Reconsideration of the lymph node metastasis pattern (N factor) from intrahepatic cholangiocarcinoma using the International Union Against Cancer TNM staging system for primary liver carcinoma.

BACKGROUND

In cholangiocarcinoma, no established method of analysis of lymph node metastasis has been reported with respect to the surgical outcome.

METHODS

The authors retrospectively examined the pattern of lymph node metastasis and the surgical outcome with reference to the International Union Against Cancer (UICC) TNM stage in 47 patients with cholangiocarcinoma who underwent complete tumor resection followed by a period of observation of >2 years.

RESULTS

The tumors were located in the left lobe of the liver in 32 patients, in the right lobe in 12 patients, and in both lobes in 3 patients. Lymph node metastasis was found in 15 patients (12 with left lobe tumors and 3 with right lobe tumors). Among those patients with the left lobe tumors, six had no metastasis in the hepatoduodenal ligament (regional lymph nodes), but did display metastasis to lymph nodes around the cardiac portion of the stomach or along the common hepatic artery (distant lymph nodes), whereas no such skip metastasis was found in those patients with right lobe tumors. The patients with lymph node metastasis showed a tendency toward a lower survival rate than those without metastasis (difference not statistically significant), but the patients with only regional lymph node metastasis showed no difference in survival rate compared with those with distant lymph node metastasis. Patients with mass-forming type tumors without bile duct invasion had less lymph node metastasis and a better survival than those with bile duct invasion.

CONCLUSIONS

The lymph node metastasis pattern of the UICC TNM classification, at least with respect to the regional lymph nodes, should be reconsidered.