The optimal surgical extent of T2 gallbladder cancer and the effect of location of the tumor

Abstract

Introduction: T2 gallbladder cancer (GBC) is subcategorized into T2a and T2b depending on the location. While extended cholecystectomy (EC) is surgery of choice for T2 GBC, some argue that simple cholecystectomy (SC) is enough for T2a. The aim was to validate the subcategorization of T2 GBC and to explore its proper surgical extent. Method: Data on 957 pathologically proven T2 GBC patients who received curative surgery were collected from Korea, Japan, Chile, and the United States. Clinical, pathological, and radiologic data were reviewed. Survival analyses were performed. Result: The median survival duration was 152 months and the 5-year survival rate (5YSR) was 71.7%. EC was performed in 724 patients (75.7%) and SC in 233 patients (24.3%). Lymph node (LN) was harvested in 81.5%. The mean size of tumor was 3.5 cm. R0 was achieved in 94.3%. T2a consisted 44.1% (N=422), T2b 50.2% (N=480), and undetermined 5.7%. LN metastasis was found in 29.0% (N=277). Recurrence occurred in 27.9% (N=267). EC group had significantly superior outcome compared to SC group (5YSR 73.0% vs. 61.7%, p=0.017). T2a had significantly better survival than T2b (5YSR 74.3% vs. 66.8%, p=0.017). For T2a, EC (N=328) had better survival compared to SC (N=94) but it was insignificant (5YSR 76.3% vs. 66.7%, p=0.207). In contrast, EC (N=374) had significantly better survival compared to SC (N=106) in T2b (5YSR 70.0% vs. 55.2%, p=0.013). Elevated CA19-9, SC, R1, and LN metastasis were independently associated with recurrence. Recurrence rate, pattern, and location were not different between T2a and T2b. Conclusion: The prognosis of T2 GBC differs according to the location which supports subcategorization into T2a and T2b. EC offers superior outcome over SC. This is true for T2b, but the statistical significance is lost in T2a. However, given the 10% 5YSR difference, SC with LN dissection should be reserved only for selected T2a GBC patients.