92P - Prognostic value of tumor location and site-specific metastases in advanced biliary tract cancer

Background

Biliary tract cancer (BTC) encompasses a spectrum of invasive tumors arising from the gallbladder or cystic duct (gallbladder carcinoma - GBC) or the biliary tree (cholangiocarcinoma- CCA). CCA is subclassified as intrahepatic (iCCA) or extrahepatic (perihilar vs distal). Patients with different metastatic sites might present different prognostic prospects and need distinct therapeutic approaches. We aimed to determine whether tumor location and patterns of metastatic spread influence survival in patients with metastatic BTC.

Methods

Retrospective unicentric study of patients with metastatic or recurrent BTC treated between January 2018 and October 2023. Survival analysis was performed using the Cox Proportional Hazards model, using as predictors the location of the primary tumor (intra-hepatic vs extra-hepatic) and metastases.

Results

We identified 56 patients. Median age was 74 years, with 59% being male. Most patients (68%) had ECOG PS of 0-1. Regarding location, 50% were iCCA, 32% extrahepatic CCA and 18% GBC. At diagnosis 62,5% were stage IV. Surgery to the primary tumor was performed on 28,5% and locoregional therapies in 21,4%. Systemic treatment was administered in 66% patients, of which 51,2% underwent more than one line of therapy. About 59% of patients had multi-site metastases. In patients with single metastases, the most common site was liver 36,3% and regional lymph nodes 27,3%. Among the patients who were pluri-metastatic, the most common sites were liver and regional lymph nodes, in all locations: iCCA (Liver and regional lymph nodes 75% respectively), extrahepatic CCA (liver and regional lymph nodes 37,5% and 50%, respectively), GCA (liver and regional lymph nodes 60% and 40%, respectively). Median follow-up was 6.1 months. In the Cox regression, metastases’ locations were not predictive of lower OS. Extrahepatic BTC was predictive of higher mortality (HR 4.6, 95% CI 1.3-7.6).

Conclusions

In our population, primary tumor location was predictive of mortality, with extra-hepatic BTC predicting lower OS. Patterns of metastatic spread were not predictive of mortality This might suggest that response to systemic treatment and tumor aggressiveness might be associated with the primary site. Further studies are needed.

Editorial acknowledgement

Clinical trial identification

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.