Abstract 456P
Background
Perioperative treatment (chemoradiotherapy or chemotherapy) is the current standard of care for EC and GEJC. Despite its importance, data are still insufficient to consider pCR as validated surrogate of long-term survival. The aim of this study was to evaluate the correlation between pCR and overall survival (OS).
Methods
This is a retrospective single-center study evaluating the association between pCR and OS of 392 patients (pts) with locally advanced EC and GEJC who received perioperative treatment followed by surgery from August 2017 to June 2023. We aim to describe the main clinical-pathological characteristics of patients at diagnosis, as well as treatment outcomes. Survival was estimated from diagnosis and measured by the Kaplan-Meier (KM) method. The log-rank test was used to evaluate differences between groups.
Results
267 (68%) had adenocarcinoma (AC), 121 (31%) squamous cell carcinoma (SCC). 290 (74%) had clinically staged node-positive tumors. 294 (75%) were males, median age at diagnosis was 65 years (range 29-89). All the pts underwent surgery with a radical intent, and among these, 336 pts (86%) received a pre-operative treatment: 173 (52%) chemoradioterapy based on CROSS regimen, 94 (28%) chemotherapy with FLOT, 36 (11%) with FOLFOX. A pCR was reported for 80/336 pts (24%), specifically 47 (59%) SCC and 33 (41%) AC. Among them, 56 (70%) have received CROSS, 14 (18%) FLOT and 3 (4%) FOLFOX. pCR was observed in 56 out of 173 pts (32%) treated with CROSS: 39 (70%) among SCC and 17 (30%) among AC. In pts treated with neoadjuvant chemotherapy regimen, 24 pCR out of 154 pts were observed (16%). At a median follow-up of 44 months (IQ 27-63), in neoadjuvant CROSS cohort, pCR was associated with better 3-yr OS and 5-yr OS than no-pCR: 80% and 70% vs 50% and 45% (p=0.004). This effect was more remarkable in SCC subgroups of patients (3-yr OS 79% vs 37%, p<.001).
Conclusions
In this large, real-world dataset we observed that pCR may correlate with OS. Pts with EC and EGJC who underwent CROSS regimen have longer survival if they achieved pCR, especially if SCC. Further studies are needed to assess the role of pCR as survival surrogate.
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.