Induction versus no induction chemotherapy before neoadjuvant chemoradiotherapy and surgery in oesophageal adenocarcinoma: a multicentre randomised phase II trial (NCCTG N0849 [Alliance])

Aim: report primary results from the first multicentre randomised trial evaluating induction chemotherapy prior to trimodality therapy in patients with oesophageal or gastro-oesophageal junction adenocarcinoma. Notably, recent data from a single-institution randomised trial reported that induction chemotherapy prolonged overall survival (OS) in patients with well/moderately differentiated tumours. Methods: In this phase 2 trial (28 centres in the U.S. NCI-sponsored North Central Cancer Treatment Group [Alliance]), trimodality-eligible patients (T_3-4N₀, T_anyN₊) were randomised to receive induction (docetaxel, oxaliplatin, capecitabine; Arm A) or no induction chemotherapy (Arm B) followed by oxaliplatin/5-fluorouracil/radiation and subsequent surgery. The primary endpoint was the rate of pathologic complete response (pathCR). Secondary/exploratory endpoints were OS and disease-free survival (DFS). Results: Of 55 patients evaluable for the primary endpoint, the pathCR rate was 28.6% (8/28) in A versus 40.7% (11/27) in B (P = .34). Given interim results indicating futility, accrual was terminated, but patients were followed. After a median follow-up of 60.4 months, a longer median OS in Arm A versus B was unexpectedly observed (3-year rates 57.1% versus 41.7%, respectively) driven by longer DFS after margin-free surgery. In posthoc analysis, induction (versus no induction) chemotherapy was associated with significantly longer OS and DFS among patients with well/moderately differentiated tumours, but not among patients with poorly/undifferentiated tumours (P_interaction = 0.037). Conclusions: Adding induction chemotherapy prior to trimodality therapy did not improve the primary endpoint, pathCR. However, induction chemotherapy was associated with longer median OS, particularly among patients with well/moderately differentiated tumours. These findings may inform further development of curative-intent trials in this disease.