DETECTION OF DISSEMINATED LUNG-CANCER CELLS IN LYMPH-NODES - IMPACT ON STAGING AND PROGNOSIS

Background. A major reason for the high incidence of tumor recurrences in patients with apparently resectable non-small cell lung cancer is presumably early tumor cell dissemination, which is clearly underestim ated by current staging procedures. Methods. In this prospective study we assessed the frequency and prognostic significance of early lympha tic tumor cell spread to regional lymph nodes staged as tumor free by conventional histopathology by applying an immunohistochemical assay u sing monoclonal antibody Ber-Ep4. Results. Ber-Ep4 positive cells were demonstrated in 27 (21.6%) of 125 patients and in 35 (6.2%) of 565 ly mph nodes, respectively. Immunohistochemical analysis resulted in an u p-staging in 24 of 27 patients. In patients previously staged as havin g pN0 disease, tumor cells were detected in 11/70 cases (15.7%). Univa riate and multivariate survival analysis showed that the detection of minimal nodal tumor cell dissemination was associated with a reduced d isease-free survival (log rank test, p = 0.0001; Cox regression model, p = 0.001). Conclusions. The use of immunohistochemistry enables one to identify many patients with regional tumor cell dissemination at th e time of operation. These patients might benefit from an adjuvant the rapeutic regimen.