Resection For Extrahepatic Cholangiocarcinoma Research Articles

Evaluating Clinical Utility of CT DNA Monitoring for Recurrence Prediction in Resected Extrahepatic Cholangiocarcinoma

Evaluating Clinical Utility of CT DNA Monitoring for Recurrence Prediction in Resected Extrahepatic Cholangiocarcinoma

Circulating tumor DNA status and dynamics predict recurrence in patients with resected extrahepatic cholangiocarcinoma

Background & AimsSurgery is the only curative therapeutic option for resectable extrahepatic cholangiocarcinoma (eCCA), but recurrence is common, and prognosis is poor. There is an unmet clinical need for improved decision-making regarding adjuvant chemotherapy (ACT). Here we evaluated the usefulness of monitoring longitudinal circulating tumor DNA (ctDNA) for minimal residual disease (MRD) in patients of the STAMP trial, which compares the efficacy of adjuvant capecitabine (CAP) versus gemcitabine plus cisplatin (GemCis). MethodsBetween July 2017 and November 2020, 101 patients were randomized 1:1 to receive GemCis (n=50) or CAP (n=51). Efficacy outcomes were analyzed with an extended follow-up of 19 months from the previous report. From a biomarker cohort of 89 patients, longitudinal plasma samples (n=254) were prospectively collected post-surgery before adjuvant chemotherapy (ACT), and on-ACT at 12 and 24 weeks from cycle 1 day 1 (C1D1). ctDNA was evaluated using a personalized, tumor-informed, 16-plex PCR-NGS assay and was correlated with clinical outcomes. ResultsIn the extended follow-up analysis, median disease-free survival (DFS) and overall survival (OS) did not significantly differ between the CAP and GemCis groups. Significantly inferior DFS was associated with ctDNA-positivity before ACT (HR, 1.8; p=0.029), on-ACT at 12 weeks from C1D1 (HR, 7.72; p<0.001), on-ACT at 24 weeks from C1D1 (HR, 5.24; p<0.001), and anytime post-surgery (HR, 3.81; p<0.001). Analysis of pre-treatment to on-treatment ctDNA dynamics revealed that serially ctDNA-negative patients exhibited a significantly longer DFS compared to those with sustained ctDNA-positivity (HR, 6.7; p<0.001) or who turned ctDNA-positive (HR, 5.8; p<0.001). ConclusionIn patients with resected eCCA, ctDNA status and dynamics predicted recurrence during adjuvant therapy, and may help optimize clinical decision-making. Impact and implicationsThe findings from this study highlight the critical role of ctDNA as a prognostic biomarker and monitoring tool for patients with resected extrahepatic cholangiocarcinoma (eCCA). By demonstrating the superiority of ctDNA to predict disease recurrence compared to conventional biomarkers such as CA 19-9 and CEA, this study underscores its potential in guiding decision-making during adjuvant chemotherapy. These results may be crucial to refine post-surgical treatment strategies and improve patient outcomes. The practical application of ctDNA monitoring could lead to more personalized treatment approaches, enabling timely interventions based on minimal residual disease (MRD) status. Clinical Trial Registration numberNCT03079427

Abstract 6422: Comprehensive proteogenomic profiling and biomarker analyses in resected extrahepatic cholangiocarcinoma: A prespecified exploratory analysis of the phase 2 STAMP trial

