Diagnostic radiation procedures and risk of prostate cancer.

Exposure to ionising radiation is an established risk factor for many cancers. We conducted a case-control study to investigate whether exposure to low dose ionisation radiation from diagnostic x-ray procedures could be established as a risk factor for prostate cancer. In all 431 young-onset prostate cancer cases and 409 controls frequency matched by age were included. Exposures to barium meal, barium enema, hip x-rays, leg x-rays and intravenous pyelogram (IVP) were considered. Exposures to barium enema (adjusted odds ratio (OR) 2.06, 95% confidence interval (CI) 1.01-4.20) and hip x-rays (adjusted OR 2.23, 95% CI 1.42-3.49) at least 5 years before diagnosis were significantly associated with increased prostate cancer. For those with a family history of cancer, exposures to hip x-rays dating 10 or 20 years before diagnosis were associated with a significantly increased risk of prostate cancer: adjusted OR 5.01, 95% CI 1.64-15.31 and adjusted OR 14.23, 95% CI 1.83-110.74, respectively. Our findings show that exposure of the prostate gland to diagnostic radiological procedures may be associated with increased cancer risk. This effect seems to be modified by a positive family history of cancer suggesting that genetic factors may play a role in this risk association.

Is the conservative management of chronic retention in men ever justified?

OBJECTIVE: To assess the outcome of men presenting with lower urinary tract symptoms (LUTS) associated with large postvoid residual urine volumes (PVR). PATIENTS AND METHODS: The study included men presenting with LUTS and a PVR of > 250 mL who, because of significant comorbidity, a low symptom score or patient request, were managed conservatively and prospectively, and were followed with symptom assessment, serum creatinine levels, flow rates and renal ultrasonography. Patients were actively managed if there was a history of previous outflow tract surgery, prostate cancer, urethral strictures, neuropathy, elevated creatinine or hydronephrosis. In all, 93 men (mean age 70 years, range 40-84) with a median (range) PVR of 363 mL (250-700) were included in the study and followed for 5 (3-10) years. At presentation, the median maximum flow rate was 10.2 (3-30) mL/s and the voided volume 316 (89-714) mL. RESULTS: The measured PVR remained stable in 47 (51%), reduced in 27 (29%) and increased in 19 (20%) patients; 31 patients (33%) went on to transurethral resection of the prostate after a median of 30 (10-120) months, because of serum creatinine elevation (two), acute retention (seven), increasing PVR (eight) and worsening symptoms (14). Of 31 patients 25 were available for evaluation after surgery; their median PVR was 159 (0-1000) mL, flow rate 18.4 (4-37) mL/s and voided volume 321 (90-653) mL. Symptoms were improved in all but five men. There was no difference in initial flow rate, voided volume or PVR between those who developed complications or went on to surgery and those who did not. Urinary tract infections (UTIs) occurred in five patients and two developed bladder stones. CONCLUSIONS: Complications such as renal failure, acute retention and UTIs are uncommon in men with large, chronic PVRs. Conservative management for this group of patients is reasonable but outpatient review is prudent. There were no factors that could be used to predict those patients who eventually required surgery.