Good Long-term Results with Intensity Radiation Therapy for Prostate Cancer
According to the results of a study published in The Journal of Urology, use of high-dose intensity modulated radiation therapy for localized prostate cancer results in good long-term cancer control.
Localized prostate cancer refers to cancer that is confined to the prostate. Although many men with localized prostate cancer are successfully treated with therapies such as surgery and/or radiation therapy, some men will eventually experience a cancer recurrence. There is interest, therefore, in identifying treatment approaches that minimize risk of recurrence and maximize survival.
Intensity modulated radiation therapy (IMRT) is a newer approach to radiation therapy that allows for the more precise delivery of radiation to cancer cells, while sparing healthy surrounding tissue. This allows for the use of higher doses of radiation therapy.
To describe long-term outcomes after use of high-dose IMRT for the treatment of localized prostate cancer, researchers at Memorial Sloan-Kettering Cancer Center in New York evaluated 561 men who had been treated with IMRT between 1996 and 2000. Study participants were classified into prognostic groups (favorable, intermediate, or unfavorable) on the basis of tumor size, Gleason score, and pretreatment level of prostate-specific antigen (PSA).
- Eight-year survival without a PSA increase was 85% for men with favorable prognostic factors, 76% for men with intermediate prognostic factors, and 72% for men with unfavorable prognostic factors.
- Death due to prostate cancer occurred in none of the men with favorable prognostic factors, 4% of men with intermediate prognostic factors, and 16% of men with unfavorable prognostic factors.
- The probability of grade 2 or grade 3 rectal bleeding during the eight-year period was 1.6%. Urethral strictures that required dilation developed in 3% of patients.
- Erectile dysfunction developed in roughly half the men who had initially been potent.
This study provides additional evidence that high-dose intensity modulated radiation therapy is a generally safe and effective treatment for men with localized prostate cancer.
Reference: Zelefsky MJ, Chan H, Hunt M, Yamada Y, Shippy AM, Amols H. Long-term Outcome of High Dose Intensity Modulated Radiation Therapy for Patients with Clinically Localized Prostate Cancer. The Journal of Urology. 2006;176:1415-1419.