Abstract

Purpose: The 5 alpha reductase inhibitor (5ARI) reduces the size of the prostate and alleviates lower urinary tract symptoms. After stopping 5ARI, the prostate quickly recovers to its pre-medication size. The purpose of this study was to investigate the factors affecting the restoration of prostate size after 5ARI discontinuation.
Materials and Methods: Between March 2009 and May 2017, patients who visited an outpatient clinic and were diagnosed with benign prostatic hyperplasia were selected and start 5ARI medication. After 6 months of medication, the patients stopped medication for 1 year. Meanwhile, we measured the prostate volumes of patients 3 times (before and after medication, after discontinuation) and divide the patients into 3 groups (maintained, intermediate, and restored) with recovered prostate volume ratio. After classification, we investigated the relationship between the variable factors (age, serum prostate-specific antigen, initial volume, reduced volume after medication) between groups.
Results: Among the 147 selected patients, the mean age and plasma PSA level were 61.6±7.9 and 0.8±0.6, respectively. The mean initial prostate volume was 32.3±4.2 ml, which reduced to 23.2±3.2 ml after medication. After one year of discontinuation, the mean volume was 31.4±6.4 ml, with restoration to 101.5% of the reduced size. We noticed a tendency that patients with faster prostate volume recovery were generally older than those with slower recovery; however, this was not statistically significant. Other factors showed no relationship with prostate recovery.
Conclusions: When using 5ARI in elderly patients, continuous treatment seems better than intermittent treatment. If discontinuation is needed, short term follow-up is recommended.

• Keywords: Benign prostate hyperplasia; 5 alpha reductase inhibitor