Jashodeep Datta1, Matthew T McMillan1, Luis Ruffolo1, Lea Lowenfeld1, Ronac Mamtani2, John P Plastaras3, Daniel T Dempsey1, Giorgos C Karakousis1, Jeffrey A Drebin1, Douglas L Fraker1, Robert E Roses4. 1. Department of Surgery, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA. 2. Division of Hematology/Oncology, Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA. 3. Department of Radiation Oncology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA. 4. Department of Surgery, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA. robert.roses@uphs.upenn.edu.
Abstract
BACKGROUND: National guidelines endorse adjuvant chemotherapy ± radiotherapy (C ± RT) for early-stage gastric cancer (ESGC). Compliance with these guidelines and the specific impact of adjuvant C ± RT on overall survival (OS) in ESGC have not been extensively explored. METHODS: The National Cancer Data Base was queried for stage IB-II gastric adenocarcinoma patients undergoing gastrectomy (1998-2011). Multivariable modeling identified factors associated with adjuvant C ± RT receipt and compared risk-adjusted OS by treatment type (i.e., adjuvant therapy versus surgery alone). RESULTS: Of 23,461 ESGC patients (1998-2011), 79.4 % and 20.6 % received surgery alone and adjuvant C ± RT (chemoradiotherapy 17.7 %; chemotherapy alone 2.9 %), respectively. Predictors of adjuvant C ± RT receipt included age <67 years, pathologic nodal positivity, and adequate lymph node staging (LNS; ≥15 nodes examined; all p < 0.001). Survival analyses included 15,748 patients (1998-2006); median, 1-, and 5-year survival were 63.5 months, 86.0 %, and 27.0 % respectively. Omission of adjuvant C ± RT conferred an increased hazard of risk-adjusted mortality in the overall cohort, and stage IB and II subgroups (all p ≤ 0.001). The benefit of adjuvant C ± RT was most pronounced in stage II and node-positive patients-regardless of LNS adequacy (all p < 0.001)-and inadequately staged IB patients (p = 0.003). While associated with a trend toward improved OS in node-negative patients overall (p = 0.051), adjuvant C ± RT did not improve OS if surgical LNS was adequate in this subgroup (p = 0.960). CONCLUSIONS: Adoption of adjuvant C ± RT in ESGC remains incomplete nationally. Receipt of adjuvant therapy is associated with improved risk-adjusted survival relative to surgery alone; however, in adequately staged patients without lymph node metastasis, this benefit is less certain.
BACKGROUND: National guidelines endorse adjuvant chemotherapy ± radiotherapy (C ± RT) for early-stage gastric cancer (ESGC). Compliance with these guidelines and the specific impact of adjuvant C ± RT on overall survival (OS) in ESGC have not been extensively explored. METHODS: The National Cancer Data Base was queried for stage IB-II gastric adenocarcinomapatients undergoing gastrectomy (1998-2011). Multivariable modeling identified factors associated with adjuvant C ± RT receipt and compared risk-adjusted OS by treatment type (i.e., adjuvant therapy versus surgery alone). RESULTS: Of 23,461 ESGC patients (1998-2011), 79.4 % and 20.6 % received surgery alone and adjuvant C ± RT (chemoradiotherapy 17.7 %; chemotherapy alone 2.9 %), respectively. Predictors of adjuvant C ± RT receipt included age <67 years, pathologic nodal positivity, and adequate lymph node staging (LNS; ≥15 nodes examined; all p < 0.001). Survival analyses included 15,748 patients (1998-2006); median, 1-, and 5-year survival were 63.5 months, 86.0 %, and 27.0 % respectively. Omission of adjuvant C ± RT conferred an increased hazard of risk-adjusted mortality in the overall cohort, and stage IB and II subgroups (all p ≤ 0.001). The benefit of adjuvant C ± RT was most pronounced in stage II and node-positive patients-regardless of LNS adequacy (all p < 0.001)-and inadequately staged IB patients (p = 0.003). While associated with a trend toward improved OS in node-negative patients overall (p = 0.051), adjuvant C ± RT did not improve OS if surgical LNS was adequate in this subgroup (p = 0.960). CONCLUSIONS: Adoption of adjuvant C ± RT in ESGC remains incomplete nationally. Receipt of adjuvant therapy is associated with improved risk-adjusted survival relative to surgery alone; however, in adequately staged patients without lymph node metastasis, this benefit is less certain.