Extent of Lymph Node Dissection for Accurate Staging in Intrahepatic Cholangiocarcinoma

Surgical strategy for incidental intrahepatic cholangiocarcinoma in terms of lymph node dissection

BACKGROUND

Although many guidelines recommend performing lymph node dissection (LND) during surgery for intrahepatic cholangiocarcinoma (ICC), there is no evidence for patients with incidentally detected ICC who did not undergo LND. This study aimed to identify the role of LND in patients with incidental ICC.

METHODS

The data from 284 patients who had undergone radical surgery for ICC from 2000 to 2020 were retrospectively reviewed. The enrolled patients were divided into 3 groups according to their T stage (T1 vs T2 vs T3 + 4). Moreover, the patients of each T group were divided into 3 groups according to their nodal status (N0 vs N1 vs Nx) and their survival outcomes were compared.

RESULTS

Survival outcomes of Nx group were statistically similar to that of N0 group in T1 stage (Nx vs N0: disease-free survival [DFS] [months], 129.0 [75.6-182.4] vs 125.0 [65.7-184.3], P = .948; overall survival [OS] [months], 175.0 [153.9-196.1] vs 173.0 [109.0-237.0], P = .443). In contrast, survival outcomes of Nx group in the other T stage (T2 and T3 + 4) were poorer than that of N0 group and were better than that of N1 group. In addition, in the Nx subgroup analysis according to T stage, T1 group showed significantly better survival outcomes than the other groups (T1 vs T2 vs T3 + 4: DFS [months], 129.0 [75.9-182.1] vs 16.0 [9.8-22.2] vs 13.0 [0.3-25.7], P < .001; OS [months], 175.0 [153.9-196.1] vs 53.0 [30.8-75.2] vs 37.0 [17.6-56.4], P < .001).

CONCLUSION

Patients with ICC incidentally diagnosed as having T2 or above T stage may consider additional LND.

Role of routine lymph node dissection alongside resection of intrahepatic cholangiocarcinoma: Systematic review and meta-analysis

BACKGROUND

The global incidence of intrahepatic cholangiocarcinoma (ICCA) is soaring. Due to often delayed presentation, only a narrow spectrum of the disease is usually surgically resectable. To more accurately stage the disease, reduce recurrence, and improve overall survival, surgical teams are increasingly performing intraoperative lymph node dissection (LND) as well. This procedure has its associated morbidity, while there is no consensus or formal guidelines on its role in this setting. Hence, there is a need to better delineate the evidence for performing LND alongside surgical resection of the ICCA.

AIM

To perform a systematic review and meta-analysis on the role of LND in improving prognostication and survival post-resection of ICCA.

METHODS

We performed a systematic literature search using Pubmed, Medline, Embase, and the Cochrane Library, for all studies involving LND, ICCA, and surgical resection using several keywords, Medical Subject Headings (MeSH) tags, and appropriate synonyms. All clinical studies comparing curative intent resection of ICCA with LND vs resection without LND were included, while single-arm case series, studies with insufficient data, and duplicates were excluded. We included all English-language studies from the different academic databases up till early December 2022. The primary outcome measures were set for overall survival (OS) and disease-free survival (DFS).

RESULTS

This systematic review and meta-analysis included 15 studies that fulfilled the selection criteria comprising 11413 patients with surgically-resectable ICCA, of whom 6424 (56.3%) underwent hepatectomy with LND while the remainder underwent hepatectomy only. In patients who underwent LND, on average, 27.7% of the resected lymph nodes were positive for metastatic disease. Overall, the results showed that performing LND did not significantly improve OS or DFS. However, the effect of LND on OS showed a degree of variability by geographical region, in Eastern and Western countries. As LND is increasingly being performed, further time-based analysis was undertaken to identify time-dependent changes in the role of LND. An increasing adoption of LND was not associated with improved OS. Furthermore, no roles were identified for neoadjuvant/adjuvant chemotherapy or increasing lymph node retrieval in improving OS either.

CONCLUSION

LND might aid in staging, prognosticating, and deciding further management of resected ICCA, but does not improve OS and DFS and is unsuitable for high-risk patients unlikely to benefit from further treatments.

Proposal for a new N-stage classification system for intrahepatic cholangiocarcinoma

Background

The number of metastatic lymph nodes (MLNs) is not considered in the nodal status (N classification) of intrahepatic cholangiocarcinoma (ICC) in the current 8thEdition of the American Joint Committee on Cancer (AJCC) staging system. The aim of this study was to find out the optimal cut-off point based on the number of MLNs and establish a modified AJCC staging system for ICC according to the new N category.

Methods

A total of 675 ICC patients diagnosed between 2004 and 2015 were retrieved from the Surveillance, Epidemiology and End Results (SEER) database. The optimal cut-off value of MLNs affecting survival was determined by X-tile software. The relative discriminative power was assessed by Harrell's concordance index (C-index) and Akaike information criterion (AIC).

