Lymph node metastases in patients undergoing surgery for a gallbladder cancer. Extension of the lymph node dissection and prognostic value of the lymph node ratio.

BACKGROUND

Lymph node (LN) status is one of the strongest prognostic factors after gallbladder cancer (GBC) resection. The adequate extension of LN dissection and the stratification of the prognosis in N+ patients have been debated. The present study aims to clarify these issues.

METHODS

A total of 112 consecutive patients who underwent operations for GBC with LN dissection were analyzed. Twenty-five patients (22.3%) had D1 dissection (hepatic pedicle), and 87 (77.7%) had D2 dissection (hepatic pedicle, celiac and retro-pancreatic area). The LN ratio (LNR) was computed as follows: number of metastatic LNs/number of retrieved LNs.

RESULTS

The median number of retrieved LNs was 7 (1-35). Fifty-nine patients (52.7%) had LN metastases (22 N2). D2 dissection allowed the retrieval of more LNs (8 vs. 3, p = 0.0007), with similar short-term outcomes. Common bile duct (CBD) resection (n = 41) did not increase the number of retrieved LNs. In five patients, D2 dissection identified skip LN metastases that otherwise would have been missed. LN metastases negatively impacted survival (5-years survival 57.2% if N0 vs. 12.4% if N+, p < 0.0001), but N1 and N2 patients had similar survival rates. The number of LN+ (1-3 vs. ≥4) did not impact prognosis. An LNR = 0.15 stratified the prognosis of N+ patients: 5-years survival 32.7% if LNR ≤ 0.15 vs. 10.3% if LNR > 0.15 (multivariate analysis p = 0.007).

CONCLUSIONS

A D2 LN dissection is recommended in all patients, because it allows for better staging. CBD resection does not improve LN dissection. An LNR = 0.15, not the site of metastatic LNs, stratified the prognoses of N+ patients.