Objective: Define the optimal surgical margin in patients undergoing surgery for intrahepatic cholangiocarcinoma (IHCC).
Background data: Surgery is the most effective treatment for IHCC. However, the influence of R1 resection on outcome is controversial and that of margin width has not been evaluated.
Methods: We studied 212 patients undergoing curative resection of mass-forming-type IHCC. The respective influences on survival of resection status (R0 vs R1), surgical margin width, pTNM stage, and the latter's components were evaluated.
Results: Incidence of R1 resection was 24%. Overall, R1 resection was not an independent predictor of survival [odds ratio (OR) 1.2 (0.7-2.1)] in contrast to the pTNM stage [OR 2.10 (1.2-3.5)]. In the 78 pN+ patients, survival was similar after R0 and R1 resections (median: 18 vs 13 months, respectively, P = 0.1). In the 134 pN0 patients, R1 resection was an independent predictor of poor survival [OR 9.6 (4.5-20.4)], as was the presence of satellite nodules [OR 1.9 (1.1-3.2)]. In the 116 pN0 patients with R0 resections, median survival was correlated with margin width (≤1 mm: 15 months; 2-4 mm: 36 months; 5-9 mm: 57 month; ≥10 mm: 64 month, P < 0.001) and a margin >5 mm was an independent predictor of survival [OR 2.22 (1.59-3.09)].
Conclusion: Patients undergoing surgery for IHCC are at high risk of R1 resections. In pN0 patients, R1 resection is the strongest independent predictor of poor outcome and a margin of at least 5 mm should be created. The survival benefits of resection in pN+ patients and R1 resection in general are very low.