Poster Presentation Clinical Oncology Society of Australia Annual Scientific Meeting 2022

Neoadjuvant chemoradiotherapy or peri-operative chemotherapy, which is superior in gastroesophageal adenocarcinoma? - A retrospective analysis. (#243)

Zachary Wilson 1 , Gary Tincknell 2 3 , Daniel Brungs 1 2 4 , Karen Fildes 1 4
  1. Graduate School of Medicine, University of Wollongong, Wollongong, NSW, Australia
  2. Illawarra Cancer Care Centre, The Wollongong Hospital, Wollongong, NSW, Australia
  3. School of Chemistry and Molecular Biosciences, University of Wollongong, Wollongong, NSW, Australia
  4. Illawarra Health and Medical Research Institute, Wollongong, NSW, Australia

Aims: Gastric, gastroesophageal junction, and oesophageal adenocarcinomas (GOCs) have dismal 5-year survival, even when treated with curative intent. In patients with oesophageal and gastroesophageal junction adenocarcinomas, overall survival (OS) was improved by neoadjuvant chemoradiotherapy (CROSS). In gastric and gastroesophageal junction adenocarcinomas, OS was increased by perioperative chemotherapy (FLOT/ MAGIC). To date, no randomised controlled trials have been attempted between FLOT and CROSS. We aimed to compare chemoradiotherapy and chemotherapy for patients with GOC.

Methods: We performed a retrospective analysis of patients treated for GOCs within the Illawarra Shoalhaven Local Health District from 2013 to 2022. We included only patients diagnosed with GOC adenocarcinoma, excluding other histopathology, who commenced neoadjuvant or peri-operative treatments. Survival analysis was performed using Kaplan-Meier method and log-rank tests.

Results: 95 patients were treated with neoadjuvant (n=64) or perioperative (n=31) treatment with the aim for curative surgery. Forty-one tumours originated from the distal oesophagus, 36 from the gastroesophageal junction and 18 from the stomach. There was no difference in median OS between the groups (chemotherapy 52.8 months, chemoradiotherapy 36.4 months; p=0.7). Of those located at the gastroesophageal junction, no OS difference was seen between those treated with CROSS or FLOT (p=0.9). Four (6.3%) patients who completed chemoradiotherapy and 7 (22.6%) who completed chemotherapy did not proceed to surgical resection. Seven patients (7.4%) did not proceed to surgery due to upstaging at pre-operative radiologic screening or staging laparoscopy, 6 in chemotherapy and 1 in chemoradiotherapy arms. Incomplete resection was seen in 3 (4.7%) chemoradiotherapy patients, and 4 (12.9%) chemotherapy patients.

Conclusion: There appears to be no demonstratable OS difference between perioperative chemotherapy and neoadjuvant chemoradiotherapy for GOCs. Higher rates of incomplete resection and pre-operative upstaging of the disease was seen in the chemotherapy group. For those patients where the pertinent trials overlap, the two treatment regimens appear equivocal.