Efficacy of Organ Preservation Strategy by Adjuvant Chemoradiotherapy after Non-Curative Endoscopic Resection for Superficial SCC: A Multicenter Western Study

SIMPLE SUMMARY: Endoscopic resection (ER) of superficial esophageal SCC is a safe and efficient treatment. Compared with surgery, ER is minimally invasive and associated with lower morbidity and mortality. This is the largest Western study to investigate long-term outcomes after ER for superficial esophageal SCC and to measure the effect of CRT after non-curative resection. The combination therapy of ER and adjuvant CRT reduced the risk of nodal recurrence. This organ preservation strategy may be considered as an alternative to adjuvant surgery for patients with high comorbidities and high risk of nodal invasion after ER of superficial SCC. ABSTRACT: Background. In case of high risk of lymph node invasion after endoscopic resection (ER) of superficial esophageal squamous cell carcinoma (SCC), adjuvant chemoradiotherapy (CRT) can be an alternative to surgery. We assessed long-term clinical outcomes of adjuvant therapy by CRT after non-curative ER for superficial SCC. Methods. We performed a retrospective multicenter study. From April 1999 to April 2018, all consecutive patients who underwent ER for SCC with tumor infiltration beyond the muscularis mucosae were included. Results. A total of 137 ER were analyzed. The overall nodal or metastatic recurrence-free survival rate at 5 years was 88% and specific recurrence-free survival rates at 5 years with and without adjuvant therapy were, respectively, 97.9% and 79.1% (p = 0.011). Independent factors for nodal and/or distal metastatic recurrence were age (HR = 1.075, p = 0.031), Sm infiltration depth > 200 µm (HR = 4.129, p = 0.040), and the absence of adjuvant CRT or surgery (HR = 11.322, p = 0.029). Conclusion. In this study, adjuvant therapy is associated with a higher recurrence-free survival rate at 5 years after non-curative ER. This result suggests this approach may be considered as an alternative to surgery in selected patients.