48Factors associated with resectable and unresectable biliary tract cancer using claims and electronic health records

Background & Objectives

Biliary tract cancer (BTC) prognosis remains poor. We aimed to delineate distinguishing factors of resectable versus unresectable BTC to inform earlier diagnosis.

Method

This retrospective, observational study analyzed US claims and EHR de-identified Optum® Market Clarity data to identify adult patients diagnosed with resectable or unresectable BTC from January 2016-September 2023. Baseline demographics and clinical characteristics were retrieved. Logistic regression and XGBoost modeling were used to identify factors associated with resectable and unresectable BTC at diagnosis. XGBoost model performance was evaluated using receiver operating characteristic area under the curve (AUC).

Results

A total of 4448 patients with BTC were included (resectable, n = 641; unresectable, n = 3807). Median age (68-years-old) and sex (female: ∼52%) were similar in resectable versus unresectable BTC. Intrahepatic cholangiocarcinoma was common in unresectable BTC (43.6%); ampulla of Vater (AoV) and gallbladder cancer (GBC) were more common in resectable versus unresectable BTC (AoV: 17.0% vs 9.0%; GBC: 28.6% vs 17.0%).

Resectable BTC at diagnosis was associated with: primary tumor site of AoV, GBC, and extrahepatic cholangiocarcinoma (eCCA); primary biliary cholangitis (PBC); and outpatient visits for gallstones or bile duct obstruction/biliary tract disease (Table). Factors associated with unresectable BTC diagnosis included prior cancer of unknown primary, Crohn's disease, inpatient visits for hepatomegaly, and outpatient visits for abdominal pain. XGBoost results were consistent with these findings, revealing diabetes, cardiovascular disease, and obesity as additional factors associated with resectable BTC. Strong discrimination between resectable and unresectable BTC at diagnosis (AUC, 0.93 [95% CI, 0.92--0.95]) was achieved with a sensitivity of 0.93 (95% CI, 0.91--0.94) in the test set.

Conclusion

Factors such as AoV and eCCA, which may enable earlier detection, were associated with resectable BTC, as well as PBC, diabetes, and gallstones, warranting a low threshold for screening in the setting of abnormal liver tests or suggestive symptoms.