Results

The proposed new nodal category subdivided patients into three groups (N0, no MLN; N1, 1-3 MLNs; and N2, ≥ 4 MLNs) with significantly different overall survival (P < 0.001). Multivariable analysis revealed that the new nodal category was an independent prognostic factor (P < 0.001). Both the C-index and AIC for our modified staging system were better than those for the 8th AJCC edition (0.574 [95% confidence interval 0.533-0.615] versus 0.570 [95% confidence interval 0.527-0.613], and 853.30 versus 854.21, respectively).

Conclusion

The modified AJCC staging system based on the number of MLNs may prove to be a useful alternative for predicting survival of ICC patients in clinical practice.

Modified staging system of positive lymph nodes based nomogram in intrahepatic cholangiocarcinoma

BACKGROUND

Intrahepatic cholangiocarcinoma (iCCA) presents the similar trend and prevalence of lymph node metastasis to other biliary tract cancer. There is still a necessity and possibility for the current classification of lymph node in the 8th TNM of iCCA, which is the same as the criteria of hepatoma carcinoma (HCC), to further improve the prognostic capacity. We aim to explore the optimal positive lymph nodes cutoff value that could predict the survival outcomes of patients with iCCA and further establish a prognostic nomogram.

METHOD

Clinical characteristics were retrospectively collected in 292 patients with iCCA from Sun Yat-sen University Cancer Center (SYSUCC) for preliminary analysis. A retrospective analysis of 107 patients with iCCA in the First Hospital of Dalian Medical University (FHDMU) was performed for verification. R software was used to determine the optimal cutoff value of positive lymph nodes (PLN) and further establish the nomogram with the Cox regression model in the primary cohort.

RESULTS

In those patients who were graded into the N1 stage in 8th TNM staging system, the patients with PLN between 1 and 3 showed significantly better overall survival than those patients with more than 4 PLN (P < 0.0001). Moreover, there was a significant correlation between the new PLN classification and adverse clinical characteristic including Micro Invasion (P = 0.001), Lymph Vessel Invasion (P = 0.040), Satellite Sites (P < 0.001), and Tumor Size (P = 0.005). The PLN and ELN were both independent prognostic factors for survival outcomes in the multivariate analysis, and further showed large contribution to the nomogram. The nomogram achieved a satisfied C-index of 0.813 for overall survival (OS), 0.869 for progression-free survival (PFS) in the primary cohort, and 0.787 for OS, 0.762 for PFS in the validation cohort.

CONCLUSION

The modified classification of PLN in iCCA could accurately stratify the N1 stage patients in 8th TNM staging system into two groups with significantly different overall survival. The development of this nomogram can offer new evidence to precisely post-operative management of iCCA patients.

The impact of tumor location on the value of lymphadenectomy for intrahepatic cholangiocarcinoma

BACKGROUND

The therapeutic role of lymphadenectomy (LND) for intrahepatic cholangiocarcinoma (ICC) patients remains ill-defined. We sought to analyze the therapeutic value of LND relative to tumor location and preoperative lymph node metastasis (LNM) risk.

METHODS

Patients who underwent curative-intent hepatic resection of ICC between 1990 and 2020 were included from a multi-institutional database. Therapeutic LND (tLND) was defined as LND that harvested ≥3 lymph nodes.

RESULTS

Among 662 patients, 178 (26.9%) individuals received tLND. Patients were categorized into central type ICC (n = 156, 23.6%) and peripheral type ICC (n = 506, 76.4%). Central type harbored multiple adverse clinicopathologic factors and worse overall survival (OS) compared with peripheral type (5-year OS, central: 27.0% vs. peripheral: 47.2%, p < 0.001). After consideration of preoperative LNM risk, patients with central type and high-risk LNM who underwent tLND survived longer than individuals who did not (5-year OS, tLND: 27.9% vs. non-tLND: 9.0%, p = 0.001), whereas tLND was not associated with better survival among patients with peripheral type ICC or low-risk LNM. The therapeutic index of hepatoduodenal ligament (HDL) and other regions was higher in central type than in peripheral type, which was more pronounced among high-risk LNM patients.

CONCLUSIONS

Central type ICC with high-risk LNM should undergo LND involving regions beyond the HDL.

Dynamic evaluation of postoperative survival in intrahepatic cholangiocarcinoma patients who did not undergo lymphadenectomy: a multicenter study

BACKGROUND

The prognosis of Intrahepatic cholangiocarcinoma (ICC) patients who did not undergo lymphadenectomy is difficult to assess. This study aims to have a dynamic evaluation on the postoperative survival of ICC patients by calculating conditional survival.

