523. RISK FACTORS ASSOCIATED WITH NOT RECEIVING ADJUVANT CHEMOTHERAPY FOR LOCALLY ADVANCED ESOPHAGOGASTRIC ADENOCARCINOMA

Abstract

Abstract Perioperative chemotherapy is standard of care in the curative treatment of locally advanced esophagogastric adenocarcinoma in the UK. Previously used MAGIC triplet is becoming less frequently used in favor of superior FLOT quadruplet. There is however large number of patients who don't undergo adjuvant component of both of these perioperative regimens. This study aimed to investigate factors which are associated with not receiving adjuvant chemotherapy after neoadjuvant chemotherapy followed by surgical resection for esophagogastric adenocarcinoma. All patient receiving neoadjuvant chemotherapy for esophagogastric adenocarcinoma followed by curative surgery during 2010 till 2019 were identified from prospectively maintained single institution database. Patients who died in-hospital or within 90 days of surgery were excluded from analyses. Risk factors which could be associated with receiving/not receiving adjuvant component were studied. Mann U Whitney and chi-square test were used as appropriate. Multivariable logistic regression was carried out to identify risk factors independently predictive of not receiving adjuvant chemotherapy. Analyses included 624 patients of whom 273 received adjuvant chemotherapy (44%). This included ECX/ECF in 233 patients, EOX in 5 patients, FLOT in 22 patients and other/unknown regimens in 13 patients. Age, Charlson comorbidity index, return to theatre, severe postoperative complications (Clavien-Dindo grade III+) and R1 resection were associated with not receiving adjuvant chemotherapy (p 0.005, p 0.006, p 0.026, p 0.043, p 0.004 respectively). Statistically significant variables were entered into multivariable logistic regression model. Only R1 resection was independently associated with not receiving adjuvant component (OR 0.18, p 0.007). This study confirms that only less than half of patients who undergo neoadjuvant chemotherapy followed by surgery with curative intent receive adjuvant chemotherapy. Reasons for this are multifactorial but age, comorbidities, severe complications and positive longitudinal margin might play important role. These results also highlight the importance of prevention, early detection and appropriate management of postoperative complications.