Perihilar cholangiocarcinoma: paradigms of surgical management

Conversion therapy in advanced perihilar cholangiocarcinoma based on patient-derived organoids: A case report

BACKGROUND

Patient-derived organoids (PDOs) have been demonstrated to predict the response to drugs in multiple cancer types. However, it remains unclear about its application in cholangiocarcinoma.

CASE SUMMARY

A 59-year-old woman was admitted to the hospital due to upper abdominal pain for over 8 months. According to relevant examinations, she was diagnosed as perihilar cholangiocarcinoma (pCCA) with intrahepatic metastasis and perihilar lymphatic metastasis. After multidisciplinary team discussion, percutaneous transhepatic cholangiodrainage was performed to relieve biliary obstruction, and puncture biopsy was conducted to confirm the pathological diagnosis. Transarterial chemoembolization with nab-paclitaxel was used in combination with toripalimab and lenvatinib, but the levels of tumor markers including alpha fetal protein, carcinoembryonic antigen, carbohydrate antigen 15-3 and cancer antigen 125 were still raised. The PDO for drug screening showed sensitive to gemcitabine and cisplatin. Accordingly, the chemotherapy regimen was adjusted to gemcitabine and cisplatin in combination with toripalimab and lenvatinib. After 4 cycles of treatment, the tumor was assessed resectable, and radical surgical resection was performed successfully. One year after surgery, the patient was still alive, and no recurrence or occurred.

CONCLUSION

PDOs for drug sensitivity contribute to screening effective chemotherapy drugs for advanced pCCA, promoting conversion therapy and improving the prognosis.

The Role of Single-Nucleotide Polymorphisms in Cholangiocarcinoma: A Systematic Review

Single-nucleotide polymorphisms (SNPs) play an essential role in various malignancies, but their role in cholangiocarcinoma (CCA) remains to be elucidated. Therefore, the purpose of this systematic review was to evaluate the association between SNPs and CCA, focusing on tumorigenesis and prognosis. A systematic literature search was carried out using PubMed, Embase, Web of Science and the Cochrane database for the association between SNPs and CCA, including literature published between January 2000 and April 2022. This systematic review compiles 43 SNPs in 32 genes associated with CCA risk, metastatic progression and overall prognosis based on 34 studies. Susceptibility to CCA was associated with SNPs in genes related to inflammation (PTGS2/COX2, IL6, IFNG/IFN-γ, TNF/TNF-α), DNA repair (ERCC1, MTHFR, MUTYH, XRCC1, OGG1), detoxification (NAT1, NAT2 and ABCC2), enzymes (SERPINA1, GSTO1, APOBEC3A, APOBEC3B), RNA (HOTAIR) and membrane-based proteins (EGFR, GAB1, KLRK1/NKG2D). Overall oncological prognosis was also related to SNPs in eight genes (GNB3, NFE2L2/NRF2, GALNT14, EGFR, XRCC1, EZH2, GNAS, CXCR1). Our findings indicate that multiple SNPs play different roles at various stages of CCA and might serve as biomarkers guiding treatment and allowing oncological risk assessment. Considering the differences in SNP detection methods, patient ethnicity and corresponding environmental factors, more large-scale multicentric investigations are needed to fully determine the potential of SNP analysis for CCA susceptibility prediction and prognostication.

Defining Facility Volume Threshold for Optimization of Short- and Long-Term Outcomes in Patients Undergoing Resection of Perihilar Cholangiocarcinoma

BACKGROUND

We determined the minimum threshold (Tmin) of annual facility case volume to optimize outcomes for patients with resected perihilar cholangiocarcinoma.

METHODS

We identified patients with localized perihilar cholangiocarcinoma who underwent resection within the National Cancer Database (2010-2017). We used marginal structural logistic regression models to estimate the average treatment effect of receiving care in facilities meeting/exceeding Tmin on 90-day mortality and other postoperative outcomes.

RESULTS

A total of 2471 patients underwent resection for perihilar cholangiocarcinoma at 471 facilities. There was no effect of total hepatopancreatobiliary, surgical hepatopancreatobiliary, total hepatobiliary, surgical hepatobiliary, or total perihilar cholangiocarcinoma case volume on 90-day mortality. A Tmin of seven perihilar cholangiocarcinoma resections/year resulted in lower odds of 90-day mortality (IP-weighted OR = 0.49, 95% CI: 0.66-0.87). A total of two facilities met the Tmin. Patients receiving treatment at Tmin facilities had lower odds of length of stay ≥ 7 days (IP-weighted OR = 0.85, 95% CI: 0.75-0.97) and positive surgical resection margins (IP-weighted OR = 0.40, 95% CI: 0.47-0.55). Additionally, undergoing surgery at Tmin facilities resulted in higher (≥ 4 nodes) lymph node yields (IP-weighted OR = 1.94, 95% CI: 1.21-3.11) but no change in the odds of nodal positivity. There was no effect of undergoing surgery at Tmin facilities on 30-day mortality or re-admission.

