Clinical T classification predicts tumour remnants and prognosis in patients with oesophageal squamous cell carcinoma treated with neoadjuvant docetaxel/cisplatin/5-fluorouracil therapy followed by surgery

BACKGROUND: The aim of this study was to clarify the clinical significance of the newly proposed clinical T (cT) classification in the 12th edition of the Japanese Classification of Esophageal Cancer (JCEC) in patients with oesophageal squamous cell carcinoma (OSCC) who underwent neoadjuvant docetaxel/cisplatin/5-fluorouracil (DCF) therapy followed by oesophagectomy. METHODS: A total of 125 patients with thoracic OSCC who underwent neoadjuvant DCF therapy followed by oesophagectomy between 2009 and 2019 were enrolled. The cT classification was determined according to the 12th edition of the JCEC, and its association with residual tumour patterns and survival prognosis was examined. RESULTS: The distribution of pretreatment cT status was as follows: cT1 in 6% of patients, cT2 in 10%, cT3r in 75%, cT3br in 6%, and cT4 in 3%. Multivariate analysis identified cT status as an independent prognostic factor (cT3br: hazard ratio 7.87, 95% confidence interval, 1.74-35.6: P = 0.007). Tumour remnants extending across diffuse layers were frequently observed in the cT3br and cT4 groups, and no cases of pathological complete response were observed in these groups. The cT3br group had the highest 5-year cumulative recurrence rate (83.3%), which was significantly higher than that in the cT3r group (P = 0.040). Recurrence was more frequent in the cT3br and cT4 groups, particularly as local recurrence. CONCLUSION: The cT classification is predictive of residual tumour patterns and prognosis following neoadjuvant DCF therapy for OSCC. Further investigation is warranted to identify individualized treatment strategies that may improve outcomes in patients with cT3br and cT4 disease.