Proposal for a new T-stage classification system for distal cholangiocarcinoma: a 10-institution study from the U.S. Extrahepatic Biliary Malignancy Consortium

Subdivision of pT1N0 (American Joint Committee on Cancer 8th edition) distal cholangiocarcinoma for adjuvant chemotherapy consideration

BACKGROUND

The adjuvant S-1 trial affirmed adjuvant chemotherapy for biliary tract cancer but excluded pT1N0 distal cholangiocarcinoma (DCC) according to the seventh edition of the American Joint Committee on Cancer (AJCC) classification. The introduction of tumor depth of invasion (DOI) for T-classification in the eighth edition complicates identifying DCC patients less likely to benefit from adjuvant chemotherapy.

METHODS

Our cohort consisted of 185 patients with DCC who underwent pancreaticoduodenectomy between 2002 and 2019. We compared clinicopathological factors and survival outcomes between pT1N0 patients in the seventh edition and those in the eighth edition. New DOI cutoffs for subdividing pT1N0 (8th edition) patients were evaluated to identify patients less likely to benefit from adjuvant chemotherapy.

RESULTS

Transitioning to the eighth edition increased in pT1N0 cases from eight to 46. The 5-year cumulative recurrence rates of them were 14.3% for the seventh edition and 28.3% for the eighth edition. We proposed a DOI cutoff of <2 mm, at which the 5-year cumulative recurrence rate was 11.5%.

CONCLUSION

The eighth AJCC classification revealed that a significant proportion of pT1N0 DCC patients were at risk for recurrence. A DOI cutoff of <2 mm may be considered to potentially improve patient selection for adjuvant chemotherapy.

Retrospective analysis of 8th edition American Joint Cancer Classification: Distal cholangiocarcinoma

Backgrounds/Aims

This is a retrospective analysis of whether the 8th edition American Joint Committee on Cancer (AJCC) was a significant improvement over the 7th AJCC distal extrahepatic cholangiocarcinoma classification.

Methods

In total, 111 patients who underwent curative resection of mid-distal bile duct cancer from 2002 to 2019 were included. Cases were re-classified into 7th and 8th AJCC as well as clinicopathological univariate and multivariate, and Kaplan-Meier survival curve and log rank were calculated using R software.

Results

In patient characteristics, pancreaticoduodenectomy/pylorus preserving pancreaticoduodenectomy had better survival than segmental resection. Only lymphovascular invasion was found to be significant (hazard ratio 2.01, p = 0.039) among all clinicopathological variables. The 8th edition AJCC Kaplan Meier survival curve showed an inability to properly segregate stage I and IIA, while there was a large difference in survival probability between IIA and IIB.

Conclusions

The 8th distal AJCC classification did resolve the anatomical issue with the T stage, as T1 and T3 showed improvement over the 7th AJCC, and the N stage division of the N1 and N2 category was found to be justified, with poorer survival in N2 than N1. Meanwhile, in TMN staging, the 8th AJCC was able differentiate between early stage (I and IIA) and late stage (IIB and III) to better explain the patient prognosis.

Development and external validation of a prediction model for overall survival after resection of distal cholangiocarcinoma

BACKGROUND

Various prognostic factors are associated with overall survival (OS) after resection of distal cholangiocarcinoma (dCCA). The objective of this study was to develop and validate a prediction model for 3-year OS after pancreatoduodenectomy for dCCA.

METHODS

The derivation cohort consisted of all patients who underwent pancreatoduodenectomy for dCCA in the Netherlands (2009-2016). Clinically relevant variables were selected based on the Akaike information criterion using a multivariate Cox proportional hazards regression model, with model performance being assessed by concordance index (C-index) and calibration plots. External validation was performed using patients from the Belgium Cancer Registry (2008-2016), and patients from two university hospitals of Southampton (U.K.) and Verona (Italy).