Abstract Background: Biliary tract cancer constitutes a heterogeneous group of diseases with a limited understanding of its molecular characteristics and prognostic/predictive biomarkers. We performed prespecified exploratory analyses of the STAMP trial, a multicenter randomized phase 2 trial of adjuvant capecitabine (CAP) or gemcitabine plus cisplatin (GemCis) for patients with resected extrahepatic cholangiocarcinoma (EH-CCA) with regional lymph node metastasis. Methods: Among 101 patients included in the intention-to-treat population of the STAMP trial, a total of 89 patients (45 in the GemCis group and 44 in the CAP group) were included in the current biomarker analysis after excluding 12 patients without available tissue and blood samples. Whole exome sequencing and proteomics were performed using surgical specimens. Results: TP53 (63%), SMAD4 (20%), and KRAS (18%) mutations were the most frequent in the pooled population. Somatic mutations in homologous recombination deficient (HRD) genes were present in 20% of patients, while one patient (1%) had a germline ATM mutation. The prevalence of microsatellite instability was 1%. Somatic mutations in known targetable genes were observed in 54 patients (60.7%) and proteogenomic integrative analysis revealed significant HER2 pathway alteration with HER2 amplification in 4 patients (7%). The characteristics of prognostic biomarkers varied by the adjuvant regimen used. In the adjuvant GemCis group, somatic mutations were associated with poor disease-free survival (DFS) and overall survival (OS), including KRAS (log-rank p=0.004 for DFS and p=0.003 for OS), FBXW7 (p=0.021 for DFS and p=0.011 for OS), and PIK3CA (p&amp;lt;0.001 for DFS and p=0.042 for OS) mutations. In the adjuvant CAP group, copy number alterations (CNAs) such as 8q24.21 amplification (p=0.006 for DFS and p=0.707 for OS) and 3q26.1 amplification (p=0.020 for DFS and p=0.026 for OS) were associated with poor survival, while 11q13.3 amplification (p=0.017 for DFS and p=0.099 for OS) was associated with improved survival. Additionally, a higher HRD score showed a tendency toward better DFS and OS in the GemCis group, but not in the CAP group, although it did not reach statistical significance in both groups (p&amp;gt;0.05). Non-negative matrix clustering of proteomics data classified patients into 4 clusters. Among those, cluster 2, which showed alterations in the metabolism pathway, was associated with higher CNA level, higher tendency of HRD scores, and favorable survival with GemCis (p=0.039 for DFS and p=0.100 for OS) but not with CAP. Conclusions: Comprehensive proteogenomic analyses enable the identification of prognostic biomarkers and may guide the selection of adjuvant chemotherapy in resected EH-CCA. Citation Format: Hyehyun Jeong, Ji-Hye Oh, Hee-Sung Ahn, Baek-Yeol Ryoo, Kyu-pyo Kim, Jae Ho Jeong, Inkeun Park, Seung-Mo Hong, Jinho Shin, Chae Won Park, Yoo Sook Cho, Kyunggon Kim, Chang Ohk Sung, Changhoon Yoo. Comprehensive proteogenomic profiling and biomarker analyses in resected extrahepatic cholangiocarcinoma: A prespecified exploratory analysis of the phase 2 STAMP trial [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6422.

Prognostic Impact of Malnutrition Diagnosed by the GLIM Criteria for Resected Extrahepatic Cholangiocarcinoma.

Recently, the Global Leadership Initiative on Malnutrition (GLIM), which includes the world's leading clinical nutrition societies, proposed the first global diagnostic criteria for malnutrition. However, the association between malnutrition diagnosed by the GLIM criteria and prognosis in patients with resected extrahepatic cholangiocarcinoma (ECC) remains unknown. This study aimed to investigate the predictive validity of the GLIM criteria for the prognosis of patients with resected ECC. Between 2000 and 2020, 166 patients who underwent curative-intent resection for ECC were retrospectively analyzed. Prognostic significance of preoperative malnutrition diagnosed by the GLIM criteria was investigated using a multivariate Cox proportional hazards model. Eighty-five (51.2%) and 46 (27.7%) patients were diagnosed with moderate and severe malnutrition, respectively. Increased malnutrition severity tended to be correlated with increased lymph node metastasis rate (p-for-trend=0.0381). The severe malnutrition group had worse 1-, 3-, and 5-year overall survival rates than the normal (without malnutrition) group (82.2% vs. 91.2%, 45.6% vs. 65.1%, 29.3% vs. 61.5%, respectively, p=0.0159). In multivariate analysis, preoperative severe malnutrition was an independent predictor for poor prognosis (hazard ratio=1.68, 95% confidence interval=1.06-2.66, p=0.0282), along with intraoperative blood loss >1,000 ml, lymph node metastasis, perineural invasion, and curability. Severe preoperative malnutrition diagnosed by the GLIM criteria was associated with poor prognosis in patients who underwent curative-intent resection for ECC.

Radiological Shape of the Tumor Predicts Progression and Survival in Resected Extrahepatic Cholangiocarcinoma

