Background: Metastatic colorectal cancer (mCRC) constitutes one of the fatal worldwide neoplasms. Despite different modalities utilized in treatment, some patients progressed, raising the search for new predictive and prognostic markers. Vitamin D receptor (VDR) has different expression degrees in many cancers including those of colorectum and has a crucial role in the pathogenesis of intestinal neoplasm through different signaling pathways.
Objectives: The study aims to analyze the relation between VDR expression in mCRC patients receiving irinotecan-based systemic therapy, clinicopathological features, therapy response, and patient survival.
Patients and Methods: This study included 53 mCRC patients, their demographic data, clinicopathological features of their tumors, therapy response, and survival outcome with different IHC VDR expressions were analyzed.
Results: We noticed that the patients' mean age is 42(±14.6) years with 28/53 patients (52.8%) younger than 45 years. Of the studied patients 32/53 (60.4%) were diagnosed with stage IV and the other 21/53 patients with stage II and III before developing secondary metastases. Wild KRAS was more common in our patients 37/53 (69.8%).VDR expression was positive in 34/53 (64.2%) and negative in 19/53 (35.8%). Patients with positive VDR expression are associated with a significant reduction in duration of response by 8 months and progression-free survival by 5 months than those with negative expression, but no correlation with overall survival.
Conclusion: Positive VDR expression could be a poor predictive factor in mCRC patients treated with irinotecan-based therapy and may be incorporated into the predictive and prognostic mCRC panel. This mandate further studies with large sample size.