Is There a Role for Neoadjuvant Systemic Therapy for cT4bM0 Colon Cancer? A Propensity-Score Matched Analysis of the National Cancer Database.
Academic Article
Overview
abstract
BACKGROUND: Non-metastatic T4b colon-cancer has been traditionally treated with upfront surgery, often requiring technically challenging multiorgan resection. Neoadjuvant chemotherapy can potentially downsize and improve resectability of those tumors. OBJECTIVE: To explore trends and outcomes of neoadjuvant chemotherapy use in non-metastatic T4b colon cancer patients, compared to upfront surgery. To determine factors associated with increased neoadjuvant chemotherapy use and with overall survival. DESIGN: Retrospective cohort-study. SETTINGS: Conducted using the National Cancer Database. PATIENTS: Non-metastatic T4b colon cancer patients who underwent colectomy (2006-2016). Patients receiving neoadjuvant chemotherapy were propensity-matched (1:2) to those who underwent upfront surgery, in either clinical node-negative or node-positive disease. MAIN OUTCOME MEASURES: Postoperative outcomes (length of stay, 30-day readmission, 30/90-day mortality), oncologic resection adequacy (R0-rate, number of resected/positive nodes), and overall-survival. RESULTS: Neoadjuvant chemotherapy was used in 7.7% of the patients. Neoadjuvant chemotherapy use increased over the study period from 4% to 16% in the entire cohort; from 3% to 21% in patients with clinical node-positive disease; and from 6% to 12% in patients with clinical node-negative disease. Factors associated with increased use of neoadjuvant chemotherapy included younger age (OR0.97,95%CI:0.96-0.98, p < 0.001), male gender (OR1.35,95%CI:1.11-1.64, p = 0.002), recent diagnosis year (OR1.16,95%CI:1.12-1.20, p < 0.001), academic centers (OR2.65,95%CI:2.19-3.22, p < 0.001), clinical node-positive (OR1.23,95%CI:1.01-1.49, p = 0.037), and tumor located in sigmoid colon (OR2.44,95%CI:1.97-3.02, p < 0.001). Patients who received neoadjuvant chemotherapy had significantly higher R0 resection compared with upfront surgery (87%vs.77%, p < 0.001). On multivariable analysis, neoadjuvant chemotherapy was associated with higher overall-survival (HR0.76,95%CI:0.64-0.91, p = 0.002). On propensity-matched analyses, neoadjuvant chemotherapy was associated with a higher 5-year overall-survival compared to upfront surgery in patients with clinical node-positive disease (57% vs.43%, p = 0.003) but not in clinical node-negative disease (61% vs.56%, p = 0.090). LIMITATIONS: Retrospective design. CONCLUSION: Neoadjuvant chemotherapy use for non-metastatic T4b has increased significantly on the national level, more so in patients with clinical node-positive disease. Patients with node-positive disease treated with neoadjuvant chemotherapy had higher overall-survival compared to upfront surgery.
