Neoadjuvant chemotherapy for locally advanced colon cancer patients: Long-term results from a single institutional experience.

Abstract

e15598 Background: Neoadjuvant chemotherapy (NAC) is an emerging alternative in the management of patients with locally advanced colorectal cancer (LACRC), with promising results in terms of R0 resection rates, compliance, postoperative morbidity and a trend towards reduced risk of relapse. However, more mature data are required. We evaluated the long-term outcome of this strategy in our institution. Methods: We retrospectively analysed LACRC patients treated preoperatively with either biweekly FOLFOX or XELOX at standard doses as a follow-up of our previous experience with this neoadjuvant approach. Patients were identified from a prospectively collected tumor registry database from our institution. Clinical staging was based on colonoscopy and CT-scan. Only patients with radiological signs of lymph node involvement and/or extramural invasion > 5 mm were included. The uracil/dihidrouracil ratio was calculated at baseline as a surrogate marker of DPD deficiency. Pathological tumor regression was graded according to the MSKCC and toxicity with the NCI-CTCAE 4.0. Results: From February 2006 to November 2019 91 pts with MSS LACRC (M/F: 62/29; median age 66. Clinical stage; T3: 60.4%, T4: 37.4%, N+: 75.8%; Sideness: 82.4% left located were analysed. Preoperative chemo was FOLFOX in 46 pts and CAPOX in 45 pts. Median number of preoperative cycles was 4 (range 1-10). Side effects profile included G3-4 diarrhea (3.3%), G2 sensitive neuropathy (12.1%) and G2 neutropenia (4.4%). 9 pts had a treatment delay due to haematological toxicity. No progressive disease was noted during neoadjuvant chemotherapy. All patients underwent surgery, most of them (63.7%) by a laparoscopic approach. pCR was found in 11 pts (12.1%). Grade 3, 3+ and 4 tumor regression according to MSKCC score was reached in 50.5% of the patients (Median number of harvested nodes was 17 (range 7-51), with 75.8% being ypN0. Lymphovascular and perineural invasion were found in 7.7% and 6.6% of the patients, respectively. The median hospital stay was 7 days (3-36) and 13 pts develop any surgical complication. 37.4% received adjuvant treatment. After a median follow-up of 63 months, median progression-free (PFS) and overall survival (OS) have not been reached. 5-year actuarial PFS for right and left LACRC was 77 and 87%, respectively. Conclusions: Our data add to the growing evidence suggesting that NAC may play a meaningful role in LACRC patients