Adjuvant chemotherapy versus perioperative chemotherapy (CTx) for resectable gastric signet ring cell (SRC) gastric cancer: A multicenter, randomized phase II study (PRODIGE 19).
4019 Background: The incidence of SRC gastric cancers is markedly increasing in Western countries. SRC cancers may harbor intrinsic resistance to chemotherapy (CTx) leaving many clinicians unsure of the benefits of delaying surgery to pursue a neoadjuvant approach. The primary objective of this study was to assess whether upfront surgery plus adjuvant CTx would provide enough survival benefit for study in a phase III trial when compared to perioperative CTx. Methods: Patients with stage IB-III SRC gastric cancer were randomly assigned to receive upfront surgery plus adjuvant CTx (epirubicin, cisplatin and 5-fluorouracil [ECF regimen], 6 cycles; experimental arm [SurgFirst]) or perioperative CTx (ECF, 3 cycles before and 3 cycles after surgery; control arm [CTxFirst]). Randomization (1:1) was stratified by tumor stage, tumor location, performance status and center. The primary endpoint was overall survival (OS) at 2 years (OS2; target (H1): OS2 > 26%). Results: 83 eligible patients were included in 27 centers from 11/12 to 09/16 (median age, 61 years (range: 32-80 years); male, 59%; ECOG PS 0-1, 99%). Results were (CTxFirst/SurgFirst): full completion of CTx, 87%/77%; surgical resection, 82.5%/90%; major postoperative complications (Clavien Dindo III-IV), 24%/23%; R0 resection rate, 88%/78%; OS2, 60%/53.5%; and median OS, 39/28 months (exploratory hazard ratio, 0.71 [95%CI: 0.40-2.64]). Conclusions: This trial met its primary endpoint (OS2 > 26% in the experimental arm). With OS2 rates > 50%, both CTx modalities deserve further evaluation in Phase III studies in stage IB-III SRC gastric cancer. Clinical trial information: NCT01717924.