BackgroundThe histological features and radiological shape of extrahepatic cholangiocarcinoma (eCCA) have not been widely studied in relation to prognosis. Multi-detector computed tomography (MDCT) is thought to be useful in diagnosis of progress and tumor distribution; it can also show morphological differences (round, triangular, and square forms) at the tumoral obstruction sites. Histological types of eCCA may be revealed, with potential association with tumor growth and survival. MethodsWe examined the distribution of tumor radiological shape subtypes on MDCT. The surgical outcomes of consecutive patients with eCCA who underwent macroscopic curative resection were reviewed. ResultsCT subtypes in 109 patients were 62 triangular, 35 square, and 12 round. There were clear prognostic differences in long-term survival rates (P < 0.001); 5-year survival rates were 100% in round, 64% in triangular, and 19% in square types. There was no recurrence in any cases of round-type tumor at the site of obstruction. Depth of tumor invasion and rates of nodal involvement were significantly higher in triangular and square-type tumors than in round-type tumors. In papillary adenocarcinoma, radiological obstructions were round type in seven patients (78%) and triangular type in two patients (22%). In tubular adenocarcinoma, all round-type tumors were well differentiated, the ratio of square-type tumors increasing as the degree of differentiation decreased from “well” to “moderate,” and “poor” respectively (23%, 39%, 57%; P = 0.033). ConclusionsTumor radiological shape predicts tumor progression, histological type, and survival in eCCA. This information may be helpful in preoperative radiological staging on MDCT.

Outcomes of adjuvant radiation therapy after chemotherapy in resected extrahepatic cholangiocarcinoma: A National Cancer Database analysis.

Adjuvant capecitabine is considered a standard of care for resected cholangiocarcinoma per the BILCAP trial. The role of adjuvant radiation therapy in that trial was not addressed. This study was designed to examine the outcomes of adjuvant radiation in patients who received chemotherapy for resected cholangiocarcinoma. Using the National Cancer Database, the authors identified high-risk patients with resected extrahepatic cholangiocarcinoma with either positive nodes (N+) or margins (R1) who received adjuvant chemotherapy between 2006 and 2014. Overall survival (OS) was determined with the Kaplan-Meier method. Propensity score matching (PSM) and multivariate analysis (MVA) were performed to identify prognostic factors for survival. The authors identified 1478 patients after PSM who were included in the analysis. There was no difference in OS between patients receiving single-agent chemotherapy and patients receiving multiagent chemotherapy (p=.69). There was a significant OS benefit associated with radiation therapy. The median OS and the 5-year OS rate for radiated patients versus nonradiated patients were 34months and 33% versus 27months and 24% (p<.001) for the whole group, 30months and 29% versus 24months and 19% (p=.007) for the N+ subgroup, and 25months and 23% versus 20months and 12% (p=.03) for the R1 subgroup. MVA demonstrated that age, N stage, T stage, R1, and grade were associated with increased mortality, whereas adjuvant radiation was associated with decreased mortality (p<.001). This is the first study showing that adjuvant radiation therapy after chemotherapy resulted in a significant OS benefit for patients with resected high-risk extrahepatic cholangiocarcinoma. Trials are needed to address the role of radiation therapy in this population.

Preoperative peripheral blood inflammatory markers especially the fibrinogen-to-lymphocyte ratio and novel FLR-N score predict the prognosis of patients with early-stage resectable extrahepatic cholangiocarcinoma.

Systemic inflammation is important in the development of extrahepatic cholangiocarcinoma (ECC). The aim of this study was to compare the prognostic power of preoperative peripheral blood inflammatory markers and the novel FLR-N score in patients with resectable ECC. A total of 140 patients with resectable ECC and 140 healthy controls (HCs) were recruited for the study. The Mann-Whitney U test was used to evaluate the differences in inflammatory markers between groups. Kaplan-Meier and Cox regression analyses were used to evaluate the prognostic power of preoperative fibrinogen, albumin, prealbumin, bilirubin, neutrophils, lymphocytes, monocytes, platelets, fibrinogen-to-lymphocyte ratio (FLR), fibrinogen-to-albumin ratio (FAR), fibrinogen-to-prealbumin ratio (FPR), neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), monocyte-to-lymphocyte ratio (MLR), FLR-neutrophil (FLR-N) score, and CA19-9 in patients with resectable ECC. Nomogram was developed based on the results of multivariate Cox analyses. Patients with resectable ECC had significantly higher levels of neutrophils, monocytes, fibrinogen, FLR, FAR, FPR, NLR, PLR, and MLR and lower levels of lymphocytes, albumin, and prealbumin than HCs (all P < 0.01). Albumin, prealbumin, and FPR had a good ability to distinguish between ECC patients with total bilirubin < 34 µmol/L and HCs (AUCs of 0.820, 0.827, and 0.836, respectively). Kaplan-Meier analysis showed that high neutrophil, fibrinogen, FLR, FAR, PLR, MLR, and FLR-N score values were associated with poor survival in patients with resectable ECC. Multivariate analyses indicated that neutrophils (P = 0.022), FLR (P = 0.040), FLR-N score (P < 0.0001), and positive lymph node metastasis (P = 0.016) were independent factors for overall survival (OS). Nomogram were developed to predict OS for patients with ECC. The prognostic roles of inflammatory markers in patients with resectable ECC were different. The preoperative neutrophil count, FLR and FLR-N score could serve as noninvasive markers for predicting the prognosis of resectable ECC.