CONCLUSIONS

Resection of perihilar cholangiocarcinoma is infrequently performed at a high number of facilities. A Tmin of ≥ 7 resections/year resulted in lower 90-day mortality and improved postoperative outcomes. Our data suggest that regionalization of care for patients with perihilar cholangiocarcinoma could potentially improve outcomes in the USA.

Diagnostic accuracy of probe-based confocal laser endomicroscopy and tissue sampling by endoscopic retrograde cholangiopancreatography in indeterminate biliary strictures: a meta‑analysis

Probe-based confocal laser endomicroscopy (pCLE), also known as optical biopsy, is a new endoscopic technique that provides real-time magnification of 1000 × microscopic tissue information to diagnose indeterminate biliary strictures. Tissue sampling by endoscopic retrograde cholangiopancreatography (ERCP) is routinely performed to evaluate indeterminate biliary strictures. To evaluate the accuracy of pCLE and tissue sampling by ERCP in the diagnosis of indeterminate biliary strictures, 18 articles were included from 2008 to 2021 through Embase, PubMed, Web of Science, and Cochrane library databases. The summary estimates for the pCLE diagnosis of indeterminate biliary strictures were: sensitivity 0.88 (95% confidence interval (CI), 0.84-0.91); specificity 0.79 (95% CI 0.74-0.83); and Diagnostic Odds Ratio (DOR) 24.63 (95% CI 15.76-38.48). The summary estimates for tissue sampling by ERCP diagnosis for indeterminate biliary strictures were: sensitivity 0.54 (95% CI 0.49-0.59); specificity 0.96 (95% CI 0.94-0.98); and DOR 11.31 (95% CI 3.90-32.82). The area under the sROC curve of pCLE diagnosis of indeterminate biliary strictures is 0.90 higher than 0.65 of tissue sampling by ERCP. The pCLE is a better approach than tissue sampling by ERCP for the diagnosis of indeterminate biliary strictures by providing real-time microscopic images of the bile ducts.

Cordycepin Sensitizes Cholangiocarcinoma Cells to Be Killed by Natural Killer-92 (NK-92) Cells

Immunotherapy harnessing immune functions is a promising strategy for cancer treatment. Tumor sensitization is one approach to enhance tumor cell susceptibility to immune cell cytotoxicity that can be used in combination with immunotherapy to achieve therapeutic efficiency. Cordycepin, a bioactive compound that can be extracted from some Cordyceps spp. has been reported to effectively inhibit tumor growth, however, the mechanism of its tumor sensitization activity that enhances immune cell cytotoxicity is unknown. In the present study, we investigated the potency of cordycepin to sensitize a lethal cancer, cholangiocarcinoma (CCA), to natural killer (NK) cells. Treatment with cordycepin prior to and during co-culturing with NK-92 cells significantly increased cell death of KKU-213A as compared to solitary cordycepin or NK treatment. Moreover, sensitization activity was also observed in the combination of NK-92 cells and Cordyceps militaris extract that contained cordycepin as a major component. The cordycepin treatment remarkably caused an increase in TRAIL receptor (DR4 and DR5) expression in KKU-213A, suggesting the possible involvement of TRAIL signaling in KKU-213A sensitization to NK-92 cells. In conclusion, this is the first report on the sensitization activity of cordycepin on CCA cells to NK cytotoxicity, which supports that cordycepin can be further developed as an alternate immunomodulating agent.

Prediction of prognosis and resectability using MR imaging, clinical, and histopathological findings in patients with perihilar cholangiocarcinoma

PURPOSE

To predict poor overall survival (OS) and risk of residual tumor after surgery using MR imaging, clinical, and histopathological findings in perihilar cholangiocarcinoma.

METHODS

196 patients with perihilar cholangiocarcinoma who underwent preoperative MRI and curative-intent surgery were retrospectively included. MRI findings were assessed by two radiologists. Clinical characteristics and histopathological results such as serum carcinoembryonic antigen (CEA), carbohydrate antigen 19-9 (CA 19-9), T and N stage, and resection status, were also investigated. Cox regression analysis and the Kaplan-Meier method were used to identify prognostic factors for OS. We further analyzed the correlation between MRI features and residual tumors using logistic regression analysis.

