The Prognostic Importance of the Number of Metastatic Lymph Nodes for Patients Undergoing Curative Resection Followed by Adjuvant Chemoradiotherapy for Extrahepatic Bile Duct Cancer

Adequate lymph node dissection is essential for accurate nodal staging in intrahepatic cholangiocarcinoma: A population-based study

PURPOSE

To comprehensively investigate the implications of lymph node dissection (LND) and the prognostic impact of the number of lymph node (LN) metastases on survival in intrahepatic cholangiocarcinoma (ICC) using a large-scale study.

METHODS

Patients who underwent surgical resection for ICC between 2004 and 2018 were identified from the Surveillance, Epidemiology, and End Results (SEER) registries. The Kaplan-Meier and log-rank tests were used to compare cancer-specific survival (CSS) and overall survival (OS) between different groups. Propensity score matching (PSM) and subgroup analyses were performed to balance potential confounding factors. A multivariate Cox proportional hazards regression model was used to identify prognostic factors of survival outcomes. Restricted cubic splines fitted in the Cox proportional hazard regression models were also conducted to examine associations between continuous variables and outcomes.

RESULTS

In all, 1028 patients were enrolled. There were 652 (63.4%) patients undergoing LND, with lymph node metastasis (LNM) confirmed in 212 (32.5%) cases. Patients receiving LND did not show better survival outcomes than those receiving non-LND (NLND). We divided the LND group into two subgroups: patients with LNM (+) and those without LNM (-). Among these three groups, patients with LNM experienced the worst CSS and OS, while NLND patients had similar survival times to LNM (-) patients. Restricted cubic spline analysis indicated that an increased number of LNM was associated with a decreased chance of survival (p < 0.001). Patients who received LND were further categorized as having no nodal metastasis (N0), 1-2 LNM (N1), or ≥3 LNM (N2) according to the number of LNM. The Kaplan-Meier curves showed that the mortality risk of patients with N0, N1, and N2 disease (median CSS, N0 50.0 vs. N1 22.0 vs. N2 14.0 months; median OS, N0 46.0 vs. N1 21.0 vs. N2 14.0 months, all p < 0.01) increased significantly, except for patients who had <6 LNs harvested. On multivariable survival analysis, a higher nodal stage (N1 vs. N0: CSS, hazard ratio [HR] 2.135, 95% CI 1.636-2.788, p < 0.001; OS, HR 2.100, 95% CI 1.624-2.717, p < 0.001; N2 vs. N0: CSS, HR 4.027, 95% CI 2.791-5.811, p < 0.001; OS, HR 3.678, 95% CI 2.561-5.282, p < 0.001) was an independent prognostic risk factor for survival.

CONCLUSIONS

Despite the lack of a clear survival benefit of LND in patients with ICC, a significant positive association between the number of LNM and poor outcomes was observed. We still suggest adequate LND by examining at least six LNs to ensure precise staging. On this basis, the recently proposed nodal classification of N0, N1, and N2 stages may also allow better prognostic stratification of ICC patients.

Prognostic impact of the number of metastatic lymph nodes in distal bile duct cancer: An analysis of Japanese registration cases by the study group for biliary surgery of the Japanese Society of Hepato-Biliary-Pancreatic Surgery

BACKGROUND

Lymph node metastasis is an important prognostic factor for distal bile duct cancer. The number of lymph node metastases was adopted for nodal classification. However, different cutoff values have been proposed, ranging from two to five.

METHODS

A total of 1748 cases who underwent curative surgery with pancreatoduodenectomy for distal bile duct cancer registered in the nationwide biliary tract cancer registry in Japan from 2008 to 2013 were included. Univariate Cox regression was performed to assess the effect of prognostic lymph node metastasis counts on mortality and to determine cutoff values.

RESULTS

The overall survival rate after resection was 47.4% at 5 years. Univariate and multivariate analysis found prognostic factors to include lymph node metastasis. The cutoff point was set to two lymph node metastases using the Cox model. There were significant differences in pairwise comparisons between three groups by the number of metastatic lymph node (P < .001 for 0 vs 1-2 and P = .003 for 1-2 vs ≥3).

CONCLUSION

Our data suggest lymph node classification as N0 (patients without lymph node metastases), N1 (metastasis in 1-2 regional lymph nodes), and N2 (metastases in ≥3 regional lymph nodes).

Prognostic Significance of the Lymph Node Ratio in Surgical Patients With Distal Cholangiocarcinoma

BACKGROUND

The aim of this study was to compare the prognostic impact of the lymph node ratio (LNR) versus positive lymph node count (PLNC) in patients who had undergone resection for distal cholangiocarcinoma.

