Tertiary lymphoid structures and clinicopathological characteristics in pT1b Esophageal squamous cell carcinoma

The objective of the current study is to investigate the clinicopathological and prognostic significance of Tertiary lymphoid structures (TLSs) in T1b ESCC.

A total of 291 T1b ESCC patients who underwent esophagectomy and regional lymphadenectomy between 2008 and 2017 were included. Hematoxylin and eosin staining slides were used to evaluate TLSs and pathological features.

Intratumoral TLSs (iTLSs), mature iTLSs, peritumoral TLSs (pTLSs), mature pTLSs, distal TLSs (dTLSs), mature dTLSs, high grade dysplasia TLSs (HGD TLSs), and mature HGD TLSs were found in 51.2 %, 21.3 %, 86.9 %, 55.7 %, 58.8 %, 7.2 %, 95.5 %, and 68.1 % patients, respectively. There were significant correlation between iTLSs and mature iTLSs (P < 0.001), iTLSs and pTLSs (P = 0.025), pTLSs and mature pTLSs (P < 0.001), pTLSs and dTLSs (P = 0.048), dTLSs and mature dTLSs (P < 0.001), HGD TLSs and mature HGD TLSs (P < 0.001). High iTLSs or mature iTLSs correlated positively with INFc, lymphovascular invasion, high tumor stroma (P < 0.05). Multivariate Cox regression analyses identified tumor budding (P = 0.040) and differentiation (P = 0.016) as independent prognostic factors for disease-free survival (DFS), and tumor size (P = 0.049) and differentiation (P = 0.001) as independent indicators for overall survival (OS).

TLSs and mature TLSs, especially in peritumoural dysplasia tissues, were common in T1b ESCC, which couldn't predict prognosis for these patients. Tumor budding and differentiation reflect the biological activity of the tumor and may be useful prognostic indicators in T1b ESCC.