Metastasis-directed therapy may prolong progression-free survival

Image credit National Cancer Institute

CANCER DIGEST – Nov. 12, 2022 – For patients with prostate cancer that has spread to a single site outside the prostate, a therapy approach called metastasis-directed therapy (MDT) might extend the progression-free period following initial treatment, a small study shows in the Dec. 1, 2022 issue of The Journal of Urology.

Normally after surgery or radiation therapy to eradicate prostate cancer, men whose tumors had spread to a single nearby lymph nodes or bone, called "oligorecurrent cancer" are given androgen deprivation therapy (ADT) in an effort to keep the cancer from continuing to grow. 

The therapy blocks testosterone and other male hormones that are used by cancer tumors to speed growth. ADT, however, has a number of adverse effects including sexual dysfunction, bone thinning, muscle loss and other effects.

In a small clinical trial of 124 patients led by Jack Andrews, MD, of the Mayo Clinic in Phoenix, AZ, 67 patients whose prostate cancer had spread to lymph nodes or other tissues were treated with surgery to remove the metastasized tumor, and 57 were treated with radiation therapy directed at the cancer that had spread to bone.

The patients were then followed for a median of four and half years. Of those treated with surgery, 80.5 percent achieved a 50 percent reduction in their prostate specific antigen (PSA) levels, and 40.3 percent of those treated with radiation achieved a 50 percent reduction in PSA.

The median time to cancer progression was three years for 29 percent of the surgery group and 17 percent of the radiation therapy. The median time to progression was 18.5 months for the surgery group and 17.8 months for the radiation month.

"These results suggest that MDT without ADT can delay initiation of systemic therapy" in men with oligorecurrent prostate cancer," Dr. Andrews and colleagues concluded.

The limitations of the study make the results insufficient to change current guidelines for the treatment of prostate cancer. The researchers call for further studies to determine which patients with solitary metastases can benefit the most from MDT.

Sources: Press release from Wolter Kluwer Health and The Journal of Urology