Management Strategies for Disappearing Colorectal Liver Metastases After Systemic Chemotherapy: Long‐Term Outcomes and Preoperative Prediction of ‘True Complete Response’

ABSTRACT Background Determining whether to resect disappearing liver metastases (DLMs) after chemotherapy for colorectal liver metastases (CRLMs) remains challenging. Methods Patients who underwent hepatectomy after systemic chemotherapy for initially unresectable CRLMs were reviewed. True complete response (CR) was defined as either resected DLMs with pathological CR or unresected DLMs without local recurrence. Long‐term outcomes were compared between patients with and without resection of all DLMs. Results Among 58 patients, 26 (44.8%) had DLMs, totaling 106 lesions. True CR was achieved in 70.8% of DLM lesions. Long‐term outcomes did not differ between patients with and without resection of all DLMs (median recurrence‐free survival, 11.1 vs. 7.6 months, p  = 0.594; median surgical failure‐free survival, 11.1 vs. 17.2 months, p  = 0.758; median overall survival, 43.6 vs. 53.6 months, p  = 0.819). DLM lesions with true CR had smaller initial diameters than those without true CR (5 vs. 9 mm, p  = 0.013). Conclusion Regardless of whether all DLMs were resected, patients had acceptable long‐term outcomes. DLM lesions with a larger initial diameter before chemotherapy may warrant proactive intraoperative exploration for residual disease using contrast‐enhanced ultrasonography.