Is lymph-node micrometastasis in gallbladder cancer a significant prognostic factor?

Incidental gallbladder cancer diagnosis confers survival advantage irrespective of tumour stage and characteristics

BACKGROUND

Incidental gallbladder cancer (IGBC) represents 50%-60% of gallbladder cancer cases. Data are conflicting on the role of IGBC diagnosis in oncological outcomes. Some studies suggest that IGBC diagnosis does not affect outcomes, while others that overall survival (OS) is longer in these cases compared to non-incidental diagnosis (NIGBC). Furthermore, some studies reported early tumour stages and histopathologic characteristics as possible confounders, while others not.

AIM

To investigate the role of IGBC diagnosis on patients’ overall survival, especially after surgical treatment with curative intent.

METHODS

Retrospective analysis of all patient referrals with gallbladder cancer between 2008 and 2020 in a tertiary hepatobiliary centre. Statistical comparison of patient and tumour characteristics between IGBC and NIGBC subgroups was performed. Survival analysis for the whole cohort, surgical and non-surgical subgroups was done with the Kaplan-Meier method and the use of log rank test. Risk analysis was performed with univariable and multivariable Cox regression analysis.

RESULTS

The cohort included 261 patients with gallbladder cancer. 65% of cases had NIGBC and 35% had IGBC. A total of 90 patients received surgical treatment (66% of IGBC cases and 19% of NIGBC cases). NIGBC patients had more advanced T stage and required more extensive resections than IGBC ones. OS was longer in patients with IGBC in the whole cohort (29 vs 4 mo, P < 0.001), as well as in the non-surgical (14 vs 2 mo, P < 0.001) and surgical subgroups (29 vs 16.5 mo, P = 0.001). Disease free survival (DFS) after surgery was longer in patients with IGBC (21.5 mo vs 8.5 mo, P = 0.007). N stage and resection margin status were identified as independent predictors of OS and DFS. NIGBC diagnosis was identified as an independent predictor of OS.

CONCLUSION

IGBC diagnosis may confer a survival advantage independently of the pathological stage and tumour characteristics. Prospective studies are required to further investigate this, including detailed pathological analysis and molecular gene expression.

Survival analysis following resection of AJCC stage III gallbladder carcinoma based on different combinations of T and N stages

Backgrounds/Aims

According to 7th AJCC TNM staging system, gallbladder carcinoma (GBC) with lymph node (LN) metastasis is classified as N1 or N2; thus making the stage IIIB (N1) or IVB (N2). Stage IIIB consists of N1 status with wide coverage of T1-3, but T3N1 group often showed poorer outcomes than T1-2N1 groups. This study intended to assess post-resection prognosis of T3N1 versus other stage III subgroups.

Methods

We selected 103 patients from our institutional database of GBC who underwent R0 resection between July 1996 and June 2009 and whose GBC was confined to stage T3N0, T1-3N1 or T1-3N2. These patients were stratified into five groups, namely, T3N0 (n=26), T1N1 (n=13), T2N1 (n=35), T3N1 (n=20) and T1-3N2 (n=9), and were followed for ≥5 years or until death.

Results

Surgical procedures were minor liver resection (n=53), minor liver resection with bile duct resection (n=23), major liver resection (n=12), major liver resection with bile duct resection (n=5), and hepatopancreatoduodenectomy (n=12). Mean follow-up period was 57.2±68.5 months. Overall 5-year survival rate based on all-cause death and cancer-associated death, respectively, was 57.7% and 60.6% in T3N0, 15.4% and 15.4% in T1N1 (n=13), 28.6% and 28.6% in T2N1 (n=35), 5.0% and 5.7% in T3N1 (n=20), and 22.2% and 22.2% in T1-3N2. The survival outcome of T3N1 group was the poorest among the four stage III groups and was comparable to that of stage IVB (p=0.53).

Conclusions

The prognosis of T3N1 GBC is unusually poor even after R0 resection, thus we suggest extensive LN dissection may be necessary in patients with T3 tumors for accurate prognostic evaluation and radical removal of potential nodal micrometastasis. Further validation of this result is necessary in large patient populations from multiple centers.