Clinical efficacy of preoperative neoadjuvant chemoradiotherapy for unresectable locally advanced adherent colon cancer in 40 patients

Objective: To investigate the efficacy and toxicities of neoadjuvant chemoradiotherapy (neoCRT) in the management of unresectable locally advanced adherent colon cancer (LAACC). Methods: A retrospective analysis was performed on the clinical records of 40 patients with initially diagnosed unresectable LAACC who received preoperative neoCRT in our center from October 2010 to December 2015. Results: Thirty-nine patients completed the preoperative neoCRT. Thirty-four patients underwent radical resection after neoCRT, and the R0 resection rate, pathological complete response rate (pCR), tumor downstaging rate, nodal downstaging rate, and clinical downstaging rate were 91%, 24%(8/34 patients), 76%(26/34 patients), 100%(32/32 patients), and 94%(32/34 patients), respectively. Among the 21 patients with bladder invasion, the full bladder was preserved in 7 patients (33%) and partial cystectomy was performed in 11 patients (52%). During the course of neoCRT, the grade 3-4 hematologic toxicity rate, grade 3 hand-foot syndrome rate, grade 3 radiodermatitis, and incomplete intestinal obstruction rate were 23%, 3%, 3%, and 5%, respectively. The 3-year sample size was 25 patients. For all the patients, the 3-year overall survival (OS) and progression-free survival (PFS) rates were 75% and 80%, respectively. Of the 34 patients who received surgical radical resection, the 3-year OS and disease-free survival (DFS) rates were 87% and 81%, respectively. In addition, local tumor recurrence was identified in 3 patients, and distant metastasis was identified in 6 patients. Conclusions: NeoCRT is an effective treatment for unresectable LAACC that results in significant tumor downstaging and enhanced R0 resection rate without an increase in surgical complications. The patients treated with radical surgical resection after neoCRT show a satisfactory short-term outcome. Further studies will be required to determine the clinical value of neoCRT in treating LAACC. (authors)