ASO Author Reflections: Is Systemic Immune-Inflammation Index a Useful Biomarker After Resection of Extrahepatic Cholangiocarcinoma: Results from the U.S. Extrahepatic Biliary Malignancy Consortium.

ASO Author Reflections: Is Systemic Immune-Inflammation Index a Useful Biomarker After Resection of Extrahepatic Cholangiocarcinoma: Results from the U.S. Extrahepatic Biliary Malignancy Consortium.

Significance of dysplasia in bile duct resection margin in patients with extrahepatic cholangiocarcinoma: A retrospective analysis.

BACKGROUNDRadical resection is the only indicator associated with survival in extrahepatic cholangiocarcinoma (EHCC). However, limited data are available regarding the implications of dysplasia at the resection margin following surgery. AIMTo evaluate the prognostic significance of dysplasia-positive margins in patients diagnosed with EHCC.METHODSWe reviewed the records of patients who had undergone surgery for EHCC with curative intent between January 2013 and July 2017. We retrospectively analyzed the clinicopathological data of 116 patients followed for longer than 3 years. The status of resection margin was used to classify patients into negative low-grade dysplasia (LGD) and high-grade dysplasia (HGD)/carcinoma in situ (CIS) categories.RESULTSBased on postoperative status, 72 patients underwent resection with negative margins, 19 had LGD-positive margins, and 25 showed HGD/CIS-positive margins. The mean survival rates of the patients with negative margins, LGD margins, and HGD/CIS margins were 49.1 ± 4.5, 47.3 ± 6.0, and 20.8 ± 4.4 mo, respectively (P < 0.001). No difference in survival was found between groups with LGD margins and negative margins (P = 0.56). In the multivariate analysis, age > 70 years and HGD/CIS-positive margins were significant independent factors for survival (hazard ratio = 1.90 and 2.47, respectively). CONCLUSIONHGD/CIS margin in resected EHCC is associated with a poor survival. However, the LGD-positive resection margin is not a significant indicator of survival in patients with EHCC.

Antibiotic-Resistant Bacteria Colonizing the Bile Duct Are Associated with Increased Morbidity and Mortality after Resection of Extrahepatic Cholangiocarcinoma.

Background: Patients with extrahepatic cholangiocarcinoma (CCA) face considerable morbidity including septic complications after surgery. The aim of this study was to characterize the bacterial spectrum of the common hepatic duct (CHD) and its clinical relevance regarding morbidity and mortality after resection of extrahepatic CCA. Methods: We retrospectively analyzed data from 205 patients undergoing surgery for extrahepatic CCA in our department between January 2000 and March 2015. Patients were reviewed for pre-operative medical conditions, biliary bacterial flora obtained from intra-operative swabs, different septic complications, and post-operative outcome. Results: Bacterial colonization of the CHD was observed in 84.9% of the patients, with Enterococcus faecalis being detected most frequently (28.3%). Wound infections occurred in 30.7% of patients. Bacterial flora of the CHD and of the post-operatively colonized wounds coincided in 51.5% and of intra-abdominal swabs obtained during surgical revisions in 40.0%. Ciprofloxacin-resistant bacteria in the CHD were identified as independent risk factor for wound infections (odds ratio [OR], 3.330; 95% confidence interval [CI], 1.771-6.263; p < 0.001) and for complications requiring surgical revision (OR, 2.417; 95% CI, 1.288-4.539; p = 0.006). Most important independent risk factors for intra-hospital mortality were ampicillin-sulbactam-resistant bacteria in the CHD (OR, 3.969; 95% CI, 1.515-10.399; p = 0.005) and American Society of Anesthesiologists (ASA) grading >2 (OR, 2.936; 95% CI, 1.337-6.451; p = 0.007). Conclusions: Antibiotic-resistant bacteria from the CHD are associated with increased morbidity and mortality in patients undergoing resection for extrahepatic CCA.

