Malignant peritoneal cytologic contamination with robotic hysterectomy for endometrial cancer.

Background: Malignant peritoneal cytology in endometrial cancer (EC) is not considered an independent adverse prognostic factor for uterine-confined disease and is not a determinant factor in the International Federation of Gynecology and Obstetrics (FIGO) staging system. NCCN Guidelines still recommend obtaining cytologies. The aim of this study was to determine the prevalence of peritoneal cytologic contamination following robotic hysterectomy for EC.

Methods: Peritoneal cytology from the pelvis and diaphragm were obtained at the initiation of surgery, and from the pelvis only at the completion of robotic hysterectomy with sentinel lymph node mapping (SLNM). Cytology specimens were evaluated for the presence of malignant cells. Pre- and post-hysterectomy cytology results were compared, and pelvic contamination was defined as conversion from negative to positive cytology following surgery.

Results: 244 patients underwent robotic hysterectomy with SLNM for EC. Pelvic contamination was identified in 32 (13.1%) cases. In multivariate analysis, pelvic contamination was associated with >50% myometrial invasion, tumor size >2 cm, lymphovascular space invasion (LVSI), and lymph node metastasis. There was no association with FIGO stage or histology subtypes.

Conclusions: Malignant peritoneal contamination occurred during robotic surgery for EC. Large lesions (>2 cm), deep invasion (>50%), LVSI, and lymph node metastasis were each independently associated with peritoneal contamination. Whether or not peritoneal contamination increases risk for disease recurrence should be studied in larger series, including an evaluation of patterns of recurrence and the potential impact of adjuvant therapies. Until the clinical impact of peritoneal contamination during hysterectomy for EC is better understood, methods to reduce peritoneal contamination are warranted.