Carcinogenesis Advance Access originally published online on May 2, 2008
Carcinogenesis 2008 29(9):1781-1787; doi:10.1093/carcin/bgn107
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COX-2/EGFR expression and survival among women with adenocarcinoma of the lung
Cancer Biology Program
1 Population Studies and Prevention Program
2 Department of Internal Medicine
3 Department of Pathology, Karmanos Cancer Institute, Wayne State University School of Medicine, Detroit, MI 48201, USA
4 Developmental Therapeutics Program, Karmanos Cancer Institute, Wayne State University School of Medicine, Detroit, MI 48201, USA
* To whom correspondence should be addressed. Tel: +1 313 578 4314; Fax: +1 313 578 4306; Email: avandyk{at}med.wayne.edu
Previous studies suggest that cyclooxygenase-2 (COX-2) expression may predict survival among patients with non-small cell lung cancer. COX-2 may interact with epidermal growth factor receptor (EGFR), suggesting that combined COX-2/EGFR expression may provide predictive value. The extent to which their independent or combined expression is associated with prognosis in women with adenocarcinoma of the lung is unknown. In the present study, we examined relationships between COX-2 expression (n = 238), EGFR expression (n = 158) and dual COX-2/EGFR expression (n = 157) and survival among women with adenocarcinoma of the lung. Overall survival was estimated by constructing Cox proportional hazards models adjusting for other significant variables and stratifying by stage at diagnosis and race. Clinical or demographic parameters were not associated with either COX-2 or EGFR expression. Patients with COX-2-positive tumors tended to have poorer prognosis than did patients with COX-2-negative tumors [hazard ratio (HR) 1.67, 95% confidence interval (CI) 1.01–2.78]. African-Americans with COX-2-positive tumors had a statistically non-significant higher risk of death than African-Americans with COX-2-negative tumors (HR 5.58, 95% CI 0.64–48.37). No association between COX-2 expression and survival was observed among Caucasians (HR 1.29, 95% CI 0.72–2.30). EGFR expression was associated with a 44% reduction in the risk of death (HR 0.56, 95% CI 0.32–0.98). COX-2–/EGFR+ tumor expression, but not COX-2+/EGFR+ tumor expression, was associated with survival when compared with other combined expression results. In conclusion, COX-2 and EGFR expression, but not combined COX-2+/EGFR+ expression, independently predict survival of women with adenocarcinoma of the lung.
Abbreviations: CI, confidence interval; COX-2, cyclooxygenase-2; EGFR, epidermal growth factor receptor; HR, hazard ratio; IHC, immunohistochemistry; mRNA, messenger RNA; NSAID, non-steroidal anti-inflammatory drug; NSCLC, non-small cell lung cancer; TKI, tyrosine kinase inhibitor
Received January 31, 2008; revised April 24, 2008; accepted April 25, 2008.