RESULTS

The median OS was 25.0 ± 26.6 months. T stage (hazard ratio [HR] 6.26, p = 0.014), N stage (HR 1.86, p = 0.002), CA-19-9 >37 U/mL (HR 2.06, p < 0.001), enlarged LN on MRI (HR 1.69, p = 0.006), and residual tumor (HR 1.52, p = 0.034) were important predictors of poor survival. The 5-year OS of the complete resection group (n = 107) was significantly better than that of the residual tumor group (n = 89) (35.5% vs. 18.8%, p = 0.002). Additionally, peritumoral fat stranding (odds ratio[OR] 2.09, p = 0.027), Bismuth type III/IV (OR 1.95, p = 0.022), and common bile duct (CBD) involvement (OR 2.3, p = 0.008) on MRI were important predictors of residual tumors in univariate analyses. However, absence of peritumoral fat stranding was a significant independent predictor for complete resection (OR 1.99, p = 0.048) and showed the highest sensitivity, at 79.8%.

CONCLUSION

MR imaging, clinical and histopathological results are useful for predicting poor survival after surgery for perihilar cholangiocarcinoma. Furthermore, MRI findings, including peritumoral fat stranding, CBD involvement, and Bismuth type, are important for the prediction of residual tumors.

Left-side vs. right-side hepatectomy for hilar cholangiocarcinoma: a meta-analysis

GOALS

We aim to draw a conclusion which type of hepatectomy could be the priority for hilar cholangiocarcinoma patients.

BACKGROUND

Surgery is established as only potentially curative treatment for hilar cholangiocarcinoma. However, whether hepatectomy should be preferred to the left-side hepatectomy, which includes left hemihepatectomy, extended left hemihepatectomy, and left trisectionectomy, or right-side hepatectomy, which represents right hemihepatectomy, extended right hemihepatectomy, and right trisectionectomy, is debated. In this meta-analysis, we evaluated and compared the efficacy and safety of left-side hepatectomy and right-side hepatectomy in patients with hilar cholangiocarcinoma.

STUDY

We systematically retrieved the MEDLINE, PubMed, and Cochrane library and related bibliography up to February 2020. The primary outcome is overall survival, and the secondary outcome includes 1-, 3-, and 5-year survival rates, morbidity, mortality, R0 resection rate, and operation time. Based on heterogeneity, fixed-effects model or random-effects models were established through meta-analysis.

RESULTS

Eleven studies (11 cohort studies, totally 1031 patients) were involved in this study. The overall survival of patients who underwent left-side hepatectomy was comparable to that of patients who underwent right-side hepatectomy (hazard ratio, 1.27 [95% confidence interval, 0.98-1.63]). And there was no significant difference observed in 1-year (relative risk, 1.01 [95% CI, 0.89-1.15]), 3-year (relative risk, 0.94 [95% confidence interval, 0.80-1.11]), and 5-year survival (relative risk, 0.82 [95% confidence interval, 0.67-1.01]) rates between the left-side hepatectomy group and the right-side hepatectomy group. Comparing with the right-side hepatectomy cluster, the hilar cholangiocarcinoma patients in the left-side hepatectomy cluster presented better overall postoperative morbidity (relative risk, 0.82 [95% confidence interval, 0.71-0.96]) and major postoperative morbidity (relative risk, 0.73 [95% confidence interval, 0.56-0.95]). The post-hepatectomy liver failure rate (relative risk, 0.22 [95% confidence interval, 0.09-0.56]) and procedure-related mortality (relative risk, 0.41 [95% confidence interval, 0.23-0.70]) in the left-side hepatectomy group were better than those of the right-side hepatectomy group. Besides, the R0 resection rate was similar between the left-side hepatectomy group and the right-side hepatectomy group (relative risk, 0.95 [95% confidence interval, 0.87-1.03]). And the operation time for the left-side hepatectomy was significantly longer than that for the right-side hepatectomy (mean difference, 38.68 [95% confidence interval, 7.41-69.95]).

CONCLUSION

Through meta-analysis, we explored the comparable long-term outcomes and better short-term outcomes in the left-side hepatectomy group as is compared to the right-side hepatectomy group of hilar cholangiocarcinoma patients. In this study, the evidence obtained might indicate that the choice of left-side hepatectomy or right-side hepatectomy depends on the site of hilar cholangiocarcinoma in every patient.

