Small cell lung carcinoma (SCLC): the angiogenic phenomenon

Abstract

Objectives: Tumor angiogenesis, expressed by the microvessel count (MVC), and its mediators (i.e. vascular endothelial growth factor) significantly correlate with metastases in surgically treated non-small cell lung carcinoma/cancer (NSCLC). SCLC is rarely treated by surgery, as a consequence, few specimens are available to perform a biological characterization. We reviewed our experience in the surgical treatment of SCLC with particular reference to the angiogenetic expression and its correlation to the stage of disease and prognosis.

Methods: We retrospectively investigated a homogenous cohort of 87 patients with SCLC, who were primarily operated on and then underwent adjuvant chemotherapy between 1980 and 1998. Their median age was 62 years (range 34-73). All the patients were completely staged. The surgical procedures included: 32 pneumonectomies and 55 lobectomies. There were 46 N0, 17 N1 and 24 N2-disease. The adjuvant chemotherapy consisted of four to six courses of cyclophosphamide, epidoxorubicine and etoposide. The MVC was determined highlighting the microvessels with anti-CD34 monoclonal antibodies. Immunostaining for VEGF was performed using the ABC method with anti-VEGF monoclonal antibodies. The p53 protein expression was assessed by NCL-DO7 anti-p53 monoclonal antibody.

Results: With a median follow-up of 109.6 months (range 25-238), 37 patients are alive and well, two are alive with systemic metastases. Forty-four patients died of local (n=5) or systemic (n=39) relapse, while four patients died from other causes. The median MVC was 59 (range 18-145). Among the clinico-pathological parameters, metastatic nodal-involvement (P=0.002) and advanced stage of disease (P=0.005) were associated with a worse overall survival (OS). MVC and VEGF protein expression significantly affected the survival (P<0.001 and P=0.0008, respectively). No statistical association was found between p53 alterations and OS as well as no association was found among p53 alterations, MVC and VEGF expression. On multivariate analysis only the VEGF expression (P=0.003) was an independent prognostic factor.

Conclusions: Angiogenesis plays a role in the metastatic process of the SCLC as well as NSCLC. SCLC has a higher vascularization than NSCLC as results from the higher number of microvessels; however, tumor angiogenesis tested by the MVC and the VEGF protein expression correlates with the prognosis also in SCLC. SCLC may be an ideal field to test new antiangiogenic drugs associated to chemotherapy.