⁶ using an all-payer database found that 1 in 368 women who underwent morcellation had uterine cancer. However, the estimates in this study⁶ were limited by the selective participation of hospitals and by the lack of pathologic confirmation. The literature estimates used by the FDA are prone to referral and reporting bias. We sought to determine the population-based estimates of the prevalence of uterine sarcoma, as well as the risks of major complications following open surgery.

We used the Surveillance, Epidemiology, and End Results (SEER) data.⁷ We identified uterine sarcoma cases recorded between 2008 and 2011 from all California registries. Patients with multiple malignant tumors in the uterus were excluded. Population denominators were obtained by selecting patients undergoing a hysterectomy or a myomectomy from the California State Inpatient Database and the State Ambulatory Surgery Database between 2008 and 2011 (http://www.hcup-us.ahrq.gov/databases.jsp). These are de-identified, publicly available databases. Data analysis protocols were reviewed by the institutional review board of Cornell University and were granted exempt status.

A diagnosis of uterine leiomyomata and surgical procedures were identified using International Classification of Diseases, Ninth Revision (ICD-9) codes and Current Procedural Terminology, Fourth Edition codes. We calculated 2 estimates to provide a reasonable range of uterine sarcoma prevalences. Estimate 1 was obtained by using as population denominator the patients who received a diagnosis of leiomyomata and who underwent a hysterectomy or a myomectomy, which overestimates the prevalence of uterine sarcoma. Estimate 2 included in the denominator all patients who underwent a hysterectomy or a myomectomy (any diagnosis), leading to a possible underestimation of uterine sarcoma prevalence. Age- and race-stratified prevalence was calculated. Major complications following surgery were identified using ICD-9 codes.

The sarcoma prevalence estimates were highly dependent on age, with the lowest prevalence for women younger than 50 years of age (0.08%-0.13%) and the highest prevalence for women older than 60 years of age (between 0.36% and 1.53%). Using conservative estimates for surgical treatment of leiomyomata (0.13%-1.53%), these rates translate into 1 in 769 women younger than 50 years of age having sarcomas and 1 in 65 women older than 60 year of age having sarcomas (Table 1). Race stratification showed a higher prevalence among white and black women than among women of other races. Stratified by 3 age groups, open surgery was associated with a 0.01% to 0.33% in-hospital mortality and a 0.32% to 0.92% risk of acute myocardial infarction (Table 2).

Using stratified analyses, we found a more than 10-fold higher prevalence of uterine sarcoma among women older than 60 years of age compared with women younger than 50 years of age. The wide, patient-centered variability in the estimates of the prevalence of uterine sarcoma requires that stakeholders reflect on this and come up with more patient-centered recommendations.

In the panel discussion at the FDA,^3,4 there was an agreement that morcellation should not be used for patients with known or suspected malignant tumors and that the risks of morcellation should be included in the labeling. However, there is no reliable method to diagnose uterine leiomyosarcoma preoperatively. Our results should help update these recommendations. The risk of cancer dissemination should be weighted against the possible reduced risk of complications following open surgery. For example, morcellation for patients younger than 50 years of age is associated with 1 in 769 patients having sarcoma and with the risk of dissemination. But can morcellation prevent 1 death in 10 000 patients or 1 myocardial infarction in 1000 patients undergoing surgery?

Corresponding Author: Art Sedrakyan, MD, PhD, Patient-Centered Comparative Effectiveness, Program and Medical Device Epidemiology Network’s Science and Infrastructure Center, Weill Cornell Medical College of Cornell University, New York–Presbyterian Hospital, Ste LA223, 402 E 67th St, New York, NY 10065 (ars2013@med.cornell.edu).

Published Online: February 4, 2015. doi:10.1001/jamasurg.2014.3518.

Author Contributions: Dr Sedrakyan had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.

Study concept and design: Mao, Pfeifer, Schlegel, Sedrakyan.

Acquisition, analysis, or interpretation of data: All authors.

Drafting of the manuscript: Mao, Sedrakyan.

Critical revision of the manuscript for important intellectual content: All authors.

Statistical analysis: Mao, Zheng, Sedrakyan.

Obtained funding: Sedrakyan.

Administrative, technical, or material support: Sedrakyan.

Study supervision: Schlegel, Sedrakyan.

Conflict of Interest Disclosures: Dr Sedrakyan founded the Medical Device Epidemiology Network’s Science and Infrastructure Center at Cornell University with FDA and institutional funding. No other disclosures are reported.