Unaltered Liver Regeneration in Post-Cholestatic Rats Treated with the FXR Agonist Obeticholic Acid

In a previous study, obeticholic acid (OCA) increased liver growth before partial hepatectomy (PHx) in rats through the bile acid receptor farnesoid X-receptor (FXR). In that model, OCA was administered during obstructive cholestasis. However, patients normally undergo PHx several days after biliary drainage. The effects of OCA on liver regeneration were therefore studied in post-cholestatic Wistar rats. Rats underwent sham surgery or reversible bile duct ligation (rBDL), which was relieved after 7 days. PHx was performed one day after restoration of bile flow. Rats received 10 mg/kg OCA per day or were fed vehicle from restoration of bile flow until sacrifice 5 days after PHx. Liver regeneration was comparable between cholestatic and non-cholestatic livers in PHx-subjected rats, which paralleled liver regeneration a human validation cohort. OCA treatment induced ileal Fgf15 mRNA expression but did not enhance post-PHx hepatocyte proliferation through FXR/SHP signaling. OCA treatment neither increased mitosis rates nor recovery of liver weight after PHx but accelerated liver regrowth in rats that had not been subjected to rBDL. OCA did not increase biliary injury. Conclusively, OCA does not induce liver regeneration in post-cholestatic rats and does not exacerbate biliary damage that results from cholestasis. This study challenges the previously reported beneficial effects of OCA in liver regeneration in cholestatic rats.

Anti-Proliferative Effects of Compound A and Its Effect in Combination with Cisplatin in Cholangiocarcinoma Cells

BACKGROUND

Cholangiocarcinoma (CCA) is a fatal cancer with high resistance to anticancer drugs.  The development of new drugs or compounds to be used alone or in combination with currently available chemotherapeutic agents to improve the treatment of CCA is needed. Compound A (CpdA), which is a small plant-derived glucocorticoid receptor modulator, strongly inhibited the growth and survival of several cancers.  However, the effect of CpdA on cholangiocarcinoma has not been elucidated. The aim of this study was to investigate the effect of CpdA on CCA.

METHODS

Cytotoxicity of CpdA was tested in primary cells including peripheral blood mononuclear cells (PBMCs), fibroblasts, and human umbilical vein endothelial cells (HUVECs), as well as on CCA cell lines (KKU-100, KKU-055, and KKU-213) was examined. Cell cycle distribution and IL-6 expression was assessed by flow cytometry and real-time polymerase chain reaction, respectively.  The effect of combination CpdA and cisplatin was evaluated by cell viability assay.

RESULTS

CpdA significantly inhibited cell cycle at G1 phase in CCA cell lines, and reduced IL-6 mRNA expression.  However, combination CpdA and cisplatin did not enhance the inhibitory effect. TGFβR-II expression was increased in CCA cells after the combination treatment.

CONCLUSIONS

These results indicate the potential of CpdA for CCA treatment. However, combination treatment with CpdA and cisplatin increased CCA cell survival. The molecular mechanism is likely attributable to promotes cell survival via the TGFβR-II signaling pathway. The combination of CpdA with other anticancer drugs for CCA treatment should be further examined.

Mass-forming intrahepatic cholangiocarcinoma with portal vein tumor thrombus and bile duct tumor thrombus: A case report

•

This is the first case of mass-forming intrahepatic cholangiocarcinoma with portal vein tumor thrombus and bile duct tumor thrombus, where the extrahepatic bile duct was preserved with thrombectomy.

•

Thrombectomy can be a valid option for intrahepatic cholangiocarcinoma with tumor thrombus, as well as for hepatocellular carcinoma.

Introduction

We report the first case of mass-forming intrahepatic cholangiocarcinoma (ICC) with portal vein tumor thrombus (PVTT) and bile duct tumor thrombus (BDTT), where the extrahepatic bile duct was preserved with thrombectomy.

Presentation of case

A 70-year-old male. Magnetic resonance imaging (MRI) showed the tumor extending from the hepatic hilum to the left hepatic duct with complete obstruction of the left hepatic duct and a defect at the left portal vein. We planned to perform extended left lobectomy, lymph node dissection, extra hepatic bile duct resection and reconstruction based on the diagnosis of mass-forming ICC with left portal vein and left hepatic duct infiltration (cT3N0M0 Stage III). Intraoperative cholangiography revealed a crab claw-like filling defect at the left hepatic duct, which suggested tumor thrombus. Accordingly, we performed thrombectomy. The margin of the left hepatic duct was tumor negative, so we performed extended left lobectomy, lymph node dissection and thrombectomy. Pathologically, the tumor was diagnosed as ICC (pT4N0M0 Stage IVA, vp3, b3). Tumors in the left hepatic duct and left portal vein proved to be tumor thrombus. The postoperative course was uneventful. He is doing well without recurrence.

