Hepatectomy of segment 4b and 5 with extrahepatic bile duct resection for pT2 gallbladder carcinoma is valid: a single-institution result

Systematic review and meta-analysis of survival outcomes in T2a and T2b gallbladder cancers

BACKGROUND

The 8th edition of AJCC TNM staging of Gallbladder cancer subdivided T2 stage into T2a and T2b based on tumour location. This meta-analysis aimed to investigate the long-term outcomes in T2a and T2b gallbladder cancers.

METHODS

Literature search of Medline, Web of science, Embase and Cochrane databases was performed. Study characteristics, survival and recurrence data were extracted for meta-analysis of effect estimates and of individual patient data.

RESULTS

Fifteen retrospective studies (2531 patients, T2a = 1332, T2b = 199) were included in the meta-analysis. Overall survival (OS) was significantly worse in patients with T2b compared to T2a tumours (HR 2.18, 95% CI 1.67-2.86, p < 0.0001). Meta-analysis of individual patient data (n = 629) showed similar results (HR 1.92, 95% CI 1.43-2.58, p < 0.00001). Patients with T2b tumours had higher risk of recurrence compared to T2a (OR 3.19, 95% CI 1.40-7.28, p = 0.006) and were more likely to receive adjuvant chemotherapy (OR 1.76, 95% CI 1.12-2.84, p = 0.014). Liver resection improved OS in T2b tumours (HR 2.99, CI 1.73-5.16, p < 0.0001).

CONCLUSION

T2b gallbladder tumours have worse overall survival and increase risk of recurrence compared to T2a. Liver resection appears to improve OS in patients with T2b tumours. However, high quality multicenter data is required to confirm these results.

Improvement in the diagnosis and treatment of T2 gallbladder carcinoma is pivotal to improvement in the overall prognosis for this disease

Since the American Joint Committee on Cancer (AJCC) subdivided the T2 stage of gallbladder carcinoma (GBC) into T2a and T2b, the diagnosis and treatment of those stages have been a subject of heated discussion and controversy. T2 is a stage of GBC that might be treatable. Based on the extent of lymph node metastasis and distant metastasis, T2 GBC can be classified into various pathological stages such as IIA, IIB, IIIB, and IVB, leading to controversy in clinical settings. This review aims to discuss the effectiveness of and controversies concerning S4b+5 resection, the acceptable extent of lymph node dissection, the timing for treatment of incidental gallbladder cancer, and adjuvant therapy. This review also aims to suggest directions for and recommendations regarding clinical research in the future.