Abstract
RATIONALE: Neoadjuvant immunotherapy combined with chemotherapy can offer a higher surgical conversion rate for patients with locally advanced unresectable colon cancer while maintaining safety. PATIENT CONCERNS: Patients are primarily concerned about treatment plans and their efficacy, including the number of cycles for neoadjuvant therapy, the timing of surgery, and potential side effects associated with the treatment. DIAGNOSES: Colonoscopy and biopsy were conducted to confirm the malignant nature of the colon tumor. A computed tomography scan of the abdomen showed that the maximum diameter of the tumor was 6.5 cm×5.5 cm, and the tumor markedly invaded adjacent tissues, making it inoperable. INTERVENTIONS: After 3 cycles of neoadjuvant therapy, a reexamination of abdominal computed tomography showed that the patient reached the criteria for surgery. Subsequently, a laparoscopic radical right hemicolectomy was conducted. OUTCOMES: The surgery was successful and no surviving tumor cells were seen in postoperative pathological examination. LESSONS: Surgical resection of colon cancer after chemotherapy combined with immunotherapy can achieve R0 resection and pathological complete response, which is a complex but promising treatment.