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

162 Background: Intrahepatic cholangiocarcinoma (ICC) is a rare and poorly understood primary liver cancer. The role of routine lymphadenectomy at the time of surgical resection remains poorly defined. We sought to identify factors associated with outcome following surgical management of ICC and examine the impact of lymph node (LN) assessment on survival.METHODS411 patients who underwent curative intent surgery for ICC between 1973-2010 were identified from an international multi-institutional database. Clinical and pathologic data were evaluated using uni- and multivariate analyses.RESULTSMedian tumor size was 6.5 cm. Most patients had a solitary tumor (55%) and no evidence of vascular invasion (64%). Resection involved ≥hemi-hepatectomy (74%) and margin status was R0 (82%). Overall median survival was 28 months and 5-year survival was 32%. Factors associated with adverse prognosis included positive margin status (HR=3.11; p<0.001), multiple lesions (HR=2.16; p=0.007) and vascular invasion (HR=2.13; p=0.01). Tumor size was not a prognostic factor (HR=1.05; p=0.08). Lymphadenectomy was performed in 233 (57%) patients; 87 (37%) had LN metastasis. LN metastasis was associated with worse outcome (median survival: N0 39 months vs. N1 21 months; p=0.02). Preoperative factors such as tumor size, number, and morphologic subtype did not predict presence of LN metastasis (all p>0.05); however, vascular invasion did (OR=2.24; p=0.003).CONCLUSIONSWhile tumor size provides no prognostic information, tumor number, vascular invasion, and LN metastasis were associated with survival. Presence of LN metastasis cannot be predicted using preoperative tumor features. Lymphadenectomy should be routinely performed for ICC as up to one-quarter of patients will have LN metastasis. No significant financial relationships to disclose.