Neuroendocrine and biologic features of primary tumors and tissue in pulmonary large cell carcinomas.

Background: Because biological behavior in lung tumors with neuroendocrine differentiation is highly dependent on cell death (apoptosis) and angiogenesis, p21(waf1/cip1) and microvessel density have been targeted as potentially useful tumor markers. We sought to validate the importance of p21(waf1/cip1) and microvessel density and study their interrelationship, analyzing clinical factors, subclassifications, and tumor and stromal markers.

Methods: We examined p21(waf1/cip1) and other markers in tissue from 61 patients with surgically excised large cell carcinomas.