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

Preoperative prognostic stratification and prediction of long-term outcomes after pancreatoduodenectomy for distal cholangiocarcinoma

BACKGROUND

Patients with distal cholangiocarcinoma (DCC) frequently receive adjuvant chemotherapy in preoperative and postoperative settings, but prediction of prognostic risk at the time of treatment selection remains challenging.

METHODS

This single-center retrospective study enrolled DCC patients who underwent initial pancreatoduodenectomy (PD) between 2009 and 2022. Preoperative clinical parameters were collected, and Cox regression analysis was used to identify risk factors for overall survival (OS).

RESULTS

Among 170 patients examined, the median tumor depth was 10 mm, and 37 % of the patients were diagnosed with pT3. Overall, 46 % of patients had lymph node metastasis. The median and 5-year OS was 58.2 months and 50 %, respectively. Multivariate analysis revealed tumor size on computed tomography (CT) ≥15 mm and main pancreatic duct (MPD) dilatation (≥3 mm) as independent risk factors for OS among various preoperative parameters; the prognosis was stratified based on these two parameters. Patients with one risk factor had similar outcomes (5-year OS: 39 %) to pStage IIB DCC (pT2N1 or pT3), while those with two risk factors had a prognosis akin to pStage IIIA (pN2), with a high early recurrence rate of 64 % (5-year OS: 8 %). Among non-risk group patients with low carbohydrate antigen (CA)19-9 levels (<37 U/mL), the prognosis was comparable (5-year OS: 72 %) to those with pStage I DCC.

CONCLUSION

A simple stratification approach was developed to predict long-term postoperative outcomes. To improve poor prognosis, intensive therapy, including neoadjuvant chemotherapy, should be considered for patients with two risk factors.

Clinical impact of pancreatic invasion in T1-stage distal bile duct cancer and prognostic factors associated with long-term survival: A multicenter study

BACKGROUND/PURPOSE

The eighth edition of the AJCC staging system introduced a shift in the staging of distal bile duct cancer (DBC), emphasizing the depth of invasion over adjacent organ invasion. This study aimed to evaluate the clinical impact of pancreatic invasion in pT1-stage DBC and identify prognostic factors for long-term survival.

METHODS

This multicenter retrospective analysis encompassed DBC patients who underwent pancreaticoduodenectomy between 2009 and 2019 in six Korean tertiary centers, specifically those with final pathology confirming AJCC eighth edition T1 stage and intrapancreatic bile duct tumor origin. Primary endpoints were five-year recurrence-free survival (RFS) and overall survival (OS). Secondary objectives included the identification of prognostic determinants.

RESULTS

This study involved 287 patients, comprising 190 without and 97 with pancreatic invasion. Pancreatic invasion did not significantly influence five-year OS and RFS rates (OS: without pancreatic invasion 69.9% vs. with pancreatic invasion 54.1%, p = .25; RFS: 56.3% vs. 55.4%, p = .97). Multivariate analysis highlighted male gender, age, lymphovascular invasion, and N stage as significant OS determinants. Notably, male gender, ampulla of Vater invasion, lymphovascular invasion, and N1 stage were also associated with RFS.

CONCLUSIONS

In pT1 DBC, pancreatic invasion demonstrates no substantial impact on long-term prognosis, in accordance with the depth-based paradigm of the eighth edition AJCC staging system. The prognostic factors influencing OS were identified as male gender, age, lymphovascular invasion, and nodal metastasis.

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.

Benefit of lymph node dissection for perihilar and distal cholangiocarcinoma according to lymph node stations

BACKGROUND

The benefits of lymph node (LN) dissection at each station have not previously been fully investigated in perihilar cholangiocarcinoma (PHCC) and distal cholangiocarcinoma (DCC).

METHODS

The efficacy index (EI) was calculated in patients who underwent surgery for PHCC (n = 134) and DCC (n = 135) by multiplying the frequency of metastasis to the LN station and the 5-year overall survival (OS) rate of patients with metastasis to that station.

