Classification of Intrahepatic Cholangiocarcinoma into Perihilar Versus Peripheral Subtype.

BACKGROUND: Intrahepatic cholangiocarcinoma (ICC) constitutes a group of heterogeneous malignancies within the liver. We sought to subtype ICC based on anatomical origin of tumors, as well as propose modifications of the current classification system. METHODS: Patients undergoing curative-intent resection for ICC, hilar cholangiocarcinoma (CCA), or hepatocellular carcinoma (HCC) were identified from three international multi-institutional consortia of databases. Clinicopathological characteristics and survival outcomes were assessed. RESULTS: Among 1264 patients with ICC, 1066 (84.3%) were classified as ICC-peripheral subtype, whereas 198 (15.7%) were categorized as ICC-perihilar subtype. Compared with ICC-peripheral subtype, ICC-perihilar subtype was more often associated with aggressive tumor characteristics, including a higher incidence of nodal metastasis, macro- and microvascular invasion, perineural invasion, as well as worse overall survival (OS) (median: ICC-perihilar 19.8 vs. ICC-peripheral 37.1 months; p < 0.001) and disease-free survival (DFS) (median: ICC-perihilar 12.8 vs. ICC-peripheral 15.2 months; p = 0.019). ICC-perihilar subtype and hilar CCA had comparable OS (19.8 vs. 21.4 months; p = 0.581) and DFS (12.8 vs. 16.8 months; p = 0.140). ICC-peripheral subtype tumors were associated with more advanced tumor features, as well as worse survival outcomes versus HCC (OS, median: ICC-peripheral 37.1 vs. HCC 74.3 months; p < 0.001; DFS, median: ICC-peripheral 15.2 vs. HCC 45.5 months; p < 0.001). CONCLUSIONS: ICC should be classified as ICC-perihilar and ICC-peripheral subtype based on distinct clinicopathological features and survival outcomes. ICC-perihilar subtype behaved more like carcinoma of the bile duct (i.e., hilar CCA), whereas ICC-peripheral subtype had features and a prognosis more akin to a primary liver malignancy.

Long-term survivors after curative-intent resection for intrahepatic cholangiocarcinoma.

OBJECTIVES: The objective of the current study was to characterize prognostic factors related to long-term recurrence-free survival after curative-intent resection of intrahepatic cholangiocarcinoma (ICC). METHODS: Data on patients who underwent curative-intent resection for ICC between 2000 and 2020 were collected from an international multi-institutional database. Prognostic factors were investigated among patients who recurred within 5 years versus long-term survivors who survived more than 5 years with no recurrence. RESULTS: Among 635 patients who underwent curative-intent resection for ICC, 104 (16.4%) patients were long-term survivors with no recurrence beyond 5 years after surgery. Patients who survived for more than 5 years with no recurrence were more likely to have less aggressive tumor features, as well as have undergone an R0 resection versus patients who recurred within 5 years after resection. On multivariable analysis, tumor size (>5 cm) (HR: 1.535, 95% CI: 1.254-1.879), satellite lesions (HR: 1.253, 95% CI: 1.003-1.564), and lymph node metastasis (HR: 1.733, 95% CI: 1.349-2.227) were independently associated with recurrence within 5 years. Patients who recurred beyond 5 years (n = 23), 2-5 years (n = 60), and within 2 years (n = 471) had an incrementally worse post-recurrence survival (PRS, 28.0 vs. 20.0 vs. 12.0 months, p = 0.032). Among patients with N0 status, tumor size (>5 cm) (HR: 1.612, 95% CI: 1.087-2.390) and perineural invasion (PNI) (HR: 1.562,95% CI: 1.081-2.255) were risk factors associated with recurrence. Among patients with N1 disease, only a minority (5/128, 3.9%) of patients survived with no recurrence to 5 years. CONCLUSION: Roughly 1 in 6 patients survived for more than 5 years with no recurrence following curative-intent resection of ICC. Among N0 patients, tumor recurrence was associated with tumor size and PNI. Only a small subset of N1 patients experienced long-term survival.

Lymph Node Examination and Patterns of Nodal Metastasis Among Patients with Left- Versus Right-Sided Intrahepatic Cholangiocarcinoma After Major Curative-Intent Resection.

