Who Benefits From Adjuvant Chemotherapy After Neoadjuvant Therapy for Esophagogastric Cancer?: ESMO GI | August 2026

Introduction:

Perioperative chemotherapy is standard for locally advanced esophagogastric adenocarcinoma, yet many patients struggle to receive postoperative treatment after major surgery. Whether all patients need the adjuvant component remains uncertain. This meta-analysis examined whether pathological response to neoadjuvant chemotherapy can identify patients most likely to benefit from further chemotherapy.

Why was this study needed?

Only a proportion of patients complete postoperative chemotherapy.

Pathological response provides an in-vivo measure of tumor sensitivity to systemic therapy.

Complete responders may already have excellent outcomes, whereas minimal responders may represent treatment-resistant disease.

Identifying the subgroup with genuine adjuvant benefit could reduce unnecessary toxicity.

Results:

The systematic review included 11 studies and 6,600 patients; five studies involving 4,688 patients were meta-analyzed.

Partial responders showed the clearest benefit from adjuvant chemotherapy: OS improved by ~36% (HR 0.64) and RFS by ~29% (HR 0.71).

Complete responders showed no demonstrated additional OS or RFS benefit from adjuvant chemotherapy.

Minimal responders also showed no significant benefit, suggesting that simply continuing the same chemotherapy may not overcome resistant tumor biology.

Clinical Impact:

The findings suggest a biologically attractive response-adapted strategy:

Complete response → consider whether additional chemotherapy can be safely de-escalated

Partial response → strongest rationale to complete adjuvant therapy

Minimal/no response → consider alternative strategies rather than automatically continuing an ineffective regimen

However, these findings are largely derived from retrospective studies and should not yet override current perioperative treatment standards. They are particularly relevant for designing future response-adapted randomized trials.

Bottom Line:

The benefit of postoperative chemotherapy after neoadjuvant treatment may not be uniform in esophagogastric adenocarcinoma. Partial pathological responders appear to derive the greatest survival benefit, whereas complete and minimal responders show no clear additional benefit—supporting pathological response as a potential biomarker for future personalized adjuvant therapy.