A Diagnosis-to-Surgery Interval Time of >30 Days Does Not Independently Predict Significantly Poorer Survival Outcomes in Thai Patients with Non-metastatic/stage I-III Colorectal Cancer

Objective: To identify the cutoff value for the optimal number of days to surgery, and to investigate the independent association between the diagnosis-to-surgery interval time (DIT) and survival outcome in Thai patients with non-metastatic/stage I-III colorectal cancer. Materials and Methods: A chart review of patients diagnosed with and operated upon for stage non-metastatic/stage I-III colorectal cancer at Siriraj Hospital (Bangkok, Thailand) during January 2010-December 2020 was conducted. The primary outcome was the survival rate compared between two different DITs. Multivariate regression was used to identify independent predictors of decreased survival. Results: A total of 979 patients (median age: 65 years) were included. Of those, 18.4% had stage I, 38.6% had stage II, and 43.0% had stage III disease. The calculated median DIT of 30 days (IQR: 19-47) was used as the cutoff value to categorize patients into the ≤30-days or >30-days group. The 5-year overall survival rate was 97.6% and 97.1% (p=0.536), and the median survival time was 59.4 and 58.9 months - both respectively. The 3-year disease-free survival (DFS) rate was 86.9% and 85.7%, respectively (p=0.523). The independent predictors of decreased 3-year DFS among all patients were lymph node metastasis (p=0.037), adjuvant chemotherapy (p=0.005), and lymphovascular invasion (p=0.051). Further multivariate analysis in the DIT >30-days group found low preoperative albumin level (p=0.035), perineural invasion (p=0.011), and adjuvant chemotherapy (p<0.001) to independently predict significantly poorer 3-year DFS. Conclusions: A DIT >30 days was not found to independently predict significantly poorer survival outcomes in Thai patients with non-metastatic/stage I-III colorectal cancer.