The purpose of this study was to determine the clinical significance of nodal micrometastasis detected by immunohistochemistry in patients that had undergone curative surgery for pancreatic cancer. Between 2005 and 2006, a total of 208 lymph nodes from 48 consecutive patients with pancreatic cancer that had undergone curative resection were immunostained with monoclonal antibody against pan-ck and CK-19. Micrometastasis was defined as metastasis missed by a routine H&E examination but detected during an immunohistochemical evaluation. Relations between immunohistochemical results and clinical and pathologic features and patient survival were examined. Nodal micrometastases were detected in 5 (29.4%) patients of 17 pN0 patients. Nodal micrometastasis was found to be related to tumor relapse (P = 0.043). Twelve patients without overt nodal metastasis and micrometastasis had better prognosis than 5 patients with only nodal micrometastasis (median survival; 35.9 vs 8.6 months, P < 0.001). The Cox proportional hazard model identified nodal micrometastasis as significant prognostic factors. Although the number of patients with micrometastasis was so small and further study would be needed, our study suggests that the lymph node micrometastasis could be the predictor of worse survival and might indicate aggressive tumor biology among patients undergoing curative resection for pancreas cancer.
Aged ; Antibodies, Monoclonal/immunology ; Female ; Humans ; Immunohistochemistry ; Keratin-19/immunology/metabolism ; Lymph Nodes/pathology ; Lymphatic Metastasis ; Male ; Middle Aged ; Pancreatic Neoplasms/mortality/*pathology/surgery ; Prognosis ; Survival Rate

Small pancreatic cancers (longest diameter < or =2 cm) have been regarded as preliminary to early pancreatic cancer, which was thought to be highly curable. During our experience since 1989, we evaluated 542 cases of pancreatic cancer. Among them we found 74 cases of tumors < or =2 cm in diameter, small pancreatic cancer (TS1 pancreatic cancer). Well-differentiated adenocarcinomas (18.9%) and absence of symptoms (8.1%) were more frequent in patients with TS1 than in those with larger pancreatic tumors. Only 16 of the 74 patients (21.6%) with small pancreatic cancers had T1 tumors. According to the International Union Against Cancer (UICC) staging, only 11 patients (14.9%) were stage IA: their 5-yr survival rate was 23.3% and their median survival was 30.0 months. Among these 11 patients, 3 had tumors <1 cm; their median survival time was 30.0 months and their 5-yr survival rate was 50.0%. These findings may indicate that 'small' pancreatic cancer is not equivalent to 'early' pancreatic cancer.
Adenocarcinoma/pathology ; Adenocarcinoma, Mucinous/pathology ; Adenocarcinoma, Papillary/pathology ; Adult ; Aged ; CA-19-9 Antigen/metabolism ; Carcinoembryonic Antigen/metabolism ; Carcinoma/pathology ; Carcinoma, Adenosquamous/pathology ; Carcinoma, Pancreatic Ductal/pathology ; Female ; Humans ; Korea/epidemiology ; Male ; Middle Aged ; Neoplasm Staging ; Pancreatic Neoplasms/immunology/mortality/*pathology ; Prognosis ; Survival Rate ; Tumor Burden