The clinical relevance of regional lymph node microarchitecture in oesophageal cancer patients - Results from the UK MRC OE02 trial.

BACKGROUND

In oesophageal cancer (OeC) patients, neoadjuvant chemotherapy followed by surgery improves survival. Anti-tumour immune responses are mediated by lymph node (LN) microarchitecture. We investigated whether neoadjuvant chemotherapy and/or presence of tumour changes LN microarchitecture, and whether such changes are associated with survival.

METHODS

Microarchitectural features (lymphocytes, germinal centres (GermC), histiocytes) were quantified morphometrically in 433 LNs from 333 OE02 trial patients (165 neoadjuvant chemotherapy+surgery (CS), 168 surgery alone (S)). Features were compared between tumour-negative (LNneg) and tumour-positive LN (LNpos) by treatment group. Associations with clinicopathological variables and overall survival (OS) were evaluated.

RESULTS

LNneg GermC density was lower in CS patients than in S patients (median: 1% vs 2%; p = 0.0004). No other microarchitectural features differed by treatment group or LN status (LNneg vs LNpos). Low histiocyte content in LNneg and LNpos was associated with improved OS in S patients only (HR:0.67, 95%CI: 0.46-0.97, p = 0.03). Multivariable analysis confirmed the independent prognostic significance of LNneg histiocytes (HR:0.62, 95%CI: 0.42-0.9, p = 0.01).

CONCLUSION

These findings suggest that LN microarchitecture may be a biomarker for treatment-related immune modulation and prognosis in patients with resectable OeC. These findings warrant independent validation and further investigation to determine whether LN microarchitectural features could inform personalised therapeutic strategies.