A prospective trial investigating the role of Serum 25-Hydroxyvitamin D in diagnosis and prognosis of bladder cancer

Purpose Higher levels of serum 25-hydroxyvitamin D 25(OHD) are associated with better prognosis in breast and colorectal cancer. However, the evidence is still inconclusive for bladder cancer (BC). Herein, we investigated the diagnosis and prognosis roles of serum levels of 25 (OHD) in suspected BC patients presented by hematuria. Methods This prospective cohort study involved suspected patients of BC presented with hematuria. Patients were evaluated by CT urogram, office cystoscopy and urine cytology with subsequent inpatient biopsy for positive findings. Baseline blood samples were collected for measurement of 25(OHD) by electrochemiluminescence binding assay at the time of diagnosis. Patients with non-muscle-invasive BC (NMIBC) underwent transurethral resection of bladder tumor (TURBT) and adjuvant intravesical chemotherapy or BCG instillation. Patients were followed up for their recurrence status during 10 to 24 months. Recurrence was defined as the first time of NMIBC pathological relapse during the follow up period. Results A total of 115 patients were included in the final analysis. Patients had proven pathological BC (64 with NMIBC, and 20 with muscle invasive) and 31 patients were considered as control group. Controls were those patients with BC-free workup (including cytology, cystoscopy, and upper tract imaging). BC group showed a lower level of 25(OHD) than control group 16.47 +/- 5.88 versus 28.99 +/- 3.19 ng/mL (p<0.001). In addition, muscle invasive group also showed a lower level than NMIBC group 13.17 +/- 4.5 versus 17.49 +/- 5.04 ng/mL (P = 0.003). During the follow-up period of, tumor recurrence occurred in 16 (25%) of NMIBC patients. The baseline 25(OHD) were decreased in patients who experienced early recurrence; without being statistically significant (15.99 +/- 5.17 vs. 18.38 +/- 5.14 ng/mL; p = 0.08). 25(OHD) deficiency/insufficiency occurred in 5 (16.1%) and 64 (76.2%) in control and BC patients, respectively, (odds-ratios (OR): 2.13; 95% confidence intervals (CI), 1.52-2.99; P < 0.0001). Conclusion Serum 25(OHD) is significantly decreased in BC patients especially those with tumor muscle invasive group. However, the baseline serum 25(OHD) does not predict the recurrence in the NMIBC patients.