Introduction: Most of the time, biological parameters are evaluated on tissues obtained on surgical samples of the primary tumour. New approaches in non small cell lung cancer (NSCLC) treatment consist to administer neoadjuvant chemotherapy or anti-EGF-R (epidermal growth factor receptor) drug.
Methods: We assessed the expression of EGF-R by immunohistochemistry on biopsy samples and on the paired resected tumours in 27 patients.
Results: The mean percentage of EGF-R positive neoplastic cells was 11% in surgical specimens compared to 28% in biopsy specimens (p=0.02) although a good correlation (R=0.67; p=0.0001) between biopsies and surgical specimens was observed. Furthermore, the positivity (cut-off > 1% cells) rate was not statistically different between biopsies (55%) and tumours (48%) (p=0.63). In term of positivity rate, we found 85% concordant results between biopsies and resected tumours, 4% false negative and 11% false positive on biopsies in comparison with the resected tumours. The positive and negative predictive value of the biopsies were respectively 80% and 92%.
Conclusions: The evaluation of EGF-R by immunohistochemistry on biopsies may provide reliable information about non small cell lung cancer EGF-R status.