METHODS

We identified 448 patients with resected distal cholangiocarcinoma from the Surveillance, Epidemiology, and End Results database. The X-Tile program was used to calculate the cutoff values for the LNR and PLNC that discriminate survival. The overall survival and cancer-specific survival rates were calculated. Relationships between clinicopathological factors and patient survival were assessed using univariate and multivariate analyses.

RESULTS

The optimal cutoff values for the LNR and PLNC were 0.45 and 3, respectively. Univariate analysis revealed that tumor size, the American Joint Committee on Cancer stage, T stage, the LNR and PLNC were significantly associated with prognosis (P < 0.05). Multivariate analysis demonstrated that the LNR, T stage, and tumor size were independent prognostic factors for cancer-specific and overall survival, whereas PLNC was not. In the subgroup of patients with positive lymph nodes, patients with an LNR of greater than 0.45 had significantly worse cancer-specific survival (hazard ratio, 2.418; 95% confidence interval, 1.588 to 3.682; P < 0.001) and overall survival (hazard ratio, 2.149; 95% CI, 1.421 to 3.249; P < 0.001) than those with an LNR of 0.45 or less.

CONCLUSIONS

The LNR was a better predictor of long-term prognosis than PLNC in patients with distal cholangiocarcinoma.

Prognostic predictability of the new American Joint Committee on Cancer 8th staging system for distal bile duct cancer: limited usefulness compared with the 7th staging system

BACKGROUND

The new 8th American Joint Committee on Cancer (AJCC) staging has recently been released and there are major changes in distal bile duct (DBD) cancer staging. However, clinical validation is needed before the changes can be widely implemented.

METHODS

This study was performed to evaluate the prognostic predictability of the 8th AJCC staging compared with that of the 7th using C statistics.

RESULTS

A total of 293 consecutive patients who had curative-intended surgery were enrolled. There was no significant difference of the 5-year survival rate between 7th T1 and T2 (P = 0.123), but significant difference between T2 and T3 (P = 0.039). There were significant differences in pairwise comparisons between the 8th T stage (T1 vs. T2, P = 0.001; T2 vs. T3, P = 0.014). The number of regional lymph node metastases also showed prognostic predictability. The 8th T and N stage both showed comparable prognostic predictability with the 7th (95% confidential intervals for C; T, -0.043 -0.097, N, -0.001 - 0.008).

CONCLUSIONS

The 8th AJCC staging for DBD cancer does not have better prognostic predictability than the 7th stage does. The previous pathologic results would become useless unless they were reviewed entirely. Therefore, introduction of the AJCC 8th staging has to be reconsidered, especially for new T staging.

The number of positive lymph node is a better predictor of survival than the lymph node metastasis status for pancreatic neuroendocrine neoplasms: A retrospective cohort study

BACKGROUND

The recently released AJCC TNM staging system of pancreatic adenocarcinoma has endorsed the number of positive lymph node(NPLN) as the criterion of N staging. However, the prognostic role of NPLN is still unclear for pancreatic neuroendocrine neoplasms (pNENs).

METHODS

Patients underwent resection and at least one lymph node examined were identified from the Surveillance, Epidemiology, and End Results database. The overall survival (OS) and disease specific survival (DSS) were estimated using Kaplan-Meier analysis and compared by log-rank test. The prognostic factors were determined by cox proportional regression model.

RESULTS

Totally, 1,269 pNENs were included in the present study. The increasing NPLN (NPLN > 3) was corresponding significantly (P < 0.05) shorter OS and DSS in both entire cohort (OS: NPLN ≤ 3 vs. NPLN > 3, 93.624 ± 1.765 months vs. 75.075 ± 4.005 months; DSS: NPLN ≤ 3 vs. NPLN > 3, 104.829 ± 1.455 months vs. 85.443 ± 3.938 months, respectively) and cohort with the number of examined lymph node more than 11 (OS: NPLN ≤ 3 vs. NPLN > 3, 88.759 ± 2.756 months vs. 73.664 ± 4.700 months; DSS: NPLN ≤ 3 vs. NPLN > 3, 99.021 ± 2.212 months vs. 85.139 ± 4.686 months, respectively). Furthermore, the multivariate analysis showed the NPLN > 3 rather than lymph node status was the independent prognostic factors for OS and DSS in these two cohorts.

CONCLUSIONS

The NPLN seems more meaningful than the lymph node metastasis status as prognostic factor for survival. Taking into account the prognostic value of NPLN for pNENs might improve the current TNM staging systems. However, prospective study is needed to demonstrate our findings.