Diabetes Mellitus as a Prognostic Factor for Locally Advanced Rectal Cancer

Background/Aim: Currently, the impact of diabetes mellitus (DM) on rectal cancer patients is complex and just partly elucidated. The purpose of this study was to investigate the impact of diabetes mellitus on rectal cancer patients focusing on tumor differentiation grade, neoadjuvant chemoradiotherapy (NACRT) response, disease-free (DFS) and overall (OS) survival. Patients and Methods: Our study's population consisted of a group of 53 patients diagnosed with locally advanced rectal cancer, who underwent NACRT, followed by radical oncological surgery. This patient population was further divided into two groups according to diabetes presence. Results: Downstaging rates, local control, DFS, and OS were lower in the DM subgroup compared to the non-DM locally advanced rectal cancer patients. Conclusion: The presence of DM at the time of diagnosis of locally advanced rectal cancer patients may be a negative predictive factor for response to neoadjuvant therapy, distant metastases, and local recurrences rates.