Analysis of the Extent of Liver Oncological Extended Resection for Incidental Gallbladder Cancer: How Much Is Too Much?

BACKGROUND: Liver resection is pivotal in treating incidental gallbladder cancer (IGBC). However, the adequate volume of liver resection remains controversial. METHODS: A cross-sectional retrospective analysis was performed on resected IGBC patients between 1999 and 2018. Morbidity was evaluated according to the Clavien-Dindo classification. The theoretical volume of a 2-cm and 1.5-cm wedge liver resection was calculated (105 cm3 and 77.5 cm3, respectively) and used as reference. Overall survival (OS) was estimated using Kaplan-Meier and Cox regression analyses. RESULTS: Among 111 patients re-resected for IGBC, 84 provided sufficient data to calculate liver resection volume. Patients with a resection volume ≥ 105 cm3 had a higher rate of overall morbidity (P = 0.001) and length of stay (P = 0.012), with no difference in mortality. There was no significant difference in OS according to residual cancer or T-category. A resection volume ≥ 77.5 cm3 was more frequent in T ≥ 3 than in T1-2 patients (P = 0.026), and residual cancer was higher (P = 0.041) among patients with ≥ 77.5 cm3 resected. Cox multivariate regression showed that residual cancer (HR = 11.47, P < 0.001), perineural/lymphovascular invasion (HR = 2.48, P = 0.021), and Clavien-Dindo ≥ IIIa morbidity (HR = 5.03, P = 0.003) predict worse OS, but not liver volume resection. CONCLUSION: There are no significant differences in OS based on resected liver volume of IGBC, when R0 is achieved. There is a significant difference in morbidity and length of stay when liver wedges are ≥ 105 cm3, which is lost when analyzed by Clavien-Dindo ≥ IIIa. A 77.5-105 cm3 resection is indicated in ≥ T3 patients, minimizing morbidity risk, while addressing concerns of overall survival.

Positive cystic duct margin at index cholecystectomy in incidental gallbladder cancer is an important negative prognosticator.

BACKGROUND: Prognostic factors following index-cholecystectomy in patients with incidental gallbladder cancer (IGBC) are poorly understood. The aim of this study was to assess the value of the initial cystic duct margin status as a prognosticator factor and to aid in clinical decision making to move forward with curative intent oncologic extended resection (OER). METHODS: This retrospective study included patients with IGBC who underwent subsequent OER with curative intent at 2 centers (USA and Chile) between 1999 and 2016., Patients with and without evidence of residual cancer (RC) at OER were included. Pathologic features were examined, and predictors of overall survival (OS) were analyzed. RESULTS: The study included 179 patients. Thirty-three patients (17%) had a positive cystic duct margin at the index cholecystectomy. Forty-two patients (23%) underwent resection of the common bile duct. OS was significantly worse in the patients with a positive cystic duct margin at index cholecystectomy (OS rates at 5 years, 34% vs 57%; p = 0.032). Following multivariate analysis, only a positive cystic duct margin at index cholecystectomy was predictive of worse OS in patients with no evidence of residual cancer (RC) at OER (hazard ratio, 1.7 95%CI 1.04-2.78; p = 0.034). CONCLUSIONS: A positive cystic duct margin at index-cholecystectomy is a strong independent predictor of worse OS even if no further cancer is found at OER. In patients with positive cystic duct margin and no RC at OER common bile duct resection leads to improved outcomes.

Incidental Gallbladder Cancer: Residual Cancer Discovered at Oncologic Extended Resection Determines Outcome: A Report from High- and Low-Incidence Countries.

BACKGROUND: Gallbladder cancer detected incidentally after cholecystectomy (IGBC) currently is the most common diagnosis of gallbladder cancer, and oncologic extended resection (OER) is recommended for tumors classified higher than T1b. However, the precise prognostic significance of residual cancer (RC) found at the time of OER has not been well established. This analysis aimed to determine the prognostic impact of RC found in patients with IGBC undergoing OER. METHODS: Outcomes for IGBC at a center for a low-incidence country (USA) and a high-incidence country (Chile) between January 1999 and June 2015 were analyzed. Residual cancer was defined as histologically proven cancer at OER. Predictors of disease-specific survival (DSS) were analyzed. RESULTS: Of 187 patients, 171 (91.4%) achieved complete resection (R0) at OER. The rates of surgical mortality and severe morbidity were respectively 1.1 and 9.6%. Of the 187 patients, 73 (39%) had RC. Perineural invasion and/or lymphovascular invasion and T3 stage were associated with the presence of RC. In both countries, RC was associated with a significantly shorter median survival (23% vs not reached; p < 0.001) and lower 5-year DSS rate (19% vs. 74%; p < 0.001) despite R0 resection. In the multivariable analysis, RC was an independent poor predictor of DSS (hazard ratio [HR], 4.00; 95% confidence interval [CI], 2.13-7.47; p < 0.001), as were lymphovascular and/or perineural invasion (HR, 1.95; 95% CI, 1.19-3.21; p = 0.008). CONCLUSIONS: The presence of RC in patients undergoing OER for IGBC is associated with poor DSS in both high- and low-incidence countries, even when R0 resection is achieved. Residual cancer defines a high-risk cohort for whom adjuvant therapy may be beneficial.