Prognosis and Risk Factors in Patients With Non-radical Circumferential Resection Margin After Rectal Cancer Surgery.

BACKGROUND/AIM: Circumferential resection margin (CRM) has been shown to be a strong predictor of risk of local recurrence (LR) and distant metastases (DM) in patients with rectal cancer treated with total mesorectal excision (TME). However, not all patients with a CRM of zero develop LR or DM. This study aimed to identify factors associated with disease-free survival (DFS) despite non-radical excision (CRM=0 mm).

PATIENTS AND

METHODS

Patients surgically treated for adenocarcinoma of the rectum between 2005 and 2013 were identified through the Swedish ColoRectal Cancer Registry.

RESULTS

Of 8,392 patients included in the study, 159 (1.8%) were found to have CRM 0 mm. The rates of LR (n=27; 17%) and DM (n=62; 39%) were high in the CRM 0 mm group; however, more than half of these patients developed neither (n=84; 52.8%). Stage II disease was associated with a higher DFS [odds ratio (OR)=2.15; 95% confidence interval (CI)=1.11-4.18] compared with stage III disease. Neoadjuvant chemotherapy was a negative prognostic factor of DFS (OR=0.47, 95% CI=0.23-0.97) independent of the stage of disease.

CONCLUSION

Over half of the patients with CRM 0 mm after rectal cancer surgery did not develop LR or DM. Lower stage of disease and no neoadjuvant chemotherapy were associated with a better DFS. These findings suggest that other biological or molecular factors may influence prognosis after non-radical excision, highlighting the need for further research to improve postoperative management and follow-up.