Researchers developed a prognostic nomogram for predicting postoperative overall survival (OS) in patients with node-negative perihilar cholangiocarcinoma (PHC) and discovered it had better statistical accuracy than the American Joint Committee on Cancer (AJCC) staging system, according to a study published in the Asian Journal of Surgery. 

PHC constitutes about 50% of all cholangiocarcinomas (CCA) and is located at the hilar section of the bile ducts. Surgery remains the only curative option, but late presentation renders it less effective, with OS being low.

The most commonly used method for predicting prognosis in PHC is the AJCC staging system. However, the authors of the study stated, “its prognostic accuracy remains modest.” This is particularly true in node-negative PHC since the AJCC scoring system predicts prognosis based on the depth of tumor invasion. 


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The authors of this study decided to create a nomogram that could more accurately predict prognosis than the AJCC staging system. They were encouraged by the success of nomograms in predicting prognosis in other malignancies such as gallbladder cancer and ampullary carcinoma.

Using the National Cancer Institute’s Surveillance, Epidemiology, and End Results (SEER) database, researchers retrieved data on patients who were diagnosed with node-negative PHC and underwent surgical resection between 2004 and 2015. They also recruited 100 node-negative PHC patients from the First Affiliated Hospital of Sun Yat-sen University (FAHSYSU) in Guangzhou, China, between 2003 and 2018. The first group of patients was assigned as the design cohort, while the second group of patients was assigned as the external validation cohort. 

Researchers then developed a nomogram via multivariate regression analysis. Results showed that prognostic factors such as age, tumor grade, and the number of lymph nodes examined were independent prognostic factors for OS in node-negative PHC patients. The nomogram performed very well; it had C-indices of 0.603 and 0.626 in the design cohort and external validation cohort, respectively, both of which were better than the AJCC staging system (P <.05). 

“The nomogram could be used to help guide the postoperative treatment strategy of patients with node-negative PHC,” the authors wrote.

Reference

Huang XT, Cai JP, Chen W, et al. Establishment and validation of a nomogram for predicting overall survival of node-negative perihilar cholangiocarcinoma. Asian J Surg. Published online August 9, 2021. doi:10.1016/j.asjsur.2021.07.039