A retrospective analysis of the role of gefitinib in the definitive management of esophageal/gastroesophageal junction (E/GEJ) cancer.

Abstract

e15000 Background: The role of epidermal growth factor receptor (EGFR) inhibition in resectable E/GEJ cancer is uncertain. We update and retrospectively compare results from two Cleveland Clinic trials of concurrent chemoradiotherapy (CCRT) and surgery; the second study differing only by the addition of gefitinib (G) to the treatment regimen. Methods: Eligibility required a diagnosis of E/GEJ squamous cell or adenocarcinoma (ACA), with an endoscopic ultrasound stage of at least T3, N1, or M1a (AJCC 6th). Patients (pts) in both trials received 5-FU (1000mg/m2/d) and cisplatin (20mg/m2/d) as continuous infusions over days 1-4 along with 30 Gy radiation at 1.5 Gy bid. Surgery followed in 4-6 weeks; identical CCRT was given 6-10 weeks later. The second trial added G, 250mg/d, on day 1 for 4 weeks, and again with postoperative CCRT for 2 years. Preliminary results and comparisons have been previously published. Results: Clinical characteristics were similar between the 80 pts on the G trial (2003-2006) and the 93 pts on the no-G trial (1999-2003): median age (58 vs. 59 years), male gender (91% vs. 86%), ACA (94% vs. 83%), and HER2 positivity (28% vs. 18%). Minimum follow-up for all pts was 5 years. Multivariable Cox analyses comparing the G vs. no-G pts and adjusting for statistically significant covariates demonstrated improved overall survival (HR 0.62, 95% CI 0.44-0.88, p=0.008), relapse-free survival (RFS) (HR 0.59, 95% CI 0.41-0.84, p=0.003), and distant metastatic recurrence (HR 0.64, 95% CI 0.43-0.96, p=0.03), but not locoregional recurrence. Further subgroup analyses demonstrated improved RFS with G in pts not experiencing a pathologic response (HR=0.59, 95% CI 0.38-0.92, p=0.021), with T4 or M1a disease at surgery (HR=0.33, 95% CI 0.13-0.87, p=0.024), or with HER2-negative tumors (HR=0.65, 95% CI 0.42-0.99, p=0.048). Conclusions: Although this retrospective comparison can only be considered exploratory, it suggests that gefitinib may improve clinical outcomes when combined with CCRT and surgery in the definitive treatment of E/GEJ cancer. Clinical benefit may be greatest in pts with a poor response to preoperative chemoradiation, and in those with HER2-negative tumors. Clinical trial information: NCT00258323.