RESULTS

In PHCC, the frequency of metastasis, 5-year OS rates, and the EI in para-aortic LNs (4.7%, 0%, and 0, respectively) and posterior pancreaticoduodenal LNs (8.1%, 0%, and 0, respectively) were lower than those in hepatoduodenal ligament LNs (30.1%, 24.1%, and 7.25, respectively) and LNs along the common hepatic artery (CHA) (16.2%, 15.0%, and 2.43, respectively). In DCC, these values were lower in LNs along the CHA (6.4%, 0%, and 0, respectively) than in the posterior pancreaticoduodenal LNs (31.2%, 34.5%, and 10.8, respectively), the hepatoduodenal ligament LNs (14.8%, 15.2%, and 2.25, respectively), and para-aortic (4.0%, 25.0%, and 0.99, respectively) LNs.

CONCLUSIONS

According to the EI, this study raises concerns about the effectiveness of dissection in the posterior pancreaticoduodenal LNs in PHCC and LNs along the CHA in DCC.

Subserosal Layer and/or Pancreatic Invasion Based on Anatomical Features as a Novel Prognostic Indicator in Patients with Distal Cholangiocarcinoma

The American Joint Committee on Cancer (AJCC) 8th edition T-staging system for distal cholangiocarcinoma (DCC) proposes classification according to the depth of invasion (DOI); nevertheless, DOI measurement is complex and irreproducible. This study focused on the fibromuscular layer and evaluated whether the presence or absence of penetrating fibromuscular invasion of DCC contributes to recurrence and prognosis. In total, 55 patients pathologically diagnosed with DCC who underwent surgical resection from 2002 to 2022 were clinicopathologically examined. Subserosal layer and/or pancreatic (SS/Panc) invasion, defined as penetration of the fibromuscular layer and invasion of the subserosal layer or pancreas by the cancer, was assessed with other clinicopathological prognostic factors to investigate recurrence and prognostic factors. According to the AJCC 8th edition, there were 11 T1, 28 T2, and 16 T3 cases, with 44 (80%) cases of SS/Panc invasion. The DOI was not significantly different for both recurrence and prognostic factors. In the multivariate analysis, only SS/Panc was identified as an independent factor for prognosis (hazard ratio: 16.1; 95% confidence interval: 2.1-118.8, p = 0.006). In conclusion, while the determination of DOI in DCC does not accurately reflect recurrence and prognosis, the presence of SS/Panc invasion may contribute to the T-staging system.

The Impact of CT-Assessed Liver Steatosis on Postoperative Complications After Pancreaticoduodenectomy for Cancer

INTRODUCTION

Liver steatosis (LS) has been increasingly described in preoperative imaging of patients undergoing pancreaticoduodenectomy (PD). The aim of this study was to assess the impact of preoperative LS on complications after PD and identify possible contributors to LS development in this specific cohort.

METHODS

Pancreatic head adenocarcinoma (PDAC) patients scheduled for PD, with preoperative CT-imaging available were included in the study. LS was defined as mean liver density lower than 45 Hounsfield units. Patients showing preoperative LS were matched for patient age, gender, BMI, ASA score, neoadjuvant treatment, and vascular and multivisceral resections, based on propensity scores in a 1:2 ratio to patients with no LS. The primary outcome was postoperative complication severity at 90 days as measured by the comprehensive complication index (CCI) RESULTS: Overall, 247 patients were included in the study. Forty-three (17%) patients presented with LS at preoperative CT-scan. After matching, the LS group included 37 patients, whereas the non-LS group had 74 patients. LS patients had a higher mean (SD) CCI, 29.7 (24.5) versus 19.5 (22.5), p = 0.035, and a longer length of hospital stay, median [IQR] 12 [8-26] versus 8 [7-13] days, p = 0.006 compared with non-LS patients. On multivariate analysis, variables independently associated with CCI were: LS (16% increase, p = 0.048), male sex (19% increase, p = 0.030), ASA score ≥ 3 (26% increase, p = 0.002), fistula risk score (FRS) (28% increase for each point of FRS, p = 0.001) and vascular resection (20% increase, p = 0.019).

CONCLUSION

Preliminary evidence suggests that preoperative LS assessed by CT-scan influences complication severity in patients undergoing PD for PDAC.