BACKGROUND: We sought to investigate whether the unique lateral patterns of lymphatic drainage impacted lymphadenectomy (LND), lymph node metastasis (LNM), and long-term survival of patients after curative hemi-hepatectomy for left- versus right-sided intrahepatic cholangiocarcinoma (ICC). METHODS: Data on patients who underwent curative hemi-hepatectomy for left- or right-sided ICC were collected from 15 high-volume centers worldwide, as well as from the Surveillance, Epidemiology, and End Results (SEER) registry. Primary outcomes included overall survival (OS) and disease-free survival (DFS). RESULTS: Among 697 patients identified from the multi-institutional database, patients who underwent hemi-hepatectomy for left-sided ICC (n = 363, 52.1%) were more likely to have an increased number of LND versus patients with right-sided ICC (n = 334, 47.9%) (median, left 5 versus right 3, p = 0.012), although the frequency (left 66.4% versus right 63.8%, p = 0.469) and station (beyond station no. 12, left 25.3% versus right 21.1%, p = 0.293) were similar. Consequently, left-sided ICC was associated with higher incidence of LNM (left 33.3% versus right 25.7%, p = 0.036), whereas the station and number of LNM were not different (both p > 0.1). There was no difference in OS (median, left 34.9 versus right 29.6 months, p = 0.130) or DFS (median, left 14.5 versus right 15.2 months, p = 0.771) among patients who underwent hemi-hepatectomy for left- versus right-sided ICC, which were also verified in the SEER dataset. LNM beyond station no. 12 was associated with even worse long-term survival versus LNM within station no. 12 among patients with either left- or right-sided ICC after curative-intent resection (all p < 0.05). CONCLUSIONS: The unique lateral patterns of lymphatic drainage were closely related to utilization of LND, as well as LNM of left- versus right-sided ICC.

Dynamic Prediction of Survival After Curative Resection of Intrahepatic Cholangiocarcinoma: A Landmarking-Based Analysis.

BACKGROUND: The current study aimed to develop a dynamic prognostic model for patients undergoing curative-intent resection for intrahepatic cholangiocarcinoma (ICC) using landmark analysis. METHODS: Patients who underwent curative-intent surgery for ICC from 1999 to 2017 were selected from a multi-institutional international database. A landmark analysis to undertake dynamic overall survival (OS) prediction was performed. A multivariate Cox proportional hazard model was applied to measure the interaction of selected variables with time. The performance of the model was internally cross-validated via bootstrap resampling procedure. Discrimination was evaluated using the Harrell's Concordance Index. Accuracy was evaluated with calibration plots. RESULTS: Variables retained in the multivariable Cox regression OS model included age, tumor size, margin status, morphologic type, histologic grade, T and N category, and tumor recurrence. The effect of several variables on OS changed over time. Results were provided as a survival plot and the predicted probability of OS at the desired time in the future. For example, a 65-year-old patient with an intraductal, T1, grade 3 or 4 ICC measuring 3 cm who underwent an R0 resection had a calculated estimated 3-year OS of 76%. The OS estimate increased if the patient had already survived 1 year (79%). The discrimination ability of the final model was very good (C-index: 0.80). CONCLUSION: The long-term outcome for patients undergoing curative-intent surgery for ICC should be adjusted based on follow-up time and intervening events. The model in this study showed excellent discriminative ability and performed well in the validation process.

Prognostic impact of perineural invasion in intrahepatic cholangiocarcinoma: multicentre study.