Prognostic Impact of Inflammation-Based Scores for Extrahepatic Cholangiocarcinoma

Introduction: Although the relationship between systemic inflammatory responses and prognosis has been known in various cancers, it remains unclear which scores are most valuable for determining the prognosis of extrahepatic cholangiocarcinoma. We aimed to verify the usefulness of various inflammation-based scores as prognostic factors in patients with resected extrahepatic cholangiocarcinoma. Methods: We analyzed consecutive patients undergoing surgical resection for extrahepatic cholangiocarcinoma at our institution between January 2000 and December 2019. The usefulness of the following inflammation-based scores as prognostic factor was investigated: glasgow prognostic score (GPS), modified GPS, neutrophil-to-lymphocyte ratio, platelet to lymphocyte ratio, lymphocyte-to-monocyte ratio, prognostic nutrition index, C-reactive protein to albumin ratio (CAR), controlling nutritional status (CONUT), and prognostic index. Results: A total of 169 patients were enrolled in this study. Of the nine scores, CAR and CONUT indicated prognostic value. Furthermore, multivariate analysis for overall survival revealed that high CAR (>0.23) was an independent prognostic factor (hazard ratio: 1.816, 95% confidence interval: 1.135–2.906, p = 0.0129), along with lymph node metastasis and curability. There was no difference in tumor staging and short-term outcomes between the low CAR (≤0.23) and high CAR groups. Conclusions: CAR was the most valuable prognostic score in patients with resected extrahepatic cholangiocarcinoma.

Does adjuvant chemoradiation benefit patients with lymph node-positive biliary tract cancer? A secondary analysis of SWOG S0809.

4104 Background: Biliary tract cancers are rare tumors with a median overall survival (OS) of 16 months for node-positive (N+) and 37 months for node-negative (N0) disease despite resection. Lymph node status is a known strong prognostic factor for local recurrence with an average estimated 2-year disease-free survival (DFS): 65.5% for N0 and 29.7% for N+ tumors. The Phase II Intergroup Trial S0809 showed that adjuvant capecitabine and gemcitabine followed by radiotherapy and concurrent capecitabine improved OS in patients with extrahepatic cholangiocarcinoma (EHCC) and gallbladder cancer (GBC) compared to historical controls. We hypothesized that nodal status is a prognostic factor for local recurrence in this patient population who received adjuvant therapy. Methods: This analysis included patients with stage pT2-4, N+ or positive margin EHCC or GBC. Treatment included four cycles of gemcitabine (1,000 mg/m2 intravenously on days 1 and 8) and capecitabine (1,500 mg/m2 per day on days 1 to 14) every 21 days followed by concurrent capecitabine (1,330 mg/m2 per day) and radiotherapy (45 Gy to regional lymphatics; 52.5 to 59.4 Gy to tumor bed). S0809 patients who did not receive radiotherapy were excluded from analysis. Correlations between nodal status, resection margin, and other clinicopathological factors, patterns of recurrence and survival were analyzed, and Cox regression models were used to estimate the prognostic significance of nodal status. A Z-test was used to compare DFS rates between these patients and historical data. Results: A total of 69 patients [EHCC n = 46 (66%); GBCA n = 23 (33%)] were evaluated with a median age of 61.7 (26.1-80.6). The majority of N0 patients were female (17/24, 70.8%), whereas most N+ patients were male (25/45, 55.6%; p &lt; 0.04). Distribution of R0 (66.7%) and R1 (33.3%) resections was similar in the N0 and N+ groups. Thirty-four patients with EHCC had N+ disease (73.9%) compared with 11 patients with GBCA (47.8%, p = 0.03). Nodal status did not significantly impact OS (HR = 2.03, 95% CI 0.92-4.49, p = 0.08) or DFS (HR = 1.75, 95% CI 0.85-3.59, p = 0.13). Two-year OS was 70.6% for N0 and 60.9% for N+ disease (p = 0.11). Nodal status was not significantly associated with 2-year DFS: 62.5% for N0 and 49.8% for N+ (p = 0.20). N+ vs N0 tumors showed higher rates of distant failure (51.1% vs 25.0%, p &lt; 0.04), but similar local recurrence (17.8% vs 12.5%, p = 0.88). The observed 2-year DFS in patients with N+ tumors was significantly longer compared to the historical rate of 29.7% (p = 0.004). Conclusions: This combination adjuvant treatment regimen following curative resection for EHCC and GBCA provides favorable outcomes regardless of nodal status. These data suggest that adjuvant chemoradiation may positively impact local control in N+ patients. These findings need to be validated in future clinical trials. Clinical trial information: NCT00789958.

The clinical significance of preoperative C-reactive protein/albumin ratio in patients with resected extrahepatic bile duct cancer.

