Health factors used to predict patient outcome following radiation therapy in prostate cancer

The authors aimed to determine if a new risk classification system could help determine treatment and outcome in individuals with intermediate-risk prostate cancer. 

External-beam radiation therapy (EBRT) is a form of treatment that involves the application of an external radiation source focused at the site of the tumor. It can be used as a form of treatment in patients with intermediate-risk prostate cancer. 

Intermediate-risk prostate cancer includes patients with a primary Gleason pattern (scoring system that compares the differences between cancerous and healthy cells) of 4 or more, more than 50% positive biopsies (tissue tested for the presence of cancer) and more than one intermediate risk factor (includes an increased prostate specific antigen level (PSA- protein found in the blood that indicates prostate cancer) or increased tumor size).

The aim of this study was to determine if a new risk classification system could be used to help determine outcome in intermediate-risk prostate cancer patients treated with radiation therapy.

1,024 patients were used in this study with a follow-up time of 71 months after patients received EBRT.

Patients with a Gleason pattern of 4 were over 3 times more at risk of experiencing cancer spread to other organs. Patients with more than 50% positive biopsies were nearly 3 times more at risk of experiencing cancer spread. Patients with more than one intermediate risk factor had double the risk of experiencing cancer spread compared to patients with low Gleason scores, biopsies and risk factors.

Patients with unfavorable intermediate-risk prostate cancer (patients with Gleason pattern 4, more than 50% positive biopsies and more than 1 risk factor) were twice as likely to experience shorter prostate cancer recurrence-free survival (time from treatment that patient does not experience cancer growth). These patients were also over 4 times more likely to experience cancer spread to other organs and were over 7 times more likely to die from prostate cancer compared to patients with favorable intermediate-risk prostate cancer (low Gleason patterns, fewer positive biopsies and 1 risk factor).

The authors concluded that Gleason pattern, number of positive biopsies and risk factors present can be used to predict patient outcomes after external-beam radiation therapy and may help to determine if further treatment is required. 

The follow-up time in this study was short and patient numbers were small so the results cannot be widely applied.

If you are considering external-beam radiation therapy please consult your doctor for potential health risks and benefits.