Multi-Institutional Analysis of Survival and Recurrence Patterns of Different Pathological Regression Types After Neoadjuvant Chemoradiotherapy or Radiotherapy for Esophageal Squamous Cell Carcinoma.

Background: The recurrence patterns of different types of pathologic regression of the primary tumor and lymph nodes in patients with esophageal squamous cell carcinoma (ESCC) after neoadjuvant chemoradiotherapy (NCRT) are little known, especially in ypT0N+ patients.

Methods: We included 582 patients with ESCC who had esophagectomy after NCRT or neoadjuvant radiotherapy (NRT) from 3 institutions. The patients were divided into 4 groups: ypT0N0, ypT0N+, ypT+N0, and ypT+N+ according to the type of pathological regression of the primary tumor and lymph nodes. Survival, recurrence pattern and timing, and potential prognostic factors were compared.

Results: A total of 179 patients were classified as ypT0N0, 227 patients as ypT + N0, 45 patients as ypT0N+, and 131 patients as ypT + N+. The median follow-up was 31.7 months in all patients. The restricted mean survival time (RMST) of ypT0N0, ypT + N0, ypT0N+, and ypT + N+ patients decreased sequentially (70.64, 63.84, 55.93 and 39.96 months) and the recurrence rates increased sequentially (22.3%, 29.5%, 44.4% and 54.2%). Both the overall survival (OS) and recurrence-free survival (RFS) in the ypT0N+ group were significantly lower than those in the ypT0N0 group (HR: 2.226, p = 0.007; HR: 2.271, p = 0.003). The distant metastasis (DM) pattern in ypT0N+ was similar to that of ypT + N+, and higher than that of ypN0 (25.6% vs 14.3%, HR: 1.970, p = 0.040).

Conclusions: ESCC patients with various pathological regression types after receiving NCRT or NRT had significantly different survival rates. ypT0N+ patients had a lower survival rate and higher DM rate than ypT0N0 patients. For these lymph node-positive patients, adjuvant chemotherapy does not appear to improve their prognosis.