Extended Lymphadenectomy Is Required for Incidental Gallbladder Cancer Independent of Cystic Duct Lymph Node Status

Background: We examined whether the incidental cystic duct nodal status predicts the status of the hepatoduodenal ligament (D1) or common hepatic artery, the pancreaticoduodenal and paraaortic lymph nodes (D2), and the overall prognosis and thus indicates whether an oncologic extended resection (OER) is required. Methods: The study included patients who underwent OER for incidental gallbladder cancer (IGBC) during 1999–2015. Associations between a positive cystic duct node and D2 nodal status and disease-specific survival (DSS) were analyzed. Results: One-hundred-eight-seven patients were included. Seventy-three patients (39%) had the incidental cystic duct node retrieved. Cystic duct node positivity was associated with positive D1 (odds ratio 5.2, p = 0.012) but not with D2. Among all patients, a positive cystic duct node was associated with worse DSS (hazard ratio [HR] 2.09). Patients without residual cancer at OER and positive incidental cystic duct node had similar DSS to patients with negative nodes 70 vs 60% (p = 0.337). Positive D1 (HR 6.07) or positive D2 (HR 13.8) was predictive of worse DSS. Conclusions: Patients with no residual cancer at OER and regional disease limited to their incidental cystic duct node have similar DSS to pN0 patients. The status of the cystic duct node only predicts the status of hepatic pedicle nodes.