Risk factors affecting oncological outcomes of surgical resections for middle and lower rectal cancer.

Objectives: In our study, it was aimed to evaluate the factors affecting oncological outcomes in resections for rectal cancer.

Material and methods: Between January 2010 and December 2014, patients with rectal tumors were analyzed retrospectively. Demographic and pathological data and oncological outcomes were analyzed as disease-free survival, overall survival, and local recurrence.

Results: A total of 158 patients' data were obtained. Median age was 60 (22-83). Fifty-three patients were older than 65 years of age (138). Ninety-five (60%) patients were males, and 63 (40%) were females. Eighty patients (50.4%) had middle rectal, and 78 (49.6) patients had lower rectal cancer. There was no effect of tumor localization on oncological outcomes. Univariate analyses revealed the effects of age (p= 0.003), operation type (p <0.001), nodal status (p <0.001), malignant lymph node ratio (p <0.001), stage of the disease (p <0.001), distal resection margin (p= 0.047), perineural invasion (p <0.001), lymphatic invasion (p <0.001), venous-vascular invasion (p= 0.025), local recurrence (p <0.001) and distant metastasis (p <0.001) on overall survival rates. Univariate analyses revealed the effects of nodal status (p= 0.007), malignant lymph node ratio (p= 0.005), stage of the disease (p= 0.008), perineural invasion (p= 0.004) and venous-vascular invasion (p <0.001) on disease-free survival rates. Univariate analyses revealed the effects of anastomotic leak (p= 0.015) and venous-vascular invasion (p= 0.001) on local recurrence rates.

Conclusion: Older age, advanced nodal status, and distant metastasis were detected as independent risk factors for overall survival. Perineural and venous-vascular invasion were detected as independent risk factors for disease-free survival. Lastly, anastomotic leak and venous-vascular invasion were detected as independent risk factors for local recurrence.