Trends in peritoneal cytology evaluation at hysterectomy for endometrial cancer in the United States.

OBJECTIVE

The collection of a peritoneal cytologic sample at the time of surgery for endometrial cancer has traditionally been an important part of surgical staging. In 2009, the International Federation of Gynecology and Obstetrics revised the cancer staging schema for endometrial cancer and removed peritoneal cytology from the staging criteria. The current National Comprehensive Cancer Network guidelines and the International Federation of Gynecology and Obstetrics organization, however, recommend evaluation of peritoneal cytology at the time of hysterectomy. This study examined population-based trends, characteristics, and outcomes of peritoneal cytologic sampling for endometrial cancer surgery following the 2009 staging revision in the United States.

METHODS

This is a retrospective observational study querying the Surveillance, Epidemiology, and End Results Program to examine women with stage I-III endometrial cancer who underwent hysterectomy from 2010 to 2017. Trends, characteristics, and survival associated with peritoneal cytologic evaluation at the time of hysterectomy were assessed in multivariable analysis and with propensity score weighting.

RESULTS

Among 62,809 women who underwent hysterectomy, 43,873 (69.9%) had peritoneal cytologic evaluation at surgery and 18,936 (30.1%) did not. Utilization of peritoneal cytologic evaluation decreased from 75.5% to 64.9% during the study period (P < 0.001). In multivariable analysis, more recent year of surgery was independently associated with a decreased likelihood of performance of peritoneal cytology (adjusted-odds ratio of peritoneal cytology evaluation in 2017 versus 2010 0.56, 95% confidence interval [CI] 0.52-0.60). Peritoneal cytologic evaluation at the time of hysterectomy was associated with improved all-cause mortality (hazard ratio in the whole cohort 0.94, 95%CI 0.89-0.99; and hazard ratio in endometrioid histology 0.90, 95%CI 0.84-0.97).

CONCLUSION

Performance of peritoneal cytologic sampling has gradually decreased following the 2009 staging revision in the United States. Our study suggests that peritoneal cytology evaluation at hysterectomy may be associated with improved survival in certain tumor groups.