"Find Your Y": histological differences in early stage (pT) and post-treatment (ypT) oesophageal adenocarcinoma with implications for salvage endoscopic resection.

Aims: Current guidelines offer limited strategies for managing recurrent/persistent oesophageal adenocarcinoma (EAC). Salvage endoscopic mucosal/submucosal resection (ER) shows promise in oesophageal squamous cell carcinoma, however its success in EAC is limited. We aimed to elucidate histological characteristics influencing salvage ER success in patients with low-stage, pretreated EAC.

Methods: We retrospectively reviewed 272 EAC tumours postoesophagectomy from five US centres and collected clinicopathological data including discontinuous growth (DG), defined as separate tumour foci ≥2 mm from the main tumour. We selected 101 patients with low-stage disease and divided them into treatment-naïve (n=70) and neoadjuvant therapy (n=31) groups. We compared the two groups and differences in clinical, histological and outcome characteristics were identified.

Results: In the entire cohort (n=272), DGs were identified in 22% of cases. Multivariate analysis revealed DGs as an independent prognostic factor for recurrence and positive oesophagectomy margins. Lymphovascular invasion (LVI) and background intestinal metaplasia predicted DG presence and absence, respectively. Compared with the treatment-naïve low T-stage subgroup, the pretreated subgroup exhibited higher incidence of poorly differentiated carcinoma (16% vs 46%, p=0.007), larger tumours (14 vs 30 mm, p<0.001), higher tumour, node, metastases stage (7% vs 30%, p=0.004), more nodal disease (7% vs 36%, p<0.001) and frequent DGs (1% vs 13%, p=0.030).

Conclusions: In treated low T-stage EACs, DGs may contribute to suboptimal outcomes following salvage ER. Presence of LVI (as a surrogate for DGs) and poor differentiation in the absence of intestinal metaplasia in biopsy samples may serve as histological poor prognosticators in treated patients with EAC being considered for salvage ER.