BACKGROUND: The aim of this study was to investigate the prognostic impact of perineural invasion (PNI) on tumour recurrence and survival among patients with resected intrahepatic cholangiocarcinoma (ICC). METHODS: This was a multicentre, retrospective study of patients who underwent resection with curative intent for ICC between 2000 and 2017. The relationship between PNI, clinicopathological characteristics, and long-term survival was analysed in the overall cohort and the subset of patients with early-stage ICC. RESULTS: Among 1095 patients who underwent resection of ICC, PNI was present in 239 (21.8 per cent). In univariable analysis, PNI was associated with worse disease-free survival (DFS) (median 13.2 versus 16.1 months for patients with and without PNI respectively; P = 0.038) and overall survival (OS) (26.4 versus 41.5 months; P < 0.001). In multivariable analysis, PNI was an independent risk factor associated with reduced DFS (hazard ratio (HR) 1.56, 95 per cent c.i. 1.06 to 2.13; P = 0.019) and OS (HR 1.74, 1.16 to 2.60; P = 0.007). In subgroup analysis of patients with early-stage disease (AJCC T1-2, 981 patients; or N0, 249 patients), PNI remained associated with worse DFS (T1-2: median 13.7 versus 16.6 months in patients with and without PNI respectively, P = 0.019; N0: 11.7 versus 17.5 months, P = 0.022) and OS (T1-2: 28.5 versus 45.7 months, P < 0.001; N0: 34.9 versus 47.5 months, P = 0.036). CONCLUSION: PNI is a strong independent predictor of tumour recurrence and long-term survival following resection of ICC with curative intent, even among patients with early-stage disease. The presence of PNI should be assessed routinely.

Number and Station of Lymph Node Metastasis After Curative-intent Resection of Intrahepatic Cholangiocarcinoma Impact Prognosis.

OBJECTIVES: To determine the prognostic implication of the number and station of LNM, and the minimal number of LNs needed for evaluation to accurately stage patients with intrahepatic cholangiocarcinoma (ICC). BACKGROUND: Impact of the number and station of LNM on long-term survival, and the minimal number of LNs needed for accurate staging of ICC patients remain poorly defined. METHODS: Data on patients who underwent curative-intent resection for ICC was collected from 15 high-volume centers worldwide. External validation was performed using the SEER registry. Primary outcomes included overall (OS), disease-specific, and recurrence-free survival. RESULTS: Among 603 patients who underwent curative-intent resection, median and 5-year OS were 30.6 months and 30.4%. Patients with 1 or 2 LNM had comparable worse OS versus patients with no nodal disease (median OS, 1 LNM 18.0, 2 LNM 20.0 vs no LNM 45.0 months, both P < 0.001), yet better OS versus patients with 3 or more LNM (median OS, 1-2 LNM 19.8 vs ≥3 LNM 16.0 months, P < 0.01). On multivariable analysis, a proposed new nodal staging with N1 (1-2 LNM) (Ref. N0, HR 2.40, P < 0.001) and N2 (≥3 LNM) [Ref. N0, hazard ratio (HR) 3.85, P < 0.001] categories were independently associated with incrementally worse OS. Patients with no nodal metastasis, 1-2 LNM and ≥3 LNM also had an increasingly worse disease-specific survival, and recurrence-free survival (both P < 0.05). Total number of LNs examined ≥6 had the greatest discriminatory power relative to OS among patients with 1-2 LNM, and patients with ≥3 LNM in both the multi-institutional (area under the curve 0.780) and SEER database (area under the curve 0.820) (n = 1036). Among patients who underwent an adequate regional lymphadenectomy (total number of LNs examined ≥6), LNM beyond the HDL was associated with worse OS versus LNM within the HDL only (median OS, 14.0 vs 24.0 months, HR 2.41, P = 0.003). CONCLUSION: Standard lymphadenectomy of at least 6 LNs is strongly recommended and should include examination beyond station 12 to have the greatest chance of accurate staging. The proposed new nodal staging of N0, N1, and N2 should be considered to stratify outcomes among patients after curative-intent resection of ICC.

Proposed modification of the eighth edition of the AJCC staging system for intrahepatic cholangiocarcinoma.

