Upper Gastrointestinal (lips to ileocecal valve, including esophagus and stomach)
Sivesh K. Kamarajah, MBChB
Resident Physician
Department of Surgery, University Hospitals Birmingham NHS Trust, Birmingham, UK.
Birmingham, United States
Samer A. naffouje, MD
Assistant Professor of Surgery
Cleveland Clinic Foundation
Tampa, Florida, United States
Fadi S. Dahdaleh, MD, FACS, FSSO
Clinical Assistant Professor surgery
Rush Medical College
Elmhurst, Illinois, United States
Fadi S. Dahdaleh, MD, FACS, FSSO
Clinical Assistant Professor surgery
Rush Medical College
Elmhurst, Illinois, United States
Evidence assessing the additional benefits of adjuvant chemotherapy (AC) following neoadjuvant therapy (NAT; i.e. chemotherapy or chemoradiotherapy) and gastrectomy for pathologically node-negative (pN0) cancers remains limited. This study aimed to determine whether AC improves long-term survival in patients receiving NAT and gastrectomy.
Patients undergoing gastrectomy for gastric adenocarcinoma following NAT from 2004 - 2016 were identified from the National Cancer Data Base (NCDB). To account for immortality bias, patients with survival <3 months were excluded. Propensity score matching (PSM) and Cox regression was performed to account for selection bias and analyze impact of AC on overall survival.
Overall, 4,503 (85%) did not receive AC and 806 (15%) received AC. After PSM there were 785 who did not receive AC and 785 who did. After matching, AC was associated with improved survival (median: 150.0 vs 125.0 months, p< 0.001), which remained after multivariable adjustment (HR: 0.79, CI95%: 0.67 - 0.95). On multivariable interaction analyses, this benefit persisted in subgroup analysis for nodal status: N0 (HR: 0.85, CI95%: 0.69 - 0.96), N1 (HR: 0.66, CI95%: 0.56 - 0.78), N2/3 (HR: 0.80, CI95%: 0.66 - 0.97) and margin status: R0 (HR: 0.77, CI95%: 0.69 - 0.86), R1 (HR: 0.60, CI95%: 0.43 - 0.85). Further, patients with stable disease following NAT (HR: 0.60, CI95%: 0.59 - 0.80) or downstaged (HR: 0.80, CI95%: 0.68 - 0.95) disease had significant survival benefit after AC, but not patients with upstaged disease.
AC following NAT and gastrectomy is associated with improved survival in pN0 disease, even in margin-negative disease. NAT response appears crucial in identifying patients who will benefit maximally from AC, and thus future research must be focused on identifying molecular phenotype of tumours that respond to chemotherapy to maximize this prognostic benefit.