The C-reactive protein (CRP)/albumin ratio has been identified as a potential prognostic factor for several malignancies. We, therefore, assessed the prognostic role of the CRP/albumin ratio in resected extrahepatic cholangiocarcinoma (EC). A total of 235 patients were retrospectively analyzed between March 2005 and December 2017. The correlations among the preoperative CRP/albumin ratio, clinicopathological factors, and clinical outcomes were investigated. There were 143 males (60.8%), and the median age at the diagnosis was 70.1 (range 41.0-85.5) years. Patients were diagnosed with perihilar bile duct cancer (n = 61) and distal bile duct cancer (n = 174). The median recurrence-free survival and overall survival were 32.7 and 38.7months, respectively. The optimal prognostic cut-off point of the CRP/albumin ratio for the survival was 0.18 (× 103). According to the Kaplan-Meier analysis with a log-rank test, the high CRP/albumin ratio group (≥ 0.18) had a significantly shorter overall survival than the low CRP/albumin ratio group (< 0.18) (29.8 vs. 54.6months, p = 0.002). A multivariate logistic regression analysis for the overall survival showed that CA19-9 ≥ 37 and a high CRP/albumin ratio were associated with a shorter overall survival. A high CRP/albumin ratio appears to be significantly associated with clinically worse outcomes in patients with resected EC.

Prognostic Impact of Paraaortic Lymph Node Metastasis in Extrahepatic Cholangiocarcinoma.

Surgical resection in patients with extrahepatic cholangiocarcinoma (EHCC) with paraaortic lymph node metastasis (PALNM) remains controversial. The objective of this study was to investigate the prognostic impact of PALNM in resected EHCC. The present retrospective study included 410 patients, including 16 patients with PALNM, who underwent surgical resection of EHCC between September 2002 and December 2018. These were compared to 9 patients in whom EHCC was not resected due to PALNM. The clinicopathological features and survival outcomes were investigated to identify the prognostic factors in resected EHCC. The overall survival in the resected patients with PALNM was significantly better than that in unresected patients (median survival time [MST] 33.7 vs. 16.7months, p=0.009) and was not significantly worse than that of patients with regional lymph node metastasis (LNM) (MST 33.7 vs 36.0months, p=0.278). The multivariate analysis identified age > 70years, male sex, tumor location (perihilar), residual tumor status, histological grade, microscopic venous invasion, and regional LNM as independent prognostic factors. There was no significant difference in survival between the resected patients with PALNM and patients with regional LNM, and PALNM was not a significant prognostic factor in the multivariate analysis. Surgical resection may be considered an acceptable approach for EHCC with PALNM in selected patients.

Role of adjuvant (chemo)radiotherapy for resected extrahepatic cholangiocarcinoma: a meta-analysis.

Adjuvant (chemo)radiotherapy (A(C)RT) may be an important supplement to surgery for extrahepatic cholangiocarcinoma (EHCC). However, whether all patients would achieve benefits from A(C)RT and which adjuvant regimen, adjuvant radiotherapy (ART) or adjuvant chemoradiotherapy (ACRT), would be preferred, are still undetermined. The low incidence of EHCC makes it difficult to carry out randomized controlled trials (RCTs); therefore, almost all clinical studies on radiotherapy are retrospective. We have conducted a meta-analysis of these retrospective studies. We conducted a meta-analysis of current retrospective studies using PubMed, Embase, and ClinicalTrials databases. All studies published in English that were related to A(C)RT and which analyzed overall survival (OS), disease-free survival (DFS), or locoregional recurrence-free survival (LRFS) were included. Estimated hazard ratios (HRs) were calculated for OS, DFS, and LRFS. Data from eight studies including 685 patients were included. Our analysis showed that A(C)RT significantly improved OS (HR 0.69, 95% confidence interval (CI) 0.48-0.97, P=0.03), DFS (HR 0.60, 95% CI 0.47-0.76, P<0.0001), and LRFS (HR 0.27, 95% CI 0.17-0.41, P<0.00001) of EHCC overall. In subgroups, patients with microscopically positive resection margin (R1) could achieve a benefit from A(C)RT (HR 0.44, 95% CI 0.27-0.72, P=0.001). No statistically OS difference was observed in negative resection margin (R0) subgroup (HR 0.98, 95% CI 0.30-3.19, P=0.98).Significant OS benefit was found in patients who received concurrent ACRT (HR 0.40, 95% CI 0.26-0.62, P<0.0001), while the result of ART without chemotherapy showed no significant benefit (HR 1.14, 95% CI 0.29-4.50, P=0.85). In the distal cholangiocarcinoma subgroup, no significant difference was seen when ACRT and ART were included (HR 0.61, 95% CI 0.14-2.72, P=0.52), but a significant difference was seen when analyzing the concurrent ACRT only (HR 0.29, 95% CI 0.13-0.64, P=0.002). A(C)RT may improve OS, DFS, and LRFS in EHCC patients, especially in those with R1 resection margins. ACRT may be superior to ART especially in distal patients.

