Postoperative Prognosis According to Pathologic Categorization of Desmoplastic Reaction in Patients with Extrahepatic Cholangiocarcinoma.

BACKGROUND: Recent studies have demonstrated the importance of desmoplastic reaction (DR) in predicting postoperative prognosis for patients with colorectal carcinoma. However, the impact of DR on the prognosis of extrahepatic cholangiocarcinomas (EHCCs) is not established. This study aimed to clarify the associations of pathologic DR categories with clinicopathologic factors and postoperative prognosis of perihilar cholangiocarcinoma (PHCC) and distal cholangiocarcinoma (DCC). METHODS: A pathologic review of 174 patients with PHCC and 109 patients with DCC who underwent surgical resection was performed. The patients were classified into three DR categories (immature, intermediate, and mature) based on the histologic features within the fibrotic stroma in the invasive front. The association between DR categories and the distribution of fibroblasts with anti-α-smooth muscle actin (SMA) expression, seeming to be tumor-promoting cancer-associated fibroblasts (CAFs), was evaluated in 191 tissue microarray specimens of EHCCs. RESULTS: Intermediate/immature DR categories were significantly associated with a more invasive nature, including higher pT and pN stages and more tumor buds than the mature category in both PHCC and DCC. The DR categories could stratify overall survival (OS) and relapse-free survival (RFS) in both PHCC and DCC patients. In the multivariate analysis, the DR category was an independent prognostic factor for OS and RFS in both PHCC and DCC (p < 0.001). The mature and immature DR categories were significantly associated respectively with the confined and pervasive distribution of fibroblasts with α-SMA expression. CONCLUSION: In patients with EHCCs, DR categorization was an independent prognostic factor reflecting the distribution of tumor-promoting CAFs in the invasive front.

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.

CCR7 Mediates Cell Invasion and Migration in Extrahepatic Cholangiocarcinoma by Inducing Epithelial-Mesenchymal Transition.

The epithelial-mesenchymal transition (EMT) contributes to the metastatic cascade in various tumors. C-C chemokine receptor 7 (CCR7) interacts with its ligand, chemokine (C-C motif) ligand 19 (CCL19), to promote EMT. However, the association between EMT and CCR7 in extrahepatic cholangiocarcinoma (EHCC) remains unknown. This study aimed to elucidate the prognostic impact of CCR7 expression and its association with clinicopathological features and EMT in EHCC. The association between CCR7 expression and clinicopathological features and EMT status was examined via the immunohistochemical staining of tumor sections from 181 patients with perihilar cholangiocarcinoma. This association was then investigated in TFK-1 and EGI-1 EHCC cell lines. High-grade CCR7 expression was significantly associated with a large number of tumor buds, low E-cadherin expression, and poor overall survival. TFK-1 showed CCR7 expression, and Western blotting revealed E-cadherin downregulation and vimentin upregulation in response to CCL19 treatment. The wound healing and Transwell invasion assays revealed that the activation of CCR7 by CCL19 enhanced the migration and invasion of TFK-1 cells, which were abrogated by a CCR7 antagonist. These results suggest that a high CCR7 expression is associated with an adverse postoperative prognosis via EMT induction and that CCR7 may be a potential target for adjuvant therapy in EHCC.

Validation Study of Tumor Invasive Thickness for Postoperative Prognosis in 110 Patients Who Underwent Pancreatoduodenectomy for Distal Cholangiocarcinoma at a Single Institution.

The pT classification of the 8th American Joint Committee on Cancer (AJCC) for distal cholangiocarcinoma (DCC) is classified according to depth of invasion (DOI), which is the distance from the basal lamina to the most deeply advanced tumor cells. The Nagoya group proposed a new T classification for DCC based on invasive tumor thickness (ITT), which is the maximal vertical distance of the invasive cancer component (the ITT grade). In this study, we aimed to validate the ITT grade for the next pT classification of DCC in 110 patients. ITT could be measured in all patients, but DOI could only be measured in 62 (56%) patients. According to ITT grade, patients were classified into grades A to D, as follows: grade A, ITT <1 mm (n=9); grade B, ITT 1 mm or more but <5 mm (n=35); grade C, ITT 5 mm or more but <10 mm (n=40); and grade D, ITT 10 mm or greater (n=26). The median overall survival times in patients with ITT grades A, B, C, and D were 12.8, 5.7, 3.7, and 2.0 years, respectively. ITT grade could discriminate postoperative survivals between grades. On multivariate analysis, ITT grade, regional lymph node metastasis, and distant metastasis were selected as independent prognostic factors. In summary, our results showed that ITT grade was a suitable alternative to DOI for pT classification in the next edition of the AJCC for DCC.