RESULTS

Independent prognostic factors for OS in the derivation cohort of 454 patients after pancreatoduodenectomy for dCCA were age (HR 1.02, 95% CI 1.01-1.03), pT (HR 1.43, 95% CI 1.07-1.90) and pN category (pN1: HR 1.78, 95% CI 1.37-2.32; pN2: HR 2.21, 95% CI 1.63-3.01), resection margin status (HR 1.79, 95% CI 1.39-2.29) and tumour differentiation (HR 2.02, 95% CI 1.62-2.53). The prediction model was based on these prognostic factors. The optimism-adjusted C-indices were similar in the derivation cohort (0.69), and in the Belgian (0.66) and Southampton-Verona (0.68) validation cohorts. Calibration was accurate in the Belgian validation cohort (slope = 0.93, intercept = 0.12), but slightly less optimal in the Southampton-Verona validation cohort (slope = 0.88, intercept = 0.32). Based on this model, three risk groups with different prognoses were identified (3-year OS of 65.4%, 33.2% and 11.8%).

CONCLUSIONS

The prediction model for 3-year OS after resection of dCCA had reasonable performance in both the derivation and geographically external validation cohort. Calibration slightly differed between validation cohorts. The model is readily available via www. pancreascalculator.com to inform patients from Western European countries on their prognosis, and may be used to stratify patients for clinical trials.

Proposal of a new T-stage classification system for ampullary carcinoma based on Surveillance, Epidemiology and End Result (SEER) database

BACKGROUND

Tumor size is still considered a useful prognostic factor in currently available tumor-node-metastasis (TNM) classification staging systems for most solid tumors, but the significance of tumor size on the prognosis of ampullary carcinoma remains controversial. The aim of the current study was to propose a new T-stage classification system for ampullary carcinoma to address the impact of tumor size on the prognostic outcome.

METHODS

Using the Surveillance, Epidemiology, and End Results (SEER) database, we identified 1080 patients with ampullary carcinoma who underwent radical surgical resection between 2004 and 2015. Based on the results obtained from analysis of various clinicopathologic factors, a new T-stage classification system was proposed.

RESULTS

Among the 1080 patients, 618 were men and 462 were women, with a median tumor size of 2.3 (range 0.1-12) cm. Using the 7th edition of the American Joint Committee on Cancer (AJCC) staging manual, we noticed significant differences in overall survival (OS) between T2 vs. T3 tumors (P < 0.001) and T3 vs. T4 tumors (P = 0.002), but failed to observe significant differences between T1 vs. T2 tumors (P = 0.498) in our pair-wise comparison. Using the newly developed T-stage classification system, we were able to differentiate significant differences in OS between T1 vs. T2 tumors (P = 0.032), T2 vs. T3 tumors (P < 0.001) and T3 vs. T4 tumor (P = 0.003) in all pair-wise comparisons. The c-index of the new staging system was 0.653 (95% CI: 0.629-0.677), showing a better discriminatory power than the 0.636 of the 7th AJCC staging system (95% CI: 0.612-0.660).

CONCLUSIONS

The new T-stage classification system described herein can better differentiate prognostic outcomes after radical resection in patients with ampullary carcinoma by incorporating tumor size and depth of tumor infiltration.

Development and validation of an online calculator to predict early recurrence and long-term survival in patients with distal cholangiocarcinoma after pancreaticoduodenectomy

BACKGROUND

Distal cholangiocarcinoma (DCC) is a malignancy associated with a short survival time. In this study, we aimed to create an online nomogram calculator to predict early recurrence and long-term survival in patients with DCC after pancreaticoduodenectomy.

METHODS

A total of 486 patients with DCC were included. An online nomogram calculator was developed and validated in training, internal validation and external validation cohorts, respectively.

