Is there a benefit of radiation to lymph node metastases during hormone therapy?

This study examined the benefit of radiation to limited sites of cancer spread (metastases) in men no longer responding to hormone therapy. Researchers reported effective local cancer control after radiation of lymph node metastases in patients no longer responding to hormone therapy. 

Hormone therapy is the first-line treatment for advanced prostate cancer and cancer that has spread to distant organs (metastatic disease). This therapy blocks the male hormones (such as testosterone) needed for cancer growth. Over time, however, many cancers progress despite standard hormone therapy. This is known as castration-resistant prostate cancer.

Increasing evidence is suggesting that men with a limited number of metastases have a better prognosis compared to men with extensive cancer spread. In such cases, localized radiation therapy to the sites of metastases may delay further cancer spread and improve survival. More studies are needed to examine a possible benefit.

The aim of this study was to examine the effects of radiation therapy to limited metastases sites in men with castration-resistant prostate cancer.

The records of 18 men with castration-resistant prostate cancer were analyzed. 17 of these men had high-risk prostate cancer. Men underwent hormone therapy after primary treatment with surgery, radiation, or both. All men progressed after an average of 3.8 months of hormone therapy (based on blood tests). All men showed cancer spread to lymph nodes and were treated with radiation therapy to the sites of metastases while continuing hormone therapy. Patients were followed for an average of 15.6 months.

16 men (88.2%) showed no signs of disease recurrence at the sites of metastases after treatment with localized radiation therapy. 2 men (12.8%) showed local lymph node recurrence at follow-up. 8 men (44.4%) developed new lymph node metastases and/or bone metastases.

The average time until disease progression (based on blood tests) was 5.9 months. The average time until clinical progression of the disease was 9.6 months. 11 men (58.8%) were classified as responders to localized radiation therapy (based on blood tests).

No serious side effects were observed with localized radiation therapy. Side effects were skin-related or affected the digestive system or the genital and urinary organs. However, most were mild and short-lasting. No patients reported impaired urinary or fecal continence.

Researchers concluded that radiation of lymph node metastases in patients no longer responding to hormone therapy can provide effective local cancer control.

Larger studies that randomly assign patients to treatment groups are needed to confirm these results.