Mid-term oncologic outcome of a novel approach for locally advanced colon cancer with neoadjuvant chemotherapy and surgery

Neoadjuvant chemotherapy is being actively tested as an emerging alternative for the treatment of locally advanced colon cancer (LACC) patients, resembling its use in other gastrointestinal tumors. This study assesses the mid-term oncologic outcome of LACC patients treated with oxaliplatin and fluoropyrimidines-based preoperative chemotherapy followed by surgery. Patients with radiologically resectable LACC treated with neoadjuvant therapy between 2009 and 2014 were retrospectively analyzed. Radiological, metabolic, and pathological tumor response was assessed. Both postoperative complications, relapse-free survival (RFS), and overall survival (OS) were studied. Sixty-five LACC patients who received treatment were included. Planned treatment was completed by 93.8 % of patients. All patients underwent surgery without delay. The median time between the start of chemotherapy and surgery was 71 days (65-82). No progressive disease was observed during preoperative treatment. A statistically significant tumor volume reduction of 62.5 % was achieved by CT scan (39.8-79.8) (p < 0.001). It was also observed a median reduction of 40.5 % (24.2-63.7 %) (p < 0.005) of SUVmax (Standard Uptake Value) by PET-CT scan. Complete pathologic response was achieved in 4.6 % of patients. Postoperative complications were observed in 15.4 % of patients, with no cases of mortality. After a median follow-up of 40.1 months, (p (25)-p (75): 27.3-57.8) 3-5 year actuarial RFS was 88.9-85.6 %, respectively. Five-year actuarial OS was 95.3 %. Preoperative chemotherapy in LACC patients is safe and able to induce major tumor regression. Survival times are encouraging, and further research seems warranted.