The relationship between pathologic nodal disease and residual tumor viability (RV) in patients with locoregionally advanced (LRA) adenocarcinoma (ACA) of the esophagus and gastroesophageal junction (E/GEJ) receiving induction chemotherapy, surgery, and postoperative chemoradiotherapy (CRT).

Abstract

165 Background: A complete pathologic response to induction CRT has been identified as a favorable prognostic factor for patients with LRA ACA of the E/GEJ. Less is known, however, about the impact of pathologic regression after induction chemotherapy. Methods: Between 2/08 and 1/12, 60 evaluable patients with ACA of the E/GEJ enrolled in a phase II trial of induction chemotherapy, surgery, and post-operative CRT. Eligibility required a clinical stage of T3 or N1 or M1a (AJCC 6th). Induction chemotherapy with epirubicin 50mg/m2 d1, oxaliplatin 130mg/m2 d1, and fluorouracil 200mg/m2/day continuous infusion for 3 weeks, was given every 21 days for 3 courses and was followed by surgical resection. Adjuvant CRT consisted of 50-55Gy @ 1.8-2.0 Gy/d and 2 courses of cisplatin (20mg/m2/d) and fluorouracil (1000mg/m2/d) over 4 days during weeks 1 and 4 of radiotherapy. RV was defined as the amount of remaining tumor in relation to acellular mucin pools and scarring. Results: Of the 60 evaluable patients, 54 completed induction therapy and underwent curative intent surgery. The Kaplan-Meier (KM) projected 3 year OS for patients with pathologic N0 (n=20), N1 (n=12), N2 (n=13), and N3 (n=9) disease is 73%, 57%, 35%, and 0% respectively (p<0.001). The KM projected 3 year OS of patients with low (0-25%, n=19), intermediate (26-75%, n=26), and high (>75%, n=9) RV was 67%, 42%, and 17% respectively (p=0.004). On multivariable analysis, both the pN descriptor and RV were independently prognostic for OS. In patients with less nodal dissemination (N0/N1), RV was prognostic for OS [3yr OS 85% (0-25% viable) v 51% (>25% viable), p=0.028]. Outcomes were poor, however, for patients with advanced nodal disease (N2/N3) regardless of RV [3yr OS 20% (0-25% viable) v 21% (>25% viable), p=0.55]. Conclusions: RV and the pN descriptor after induction chemotherapy are independent pathologic prognostic factors for OS in patients with LRA ACA of the E/GEJ. Patients with extensive nodal disease, however, have poor outcomes irrespective of viability. Clinical trial information: NCT00601705.