BACKGROUND: To improve the prognostic accuracy of the 8th edition of the American Joint Committee on Cancer (AJCC) staging system for intrahepatic cholangiocarcinoma (ICC) with establishment and validation of a modified TNM (mTNM) staging system. METHODS: Data on patients who underwent curative-intent resection for ICC was collected from 15 high-volume centers worldwide (n = 643). An external validation dataset was obtained from the SEER registry (n = 797). The mTNM staging system was proposed by redefining T categories, and incorporating the recently proposed N status as N0 (no lymph node metastasis [LNM]), N1 (1-2 LNM) and N2 (≥3 LNM). RESULTS: The 8th AJCC TNM staging system failed to stratify overall survival (OS) of stage II versus IIIA, stage IIIB versus IV, as well as overall stage III versus IV among all patients from the two databases, as well as stage I versus II, and stage III versus III among patients who had ≥6 LNs examined. There was a monotonic decrement in survival based on the proposed mTNM staging classification among patients derived from both the multi-institutional (Median OS, stage I 69.8 vs. II 37.1 vs. III 18.9 vs. IV 16.4 months, all p < 0.05), and SEER (Median OS, stage I 87.0 vs. II 29.3 vs. III 17.7 vs. IV 14.2 months, all p < 0.05) datasets, which was also verified among patients who had ≥6 lymph node harvested from both databases. CONCLUSION: The modified TNM staging system for ICC using the new T and N definitions provided an improved means to stratify patients relative to long-term OS versus the 8th AJCC staging.

Should Utilization of Lymphadenectomy Vary According to Morphologic Subtype of Intrahepatic Cholangiocarcinoma?

OBJECTIVE: We sought to evaluate the utilization of lymphadenectomy (LND) and the incidence of lymph node metastasis (LNM) among different morphologic types of intrahepatic cholangiocarcinoma (ICC). METHODS: Clinical data of patients undergoing curative-intent resection for ICC between 1990 and 2017 were collected and analyzed. The preoperative nodal status was evaluated by imaging studies, and the morphologic and lymph node (LN) status was collected on final pathology report. RESULTS: Overall, 1032 patients had a mass-forming (MF) or intraductal growth (IG) ICC subtype, whereas 150 patients had a periductal infiltrating (PI) or MF + PI subtype. Among the 924 patients with MF/IG ICC subtype who had nodal assessment on preoperative imaging, 747 (80.8%) were node-negative, whereas 177 (19.2%) patients were suspicious for metastatic nodal disease. On final pathological analysis, 71 of 282 (25.2%) patients who had preoperative node-negative disease ultimately had LNM. In contrast, 79 of 135 (58.5%) patients with preoperative suspicious/metastatic LNs had pathologically confirmed LNM (odds ratio [OR] 4.2, p < 0.001). Among the 129 patients with PI/MF + PI ICC subtype and preoperative nodal information, 72 (55.8%) were node-negative on preoperative imaging. In contrast, 57 (44.2%) patients had suspicious/metastatic LNs. On final pathologic examination, 45.3% (n = 24) of patients believed to be node-negative on preoperative imaging had LNM; 68.0% (n = 34) of patients who had suspicious/positive nodal disease on imaging ultimately had LNM (OR 2.6, p = 0.009). CONCLUSION: Given the low accuracy of preoperative imaging evaluation of nodal status, routine LND should be performed at the time of resection for both MF/IG and PI/MF + PI ICC subtypes.

Recurrence Patterns and Timing Courses Following Curative-Intent Resection for Intrahepatic Cholangiocarcinoma.

BACKGROUND: Recurrence of intrahepatic cholangiocarcinoma (ICC) after curative resection is common. OBJECTIVE: The aim of this study was to investigate the patterns, timing and risk factors of disease recurrence after curative-intent resection for ICC. METHODS: Patients undergoing curative resection for ICC were identified from a multi-institutional database. Data on clinicopathological and initial operation information, timing and first sites of recurrence, recurrence management, and long-term outcomes were analyzed. RESULTS: A total of 920 patients were included. With a median follow-up of 38 months, 607 patients (66.0%) experienced ICC recurrence. In the cohort, 145 patients (23.9%) recurred at the surgical margin, 178 (29.3%) recurred within the liver away from the surgical margin, 90 (14.8%) recurred at extraheptatic sites, and 194 (32.0%) developed both intrahepatic and extrahepatic recurrence. Intrahepatic margin recurrence (median 6.0 m) and extrahepatic-only recurrence (median 8.0 m) tended to occur early, while intrahepatic recurrence at non-margin sites occurred later (median 14.0 m; p < 0.05). On multivariate analysis, surgical margin < 10 mm was associated with increased margin recurrence (hazard ratio [HR] 1.70, 95% confidence interval [CI] 1.11-2.60; p = 0.014), whereas female sex (HR 2.12, 95% CI 1.40-3.22; p < 0.001) and liver cirrhosis (HR 2.36, 95% CI 1.31-4.25; p = 0.004) were both associated with an increased risk of intrahepatic recurrence at other sites. Median survival after recurrence was better among patients who underwent repeat curative-intent surgery (48.7 months) versus other treatments (9.7 months) [p < 0.001]. CONCLUSIONS: Different recurrence patterns and timing of recurrence suggest biological heterogeneity of ICC tumor recurrence. Understanding timing and risk factors associated with different types of recurrence can hopefully inform discussions around adjuvant therapy, surveillance, and treatment of recurrent disease.

