The prognostic impact of differentiation at the invasive front of biliary tract cancer.

BACKGROUND

The invasive front of tumor can provide prognostic information in many cancers. We investigated the prognostic morphological factors at the invasive front including tumor differentiation (Difinv ) and tumor budding (Bud) in biliary tract cancer (BTC).

METHODS

The resected specimen from the 299 BTC patients were examined. Intrahepatic cholangiocarcinoma, extrahepatic cholangiocarcinoma, gallbladder cancer, and ampulla of Vater cancer were found in 16%, 48%, 17%, and 19%, respectively. Difinv grade (G) 3 and Bud foci ≥5 were found in 47% and 10%. Tumor with Difinv G3 showed the high frequencies of Bud, vascular invasion (Ve) and nodal metastasis (LN) compared to tumor with Difinv G1/2 (Bud: 21% vs 0%, Ve: 71% vs 50%, LN: 52% vs 36%). Multivariate analysis revealed that the independent predictors were Difinv G3 (HR: 1.71), Bud foci ≥5 (HR: 2.14), Ve (HR: 1.56) and LN (HR: 2.59) in overall survival and were positive resection margin (HR: 1.71), Difinv G3 (HR: 1.75), Ve (HR: 1.50), and LN (HR: 2.19) in relapse free survival.

CONCLUSION

Poor differentiation at the invasive front of tumor was associated with poor prognosis and early relapse in BTC patients.