Trends and Outcomes of Adjuvant Therapy in Extrahepatic/Distal Cholangiocarcinoma

Abstract

INTRODUCTION: Extrahepatic cholangiocarcinoma (ECC) of the bile duct has increasing incidence with poor survival. The current first-line therapy is surgical resection followed by adjuvant chemotherapy and radiotherapy. There is evidence that adjuvant therapy may improve survival in high-risk cases. However, due to the rarity of the disease, data are limited. The aim of this study is to analyze trends of receiving adjuvant therapy for ECC from 2006 to 2018, determine predictors for the receipt of adjuvant therapy, and determine outcomes associated with receipt of adjuvant therapy. METHODS: Using the National Cancer Data Base, cases of ECC for the years 2006 to 2018 were analyzed for the trend of using adjuvant therapy and 90-day mortality rate. Four cohorts of therapy were established: only chemotherapy, radiotherapy, combined chemoradiotherapy, and no therapy. Patients in the 4 cohorts were stratified to race, ethnicity, insurance, income, facility type, and location. RESULTS: Trends of adjuvant therapy increased steadily from 41.1% in 2006 to 58.4% in 2018. The most prominent increase was in the use of adjuvant chemotherapy from 9.9% to 35.1%; while radiation or combined chemoradiation therapy decreased from 4.9% to 1.4%, and from 26.3% to 21.9%, respectively. Outcomes in terms of 90-day mortality are improved with adjuvant therapy. Predictors of using adjuvant therapy were positively correlated with private insurance, treatment in a community cancer program, Native American race, and being in the Northeast. CONCLUSION: Adjuvant therapy use in ECC is increasing with improved mortality rate. The increase is positively correlated with private insurance and community cancer programs.