Neoadjuvant chemotherapy does not improve survival outcomes when compared to upfront surgery in patients with locally advanced colon cancer, according to research presented at the ASCO Annual Meeting 2023.
The phase 3 NeoCol trial showed similar disease-free survival (DFS) and overall survival (OS) outcomes between patients who received upfront surgery and patients who received neoadjuvant chemotherapy with oxaliplatin and capecitabine (CAPOX) or leucovorin calcium, fluorouracil, and oxaliplatin (FOLFOX).
The NeoCol trial (ClinicalTrials.gov Identifier: NCT01918527) included 248 patients with locally advanced T3 or T4 colon cancer. The patients were randomly assigned to standard upfront surgery (n=122) or surgery after neoadjuvant chemotherapy (n=126) with either 3 cycles of CAPOX or 4 cycles of FOLFOX.
Baseline characteristics were generally balanced between the arms. Patients in the neoadjuvant treatment arm received a mean 2.7 cycles of chemotherapy before surgery. For adjuvant chemotherapy, the mean number of cycles received was 5.9 in the upfront surgery arm and 4.1 in the neoadjuvant arm.
At surgery, 3% of patients in the neoadjuvant arm had a complete response, compared to none of the patients in the upfront surgery arm. There was no lymph node involvement in 59% of patients in the neoadjuvant arm and 48% of those in the upfront surgery arm. The rate of vascular invasion was 25% and 39%, respectively.
Postoperative complications that were more common in the upfront surgery arm than in the neoadjuvant treatment arm included ileus (8% vs 3%) and anastomotic leakage (8% vs 2%).
At 2 years, the DFS and OS were similar between the arms (P =.94 and .95, respectively). No additional DFS or OS data were reported.
There were no major differences in toxicity between the arms, said study presenter Lars Henrik Jensen, MD, PhD, of the University Hospital of Southern Denmark and Vejle Hospital.
During treatment, sensory neuropathy occurred in 11% of patients in the upfront surgery arm and in 7% of those in the neoadjuvant treatment arm. Motor neuropathy occurred in 2% of patients in each arm.
During follow-up, sensory neuropathy occurred in 5% of patients in the upfront surgery arm and in 2% of those in the neoadjuvant treatment arm. Motor neuropathy occurred in 3% and 1%, respectively.
“[T]he effect of neoadjuvant chemotherapy is not superior to upfront surgery in patients with locally advanced colon cancer, but … trends pointed toward neoadjuvant chemotherapy being more favorable; for example, in terms of the number of chemotherapy cycles, and hence, toxicity,” Dr Jensen said. “Furthermore, neoadjuvant chemotherapy induced downsizing of the tumor and downstaging.”
Disclosures: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures.
Jensen LH, Kjaer ML, Larsen FO, et al. Phase III randomized clinical trial comparing the efficacy of neoadjuvant chemotherapy and standard treatment in patients with locally advanced colon cancer: The NeoCol trial. ASCO 2023. June 2-6, 2023. Abstract LBA3503.