Impact of microvascular invasion on clinical outcomes after curative-intent resection for intrahepatic cholangiocarcinoma.

BACKGROUND: Microvascular invasion (MiVI) is a histological feature of intrahepatic cholangiocarcinoma (ICC) that may be associated with biological behavior. We sought to investigate the impact of MiVI on long-term survival of patients undergoing curative-intent resection for ICC. METHODS: A total of 1089 patients undergoing curative-intent resection for ICC were identified. Data on clinicopathological characteristics, disease-free survival (DFS), and overall survival (OS) were compared among patients with no vascular invasion (NoVI), MiVI, and macrovascular invasion (MaVI). RESULTS: A total of 249 (22.9%) patients had MiVI, while 149 (13.7%) patients had MaVI (±MiVI). MiVI was associated with higher incidence of perineural, biliary and adjacent organ invasion, and satellite lesions (all P < 0.01). On multivariable analysis, MiVI was an independent risk factor of DFS (hazard ratios [HR] 1.5; 95%confidence intervals [CI], 1.3-1.9; P < 0.001), but not OS (HR 1.1; 95%CI, 0.9-1.3; P = 0.379). While MiVI and MaVI patients had similar DFS (median, MiVI 14.0 vs MaVI 12.0 months, HR 0.9; 95%CI, 0.7-1.2; P = 0.377), OS was better among MiVI patients (median, MiVI 39.0 vs MaVI 21.0 months, HR 0.7; 95%CI, 0.5-0.8; P = 0.002). Whereas nodal metastasis, R1 margin, and postoperative morbidity were associated with early death (≤18 months) among patients with MiVI, only nodal metastasis was associated with late (>18 months) prognosis. CONCLUSIONS: Roughly 1 out of 5 patients with resected ICC had MiVI. MiVI was associated with advanced tumor characteristics and a higher risk of tumor recurrence.

Preoperative prognostic nutritional index predicts survival of patients with intrahepatic cholangiocarcinoma after curative resection.

BACKGROUND: Intrahepatic cholangiocarcinoma (ICC) is an aggressive malignancy. We sought to examine the association between preoperative prognostic nutritional index (PNI) and long-term overall survival among patients with ICC who underwent curative-intent resection. METHODS: Patients who underwent hepatectomy for ICC between 1990 and 2015 were identified using an international multi-institutional database. Clinic-pathological characteristics and long-term outcomes of patients with PNI ≥ 40 and <40 were compared using univariable and multivariable analyses. RESULTS: Among 637 patients, 53 patients had PNI < 40 (8.3%) and 584 patients had PNI ≥ 40 (91.7%). While there was no difference between PNI groups with regard to tumor size (P = .87), patients with PNI < 40 were more likely to have multifocal disease (PNI < 40, n = 16, 30.2% vs PNI ≥ 40, n = 65, 11.1%; P < 0.001), poorly differentiated or undifferentiated ICC (PNI < 40, n = 13, 25.5% vs PNI ≥ 40, n = 75, 13.1%; P = 0.020) and T2/T3/T4 disease vs patients with PNI ≥ 40 (PNI < 40, n = 38, 71.7% vs PNI ≥ 40, n = 265, 45.4%; P < 0.001). Patients with PNI ≥ 40 had better OS vs patients with PNI < 40 (5-year OS: PNI ≥ 40: 47.5%, 95% CI, 42.2 to 52.6% vs PNI < 40: 24.6%, 95% CI, 12.1 to 39.6%; P < 0.001). On multivariable analysis, PNI < 40 remained associated with increase risk of death (HR, 1.71; 95% CI, 1.15 to 2.53; P = 0.008). CONCLUSION: A low preoperative PNI was associated with a more aggressive ICC phenotype. After controlling for these factors, PNI remained independently associated with a markedly worse prognosis.

