Mokdad AA, et al. - Researchers sought to assess whether, for patients with gastroesophageal adenocarcinoma who received preoperative chemoradiotherapy and resection, adjuvant chemotherapy confers a survival benefit compared with observation. In these patients, adjuvant chemotherapy seemed associated with improved overall survival. Findings have important implications for the postoperative treatment of this patient group for which few data are available.

Methods

• Researchers performed a propensity score–matched analysis using the National Cancer Database.
• From 2006 to 2013, they included adult patients who received a diagnosis of clinical stage T1N1-3M0 or T2-4N0-3M0 adenocarcinoma of the distal esophagus or gastric cardia who were treated with preoperative chemoradiotherapy and curative-intent resection.
• They matched patients receiving adjuvant chemotherapy by propensity score to patients undergoing postoperative observation.
• Exposures included Adjuvant chemotherapy and postoperative observation.
• Overall survival was mainly assessed.

Results

• 10 086 patients were identified(8840 [88%] male; mean [SD] age, 61 [9.5] years); 9272 patients comprised the postoperative observation group and 814 patients comparised the adjuvant chemotherapy group.
• Adjuvant chemotherapy group patients were younger (18-54 years: 252 [31%] vs 1989 [21%]; P < .001) and were more likely to have advanced disease (ypT3/4: 458 [62%] vs 3531 [46%]; P < .001; ypN+: 572 [72%] vs 3428 [39%]; P < .001), as well as indicated shorter postoperative inpatient stays (>2 weeks: 94 [13%] vs 1589 [20%]; P < .001).
• In the adjuvant chemotherapy group, a total of 732 patients were matched by propensity score to 3660 patients in the postoperative observation group.
• Adjuvant chemotherapy group indicated improved overall survival compared with postoperative observation group(median survival: 40 months; 95% CI, 36-46 months vs 34 months; 95% CI, 32-35 months; stratified log-rank P < .001; hazard ratio, 0.79; 95% CI, 0.72-0.88).
• In this study, overall survival at 1, 3, and 5 years was 88%, 47%, and 34% in the observation group, and 94%, 54%, and 38% in the adjuvant chemotherapy group, respectively.
• Adjuvant chemotherapy indicated an association with a survival benefit compared with postoperative observation in most patient subgroups.