Adjuvant chemotherapy improves disease-free and overall survival in T1 node-positive colorectal cancer
Emelie Nilsson, Johan Mustaniemi, Carl-Fredrik Rönnow, Henrik ThorlaciusAbstract
Introduction
Adjuvant chemotherapy (AC) is considered standard treatment for lymph node-positive colorectal cancer (CRC). However, T1 patients are absent or underrepresented in landmark trials, and previous studies have suggested that this patient group may be undertreated. This study aimed to compare recurrence and survival in T1 node-positive CRC patients receiving AC with patients receiving no additional chemotherapy (NAD), and to identify factors associated with NAD.
Methods
Surgically treated T1 node-positive CRC patients were identified in the Swedish Colorectal Cancer Registry (2009–2022). Patients with distant metastases at preoperative evaluation, local resection, colectomy, death within 30 days, neoadjuvant treatment, or incomplete follow-up were excluded. Outcomes, including 5-year disease-free survival (DFS), overall survival (OS) and disease-free interval (DFI), were analysed using Kaplan-Meier analyses, log-rank tests, and adjusted Cox regressions. Logistic regression was used to identify factors associated with NAD.
Results
Of 222 eligible patients, 146 received AC and 76 NAD. Recurrence rates were 5% in the AC and 15% in the NAD treatment group (P = 0.009). Five-year DFS was 91 versus 63% (Hazard Ratio (HR) 0.41, 95% c.i. 0.18–0.94, P = 0.043); OS was 92 versus 64% (HR 0.38, 95% c.i. 0.15–0.93, P = 0.042); and DFI was 96 versus 85% (HR 0.42, 95% c.i. 0.14–1.28, P = 0.151) in the AC and NAD groups, respectively. Age at diagnosis, year of surgery, reoperation, and length of hospital stay were independently associated with NAD.
Discussion
AC improves DFS and OS in patients with T1 node-positive CRC. Higher age at diagnosis, reoperation and longer hospital stay are important factors associated with NAD.