Surgical Management of Intrahepatic Cholangiocarcinoma in Patients with Cirrhosis: Impact of Lymphadenectomy on Peri-Operative Outcomes.

BACKGROUND: The consequences of lymphadenectomy (LND) on cirrhotic patients undergoing hepatectomy for intrahepatic cholangiocarcinoma (ICC) have not been investigated. We sought to analyze the impact of LND on morbidity among patients undergoing resection for ICC. METHODS: A total of 1005 patients who underwent hepatectomy for ICC at one of the 14 participating institutions between 1990 and 2015 were identified. A propensity score match analysis was performed to reduce confounding biases between cirrhosis and non-cirrhosis groups. RESULTS: Cirrhosis was diagnosed in 118 (11.7%) patients. Among non-cirrhotic patients, 63% underwent major liver resection versus only 20% among patients with cirrhosis (p < 0.001). LND was also less common among cirrhotic versus non-cirrhotic patients (19 vs. 50%, p < 0.001). The incidence of complications was 41 and 30% among patients who did not and did have cirrhosis, respectively (p = 0.022). The propensity-matched cohort included 150 patients. The incidence of complications was 71% among patients who underwent lymphadenectomy versus 23% among patients who did not undergo lymphadenectomy (OR 8.39) (p < 0.001). In the propensity-matched analysis, the median HLN was comparable among patients independent of cirrhosis status (median HLN: non-cirrhosis, 2.5 vs. cirrhosis, 2) (p = 0.95). While lymphadenectomy was associated with a higher risk of infections (non-cirrhosis, 0% vs. cirrhosis, 21%, p < 0.001) among patients with cirrhosis, infections were not associated with lymphadenectomy among non-cirrhotic patients (p = 0.19). CONCLUSION: Lymphadenectomy was associated with an increased risk of complications among patients with cirrhosis undergoing surgery for ICC. The benefit of lymphadenectomy in cirrhotic patients should be considered in light of the higher risk of postoperative complications compared with non-cirrhotic patients.

Implications of Intrahepatic Cholangiocarcinoma Etiology on Recurrence and Prognosis after Curative-Intent Resection: a Multi-Institutional Study.

BACKGROUND: We sought to investigate the prognosis of patients following curative-intent surgery for intrahepatic cholangiocarcinoma (ICC) stratified by hepatitis B (HBV-ICC), hepatolithiasis (Stone-ICC), and no identifiable cause (conventional ICC) etiologic subtype. METHODS: 986 patients with HBV-ICC (n = 201), stone-ICC (n = 103), and conventional ICC (n = 682) who underwent curative-intent resection were identified from a multi-institutional database. Propensity score matching (PSM) was used to mitigate residual bias. RESULTS: HBV-ICC patients more often had cirrhosis, earlier stage tumors, a mass-forming lesion, well-to-moderate tumor differentiation, and an R0 resection versus stone-ICC or conventional ICC patients. Five-year recurrence-free survival among HBV-ICC and conventional ICC patients was 23.9 and 17.8%, respectively, versus a recurrence-free of only 8.3% among patients with stone-ICC. Similarly, 5-year overall survival among patients with stone-ICC was only 18.3% compared with 48.9 and 38.0% for patients with HBV-ICC and conventional ICC, respectively. On PSM, patients with stone-ICC group had equivalent long-term outcomes as HBV-ICC patients. In contrast, on PSM, stone-ICC patients had a median overall survival of only 18.0 months versus 44.0 months for patients with conventional ICC. Median overall survival after intrahepatic-only recurrence among patients who had stone-ICC (6.0 months) was worse than OS among HBV-ICC (13.0 months) or conventional ICC (12.0 months) (p = 0.006 and p = 0.082, respectively). CONCLUSIONS: While HBV-ICC had a better prognosis on unadjusted analyses, these differences were mitigated on PSM suggesting no stage-for-stage differences in outcomes compared with stone-ICC or conventional ICC. In contrast, patients with stone-ICC had worse long-term outcomes. These data highlight the relative importance of ICC etiology relative to established clinicopathological factors in the prognosis of patients with ICC.

