Metastatic Involvement of Lesser Sac in Advanced Epithelial Ovarian Cancer

In advanced epithelial ovarian cancer (AOC), lesser sac (LS) metastasis particularly to the supragastric LS (SGLS) may be overlooked, resulting in unrecognized residual disease. We aimed to identify the frequency, distribution, and predictors of LS metastasis using laparoscopic evaluation at laparotomy and perioperative surgical complications associated with evaluation and resection/ablation.

Prospective observational study in consecutive patients with AOC undergoing laparotomy for primary or interval cytoreductive surgery in 2 centers between November 2013 and December 2016.

Of 182 AOC patients undergoing laparotomy, 150 were eligible for metastasis distribution analysis; 96/150 (64%) had LS metastasis with 90/150 (60%) involving the SGLS, including lesser omentum (47.3%), floor (42%), upper recess (24.6%), and caudate lobe (22.6%), with 62/90 (68.8%) being less than 1 cm in dimension. Of 144 undergoing cytoreductive surgery, 92 (64%) had LS metastasis, which was completely resected/ablated in 77/92 (83.6%).The strongest multivariate predictors of LS metastasis were involvement of Morison pouch (P < 0.001) and peritoneal cancer index of 17 or greater (P < 0.001). The LS metastasis was significantly associated with diaphragmatic surgery (84% vs 54%), cholecystectomy (33% vs 2%), splenectomy (50% vs 14%), retroperitoneal nodal metastasis (75% vs 49%), and surgical complexity score of 8 or higher (75% vs 35%). Morbidity related to treatment of LS metastasis was minimal.

Lesser sac metastasis and SGLS metastasis are present in almost two thirds of cases of AOC and often small in size. Systematic exploration is necessary to detect and treat metastases to LS to prevent unrecognized incomplete cytoreduction.