Discussion

Thrombectomy is performed for hepatocellular carcinoma (HCC) with tumor thrombus. Furthermore, extrahepatic bile duct resection and reconstruction are recommended for ICC. In this case, intraoperative cholangiography was effective for precisely diagnosing. Thrombectomy could reduce surgical stress and prevent complications.

Conclusions

Thrombectomy can be a valid option for ICC with tumor thrombus, as well as for HCC.

Treatment of unresectable extrahepatic cholangiocarcinoma using hematoporphyrin photodynamic therapy: A prospective study

BACKGROUND

The available evidence of Photodynamic therapy (PDT) combined with stent placement treatment for unresectable extrahepatic cholangiocarcinoma (EHCC) is still insufficient. It also remains unclear whether PDT influences systemic inflammatory response.

AIM

To explore the clinical efficacy and safety of the combination treatment and the systemic inflammatory response in patients with EHCC.

METHODS

Patients with unresectable EHCC underwent either the combined treatment using Hematoporphyrin PDT and stent placement (PDT+stent group, n=12) or stent-only (stent group, n=27). The primary end-point was overall survival. Tumor necrosis factor (TNF)-α and interleukin (IL)-6 levels were measured. Quality of life was assessed using the Karnofsky performance scale (KPS) every 3 months.

RESULTS

Average survival time (13.8 vs. 9.6 months), and 6-month (91.7% vs. 74.1%), and 1-year (58.3% vs. 3.7%) survival rates of PDT+stent group were significantly increased compared with the stent group. KPS scores in the PDT+stent group were significantly improved. TNF-α and IL-6 levels were significantly increased in the PDT+stent group.

CONCLUSION

Hematoporphyrin-PDT combined with stent placement is an effective and safe treatment for EHCC. The treatment might promote systemic inflammatory response.

Evaluating the Clinical Applicability of the European Staging System for Perihilar Cholangiocarcinoma

BACKGROUND

In 2011, a new European Staging System (ESS) for perihilar cholangiocarcinoma (PHC) was proposed with the expressed purpose of comparing treatment and outcomes data between institutions. The goal of this study was to evaluate the feasibility of ESS data capture.

STUDY DESIGN

Forty-seven consecutive patients who underwent surgical resection for PHC between 1999 and 2013 were studied. Demographic variables, components of various staging systems (including the ESS), preoperative and perioperative details, pathology, and outcomes were recorded.

RESULTS

The mean patient age was 63.2 and 62% were male. Preoperative imaging included high-resolution CT in all patients, MRI in 34%, and PET in 11%. R0 resection was accomplished in 80% of patients. Four patients (8.5%) and 18 patients (38.3%), respectively, received neoadjuvant or adjuvant therapy. During a mean follow-up of 36 months, recurrence rate was 51.3% and 2- and 5-year survival rates were 69.4 and 33.3%, respectively. Analysis of data capture found that tumor (T) classification was indeterminable in 7/47 patients (14.9%). For two patients, the form (F) designation had insufficient data. The extent of vascular involvement (PV/HA) was different compared to preoperative imaging in nine patients (19.1%). The liver remnant volume (V) was calculated in only 18 patients (38.3%). The liver disease (D) variable did not account for four patients with inflammation/cirrhosis. In total, only 15 patients (31.9%) had all required elements to complete the ESS.

CONCLUSIONS

Without templated radiology, surgery, and pathology reports, the ESS cannot be applied to current clinical/research practice. Although resection continues to provide significant survival benefit to patients with perihilar cholangiocarcinoma, lack of an accurate prognostic tool for resectability and outcomes continues to be a major impediment to progress in the field.