Long-term outcomes of patients with intraductal growth sub-type of intrahepatic cholangiocarcinoma.

BACKGROUND: Intraductal-growth (IG) type of intrahepatic cholangiocarcinoma (ICC) may be associated with a favorable prognosis compared with mass-forming (MF) and periductal-infiltrating (PI) ICC. METHODS: The clinico-pathological characteristics and long-term outcomes of 1206 patients undergoing liver resection for ICC were compared based on the ICC morphological classification. RESULTS: Compared with MF patients, IG patients had a higher incidence of poor/un-differentiated tumor, lympho-vascular, and perineural invasion (poor/un-differentiated: MF, 18% vs. IG, 24%; lympho-vascular invasion: MF, 30% vs. IG, 35%; perineural invasion: MF, 17% vs. IG, 33%; all p > 0.05). The pattern of recurrence was different among MF patients (intrahepatic only: 63%; extrahepatic only: 22%; both intra- and extrahepatic: 16%) versus IG patients (intrahepatic only: 46%; extrahepatic: 25%; both intra- and extrahepatic: 29%) (p < 0.001). Moreover, while 78% of patients with MF had an early recurrence (<18 months from surgery), 59% of IG patients had and early recurrence (p = 0.039). On multivariable analysis, after controlling for competing risk factors, IG patients had a similar prognosis as MF patients (HR 0.90, p = 0.69). CONCLUSION: While IG patients more frequently presented with more adverse pathological characteristics, the prognosis of IG patients was comparable with MF patients after controlling for all these adverse factors.

Impact of Morphological Status on Long-Term Outcome Among Patients Undergoing Liver Surgery for Intrahepatic Cholangiocarcinoma.

BACKGROUND: The influence of morphological status on the long-term outcome of patients undergoing liver resection for intrahepatic cholangiocarcinoma (ICC) is poorly defined. We sought to study the impact of morphological status on overall survival (OS) of patients undergoing curative-intent resection for ICC. METHODS: A total of 1083 patients who underwent liver resection for ICC between 1990 and 2015 were identified. Data on clinicopathological characteristics, operative details, and morphological status were recorded and analyzed. A propensity score-matched analysis was performed to reduce confounding biases. RESULTS: Among 1083 patients, 941(86.9%) had a mass-forming (MF) or intraductal-growth (IG) type, while 142 (13.1%) had a periductal-infiltrating (PI) or MF with PI components (MF + PI) ICC. Patients with an MF/IG ICC had a 5-year OS of 41.8% (95% confidence interval [CI] 37.7-45.9) compared with 25.5% (95% CI 17.3-34.4) for patients with a PI/MF + PI (p < 0.001). Morphological type was found to be an independent predictor of OS as patients with a PI/MF + PI ICC had a higher hazard of death (hazard ratio [HR] 1.42, 95% CI 1.11-1.82; p = 0.006) compared with patients who had an MF/IG ICC. Compared with T1a-T1b-T2 MF/IG tumors, T1a-T1b-T2 PI/MF + PI and T3-T4 PI/MF + PI tumors were associated with an increased risk of death (HR 1.47 vs. 3.59). Conversely, patients with T3-T4 MF/IG tumors had a similar risk of death compared with T1a-T1b-T2 MF/IG patients (p = 0.95). CONCLUSION: Among patients undergoing curative-intent resection of ICC, morphological status was a predictor of long-term outcome. Patients with PI or MF + PI ICC had an approximately 45% increased risk of death long-term compared with patients who had an MF or IG ICC.

Comparative performances of the 7th and the 8th editions of the American Joint Committee on Cancer staging systems for intrahepatic cholangiocarcinoma.