RESULTS

Of the 486 patients who met the inclusion criteria, we allocated 240, 120, and 126 patients to the training, internal validation, and external validation cohorts, respectively. Multivariable analysis showed that preoperative CA19-9, maximum tumor diameter, perineural invasion, and tumor differentiation were significant risk factors for early recurrence in patients with DCC. Incorporating these four factors, the nomogram achieved good AUC values of 0.788, 0.771, and 0.723 for predicting early recurrence in the training, internal validation, and external validation cohorts, respectively. Notably, this nomogram also had good power to predict overall survival. The discrimination ability of the nomogram was evaluated by dividing the predicted probabilities of early recurrence and survival into two risk groups in the training cohort (low risk ≤ 132; high risk > 132; P < .001). Time-dependent ROC and decision curve analysis further revealed that the nomogram provided higher diagnostic capacity and superior net benefit compared to other staging systems.

CONCLUSION

This study developed and validated a web-based nomogram calculator that was capable of predicting early recurrence and long-term prognosis in patients with DCC after pancreaticoduodenectomy with high degrees of stability and accuracy.

A novel online calculator to predict recurrence risk in patients with distal cholangiocarcinoma after radical pancreaticoduodenectomy

BACKGROUND

Patients with distal cholangiocarcinoma (DCC) are prone to relapse even after radical pancreaticoduodenectomy. In this study, we sought to create an online nomogram calculator to accurately predict the recurrence risk of DCC.

METHODS

A total of 184 patients were included. Multivariate Cox regression analysis was used to identify independent prognosis factors for recurrence-free survival and overall survival. A nomogram was constructed according to the prognostic factors in the training cohort and then tested in the validation cohort.

RESULTS

Multivariate Cox analysis showed preoperative carbohydrate antigen 19-9 (p < 0.001), maximum tumor size (p = 0.076), perineural invasion (p = 0.044), and N stage (p = 0.076) were independent prognostic factors for DCC relapse. We then constructed a nomogram with these four factors. The consistency index (C-index) of the nomogram in the training and validation cohorts were 0.703 and 0.665, respectively. Time-dependent receiver operating characteristic and decision curve analyses revealed that the nomogram provided higher diagnostic power and net benefit compared with other staging systems.

CONCLUSION

In this study, we developed an online nomogram calculator that can accurately predict the recurrence risk of DCC and identify patients with a high risk of recurrence in a simple and convenient manner.

The evaluation of the 8th and 7th edition of the American joint committee on cancer tumor classification for distal cholangiocarcinoma: the proposal of a modified new tumor classification

BACKGROUND

The 7th and 8th editions of the American Joint Committee on Cancer (AJCC) tumor (T) classification of distal cholangiocarcinoma (DCC), which are based on either layer or depth, may not accurately stratify patient survival.

METHODS

A total of 121 patients who underwent resection for DCC between 2002 and 2016 were analyzed. The impact of the AJCC staging system on survival was examined and a new T classification was established based on independent prognostic factors.

RESULTS

Regarding overall survival, the optimal depth of invasion (DOI) cut-off value (8 mm) was the only independent prognostic factor. Regarding the relapse-free survival (RFS), a DOI >8 mm, portal vein (PV) invasion, and duodenal or pancreatic invasion were independent prognostic factors. A new T classification was developed as follows: T1, no invasion of adjacent organs; T2, invasion of the duodenum or pancreas; T3, invasion >8 mm into the bile duct wall; and T4, invasion of the PV or arteries. There were no significant differences in RFS according to the 8th edition of the AJCC. However, significant differences were observed in the RFS between T1 and T2 and between T2 and T3.

CONCLUSION

A new T classification based on the layer and depth may be more feasible.

Stratification of Postoperative Prognosis by Invasive Tumor Thickness in Perihilar Cholangiocarcinoma

BACKGROUND

The pathological tumor classification of distal cholangiocarcinoma in the American Joint Committee on Cancer (AJCC) Cancer Staging Manual 8th edition is based on invasive depth, whereas that of perihilar cholangiocarcinoma (PHCC) continues to be layer-based. We aimed to clarify whether invasive depth measurement based on invasive tumor thickness (ITT) could help determine postoperative prognosis in patients with PHCC.

