EARLY LYMPHATIC TUMOR-CELL DISSEMINATION IN PANCREATIC-CANCER - FREQUENCY AND PROGNOSTIC-SIGNIFICANCE

Tumor relapse occurs frequently in patients with ductal pancreatic hea d cancer despite the absence of residual tumor detectable at primary s urgery. Therefore it has to be assumed that current tumor staging proc edures fail to detect minimal amounts of disseminated tumor cells pres ent in secondary organs, which might be the seed for subsequent metast atic relapse. We evaluated lymph nodes from 18 patients without overt metastases who had undergone radical tumor resection (R-0 resection). Lymph nodes judged as ''tumor-free'' by routine histopathology were fu rther examined for the presence of single tumor cells using immunohist ochemistry with the antiepithelial monoclonal antibody Ber-EP4. Sixtee n of 37 ''tumor-free'' lymph nodes (43.2%), obtained from 13 of 18 pat ients (72.2%), displayed Ber-EP4(+) tumor cells. Twelve of these 18 pa tients presented at pT(2) stage. Nine of 12 patients (75%) staged as p N(0) had these cells. Two of six pN(1) patients had no Ber-EP4(+) in h istopathologically tumor-free lymph nodes. Using multivariate Cox's re gression analysis, the presence of Ber-EP4(+) cells in ''tumor-free'' lymph nodes was an independent factor for a significantly reduced rela pse-free survival (p = 0.006) and overall survival (p = 0.01). Remarka bly, all patients who were restaged as lymph node negative by both his topathology and immunohistochemistry survived the observation period w ithout recurrence. The frequent occurrence of disseminated tumor cells in patients with pancreatic cancer and their prognostic impact suppor t the need for a refined staging system of excised lymph nodes, which should include immunohistochemical examination. Thus patients with a m inimal residual tumor load who might benefit from an adjuvant therapy could be selected.