Intrahepatic cholangiocarcinoma: an international multi-institutional analysis of prognostic factors and lymph node assessment.

Purpose: To identify factors associated with outcome after surgical management of intrahepatic cholangiocarcinoma (ICC) and examine the impact of lymph node (LN) assessment on survival.
Patients and Methods: From an international multi-institutional database, 449 patients who underwent surgery for ICC between 1973 and 2010 were identified. Clinical and pathologic data were evaluated using uni- and multivariate analyses.
Results: Median tumor size was 6.5 cm. Most patients had a solitary tumor (73%) and no vascular invasion (69%). Median survival was 27 months, and 5-year survival was 31%. Factors associated with adverse prognosis included positive margin status (hazard ratio [HR], 2.20; P < .001), multiple lesions (HR, 1.80; P = .001), and vascular invasion (HR, 1.59; P = .015). Tumor size was not a prognostic factor (HR, 1.03; P = .23). Patients were stratified using the American Joint Committee on Cancer/International Union Against Cancer T1, T2a, and T2b categories (seventh edition) in a discrete step-wise fashion (P < .001). Lymphadenectomy was performed in 248 patients (55%); 74 of these (30%) had LN metastasis. LN metastasis was associated with worse outcome (median survival: N0, 30 months v N1, 24 months; P = .03). Although patients with no LN metastasis were able to be stratified by tumor number and vascular invasion (N0; P < .001), among patients with N1 disease, multiple tumors and vascular invasion, either alone or together, failed to discriminate patients into discrete prognostic groups (P = .34).
Conclusion: Although tumor size provides no prognostic information, tumor number, vascular invasion, and LN metastasis were associated with survival. N1 status adversely affected overall survival and also influenced the relative effect of tumor number and vascular invasion on prognosis. Lymphadenectomy should be strongly considered for ICC, because up to 30% of patients will have LN metastasis.