Adjuvant concurrent chemoradiotherapy in extrahepatic cholangiocarcinoma.

4583 Background: Resected cholangiocarcinomas are rare and have high relapse rates. Adjuvant chemotherapy is the standard of care (BiLCAP Trial). Adjuvant radiation therapy benefit is not well defined. This study aims to evaluate survival outcomes of the effect of adjuvant chemoradiotherapy compared to chemotherapy in extrahepatic cholangiocarcinoma (EHC) using the National Cancer Database (NCDB). Methods: Patients with resected EHC between 2004 and 2013 were identified from the NCDB using ICD-O-3 histology and topography codes: 8140, 8160, 8161, 8162 and C24.0. Patients with neoadjuvant therapy were excluded from this analysis. Univariate and multivariable analyses were conducted, and Kaplan-Meier Curves were used to compare overall survival (OS) based on treatment received. Results: A total of 236 EHC patients were identified. Males comprised 60.6% and 88.1% were Caucasian. Median age was 64 (range, 31-84) years. The majority were distal (72.0%, N = 157) followed by perihilar (20.6%, N = 45), hilar (6.4%, N = 14) and cystic (0.9%, N = 2). Distribution across stages I-III was 28.8% (N = 68), 56.8% (N = 134), and 14.4% (N = 34), consecutively. Adjuvant chemotherapy was given in 37.7% (N = 89) and adjuvant chemoradiotherapy in 62.3% (N = 147). The median dose of radiation was 50.4 Gy. Adjuvant chemoradiotherapy was mostly given in regional node positive disease (p = 0.016) and negative surgical margin (p = 0.002) compared to regional node negative disease and positive surgical margin, respectively. The use of adjuvant chemoradiotherapy was associated with improved OS compared to chemotherapy alone in univariate (HR 0.64; 95% CI 0.44-0.93; p = 0.019) and multivariable analysis (HR 0.65; 95% CI 0.44-0.96; p = 0.030). Median survival and 1 year-OS for patients that received chemoradiotherapy was 33.8 months (95% CI 28, NA) and 87.7% (80.9%, 92.1%) compared to chemotherapy alone which was 23.8 months (95% CI 18.9, 35.4) and 75.5% (64.9%, 83.3%). Conclusions: Adjuvant chemoradiotherapy was associated with improved survival in patients with resected EHC compared to chemotherapy alone. This conclusion warrants further prospective studies to confirm these results.

AB055. P-23. The impact of perioperative CA19-9 change on the survival and recurrence patterns after adjuvant chemoradiotherapy in extrahepatic cholangiocarcinoma

Background: Perioperative CA19-9 value in pancreato-biliary cancers has been recognized as a prognostic factor. Herein, we investigated survival differences and recurrence patterns after adjuvant chemoradiotherapy by perioperative CA19-9 change in surgically resected extrahepatic cholangiocarcinoma.

Resection margin distance in extrahepatic cholangiocarcinoma: How much is enough?

455 Background: Surgical resection is required for curative treatment of patients with extra-hepatic cholangiocarcinoma (EH-CCA). The objective of this study was to determine if the distance of surgical margin was associated with outcome. Methods: Patients who underwent curative-intent resection for EH-CCA between 2000 and 2015 at 10 hepatobiliary centers across the U.S. were evaluated using prospectively collected data. Cox proportional hazard model was utilized to evaluate the influence of the extent of the margin on outcome. Results: 538 patients with EH-CCA who underwent curative-intent resection were included: 383 (71%) undergoing R0 resection, 153 (28%) undergoing R1 resection, and 2 with R2 resection. A negative surgical margin (R0) was associated with improved recurrence-free (RFS) and overall survival (OS) (RFS: 10.5% vs. 3.6% (R1) and OS: 25.8% vs. 9.3% (R1). Subsequently, further analysis on 161 patients with complete data on distance of resection margin, all undergoing R0 resection, was performed to assess the impact of extent of margin on outcome. On multi-variable analysis, the resection margin distance, analyzed as a continuous variable, was not associated with either improved RFS (RR 1.00, 95% CI 0.96-1.05; p 0.71) or OS (RR 0.99, 95% CI 0.96-1.01; p 0.49). Increasing age, increased tumor size, and LN metastasis were identified as independent predictors of OS; while RFS were mainly dependent on tumor size and LN metastasis (Table). Conclusions: Achieving R0 resection is acceptable for EH-CCA tumors, and obtaining additional margin does not confer a benefit on overall survival. Increasing age, tumor size, and LN metastasis are independent predictors of RFS and OS, but increased margin width is not associated with improvement in either. Multivariable analysis of factors affecting OS of patients with extra-hepatic CCA who underwent surgical resection, with significant factors noted in bold. [Table: see text]

