T1b Gallbladder Cancer: Is Simple Cholecystectomy Enough or Is Radical Resection Required?

The optimal surgical extent of T1b gallbladder cancer, defined as invasion of the muscularis propria, remains controversial. The historical rationale for radical/extended cholecystectomy (EC) stems from concerns regarding lymph node metastasis (LNM) and locoregional failure, whereas several contemporary cohort and meta-analyses have reported comparable long-term outcomes with simple cholecystectomy (SC). We conducted a narrative evidence-based review integrating multicenter cohorts, national databases, systematic reviews, and contemporary guidelines. The key outcomes were LNM rates, recurrence, overall survival (OS), disease-specific survival (DSS), complications, and recommendations from international guidelines. The reported LNM rates for pathologic T1b ranged from approximately 0% to 11% in most series, with higher outliers in select single-center reports. Heterogeneity was driven by pathological re-review, stage migration, and study era. A large international multicenter study found no difference in DSS between SC and EC, and the National Cancer database analysis reported no OS advantage for EC. A 2025 Chilean multicenter cohort showed a 5-year OS rate of approximately 83%, without a difference in the extent of resection. EC is associated with greater operative burden. Guidelines diverge; some (e.g., National Comprehensive Cancer Network) list EC for T1b, whereas others allow SC in strictly defined pT1b without adverse pathology. There is no consistent survival benefit of routine EC for all T1b tumors. A risk-adapted strategy is reasonable. SC alone is sufficient for incidental pT1b with R0 margins and no high-risk features, and EC should be considered for positive margins, poor differentiation, lymphovascular/perineural invasion, or radiological suspicion of T2 or nodal disease.