Expression of ras p21 and myc p62 oncoproteins in small cell and non small cell carcinoma of the lung.

Ras p21 and myc p62 expression has been examined immunohistochemically in seventy specimens of bronchial carcinomas. Both ras and myc oncoproteins were found to be overexpressed at a higher frequency in non small cell carcinomas (squamous cell carcinomas and adenocarcinomas) compared to the small cell carcinoma specimens; however only myc p62 overexpression was found to be statistically significant. Also, ras p21 oncoprotein expression was frequently overexpressed in adenocarcinomas compared to squamous cell carcinomas (p less than 0.05). Overexpression of c-myc p62 was found to correlate with poorly differentiated squamous cell carcinomas compared to the well and moderately differentiated tumors. The results of this study indicate that both the ras and myc oncogenes are important in the progression of bronchial carcinomas.