Neoadjuvant Therapy for Extrahepatic Biliary Tract Cancer: A Propensity Score-Matched Survival Analysis

Background: Although surgery is the mainstay of curative-intent treatment for extrahepatic biliary tract cancer (EBTC), recurrence following surgery can be high and prognosis poor. The impact of neoadjuvant therapy (NAT) relative to upfront surgery (US) among patients with EBTC remains unclear. Methods: The Surveillance, Epidemiology, and End Results (SEER) databases was utilized to identify patients who underwent surgery from 2006 to 2017 for EBTC, including gallbladder cancer (GBC) and extrahepatic cholangiocarcinoma (ECC). Trends in NAT utilization were investigated, and the impact of NAT on prognosis was compared with US using a propensity score-matched (PSM) analysis. Results: Among 6582 EBTC patients (GBC, n = 4467, ECC, n = 2215), 1.6% received NAT; the utilization of NAT for EBTC increased over time (P_trend = 0.03). Among patients with lymph node metastasis, the lymph node ratio was lower among patients with NAT (0.18 vs. 0.40, p < 0.01). After PSM, there was no difference in overall survival (OS) and cancer-specific survival (CSS) among patients treated with NAT versus US (5-year OS: 24.0% vs. 24.6%, p = 0.14, 5-year CSS: 38.0% vs. 36.1%, p = 0.21). A subgroup analysis revealed that NAT was associated with improved OS and CSS among patients with stages III-IVA of the disease (OS: HR 0.65, 95%CI 0.46-0.92, p = 0.02, CSS: HR 0.62, 95%CI 0.41-0.92, p = 0.01). Conclusions: While NAT did not provide an overall benefit to patients undergoing surgery for EBTC, individuals with advanced-stage disease had improved OS and CSS with NAT. An individualized approach to NAT use among patients with EBTC may provide a survival benefit.