Adjuvant FLOT provides survival benefit for oesophagogastric junction and gastric adenocarcinoma patients with low tumour regression after neoadjuvant chemotherapy.

Oesophagogastric junction and gastric adenocarcinoma (OGA) are associated with high mortality rates, with 5-year survival rates below 50% in the curative setting. This study evaluates the efficacy of adjuvant chemotherapy (a chemotherapy regimen consisting of docetaxel, oxaliplatin, leucovorin and 5-fluorouracil [FLOT]) in patients with low tumour regression grades (TRG) following neoadjuvant FLOT (>10% viable tumour cells in surgical specimen, TRG 2/3 analogue Becker's classification). Data from all patients who had undergone ≥3 cycles of neoadjuvant FLOT with R0 resection and TRG 2/3 in surgical specimen, diagnosed between 2017 and 2020 at the University of Cologne (n = 134), were analyzed. Patients were categorised into three groups based on the administration of postoperative FLOT: 'FLOT complete' (four cycles), 'FLOT incomplete' (one to three cycles) and 'no FLOT' (0 cycles). Progression-free survival (PFS) and overall survival (OS) were compared. There is a statistically significant PFS advantage for the 'FLOT complete' group compared to 'no FLOT' (p = .028) in the total patient cohort and a tendency for an OS benefit. In the subgroup of patients with lymph node metastasis in surgical specimen (ypN+ cohort, n = 91), the PFS advantage of 'FLOT complete' was diminished and statistically no longer significant, and there is no OS benefit for these patients. However, multivariate analysis confirmed a significant PFS benefit for 'FLOT complete' both in the total cohort (p = .011) and in ypN+ patients (p = .018). These findings suggest that full adjuvant FLOT is beneficial even for OGA patients with low tumour regression; however, its efficacy appears reduced in those with lymph node metastasis, warranting further investigation into individualising treatment strategies.