METHODS

We enrolled 184 patients with PHCC who underwent hepatectomy plus extrahepatic bile duct resection or hepatopancreatoduodenectomy with curative intent. ITT was measured using simple definitions according to the sectioning direction or gross tumor pattern.

RESULTS

The median ITT was 5.8 mm (range 0.7-15.5). Using the recursive partitioning technique, ITT was classified into grades A (ITT < 2 mm, n = 9), B (2 mm ≤ ITT < 5 mm, n = 68), C (5 mm ≤ ITT < 11 mm, n = 81), and D (11 mm < ITT, n = 26). The median survival times (MSTs) in patients with grade B, C, or D were 90.8, 44.6, and 21.1 months, respectively (patients with grade A did not reach the MST). There were significant differences in postoperative prognosis between ITT grades (A vs. B, p = 0.027; B vs. C, p < 0.001; C vs. D, p = 0.004). Through multivariate analysis, regional node metastasis, invasive carcinoma at the resected margin, and ITT grade were determined as independent prognostic factors.

CONCLUSION

ITT could be measured using simple methods and may be used to stratify postoperative prognosis in patients with PHCC.

Approaches and Outcomes to Distal Cholangiocarcinoma

Distal cholangiocarcinoma is a rare malignancy with a dismal prognosis. Because of its location and aggressive nature, patients often present with locally advanced or metastatic disease, and effective treatment options are limited. For patients with resectable disease, surgery is the only chance for cure, but achieving an R0 resection is paramount. Optimal adjuvant therapy in resectable disease remains under investigation. Randomized controlled trials investigating neoadjuvant therapy and its impact on resectability and long-term outcomes are needed to continue to improve the outcomes of patients with distal cholangiocarcinoma.

Reappraisal of classification of distal cholangiocarcinoma based on tumour depth

Background

In the eighth edition of the AJCC cancer staging classification, the T system for distal cholangiocarcinoma (DCC) has been revised from a layer-based to a depth-based approach. The aim of this study was to propose an optimal T classification using a measured depth in resectable DCC.

Methods

Patients who underwent pancreatoduodenectomy for DCC at 32 hospitals between 2001 and 2010 were included. The distance between the level of the naive bile duct and the deepest cancer cells was measured as depth of invasion (DOI). Invasive cancer foci were measured as invasive tumour thickness (ITT). Log rank χ2 scores were used to determine the cut-off points, and concordance index (C-index) to assess the survival discrimination of each T system.

Results

Among 404 patients, DOI was measurable in 182 (45·0 per cent) and ITT was measurable in all patients, with median values of 2·3 and 5·6 mm respectively. ITT showed a positive correlation with DOI (rs = 0·854, P &lt; 0·001), and the cut-off points for prognosis were 1, 5 and 10 mm. Median survival time was shorter with increased ITT: 12·4 years for ITT below 1 mm, 5·2 years for ITT at least 1 mm but less than 5 mm, 3·0 years for ITT at least 5 mm but less than 10 mm, and 1·5 years for ITT 10 mm or more (P &lt; 0·001). This classification exhibited more favourable prognostic discrimination than the T systems of the seventh and eighth editions of the AJCC (C-index 0·646, 0·622 and 0·624 respectively).

Conclusion

ITT is an accurate approach for depth assessment in DCC. The four-tier ITT classification with cut-off points of 1, 5 and 10 mm seems to be a better T system than those in the seventh and eighth editions of the AJCC classification.

A Novel T-Stage Classification System for Adrenocortical Carcinoma: Proposal from the US Adrenocortical Carcinoma Study Group

BACKGROUND

The 7th AJCC T-stage system for adrenocortical carcinoma (ACC), based on size and extra-adrenal invasion, does not adequately stratify patients by survival. Lymphovascular invasion (LVI) is a known poor prognostic factor. We propose a novel T-stage system that incorporates LVI to better risk-stratify patients undergoing resection for ACC.

