Prognostic value of the quantified expression of p185 in non-small cell lung cancer

We sought to assess the relationship between tissue concentration of erb -b-2 or neu oncogene-encoded protein (p185(neu)) with overall survival in patients with non-small cell lung cancer. Levels of protein p185(neu) were determined in 102 patients with the diagnosis of non-small cell lung cancer. Concentration of p185(neu) protein was determined by using enzyme immunoassay and evaluated by using several variables. The relative prognostic importance of this marker and its influence on other prognostic factors was evaluated by using the Cox regression model. The mean p185(neu) value in these samples was 250 +/- 200 U/mg (95% confidence interval, 210-290). This distinguished two groups within the tumoral population: those with less than 350 U/mg and those with 350 U/mg or greater (80th percentile). Multivariable analysis established an independent prognostic value for protein p185(neu). Patients with p185(neu) values of the 80th percentile or greater had a risk of death that was 2.11-fold (95% confidence interval, 1.10-4.05) that of patients with values of less than 350 U/mg (P =.03), and increases in the neu oncogene of 100 U/mg increased the probability of death by 17% (P =.02; 95% confidence interval, 1.04-1.31). This study shows that the p185(neu) expression is an objective and comparable variable for the assessment of phenotypic aggressivity in non-small cell lung cancer, and in the future, it could be included in daily clinical practice.