The Strategy of Treatment for Mid to Distal Cholangiocarcinoma after Surgical Resection

The overall survival (OS) rate of extrahepatic cholangiocarcinoma (ECC) remains much lower than that for other gastrointestinal malignancies. A variety of factors have been used to predict prognosis after surgical resection for ECC, but no consensus has been reached. Therefore, this study sought to identify useful prognostic factors for patients with ECC. In our institution, within the study period, 76 patients received surgical resection for mid to distal cholangiocarcinoma. Clinicopathological data were retrospectively collected, along with survival and prognosis. In multivariate analysis for OS, ductal margin status (P = 0.008) and pT category (P < 0.02) presented independent predictors of survival. In the R0 resection group, N stage and adjuvant chemotherapy presented independent predictors of recurrence in the multivariate model. The three- and five-year survival rates were significantly better in patients with negative ductal margins (77.% at three years and 63.6% at five years) than in those with positive ductal margins (33.3% at three years and 25.0% at five years) (P < 0.05). Survival rates were similar between cases of R0 resection without gemcitabine-based chemotherapy and R1 resection with gemcitabine-based chemotherapy (P = 0.6193, Log-rank test). However, survival rates between R0 resection with gemcitabine-based chemotherapy and R1 resection with gemcitabine-based chemotherapy were significantly different (P = 0.0086, Log-rank test). For good prognosis, radical resection to ensure adequate margin may be recommended for middle common bile duct cancer. In addition, regardless of margin negativity, gemcitabine-based chemotherapy is recommended for prolongation of relapse-free time and OS time.

Identification of Patients for Adjuvant Therapy After Resection of Carcinoma of the Extrahepatic Bile Ducts: A Propensity Score-Matched Analysis.

Resectability rates for extrahepatic cholangiocarcinoma have increased over time, but long-term survival after resection alone with curative intent remains poor. Recent series suggest improved survival with adjuvant therapy. Patient subsets benefiting most from adjuvant therapy have not been clearly defined. Patients with extrahepatic cholangiocarcinoma who underwent resection with curative intent and received adjuvant therapy (chemotherapy±radiotherapy) or surgery alone (SA) were identified in the U.S. National Cancer Data Base (2004-2014). Cox regression identified covariates associated with overall survival (OS). Adjuvant therapy and SA cohorts were matched (1:1) by propensity scores based on the survival hazard in Cox modeling. Overall survival was compared by Kaplan-Meier estimates. Of 4872 patients, adjuvant chemotherapy was used frequently for 2416 (49.6%), often in conjunction with radiotherapy (RT) (n=1555, 64.4%). Adjuvant chemotherapy with or without RT was used increasingly for cases with higher T classification [reference: T1-2; T3: 1.36; 95% confidence interval (CI), 1.19-1.55; T4: 1.77; 95% CI 1.38-2.26], nodal positivity [odds ratio (OR), 1.26; 95% CI 1.01-1.56], lymphovascular invasion (OR 1.21; 95% CI 1.01-1.46), or margin-positive resection (OR 1.85; 95% CI 1.61-2.12), and was associated with significant improvements in OS for each high-risk subset in the propensity score-matched cohort. Adjuvant therapy was associated with improved median OS for hilar tumors (40.0 vs 30.6months; p=0.025) but not distal tumors (33.0 vs 30.3months; p=0.123). Chemoradiotherapy was associated with superior outcomes compared with chemotherapy alone in the subset of margin-positive resection [hazard ratio (HR), 0.63; 95% CI 0.42-0.94]. Adjuvant multimodality therapy is associated with improved survival for patients with resected extrahepatic cholangiocarcinoma and high-risk features.