1426P Gender differences in treatment characteristics and outcomes of esophagogastric cancer surgery - Data from the Dutch upper-GI cancer audit

Gender differences in clinicopathological characteristics and postoperative outcomes of curative esophagogastric cancer surgery are largely undefined. This study aimed to compare tumor and treatment characteristics and outcomes of esophagogastric cancer surgery between men and women in a national cohort. Data was acquired from the Dutch Upper-GI Cancer Audit. Patients who underwent elective surgery for a primary esophagogastric squamous cell or adenocarcinoma between 2011-2015 were included. The primary endpoint, relative survival, i.e. adjusted for the normal life expectancy, was compared between men and women with esophageal adenocarcinoma (EAC), esophageal squamous cell carcinoma (ESCC) and gastric adenocarcinoma (GAC), with subgroup analysis according to sub-location. Secondly, tumor and treatment characteristics and post-operative outcomes were compared. In total, 5617 patients were included, of which 72% were men. Similar cT- and cN-stages were observed, while lower (y)pT-stages were observed in women with ESCC and GAC ((y)pT3-tumors: 23% vs 27%, p 0.026; 37% vs 42%, p 0.014, respectively). In women, ESCC was located more proximally (mid esophagus 50% vs 39%, p<0.001) and antrum GAC was more frequent (47% vs 38%, p<0.001). In women with GAC, more poorly differentiated tumors (69% vs 57%, p<0.001) were observed. Men with GAC and EAC more often received neo-adjuvant treatment (91% vs 85%, p<0.001; 62% vs 56%, p 0.007, respectively), and men with GAC more adjuvant treatment (42% vs 37%, p 0.022). For GAC, more postoperative complications (38% vs 33%, p 0.017) and more reinterventions (16% vs 12%, p 0.008) were observed in men. No differences in 5-year relative survival for EAC, ESCC or GAC were observed. However, for corpus GAC a superior 5-year relative survival was observed in men (62% vs 48%, p 0.021). In addition to gender differences in gastro-esophageal tumor location and differentiation, women with esophageal and gastric adenocarcinoma less frequently received neo-adjuvant therapy, although 5-year relative survival was comparable. For gastric corpus adenocarcinoma, an inferior survival was observed in women.