Immunohistochemical scoring:
The primary mass EGFR expression results were compared to a negative
control (benign vocal cord polyp). By combining the two scores mentioned
above, an immunostaining score was created that ranged from 0 to 6. The
immunostaining score was then used to categorize the immunohistological
expression of EGFR: immunostaining scores of 0 indicate no expression,
1-2 indicate weak expression, 3-4 indicate moderate expression, and 5-6
indicate strong expression. Strong and moderate EGFR expression was
considered positive in the results, but no or weak EGFR expression was
regarded as negative.
The membranous expression of EGFR in tumor cells was observed. The
intensity of the staining was determined using a semi-quantitative
method, and the number of labeled cells with malignant features was
determined in accordance with both the intensity and the proportion of
stained cells. Scores were determined based on:
1- Expression of membranous EGFR
2- Intensity of staining
The intensity scale was determined using semi-quantative method in which
4 grades were obtained as follow: 0: no staining; 1: weak, 2: moderate;
and 3: intense staining. The proportion of cells staining was also
scored on a 4-point scale: 0: no cells staining; 1: less than one-third
of cells staining; 2: between one-third and two-thirds of cells
staining; 3: more than two-thirds of cells staining.