Prognostic Significance of Tumor Location in T2 Gallbladder Cancer: A Systematic Review and Meta-Analysis

Abstract

(1) Background: The AJCC Cancer Staging Manual, Eighth Edition, subdivided T2 GBC into T2a and T2b. However, there still exist a lack of evidence on the prognostic significance of tumor location. The aim of the present study was to examine the existing evidence to determine the prognostic significance of tumor location of T2 gallbladder cancer (GBC) and to evaluate the optimal surgical extent according to tumor location. (2) Methods: We searched for relevant literature published in the electronic databases PubMed, MEDLINE, Web of Science, Cochrane Library, and Embase before September 2020 using search terms related to gallbladder, cancer, and stage. Data were weighted and pooled using random-effects modeling. (3) Results: Seven studies were deemed eligible for inclusion, representing a cohort of 1789 cases of resected T2 GBC. The overall survival for T2b tumor was significantly worse than that for T2a tumor (HR, 2.141; 95% confidence interval (CI), 1.140 to 4.023; I2 = 71.4%; Pchi2 = 0.007). The rate of lymph node metastasis was lower in the T2a group (26.6%) than in the T2b group (36.6%) (OR, 2.164; 95% CI, 1.309 to 3.575). There was no evidence of a survival difference between the patients who underwent extended cholecystectomy and simple cholecystectomy in T2a GBC (OR, 0.802; 95% CI, 0.618 to 1.042) and T2b GBC (OR, 0.820; 95% CI, 0.620 to 1.083). (4) Conclusions: Hepatic side tumor was a significant poor prognostic factor in T2 GBC. Extended cholecystectomy and simple cholecystectomy showed comparable survival outcomes in T2 GBC, and additional large-scale prospective studies are warranted to establish evidence-based treatment guidelines for T2 GBC.

Outcomes of incidental versus non‐incidental T2 gallbladder cancer: A single‐institute experience of 425 cases

“…There is however, an abundance of literature indicating that presence of tumour on the hepatic side is, in fact, a negative prognostic factor in stage II GBC. [24][25][26][27] These findings do make a case for the use of NACT in incidentally detected pT2b tumours, a subset that exhibits poorer outcomes compared to their non-incidentally detected counterparts, and one which could potentially benefit from the downstaging effect of NACT, a fact well documented in literature. 16,[28][29][30] Interestingly, the outcomes of patients in our study with residual disease in the GB fossa mirrored those of patients with stage IVB disease, indicating a far worse prognostic implication than originally anticipated.…”

“…This remains a limitation in our study, as the impact of the side of the tumour was not separately analysed due to the side of tumour not being recorded accurately in a large proportion of cases, especially in the iGBC group, wherein patients underwent a simple cholecystectomy elsewhere. There is however, an abundance of literature indicating that presence of tumour on the hepatic side is, in fact, a negative prognostic factor in stage II GBC 24–27 . These findings do make a case for the use of NACT in incidentally detected pT2b tumours, a subset that exhibits poorer outcomes compared to their non‐incidentally detected counterparts, and one which could potentially benefit from the downstaging effect of NACT, a fact well documented in literature 16,28–30 …”