Prognostic Impact of Paraaortic Lymph Node Metastasis in Extrahepatic Cholangiocarcinoma

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.

Prognostic influence for hilar cholangiocarcinoma and comparisons of prognostic values of Mayo staging and TNM staging systems

The study was designed to discuss the effect of stratification factors in the Mayo staging on the prognosis of hilar cholangiocarcinoma (HCCA) patients, and to evaluate the predictive value of the Mayo staging on the prognosis. The Kaplan-Meier survival curve and Log-rank test were used to perform univariate analysis on each index and obtain statistically significant influencing factors. The Kaplan-Meier survival curve and Log-rank test were used to analyze the correlation between the two staging systems and the survival period. The receiver operating characteristic (ROC) curves were used for each single staging system trend analysis, and comparison of their curve area to determine prognosis prediction ability for patients with HCCA. According to Kaplan-Meier survival curve changes and Log-rank test results, it was found that both staging systems were correlated with the survival time of the patients (P < .001). Through a pairwise comparison within the stages, it was found that the heterogeneity between the stages within the Mayo staging is very good, which was better than the TNM staging. A single trend analysis of the prognostic assessment capabilities of the two systems found that the area under the ROC curve of Mayo staging system (AUC = 0.587) was the largest and better than the TNM staging system (AUC = 0.501). Mayo staging can be used for preoperative patient prognosis assessment which can provide better stratification ability based on a single-center small sample study, and the predictive value is better than TNM staging.

Recommendations of the clinical target volume for the para-aortic region based on the patterns of lymph node metastasis in patients with biliary tract cancer

BACKGROUND

Even though the clinical target volume (CTV) in biliary tract cancer (BTC) patients has been proposed by several previous studies, the para aortic CTV for BTC is still not well-defined. The objective of this study was to determine the precise delineation of the para aortic CTV for BTC according to the distribution pattern and failure pattern of lymph nodes.

METHODS

Computed tomography (CT)-, magnetic resonance imaging (MRI)- or positron emission tomography-computed tomography (PET-CT)-generated images of patients with BTC from 2015 to 2020 were analyzed retrospectively. The distribution patterns of lymph nodes in different regions were summarized. The diagnosed para aortic lymph nodes (PALNs) were manually mapped to standard axial CT images. The asymmetric CTV expansions from the para aortic were defined according to the distance from the volumetric centre of lymph node to the most proximal border of aorta.

RESULTS

A total of 251 positive lymph nodes were found in the study cohort (n = 61 patients, 92 PALN). All PALNs were projected onto axial CT image of the standard patient. PALNs were concentrated in the 16a2 and 16b1 regions, and the involvement rates were 17% and 13% respectively. Therefore, the upper boundary of 16a2 and the lower boundary of 16b1 were defined as the cranial and caudal border of para aortic CTV, respectively. For the study cohort, the mean distance from the volume center of all lymph nodes in 16a2 and 16b1 to the proximal border of the aorta was 9 mm (range 4-24) in the front, 7 mm (range 3-14) on the left, and 12 mm (range 5-29) on the right. For the validation cohort (n=19 patients, 56 PALN), the mean distance from the center of the lymph node to the border of the aorta were both 10 mm on the left (range 5-20) and right (range 6-23). The mean distance in front of the aorta was 9 mm (range 5-23). Finally, a CTV expansion from the aorta of 18 mm in the front, 12 mm on the left, and 24 mm on the right resulted in 96% (73/76) coverage of PALNs in the study cohort. At the time of the validation, the described CTV could include 96% (47/49) of recurrent PALNs in the validation cohort.

CONCLUSIONS

The involvement rates of PALNs in 16a2 and 16b1 were the highest. Based on the distribution of PALNs, a new para-aortic CTV was defined to construct a more accurate target volume for adjuvant radiotherapy in BTC.

Converted-hepatopancreatoduodenectomy for an intraoperative positive ductal margin after pancreatoduodenectomy in distal cholangiocarcinoma

PURPOSE

Pancreatoduodenectomy (PD) is the standard treatment for distal cholangiocarcinoma, and a negative ductal margin (DM0) is indispensable for the long-term survival. When intraoperative frozen sections of ductal margin after PD are positive, converted-hepatopancreatoduodenectomy (C-HPD) is the final option available to gain an additional ductal margin. However, the efficacy of C-HPD remains unclear.

METHODS

Patients who underwent PD or C-HPD for distal cholangiocarcinoma between 2002 and 2019 were analyzed. The type of hepatectomy in C-HPD was restricted to left hepatectomy to prevent posthepatectomy liver failure.

RESULTS

Of 203 patients who underwent PD for distal cholangiocarcinoma, 49 patients exhibited intraoperative positive ductal margin (DM1) after PD. Eleven patients underwent C-HPD for intraoperative DM1 after PD, in which intraoperative DM1 with invasive carcinoma (DM1inv) was observed in 3 patients, and intraoperative DM1 with carcinoma in situ (DM1cis) was observed in 8 patients. The median additional ductal margin yielded by C-HPD was 9 mm (interquartile range 7-13 mm). C-HPD eradicated intraoperative DM1inv in 3 patients, with 2 patients showing DM0 and 1 patient showing DM1cis. Regarding 8 patients who underwent C-HPD for intraoperative DM1cis, 4 patients had DM0, but the others had DM1cis. C-HPD was associated with a high complication rate, but no mortality was observed. The median survival time of patients who underwent C-HPD was 48.8 months.

CONCLUSION

C-HPD was able to safely eradicate intraoperative DM1inv after PD. However, the length of the resected bile duct according to C-HPD may not be sufficient to remove intraoperative DM1cis after PD.

Approach to Resectable Biliary Cancers

OPINION STATEMENT

Biliary malignancies, although rare, can be some of the most challenging to manage surgically. Intrahepatic cholangiocarcinomas are resectable if there is no evidence of metastatic disease. These tumors are managed with anatomic resection and portal lymphadenectomy when centrally located or multiple in a single lobe. Non-anatomic resection can be performed for solitary peripheral tumors with minimally invasive techniques. It is not our practice to routinely employ neoadjuvant chemotherapy prior to resection of these tumors. Hepatic arterial infusion chemotherapy is utilized at our institution in highly selected patients in the context of an ongoing clinical trial for unresectable tumors. Hilar cholangiocarcinomas, when resectable (i.e., ipsilateral arterial involvement or lack of vascular involvement), are managed with right or left (extended) hepatectomy, caudate resection, and portal lymphadenectomy. Distal cholangiocarcinomas are managed with pancreaticoduodenectomy. Neoadjuvant chemotherapy is not routinely used in our treatment algorithm of extrahepatic cholangiocarcinomas. Nodal involvement and positive margin (R1) resection necessitates adjuvant chemotherapy. Finally, gallbladder carcinoma is managed with radical cholecystectomy, anatomic segment IVb/V resection, and portal lymphadenectomy. Adjuvant chemotherapy is employed routinely amongst patients with T2 or higher tumors and those with positive lymph nodes.