Retrospective analysis of outcomes with different adjuvant treatments in cholangiocarcinoma: An NCDB review.

Abstract

e15677 Background: Annually approximately 5000 cases of cholangiocarcinoma are reported in the US. Of these, less than 40% are treated surgically with a curative intent. Post resection, local and distant recurrence rates are as high as 35% within two years. Positive surgical margins, with either Microscopic (R1) or Macroscopic (R2) disease, confer a higher risk of recurrence. We aim to analyze survival outcomes for different adjuvant treatment strategies in patients with R1/R2 resection. Methods: We queried the NCDB from 2004-2015 for patients with non-metastatic cholangiocarcinoma, who had an R1/R2 resection status post surgery. We then stratified these patients into three arms based on the adjuvant treatment they received: combined chemotherapy and radiation (CRT) vs chemotherapy (CTH) vs observation (OBS). Mean overall survival (OS) was compared for these three groups. OS was calculated from the date of diagnosis to the date of last contact or death using Kaplan Meier curves to present the cumulative probability of survival, with log-rank statistics to assess significance. Results: We identified 522 patients who met our inclusion criteria. Of these, 178 received CRT adjuvantly, 171 CTH, and 173 were observed. The OS in these arms was 42 vs 32 vs 30 months respectively (pooled p < 0.04). As compared to CRT, the hazard ratio was 1.4 (95% CI 1.07-1.72) for CTH and 1.6 (95% CI of 1.2-2.1) for OBS arm. At one year, 83% vs 41% vs 20% of the patients were alive in the respective cohorts and at 5 years, the OS rates were 56% vs 25% vs 13% respectively. Conclusions: Our data demonstrates that combined chemotherapy and radiation is superior to either chemotherapy increase in overall survival for CRT when compared to CHT and observation alone.