METHODS

Relevant data were from patients treated in 12 large-scale hospitals from December 2011 to December 2017. The influence of relevant clinical baseline data on the prognosis of ICC patients was analyzed by Cox regression. Conditional survival (CS) is a method that may predict the prognostic probability dynamically. For a patient with x years of survival, the 1-year CS (CS1) may be calculated as CS1= OS(x + 1)/OS(x).

RESULT

A total of 361 patients who met the criteria were included in the study. Conditional survival (CS) means that the patients' prognosis varies with survival time, meanwhile, relevant factors affecting the prognosis have a time-varying effect. The probability of survival assessed by CS1 increased year by year and the 1,2,3-year survival improved from 68.4% to 87.8%, while the postoperative actuarial OS decreased from 69.4% at 1 years to 36.9% at 3 years.

CONCLUSIONS

In terms of CS, the estimated survival for ICC varies with the increase of survival time after excision. Patients who live longer were likely to live longer. At the same time, with the passage of time, the role of the original adverse factors of the tumor would gradually decrease. Conditional survival allows a more accurate assessment of ICC patients who did not undergo lymphadenectomy.

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.

Surgical Aspects of Intrahepatic Cholangiocarcinoma

Intrahepatic cholangiocarcinoma (ICC) is a rare and aggressive malignancy. It originates from the bile ducts and is the second most common primary cancer of the liver. Surgery is considered the only curative treatment of ICC, offering the best chance for long-term survival. The purpose of this article is to review the available literature on ICC, with a focus on the various aspects of the surgical care in this potentially lethal malignancy.

Prognostic impact of the metastatic lymph node number in intrahepatic cholangiocarcinoma

BACKGROUND

Lymph node metastasis in intrahepatic cholangiocarcinoma is a poor prognostic factor after radical surgery. However, unlike other biliary tract malignancies, the nodal stage of intrahepatic cholangiocarcinoma only reflects the presence of metastatic lymph nodes, not the number of metastatic lymph nodes. This study aimed to identify the prognostic impact of the metastatic lymph node number in intrahepatic cholangiocarcinoma.

METHODS

The data from 87 patients with intrahepatic cholangiocarcinoma who had undergone hepatectomy with 5 or more harvested lymph nodes and covering stations 12 and 8 based on the previous criteria from January 2006 to December 2019 were retrospectively reviewed. The hazard ratio according to the increasing metastatic lymph node number was calculated with other known prognostic factors for intrahepatic cholangiocarcinoma. The patients were then divided into 3 groups according to the metastatic lymph node number (N0 [n = 45]: no metastatic lymph nodes; N⁺ <4 [n = 32]: 1 to 3 metastatic lymph nodes; N⁺ ≥4 [n = 10]: ≥4 metastatic lymph nodes). Disease-free survival and overall survival were also analyzed.

RESULTS

The metastatic lymph node number was a prognostic factor of oncologic survival (disease-free survival: hazard ratio = 1.18 [1.05-1.32], P = .005; overall survival: hazard ratio = 1.21 [1.06-1.37], P = .004). Survival analysis revealed significantly poorer outcomes with an increasing metastatic lymph node number (disease-free survival: N0 vs N⁺ <4 vs N⁺ ≥4: 36.0 [0.0-76.0] vs 8.0 [0.0-16.9] vs 2.0 [0.0-5.1] months, P < .001; overall survival: N0 vs N⁺ <4 vs N⁺ ≥4: 69.0 [24.5-113.5] vs 28.0 [18.9-37.1] vs 11.0 [6.4-15.6] months, P < .001). In post hoc analysis, a significant difference was found between adjacent groups (disease-free survival and overall survival: N⁺ <4 vs N⁺ ≥4, P = .001).

CONCLUSION

With proper lymph node dissection, the number of metastatic lymph nodes is a prognostic factor of intrahepatic cholangiocarcinoma.

Surgical management of intrahepatic cholangiocarcinoma

INTRODUCTION

Intrahepatic cholangiocarcinoma (ICC) incidence continues to rise worldwide, and overall survival remains poor. Complete surgical resection remains the only opportunity for cure in patients with ICC yet only one-third of patients present with resectable disease.

AREAS COVERED

While the low incidence rate of ICC hinders accrual of patients to large, randomized control trials, larger database and long-term institutional studies provide evidence to guide surgical management of ICC. These studies demonstrate feasibility, safety, and efficacy of aggressive surgical management in appropriately selected patients with ICC. Recent advances in the management of ICC, with a focus on surgical considerations, are reviewed.

EXPERT OPINION

Historically, little progress has been made in the management of ICC with stagnant mortality rates and poor long-term outcomes. However, regionalization of care to centers with experienced multidisciplinary teams, advances in minimally invasive surgical techniques, discovery and development of targeted and immunotherapy agents, and combination locoregional and systemic therapies offer signs of progress in the management of ICC.