Which characteristics are associated with changes in medication status for lower urinary tract symptoms among patients with prostate cancer receiving external beam radiotherapy?

Abstract. Background. We clarified the predictive factors for changes in the status of medications for lower urinary tract symptoms (LUTS) 2 years after local radiotherapy for nonmetastatic prostate cancer. Materials and methods. We retrospectively included patients who underwent local external radiotherapy for nonmetastatic prostate cancer in 8 institutions between April 2001 and March 2016. Patients were divided into the medication and no-medication group based on the use of drugs for LUTS before radiotherapy. We defined improvement of LUTS as when the patient did not require medication for LUTS at 24 months after radiotherapy in the medication group and as deterioration when medication was required in the no-medication group. Logistic regression analysis was used to evaluate predictive factors for changes in medication status. Results. Altogether, 505 patients were divided into a no-medication group (n = 352) and a medication group (n = 153). The number of patients with deterioration and improvement in LUTS was 49 (14%) and 36 (23%), respectively. In the multivariate analysis, the predictive variables for deterioration were the International Prostate Symptom Score (≥8; odds ratio [OR], 2.21; p = 0.014) and the biopsy Gleason score (≤3 + 4 = 7; OR, 2.430; p = 0.008) in the no-medication group, whereas those for improvement were age (