No abstract

Background Tumour immune microenvironment is related with carcinogenesis and efficacy of immunotherapy. B cells play major roles in humoral immunity, but detailed functions of tumour‐infiltrating B lymphocytes (TIL‐Bs) are unknown. Therefore, our aim was to investigate the functional heterogeneity of TIL‐Bs in oesophageal squamous cell carcinoma (ESCC) and lymph nodes (LNs) during chemotherapy. Methods Single‐cell transcriptome analysis was performed on 23 specimens. We also performed immunohistochemical analysis of immunoglobulin κ C (IGKC), an antibody‐secreting cell (ASC) marker, in 166 ESCC samples and evaluated the implication of IGKC in 2‐year recurrence free survival (RFS) and 3‐year overall survival (OS). Results A total of 81,246 cells were grouped into 24 clusters. We extracted B cell clusters based on canonical markers and identified 12 TIL‐B subtypes in ESCC. We found that several functions, such as co‐stimulation and CD40 signalling, were enhanced in TIL‐Bs after chemotherapy. The proportion of naive B cells (NBCs) decreased and B cell activation genes were up‐regulated in NBCs after chemotherapy. The proportion of ASCs in tumours increased with the loss of migratory abilities and antibody production in ASCs was promoted after chemotherapy. Differentially expressed genes up‐regulated with chemotherapy in ASCs correlated with prolonged survival with oesophageal cancer ( p = .028). In a metastatic LN, the ASC proportion increased and B cell differentiation was enhanced. In immunohistochemical analysis, RFS and OS of high IGKC expression cases were significantly better than those of low IGKC expression cases (RFS: p < .0001, OS: p < .0001). And in multivariable analysis, the expression of IGKC was an independent favourable prognostic factor for RFS (hazard ratio (HR): 0.23, 95% confidence interval (CI): 0.12–0.45, p < .0001) and OS (HR: 0.20, 95% CI: 0.086–0.47, p = .0002) in ESCC. Conclusions Our findings provide novel insights for the heterogeneity of TIL‐Bs during chemotherapy and will be useful to understand the clinical importance of TIL‐Bs.

A patient with small-cell carcinoma of the esophagus treated with cyclophosphamide and vincristine is described. Within 2 months after the beginning of therapy, two coexisting tumors had disappeared and the main primary lesion and metastases in the liver and lymph nodes were markedly reduced in size. The patient relapsed 5 months after the start of therapy and died with widespread metastases. Autopsy revealed that the patient was in partial remission.

For stage II and III esophageal squamous cell carcinoma (ESCC), neoadjuvant chemotherapy (NAC) followed by esophagectomy is recommended in the Japanese guidelines for the diagnosis and treatment of esophageal cancer. However, recurrence of ESCC is common regardless of the NAC regimen and surgical method, and NAC demonstrates limited efficacy against recurrence. Therefore, the present study was conducted to identify risk factors of recurrence of ESCC with surgery after NAC. The outcomes of 51 patients who underwent esophagectomy for ESCC after NAC from 2010 to 2017 at Kyushu University Hospital were retrospectively analyzed. A total of 52 patients with ESCC without NAC followed by esophagectomy from 2001 to 2017 were selected for comparison. Among patients who underwent NAC followed by surgery, only lymphatic invasion (LY; hazard ratio, 2.761; 95% CI, 1.86-6.43, P=0.018) was an independent factor significantly associated with 3-year recurrence-free survival in the multivariate analysis. In patients with pathologic lymph node metastasis (pN) and no LY after NAC, there was significantly less recurrence compared with patients with pN and LY (P=0.0085), whereas in patients without LY after NAC, the presence of pN was not significantly associated with recurrence (P=0.2401). There were significantly fewer LY (+) patients in the NAC (+) group (P=0.0158) compared with those in the NAC (-) group. The presence of LY was an independent risk factor for recurrence of ESCC after esophagectomy following NAC. Overall, adjuvant treatment after surgery may be required in cases with remnant LY after NAC.

No abstract