Comparing surgery and radiation therapies for high-risk prostate cancer

This study compared prostate surgery and radiation therapy in treating high-risk prostate cancer. Authors reported similar survival benefits with both treatments. However, high doses of total radiation combined with hormone therapy was associated with the lowest risk of disease progression.

Prostate surgery and radiation therapy are both common treatment options for localized prostate cancer. Brachytherapy is a form of radiation therapy used where a radiation source is placed directly inside the prostate. External beam radiation therapy (EBRT) involves directing high-energy rays from outside the body at the tumor site to kill cancer cells.

A number of studies have reported good treatment outcomes following both surgery and radiation among men at increased risk of disease recurrence. Both can be added to hormone therapy for a more intensive intervention. Men with high Gleason scores (tissue samples indicating aggressive cancer cells) are at particularly high risk of recurrence. More studies are needed comparing surgery and radiation in this high-risk group.

This study analyzed the records of 487 men undergoing treatment for high-risk prostate cancer. All men had Gleason scores of 9 to 10. 170 men underwent prostate surgery. 230 men received EBRT with hormone therapy (EBRT group). 87 men received EBRT with brachytherapy and hormone therapy (EBRT plus brachytherapy group). Of these, 85 received high-dose brachytherapy and 3 received low-dose brachytherapy. Treatment outcomes were followed for an average of 4.6 years.

Men undergoing surgery were significantly more likely to require additional (salvage) therapy after treatment. 49% of men undergoing surgery required additional radiation therapy, and 30.1% required salvage hormone therapy. In contrast, additional hormone therapy was administered in 19.7% of men in the EBRT group and in 16.1% of men in the EBRT plus brachytherapy group. Additional radiation therapy was less common in the two EBRT groups (administered in 0.9% to 1.2% of men).

94.6% of men in the EBRT plus brachytherapy group showed no signs of distant cancer spread (metastasis) at 5 years. This was significantly lower for men in the EBRT group (78.7%) and men that underwent surgery (79.1%). 10-year metastasis free survival rates were 89.8% for the EBRT plus brachytherapy group, 66.7% for the EBRT group, and 61.5% for the surgery group.

Higher doses of total radiation were associated with improved disease recurrence and progression rates. The duration of hormone therapy administered with radiation therapy had no effect on treatment outcomes.

No significant differences in overall survival rates or cancer specific survival rates at 5 or 10 years were observed between treatment groups. 10-year overall survival (proportion who have not died from any cause since treatment) was 59.2% for EBRT plus brachytherapy, 65.3% for EBRT, and 72.1% for prostate surgery.

The study concluded that surgery and radiation-based therapy offer a similar survival benefit for high-risk prostate cancer. The risk of disease recurrence and cancer spread was lowest when high doses of total radiation were combined with hormone therapy.

More studies that randomly assign patients to treatment groups are needed to confirm these findings. Many of the treatment protocols used were not standardized.