BACKGROUND - Platelet derived growth factor (PDGF) and PDGFR-beta are expressed and have been found to have prognostic value in several human cancers. Data in non-small-cell cancer cell lines have suggested that PDGFR is a therapeutic target for drug development. In the current study PDGFR-beta expression and prognostic value in small cell lung cancer (SCLC) was investigated.
METHODS AND MATERIALS - Paraffin-embedded tissue blocks from 53 patients with limited and extensive stage SCLC were obtained for immunohistochemical staining. Tumors from each patient were sampled 3 times and stained with PDGFR-beta specific antibody. Patients were divided into low and high staining groups based on intensity.
RESULTS - There was high intensity PDGFR-beta staining in 20 patients with SCLC. Another 29 expressed low intensity PDGFR-beta staining, with only 4 patients showing no PDGFR-beta staining. There was no statistically significant difference in 5 year overall survival between patients with low levels of PDGFR-beta staining vs. those with high level staining SCLC tumors (p = 0.538).
CONCLUSIONS - The present study found that the majority of SCLC patients express, at least, a low level of PDGF-beta. However, the level of PDGFR-beta expression was not a statistically significant predictor of 5 year overall survival in SCLC.