Prognostic Significance of Tumour Budding and Tumour-infiltrating Lymphocytes in Gallbladder Carcinoma

Abstract Background and Objective: Gallbladder cancer (GBC) frequently occurs at an advanced stage, with histological sub-type, tumour size, grade of differentiation, lymphovascular invasion (LVI), perineural invasion (PNI), nodal metastases, and surgical resection margins impacting prognosis. Tumour budding (TB) and tumour-infiltrating lymphocytes (TILs) have emerged as novel prognostic markers in various cancers. Materials and Methods: The study included gallbladder specimens operated between January 2016 and May 2022. Clinical data were retrieved from the institutional archive. Histopathological slides were reviewed for histological differentiation, neck resection margin status, LVI, PNI, serosal involvement, lymph node metastases, etc. TILs and TB were graded according to established guidelines. Statistical Package for Social Sciences version 21.0 was utilised to analyse the data. Results: Seventy-nine gallbladder adenocarcinoma (pT1 = 25.32%, pT2 = 34.18%, pT3 = 40.50%) cases were examined. Surgical resection margin, LVI, PNI, serosal involvement, and nodal metastasis were present in 13.92% (11/79), 26.58% (21/79), 29.11% (23/79), 41.77% (33/79), and 30.38% (24/79) cases, respectively; 43.04% (34/79), 36.71% (29/79), and 20.25% (16/79) of cases had TIL-1, TIL-2, and TIL-3, respectively. Bd1, Bd2, and Bd3 were noted in 63.29% (50/79), 18.99% (15/79), and 17.72% (14/79), of cases, respectively. Higher–grade TB was linked with poorer tumour histology ( P < 0.001), higher pathological stage ( P = 0.044), surgical neck resection margin involvement ( P < 0.001), LVI ( P < 0.001), PNI ( P < 0.001), serosal involvement ( P = 0.013), and nodal metastasis ( P = 0.009). High TILs predicted lower histopathological grades ( P = 0.012) and LVI ( P = 0.015). Conclusion: Age, less differentiated histological grade, pT category, LVI, and higher TB grade were independently associated with worse 4-year overall survival. Higher TB correlates with high-risk clinicopathological features and inferior overall survival, while higher TILs are associated with lower GBC histological grade and LVI incidence.