AUTHOR=Aphivatanasiri Chaiwat , Sa-Ngiamwibool Prakasit , Sangkhamanon Sakkarn , Intarawichian Piyapharom , Kunprom Waritta , Thanee Malinee , Prajumwongs Piya , Khuntikeo Narong , Titapun Attapol , Jareanrat Apiwat , Thanasukarn Vasin , Srisuk Tharatip , Luvira Vor , Eurboonyanun Kulyada , Promsorn Julaluck , Loilome Watcharin , Wee Aileen , Koonmee Supinda 

TITLE=Modification of the eighth AJCC/UICC staging system for perihilar cholangiocarcinoma: An alternative pathological staging system from cholangiocarcinoma-prevalent Northeast Thailand

JOURNAL=Frontiers in Medicine

VOLUME=Volume 9 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/medicine/articles/10.3389/fmed.2022.893252

DOI=10.3389/fmed.2022.893252

ISSN=2296-858X

ABSTRACT=Abstract
Aim: This study aims to improve the classification performance of the 8th American Joint Committee on Cancer (AJCC) staging system for perihilar cholangiocarcinoma (pCCA) by proposing the Khon Kaen University (KKU) staging system developed in cholangiocarcinoma-prevalent Northeast Thailand. Method: 488 pCCA patients who underwent partial hepatectomy between 2002-2017 at the Srinagarind Hospital, Faculty of Medicine, Khon Kaen University, Thailand, were included. Overall survival (OS) related to clinicopathological features was analyzed using the Kaplan-Meier method. Logrank test was performed in univariate analysis to compare OS data of clinicopathological features to determine risk factors for poor survival. Significant features were further analyzed by multivariate analysis (Cox regression) to identify prognostic factors which were then employed to modify the 8th AJCC staging system. Results: Multivariate analysis showed that growth pattern (HR=4.67-19.72, p<0.001), moderately and poorly differentiated histological grades (HR=2.31-4.99, p<0.05 and 0.001, respectively), lymph node metastasis N1 and N2 (HR=1.37 and 2.18, p<0.05 and 0.01, respectively), and distant metastasis (HR= 2.11, p<0.001) were independent factors when compared to their respective reference groups. There was clear separation of pCCA patients into KKU stage: I (OS = 116 months (mo.)), II (OS = 46 mo.), IIIA (OS = 24 mo.), IIIB (11 mo.), IVA (OS = 7 mo.) and IVB (OS = 6 mo.). Conclusion: The new staging system was based on incorporation of growth patterns to modify the 8th AJCC staging system. The classification performance demonstrated that the KKU staging system was able to classify and distinctly separate pCCA patients into those with good and poor outcomes. It was also able to improve stratification performance and discriminative ability of different stages of pCCA classification better than the 8th AJCC staging system. Hence, the KKU staging system is proposed as an alternative model to augment the accuracy of survival prognostication and treatment performance for pCCA patients.