Identification of risk factors associated with stage III disease in non-metastatic colon cancer: Results from a prospective national cohort study

Purpose: The study aimed to, identify possible patient and tumor-related factors associated whit the risk of stage III disease in non-metastatic colon cancer. Method: The association between stage III disease and age, sex, lymph node yield, pathologic T (pT) stage, tumor subsite, type of surgery and priority of surgery was assessed in a nationwide cohort of 13,766 patients treated by curative resection of colon cancer. Each level of age, lymph node yield and pT stage was compared to the preceding level. Results: Age, lymph node yield, pT stage, tumor sub site and priority of surgery were associated with stage III disease. Odds ratios (OR) were as follow: Age: 75 years: 1.22 (95% CI: 1.13-1.32), lymph node yield 0-5/ 6-11: 0.60 (95% CI: 0.50-0.72), lymph node yield 6-11/ 12-17: 0.84 (95% CI: 0.76-0.93), lymph node yield 12-17/ >=18: 0.97 (95% CI: 0.89-1.05). pT1/ pT2: 0.74 (95% CI: 0.57-0.95), pT2/ pT3: 0.35 (95% CI: 0.30-0.40), pT3/ pT4: 0.49 (95% CI: 0.47-0.54). Only tumors of the transverse colon were independently associated with a lower risk of stage III disease than tumors in the sigmoid colon: Sigmoid colon: 1, transverse colon: 0.84 (95% CI: 0.73-0.96). Elective surgery: 1, Acute surgery: 1.43 (95% CI: 1.29-1.60). Conclusion: In this study, stage III disease in colon cancer was significantly associated with age, lymph node yield, pT-stage, tumor subsite and priority of surgery, but not right sided location, compared with stage I and II cancers.