Erlotinib and Radiation Therapy for Elderly Patients with Esophageal Cancer - Clinical and Correlative Results from a Prospective Multicenter Phase 2 Trial

<b><i>Purpose:</i></b> Elderly patients with esophageal cancer who are not candidates for chemoradiation may benefit from targeted agents; hence erlotinib combined with radiotherapy was evaluated in this trial. <b><i>Materials and Methods:</i></b> Patients >65 years with carcinoma of the thoracic esophagus or gastroesophageal junction who were not eligible for platinum-based treatment received erlotinib daily for 1 year starting on day 1 of radiotherapy [50.4 Gy days 1-28 (Mon-Fri) at 1.8 Gy per fraction]. Response was assessed by endoscopy and computed tomography. The primary endpoint was overall survival (OS), and secondary endpoints were complete response, progression-free survival (PFS) and toxicity. <b><i>Results:</i></b> The ECOG performance status in the 17 study patients was 0,1 and 2 in 2, 12 and 3 patients, respectively; 1, 5, 7 and 4 patients were in stage I, II, III and IV, respectively; adenocarcinoma was noted in 16 patients and squamous cell carcinoma in 1; there were 3 current, 12 past and 2 never smokers. Median OS was 7.3 months (95% confidence interval, CI: 3.8-22.3) with 14 deaths. There were 2 mucosal complete responses, 1 residual carcinoma in situ and 3 partial endoscopic responses in 9 patients who had endoscopy after radiotherapy. Estimated PFS was 4.5 months (95% CI: 2.4-7.3). Progression was distant (n = 3), locoregional (n = 6), unknown (n = 5) and too early (n = 3). Estimated 1-year survival was 29% (95% CI: 11-51%), 5 patients lived >12 months. Treatment-related toxicities of grade 3-4 occurred in 5 patients. Patients with epidermal growth factor receptor amplification and never smokers had the longest OS (22.3 and 16.6 months, respectively). <b><i>Conclusions:</i></b> Erlotinib with radiotherapy is tolerable and warrants further biomarker-driven evaluation in this population.