Metastatic colon cancer from extrahepatic cholangiocarcinoma presenting as painless jaundice: case report and literature review

Cholangiocarcinoma (CCA) is a rare cancer of the biliary epithelium comprising only about 3% of all gastrointestinal malignancies. It is a highly aggressive malignancy and confers a dismal prognosis with majority of patients presenting with metastatic disease. Metastatic CCA to the colon is extremely rare with only few cases reported in the literature. We present a 61-year-old patient with incidental synchronous metastatic colonic adenocarcinoma from extra-hepatic CCA. Laboratory data revealed significant indirect hyperbilirubinemia and transaminitis. Imaging study showed intrahepatic bile ducts prominence without mass lesions. Incidentally, there was diffuse colonic thickening without mass lesions or obstruction. Endoscopic retrograde cholangiopancreatography (ERCP) showed a common bile duct stricture. Brushings were consistent with CCA. Screening colonoscopy identified nodularity and biopsy and immunostaining were consistent with CCA metastasis to colon. The patient elected for palliative and comfort care. Metastatic CCA to the colon is a rare pattern of distant spread that may pose a diagnostic challenge. Some salient characteristics may assist in the differentiation of primary colon cancer and metastatic colon cancer from CCA. Little remains known about the pathogenic behavior of metastatic secondary colorectal cancer. And more so, the management approach to such metastatic cancer still remains to be defined. Screening colonoscopy in patients presenting with resectable CCA may alter management. Furthermore, whether patients with history of resected CCA may benefit from a more frequent screening colonoscopy remains to be validated.

Is Pancreaticoduodenectomy Feasible for Recurrent Remnant Bile Duct Cancer Following Bile Duct Segmental Resection?

BACKGROUND

When bile duct cancer recurs after surgery, treatment options are limited. This study examines the usefulness of reoperative pancreaticoduodenectomy for recurrent cancer after initial segmental bile duct resection.

METHODS

Six patients (5 males, 1 females; median age 65 years) who underwent pancreaticoduodenectomy for recurrent remnant bile duct cancer following segmental bile duct resection were included: 4 underwent surgery at Severance Hospital and 2 at Gangnam Severance Hospital from January 2000 to December 2013. Medical records data were retrospectively reviewed, including demographics, type of first and second surgery, radicality of resection, TNM stage, adjuvant treatments, complications, and survival. Kaplan-Meier curves were used to analyze survival.

RESULTS

The median interval between operations was 57 (range 7-95) months. Median operation time was 6.9 (range 5.2-12.8) h, blood loss was 400 (range 50-1170) mL, intensive care unit stay was 1 (range 1-2) day, and postoperative hospital stay was 33 (range 15-55) days. No patient died. Four had severe complications. The median survival after pancreaticoduodenectomy was 16 (range 5-89) months. Four patients had recurrence. T stage, N stage, and resection radicality influenced survival.

CONCLUSION

Pancreaticoduodenectomy is reasonable for recurrent remnant bile duct cancer following segmental bile duct resection, particularly for patients with no distant metastasis, locally confined recurrence, and good general condition.

Lymph node dissection in resectable perihilar cholangiocarcinoma: a systematic review

BACKGROUND

Perihilar cholangiocarcinoma is usually unresectable at the time of diagnosis. Only few patients are candidates for a potential curative treatment. For those patients, prognosis is strongly related to negative resection margin and lymph node status. Thus, a certain benchmark of lymph node count is necessary to secure relevant lymph node recovery and to avoid understaging. However, the required minimum number of retrieved lymph nodes remains unclear for perihilar cholangiocarcinoma. The 7th American Joint Committee on Cancer tumor, nodes, metastases edition increased the requirement for the histologic examination of lymph nodes in perihilar cholangiocarcinoma patients from 3 to 15. The applicability of such recommendation appears difficult and questionable. Therefore, the purpose of this systematic review is to evaluate the number of retrieved lymph nodes for staging of patients undergoing surgery for perihilar cholangiocarcinoma.

METHODS

The MEDLINE, EMBASE, and The Cochrane Library databases were systematically screened up to December 2014. All studies reporting the number of lymph node count in perihilar cholangiocarcinoma were included and assessed for eligibility.

RESULTS

A total of 725 abstracts were screened and 20 studies were included for analysis, comprising almost 4,000 patients. The cumulative median lymph node count was 7 (2 to 24). A median lymph node count greater than or equal to 15 was reported in 9% of perihilar cholangiocarcinoma patients and could only be achieved in extended lymphadenectomy. Subgroup analysis revealed a median lymph node count of 7 (range 7 to 9), which was associated with the detection of most lymph node positive patients and showed the lowest risk for understaging patients. Lymph node count greater than or equal to 15 did not increase detection rate of lymph node positive patients.

CONCLUSIONS

This systematic analysis suggests that lymph node count greater than or equal to 7 is adequate for prognostic staging, while lymph node count greater than or equal to 15 does not improve detection of patients with positive lymph nodes.