Introduction: In search of factors that might predict outcome in patients with resected non-small cell lung cancer (NSCLC), we studied the reactivity of monoclonal antibody 123C3. This marker of neuroendocrine (NE) differentiation is directed against neural cell adhesion molecules (NCAM). Although NCAM can often be demonstrated in small cell lung cancer and carcinoids as a tumor antigen, not many data exist on NCAM in NSCLC.
Patients and methods: From 1983 through 1995, in 889 patients with NSCLC, who underwent pulmonary resection, 123C3 reactivity was tested. NCAM was correlated with tumor histology, p-TNM stage, and 5-year survival. Large cell NE carcinomas were excluded. Monoclonal antibody-1 (MOC-1) was also tested on most specimens.
Results: Reactivity of 123C3 does not correlate with tumor histology, p-TNM stage, or 5-year survival. In addition, MOC-1 reactivity was not significantly related to prognosis.
Conclusions: Positive reactivity with 123C3, indicating NE differentiation, does not have predictive value in NSCLC. Also, tumor histology or stage did not correlate with 123C3 reactivity. Reactivity of MOC-1 did not contribute to prediction of prognosis. Whether there is more chemosensitivity in NSCLC-NE than in NSCLC without NE differentiation remains an important question that is not addressed by our present study.