Real world applications of postneoadjuvant stage I of the staging system for oesophageal squamous cell cancer: What's beyond PCR?

The eighth edition of the American Joint Committee on Cancer classification system defines postneoadjuvant pathologic T0-2N0M0 (ypT0-2N0M0) stage as ypI for oesophageal cancer. This study was designed to explore the possible differences in survival among yp stage I. The records of patients with oesophageal squamous cell cancer staged ypI who underwent radical oesophagectomy between July 2009 and July 2022 in Sun Yat-sen University Cancer Center were reviewed. The survival differences were compared between ypT0, ypTis, ypT1a, ypT1b and ypT2. A total of 355 patients (65 deaths and 34 recurrences) were reviewed. The OS and DFS differed significantly between ypT0-1a and ypT1b-2 staged patients in the total population (5-OS: 81.5% vs 70.2%, p = 0.043; 5-DFS: 80.8% vs 71.9%, p = 0.016), in the NCRT group (5-OS: 82.0% vs 67.5%, p = 0.032; 5-DFS: 84.6% vs 71.2%, p = 0.027), but not in the NCT±I group (5-OS: 80.3% vs 72.9%, p = 0.34; 5-DFS: 66.5% vs 72.4%, p = 0.41). The OS and DFS of patients with ypT0 stage (PCR) disease were similar to that of patients with ypTis-1a disease in total population (p = 0.16 and 0.94) and the NCRT group (p = 0.40 and 0.57). Cox regression analysis revealed that ypT1b-2 was an independent prognostic factor for survival in total population (HR = 1.760, 95% CI = 1.056-2.933; p = 0.030). Patients with ypIa-new (ypT0-1aN0M0) disease had significant better survival with those with ypIb-new (ypT1b-2N0M0) disease among patients who received NCRT, while patients with ypIa-new (PCR and ypTis-1aN0M0) disease had similar survival. Adjuvant immunotherapy might not be required for patients with ypTis-1aN0M0 stage disease.