Cautious Optimism for Extreme Dose Escalation in Prostate Cancer

Abstract

Once again, investigators from the Memorial SloanKettering Cancer Center, under the leadership of Dr. Zelefsky, have not only have pushed the envelope (dose escalation to 86 Gy) but also report their outcomes of longterm genitourinary (GU) toxicity [1]. Long-term quality of life (QoL) and International Prostate Symptom Score (IPSS) in patients receiving radiation therapy for localized prostate cancer were rigorously collected. Changes in QoL and IPSS over a 5-yr timeline were reported, with a minimum of 3-yr follow-up. GU toxicity was scored using the Common Terminology Criteria for Adverse Events v.4.0, with events defined as an increase over baseline. IPSS sum increased by 3 over 5 yr in the entire cohort of patients, with only minimal worsening noted in the patients with mild baseline symptoms [1]. Patients with severe baseline GU function demonstrated an improvement in symptoms. The QoL index was unchanged overall but appeared to improve in patients with dissatisfied baseline QoL compared with satisfied baseline QoL. Approximately 20% and 1% of patients developed grade 2 and grade 3 late GU toxicities, respectively, with approximately half of the events resolving on further follow-up. This study should set, if not a standard, at least an example for the reporting of GU toxicity or other QoL outcomes after treatment (ie, radiation, radical prostatectomy, and/or hormone therapy) [1]. The investigators account for baseline function and follow the change in GU toxicity chronologically over a 5-yr period rather than simply reporting an overall score at a defined point in time. This is an accurate method for reporting the impact on QoL measures.