ORLANDO, FL USA (UroToday.com) - The clinical significance of many low-risk prostate cancers has been questioned while awareness of significant prostate cancer (PC) over-diagnosis increases.
The major concern of over-diagnosis is the resultant over-treatment that often follows. In the United States, the majority of men with screen-detected tumors receive aggressive treatment (up to 91% in the PLCO trial), and such treatment is unlikely to yield a survival benefit in those with indolent disease or in men older than 65 years.
While current clinical practice guidelines do not support the use of combination therapy for low risk PC, upward of 45% of patients in some geographic regions will receive combination therapy. Given the regional increase in the utilization of combination therapy, Dr. Tomaszewski and colleagues sought to compare radiation-related toxicities among men over the age of 65, with low-risk prostate cancer, treated with single or multimodal radiation therapy. SEER-Medicare linked data was used to assess the relationship between treatment type and toxicity among men with low-risk PC treated with brachytherapy (BT), external beam radiation therapy (EBRT), or combined therapy, between 2004 and 2007. Inverse probability of treatment weighting was utilized to minimize selection bias and control for confounding. Multivariate logistic regression models were used to explore the relationship between treatment and outcomes.
Overall 43.9%, 43.4%, and 12.7% of patients were treated with EBRT, BT, and combined therapy, respectively. Patients treated with combined modality therapy experienced significantly higher rates of GU incontinence, GU obstruction, and erectile dysfunction compared to monotherapy. Following adjustment, EBRT was associated with a significant protective effect against GI bleeding, GU cystitis, GU incontinence, GU obstruction, and ED when compared to combination therapy.
Among SEER-Medicare patients, the use of combined modality radiation therapy to treat men with low-risk PC is discordant with clinical guidelines and associated with higher rates of payment claims for procedures, indicating a possible association with development of GI/GU toxicities and impairment of sexual function when compared to EBRT monotherapy. Prudent patient selection and judicious use of combined therapy among men with clinically localized low-risk PC represents a targetable area to reduce the burden of over-treatment.
Click HERE to view the poster from this session
Click HERE to listen to Jeffrey J. Tomaszewski, MD, one of the authors of this study
Presented by Jeffrey J. Tomaszewski, MD at the American Urological Association (AUA) Annual Meeting - May 16 - 21, 2014 - Orlando, Florida USA
Fox Chase Cancer Center, Philadelphia, PA USA
Written by Jeffrey J.Tomaszewski, MD, medical writer for UroToday.com