BACKGROUND: We sought to evaluate and validate the 8th edition of the AJCC classification using a multi-institutional cohort of patients with intrahepatic cholangiocarcinoma (ICC). METHODS: Patients undergoing curative-intent hepatic resection for ICC between 1990 and 2015 at 14 major hepatobiliary centers were included and were staged according to 7th and 8th editions AJCC criteria. RESULTS: A total of 1154 patients underwent liver resection for ICC. When patients were staged using the AJCC 7th edition, T2a, T2b, and T4 patients had a higher hazard ratio (HR) of death compared with T1 (T2a, HR 1.43, P = 0.004; T2b, HR 1.99, P < 0.001; T4, HR 2.20, P < 0.001). T3 patients had a higher HR of death compared with T1 patients (HR 1.30, P = 0.029) but lower than T2a and T2b. According to AJCC 8th edition, T1b, T2, and T4 patients were at higher risk of death compared with T1a patients (T1b, HR 1.91, P < 0.001; T2, HR 2.29, P < 0.001; T4, HR 4.16, P < 0.001). As in the AJCC 7th edition, AJCC 8th edition T3 patients had a higher HR of death compared with T1 patients (HR 1.65, P = 0.001) but lower than T1b and T2. AJCC 8th edition. T-category performed slightly better than AJCC 7th edition with a C-index of 0.609 versus 0.590. CONCLUSIONS: A staging system that perfectly discriminates between stages has not yet been developed, but the AJCC 8th edition was able to better stratify the risk of death of Stage III and T3 patients.

Impact of adjuvant chemotherapy on survival in patients with intrahepatic cholangiocarcinoma: a multi-institutional analysis.

BACKGROUND: The benefit of adjuvant chemotherapy for resected intrahepatic cholangiocarcinoma (ICC) is unclear. The aim of the current study was to investigate the impact of adjuvant chemotherapy on survival among patients undergoing resection of ICC using a multi-institutional database. METHODS: 1154 ICC patients undergoing curative-intent hepatectomy between 1990 and 2015 were identified from 14 institutions. Cox proportional hazard modeling was used to determine the impact of adjuvant chemotherapy on overall survival (OS). RESULTS: Following resection, 347 (30%) patients received adjuvant chemotherapy, most commonly a gemcitabine-based regimen (n = 184, 52%). Patients with T2/T3/T4 disease were more likely to receive adjuvant therapy compared with patients with T1a/T1b disease (OR 2.5, 95%CI 1.89-3.23; P < 0.001). Among patients who did and did not receive adjuvant therapy, patients with T2/T3/T4 tumors had a 5-year OS of 37% (95%CI 28.9-44.4) versus 30% (95%CI 23.8-35.6), respectively (p = 0.006). Similarly patients with N1 disease who received adjuvant chemotherapy tended to have improved 5-year OS (18.3%, 95%CI 9.0-30.1 vs. no adjuvant therapy 12%, 95%CI 3.9-24.4; P = 0.050). CONCLUSIONS: While adjuvant chemotherapy did not influence the prognosis of all ICC patients following surgical resection, it was associated with a potential survival benefit in subgroups of patients at increased risk for recurrence, such as those with advanced tumors.

Redefining Conditional Overall and Disease-Free Survival After Curative Resection for Intrahepatic Cholangiocarcinoma: a Multi-institutional, International Study of 1221 patients.

OBJECTIVES: To assess conditional survival (CS) according to recurrence status, as well as conditional disease-free survival (cDFS) among patients with intrahepatic cholangiocarcinoma (ICC). METHODS: CS and cDFS were evaluated among ICC patients who underwent curative-intent resection for ICC by using a multi-institutional database. Five-year CS (CS5) at "x" years was calculated separately for patients who did and did not experience recurrence. The cDFS3 at "x" years was defined as the chance to be disease-free for an additional 3 years after not having experienced a recurrence for "x" years postoperatively. RESULTS: Among 1221 patients, median OS was 36.8 months. While estimated actuarial OS decreased over time, CS5 increased as patients survived over longer periods of time and reached 93.9% at 4 years among 139 patients who did not experience a recurrence. Among the 725 (59.4%) patients who did experience a tumor recurrence, CS5 decreased to 17.7% the first postoperative year; however, CS5 subsequently increased to 79.7% for 81 patients who had survived 4 years after surgery. While actuarial DFS decreased from 54.6% at 1 year to 28.2% at 5 years, estimated cDFS3 following liver resection increased over time. Of note, patients with known risk factors for recurrence had even more marked improvements in cDFS3 over subsequent years versus patients without risk factors for recurrence. CONCLUSION: CS and cDFS changed over time according to the presence of disease-specific risk factors, as well as the presence of recurrence.