Clinical factors associated with urinary morbidity in men undergoing combination prostate radiation therapy.

Abstract

e17128 Background: The purpose of our investigation was to determine if pre-treatment factors could predict urinary morbidity after combination brachytherapy and external beam radiation treatment for localized prostate cancer. Methods: A retrospective study of a large single-institution historical database was performed. Medical records of 278 consecutive patients who were treated starting May 2012 with prostate I-125 seed implant followed by intensity-modulated radiation therapy (IMRT) were analyzed. We investigated whether the following pre-existing comorbidities or factors were predictive for urinary morbidity: hypertension (HTN), diabetes (DM), smoking status, patient age, severity of pre-existing urinary symptoms, presence of prostate nodule, pre-procedure hormonal ablative therapy, confidence in erectile function, race, pre-procedure PSA, Gleason Score, use of alpha-blocker medications, and Body Mass Index (BMI). Urinary morbidity was defined as at least a 25% increase from baseline in the International Prostate Symptom Score (IPSS) at the 6-month and 12-month follow-up visit. Results: A total of 243 patients had complete data for inclusion at the 6-month interval and 180 patients had both 6 and 12-month data. Gleason score was 7 or higher in 173 patients. Baseline IPSS was mild (0-7) in 148 patients, moderate (8-19) in 78 patients, and severe (20-35) in 16 patients. The results are summarized in the chart below. At 6-months, strong predictive factors were the presence of pre-existing urinary morbidity (based on IPSS) and the pre-treatment use of alpha-blocker medications. Logistic regression analysis demonstrated higher risk for younger age. At 12-months, only the IPSS was predictive. The following combinations of factors were also evaluated: 1. HTN and DM, 2. HTN, DM, and Age, and 3. HTN, DM, Age, and BMI. Logistic regression analysis did not demonstrate an increased risk. Conclusions: Pre-existing urinary symptoms were strongly predictive for urinary morbidity at 6-months and 12-months post-procedure while the other multitude of factors were not. Combining pre-procedure comorbidities did not increase risk. Summary results p-values. Variable Categories p-value Hypertension (Yes, No) 0.2293 Diabetes (Yes, No) 0.3584 Smoking (Yes, No) 0.6014 Age (Categorized Under 65/Over 65) (Under 65, 65+) 0.0871 Age (Continuous) Continuous 0.0347 Pre-Tx AUA Total (Mild 0-7, Moderate 8-19, Severe 20 - 35) <.001 Pre-Tx AUA Total Continuous <.0001 Pre-Treatment Nodule present (Yes, No) 0.5409 Hormone Treatment (Yes, No) 0.7808 SHIM Confidence (Low, Moderate, High) 0.1275 Race (Black, White) 0.81 PSA (Pre-Treatment) (Below 6, 6+) 0.6714 Gleason Score (Low 6, Moderate (3+4, 4+3), High 8+) 0.6065 Alpha Blocker Medication (Yes, No) 0.0157 BMI (Obese, Not Obese) 30+ 0.5165 BMI Continuous 0.3605