Study design, materials and methods
The participants were 24,464 male patients who were newly diagnosed with prostate malignancy (ICD-9-CM 185) from the LHID of catastrophic illness patients in 2000–2008. Patients who received ADT within 30 days after the date of prostate malignancy diagnosis were excluded. Patients were grouped into two cohorts, namely, the ADT cohort and the non-ADT cohort, based on whether or not they received ADT. The index date in the ADT cohort was defined by the date of ADT treatment. ADT patients with other malignancy diagnoses (ICD-9-CM 140–184 and 186–208) before
the date of prostate malignancy diagnosis or with age < 20 years were excluded. We also excluded patients with acute urine retention (AUR, ICD-9-CM 788.2) development within1 year after the index date to avoid reverse causation. The
non-ADT cohort was randomly selected from prostate malignancy patients with frequency-matched criteria according to age strum (such as 20–24, 25–29, and 30–34), and the year of index date at a ratio 1:1 for the ADT cohort. Similar exclusion criteria were applied for non-ADT cohort.
Results
All 5,574 ADT patients and 5,574 matched comparisons were collected in this retrospective cohort study. In the ADT cohort, 71.3% of the patients were older than the 70 years, and the mean age was 73.8 years (SD = 8.20) (Table 1). Compared with the non-ADT cohort, the ADT cohort had less prevalence of CAD (37.1% vs. 43.5%), diabetes (25.1% vs. 27.1%), stroke (24.5% vs. 28.4%), and hypertension (65.3% vs.67.5%). Except for radiotherapy treatment, ADT patients received less treatments, including prostatectomy, alpha blockers, and 5ARIs than the comparisons. In the ADT cohort, the duration between the occurrence of prostate malignancy and receiving ADT treatment was 0.73 years (SD = 1.48).
During the study period, 286 and 307 patients had AUR, and the incidence rates of AUR were 12.49 and 9.86 per 1000 person-years in the ADT and non-ADT cohorts,respectively. Compared with the non-ADT cohort, the ADT cohort had a
1.35- and 1.21-fold AUR risk in crude and adjusted model (95% CI = 1.14–1.59 and 1.03–1.43, respectively) (Table 2). Based on the duration between the occurrence of prostate malignancy and receiving ADT treatment, over 75% of patients receiving early treatment within 6 months had high AUR incidence (13.19 per 1000 person-years), followed by late treatment (9.54 per 1000 person-years). Compared with the non-ADT cohort, ADT patients with early treatment had significantly high AUR risk (HR = 1.24, 95% CI =1.04–1.48) after adjusting for potential risk factors. In addition, approximately 67% of patients were receiving only LHRH treatment, 24% only orchiectomy, and 9% both treatments. Patients receiving only LHRH treatment had a 1.23-fold increase in AUR risk (95% CI = 1.03–1.49) compared with non-ADT patients.
Interpretation of results
Men with PC suffer from AUR due to the concurrent benign prostatic enlargement or following radiotherapy.However, the mechanisms and associations between ADT and AUR are still controversial. ADT may be related to metabolic syndrome, which aggravates male LUTS through inflammatory processes is linked to bladder outlet obstruction, and might also be associated with episodes of AUR.[1]
ADT-related cognitive dysfunction might be another possible issue associated with AUR.One recent study proposed the association between urinary dysfunction and cognitive impairment in patients with Parkinson’s disease. [2] In another study, patients with multiple sclerosis experienced incomplete bladder emptying due to cognitive dysfunction; this condition required catheterization to improve quality of life.[3]