Correlation Between Pelvic Peritoneal Disease and Nodal Metastasis in Advanced Ovarian Cancer: Can Intraoperative Findings Define the Need for Systematic Nodal Dissection?

To explore the relationship of peritoneal, and rectal involvement with lymph nodal metastases to identify clinical parameters to guide systematic nodal dissection in advanced ovarian cancer (stage 3c). It is a retrospective study of stage III C epithelial ovarian cancers undergoing cytoreductive surgery with systematic nodal dissection, from January 2011 to December 2016. LS3 score is a cumulative score given for the presence of size 3 lesion (peritoneal disease measuring more than 5 cm) in regions 5, 6, and 7. The depth of rectal involvement was assigned progressive numerical values from 1 (for serosa) to maximum 4 (for mucosa) to generate rectal involvement score. There were 91 patients. 48.35% patients had LS3 lesions in regions 5, 6, 7. Of these, 36% (27/44) had positive nodes. Of the 41 node-positive cases, 43.9% had single and 34.14% had two station involvements. Rectum was involved in 47 patients (51.64%), serosal involvement being the most common type (50.57%). Twenty patients had positive mesorectal nodes (42.55%). The presence of rectal involvement was influenced by the Peritoneal Carcinomatosis Index (PCI) score, the presence of LS3 in lower quadrants (p = 0.008), and LSE score of lower quadrants (p = 0.003). With the increasing depth of rectal infiltration, mesorectal positivity increased significantly (p = 0.000). In multivariate analysis, lower quadrant (regions 5, 6, 7) PCI, LS3 in lower quadrants, LS3 score, rectal involvement score, and the total number of lines of chemotherapy significantly affected different nodal disease parameters. In advanced ovarian cancer, LS3 disease in regions 5, 6, and 7 and rectal involvement directly impact the nodal metastasis and hence mandates a systematic nodal dissection. Mesorectal nodal involvement significantly increases with the increasing depth of rectal involvement necessitating systematic mesorectal nodal clearance for all rectal resections.