[A Case Report of Organ Preservation by Total Neoadjuvant Therapy and Local Excision for Lower Rectal Cancer].

In our department, total neoadjuvant therapy(TNT), which is a combination of preoperative chemotherapy and preoperative chemoradiotherapy(nCRT), has been introduced for the purpose of local and systemic disease control for lower rectal cancer. For patients in whom a clinical complete response(cCR)was obtained by TNT, we avoid the surgery and preserve organs, and follow-up strictly under the informed consent(watch and wait). In addition, for patients with remarkably reduced primary lesions(near cCR)without lymphadenopathy after TNT, the option of omitting total mesorectal excision (TME)and performing organ preservation by local excision can be introduced. Here, we report a case in which near cCR was obtained by TNT and organ preservation was performed by local excision. A 67-year-old man with lower rectal cancer(AV 5 cm, 15 mm, type 2, cT2N0M0, cStage Ⅰ)was referred to our department with a desire to preserve the anus. TNT with nCRT→CAPOX was performed, and near cCR was obtained. After that, full thickness local excision of the residual disease was performed by transanal minimally invasive surgery(TAMIS). The final pathological diagnosis was Rb, 0.7 mm, por2, ypT1a, ypPM0, ypDM0, ypRM0. No recurrence is recognized for 3 years and 10 months after the operation.