Tumor-derived Vascular Endothelial Growth Factor and Angiopoietin-2 in Non-small Cell Lung Cancer

Lung cancer is a common disease with a dismal prognosis. Accurate staging is
crucial for defining operability, selecting treatment regimens, and predicting survival.
Methods of mediastinal lymph node staging include imaging and surgical sampling
by different tools with many disadvantages. Angiogenesis is essential process in
tumor growth, maintenance and metastasis. The tumor with high vessels density is
related to metastasis and poor clinical outcome. Angiogenesis is regulated by balance
between stimulatory and inhibitory regulators of endothelial cell activation. Vascular
endothelial growth factor (VEGF) and Angiopoietin-2 (Ang-2) are two of the most
potent angiogenic molecules. In this study we were evaluated the clinical effectiveness
of serum level of Ang-2 and VEGF to aid management decision relating to diagnosis
and staging of non-small cell lung cancer (NSCLC). The present work was conducted
on 60 subjects. They were divided into 3 groups. Group 1 (15 healthy volunteers),
Group 2 (15 patients with pulmonary diseases other than cancer) and Group 3 (30
patients with NSCLC).The latter were divided into two subgroups: Group 3a:15
patients with operable (NSCLC), and Group 3b:15 patients with non-operable
NSCLC). Serum levels of Ang-2 and VEGF in different groups were measured using
ELISA technique. The serum Ang-2 and VEGF were significantly higher in patients
with NSCLC than patients with non-neoplastic lesions compared to healthy controls
(p<0.001).There was a significant positive correlation between both levels in patients
with NSCLC. With stage progression in NSCLC, the non-operable group (3b) had
significantly higher levels than operable group (3a). Patients with distant metastasis
had higher levels than those without (p< 0.001). But, no notable significant
differences were found in either serum levels of VEGF or Ang-2 concerning the cell
type .Among 30 NSCLC patients, stages of 7 patients (23.3%) were misdiagnosed
because of they had normal sized lymph node on CT image . Five of them were
Squamous carcinoma and the other two were adenocarcinoma on histopathological
examination that need mediastioscopy. But, all NSCLC patients had high level of both
markers according to their nodal staging. The operable group (3a)showed significant
decrease in both levels after surgical resection (P<0.001). Conclusion:The present
findings suggest that assessment of circulating levels of VEGF and Ang-2 may be
simple noninvasive future tools for diagnosis, staging, treatment planning and
monitoring of treatment in patients with NSCLC