Purpose: Despite the availability of cellular markers associated with cell cycle, apoptosis, and DNA repair, predictive factors for pathological complete response (CR) and overall survival (OS) are few in patients with locally advanced esophageal cancer. This study evaluates the role of clinical and cellular markers in predicting CR and OS in patients with esophageal cancer.
Experimental design: Patients were treated with infusional cisplatin and 5-fluorouracil combined with daily radiotherapy followed by esophagectomy. Pretreatment tumors (n = 54) were analyzed for epidermal growth factor receptor (EGF-R), bax, and bcl-2 expression by immunohistochemistry and for p53 mutations by direct DNA sequencing of exons 5-8. Clinical covariates included patients' age at enrollment; gender; Barrett's metaplasia; and tumor location, histology, and differentiation. Logistic regression and survival analyses were used to evaluate the predictors.
Results: Age ranged from 32 to 75 years; most patients were male (45 male; 9 female); and tumors were distal (47 distal; 7 mid), adenocarcinoma (41 adenocarcinomas; 13 squamous cell carcinomas), and moderately differentiated (33 moderate; 6 well; 15 poor). Female gender predicted CR (odds ratio 7.5; 95% confidence interval, 1.4-41). The OS was 43% at 5 years. Presence of CR (P < 0.001 log rank) and p53 mutation (P = 0.051 log rank) correlated with increased OS, whereas increased EGF-R expression predicted poor OS (P = 0.009 log rank). EGF-R remained significant when adjusted for clinical covariates. There was a trend toward increased OS related to better tumor differentiation and decreased bcl-2.
Conclusions: These data suggest that EGF-R and p53 mutation may be used as both outcome predictors and targets for molecular therapy for esophageal cancer.