ASO Author Reflections: The Challenging Journey from cCR to pCR After Neoadjuvant Treatment for Esophageal Squamous Cell Carcinoma

Pathological complete response (pCR) is a postoperative pathological description that occurs after preoperative comprehensive treatment with chemotherapy and/or immunotherapy and/or radiotherapy, which is a great achievement of systemic treatment for esophageal cancer. Broadly, pCR refers to the complete regression of primary tumors, regional metastatic lymph nodes, potential metastatic lesions in tissues and organs outside the esophagus, and possible circulating tumor cells. Therefore, there is no doubt that pCR potentially represents a complete cure for the patients. However, strictly speaking, the generalized pCR is currently only a theoretical concept, and there are two reasons for this. First, pCR is currently mainly used in pathological manifestations after thorough examination for the surgical specimens, including primary tumors and lymph nodes), after preoperative treatment. Therefore, surgical resection is a necessary step to diagnose pCR. Second, the detection methods for blood microresidual disease (MRD) are not yet mature, and further exploration of more novel and sensitive detection methods is needed. Nevertheless, no matter how difficult it is to prove this theoretical pCR in clinical practice, we have reason to believe that theoretical pCR truly exists in some patients and is our ultimate pursuit in treating esophageal cancer. Dr. Wu¹ reported the clinical outcome of esophageal squamous cell carcinoma patients who obtained pCR after neoadjuvant chemotherapy in their institution, providing references for the understanding of tumor regression brought by preoperative treatment. …