METHOD

Patients undergoing curative-intent resections for ACC from 1993 to 2014 at 13 institutions comprising the US ACC Group were included. Primary outcome was disease-specific survival (DSS).

RESULTS

Of the 265 patients with ACC, 149 were included for analysis. The current T-stage system failed to differentiate patients with T2 versus T3 disease (p = 0.10). Presence of LVI was associated with worse DSS versus no LVI (36 mo vs. 168 mo; p = 0.001). After accounting for the individual components of the current T-stage system (size, extra-adrenal invasion), LVI remained a poor prognostic factor on multivariable analysis (hazard ratio 2.14, 95% confidence interval 1.05-4.38, p = 0.04). LVI positivity further stratified patients with T2 and T3 disease (T2: 37 mo vs. median not reached; T3: 36 mo vs. 96 mo; p = 0.03) but did not influence survival in patients with T1 or T4 disease. By incorporating LVI, a new T-stage classification system was created: [T1: ≤ 5 cm, (-)local invasion, (+/-)LVI; T2: > 5 cm, (-)local invasion, (-)LVI OR any size, (+)local invasion, (-)LVI; T3: > 5 cm, (-)local invasion, (+)LVI OR any size, (+)local invasion, (+)LVI; T4: any size, (+)adjacent organ invasion, (+/-)LVI]. Each progressive new T-stage group was associated with worse median DSS (T1: 167 mo; T2: 96 mo; T3: 37 mo; T4: 15 mo; p < 0.001).

CONCLUSIONS

Compared with the current T-stage system, the proposed T-stage system, which incorporates LVI, better differentiates T2 and T3 disease and accurately stratifies patients by disease-specific survival. If externally validated, this T-stage classification should be considered for future AJCC staging systems.

Surgical Site Infection Is Associated with Tumor Recurrence in Patients with Extrahepatic Biliary Malignancies

BACKGROUND

Surgical site infections (SSI) are one of the most common complications after hepato-pancreato-biliary surgery. Infectious complications may lead to an associated immune-modulatory effect that inhibits the body's response to cancer surveillance. We sought to define the impact of SSI on long-term prognosis of patients undergoing surgical resection of extrahepatic biliary malignancies (EHBM).

METHODS

Patients undergoing surgery for EHBM between 2000 and 2014 were identified using a large, multi-center, national cohort dataset. Recurrence free survival (RFS) was calculated and a multivariable Cox proportional hazards model was utilized to identify potential risk factors for RFS including SSI.

RESULTS

Seven hundred twenty-eight patients included in the analytic cohort; 236 (32.4%) patients had perihilar cholangiocarcinoma, 241 (33.1%) gallbladder cancer, and 251 (34.5%) distal cholangiocarcinoma. A major resection, liver resection, was performed in 205 (28.3%) patients, while 110 (15.2%) patients had a pancreaticoduodenectomy. The overall incidence of morbidity was 55.8%; among the 397 patients who experienced a complication, 161 patients specifically had an SSI. The SSI occurred as an infection of the surgical site (n = 70, 9.6%) or formation of an abscess in the operative bed (n = 91, 12.5%). SSI was associated with long-term survival as patients who experienced an SSI had a median RFS of 19.5 months compared with 30.5 months for those patients who did not have an SSI (HR 1.40, 95% CI 1.08-1.80; p = 0.01). Among 279 patients who had EHBM that had no associated lymph node metastases, well-to-moderate tumor differentiation, as well as an R0 resection margin, SSI remained associated with worse RFS (HR 1.84, 95% CI 1.03-3.29; p = 0.038), as well as overall survival (HR 1.87, 95% CI 1.18-2.97; p = 0.008).

CONCLUSION

SSI was a relatively common occurrence following surgery for EHBM as 1 in 10 patients experienced an SSI. In addition to standard tumor-specific factors, the occurrence of postoperative SSI was adversely associated with long-term survival.