PSMA therapy may postpone hormone treatment in prostate cancer patients

Where previous research showed that PSMA therapy for prostate cancer can prolong the lives of patients who have exhausted all other treatment options, a new study now demonstrates that the therapy is also effective in an earlier stage of the disease. As a result, more burdensome hormone therapy can be postponed by twenty additional months, shows research led by Radboudumc.

Each year, approximately 15,000 men in the Netherlands are diagnosed with prostate cancer. Various treatments exist for this condition, including radiation, hormone therapy, and chemotherapy. A new treatment is irradiating the tumor from within using lightly radioactive PSMA. This therapy shows positive effects in about two out of three patients who have no remaining treatment options: longer survival and improved quality of life.

Researchers investigated in a recent study whether this PSMA therapy also works in an earlier stage of prostate cancer. They used the therapy in cases of limited metastatic prostate cancer, with a maximum of five metastases. The therapy was administered after targeted radiation or surgery, but before the more burdensome hormone therapy. The study was led by Radboudumc with participation from many other hospitals, including Amsterdam UMC and UMCG.

Delaying treatment

'More and more men want to avoid hormone therapy because of the unpleasant side effects that can occur', says Nuclear Medicine Physician and project leader James Nagarajah. These side effects resemble menopausal symptoms, such as hot flashes, loss of muscle strength, and fatigue. 'We therefore wanted to investigate whether PSMA therapy could delay hormone therapy, and whether it might become a suitable alternative in the future.'

A total of 58 men participated in the study. Half received PSMA therapy immediately. The other half, the control group, was treated only when the disease progressed. Normally, the next step would be hormone therapy, but in this study, these men also received PSMA therapy. The treatment consisted of four sessions. All participants were monitored for at least two years.

Radiation therapy again

Among the men who received PSMA therapy, 52% experienced disease progression after 27 months. In the control group, this was 97%. PSMA therapy delayed the need for follow‑up treatments, such as hormone therapy, by an average of twenty months. The therapy caused few side effects and preserved quality of life. These results are now published in Lancet Oncology.

According to the publication's first author, Bastiaan Privé, PSMA therapy may play a significant role in treating limited metastatic prostate cancer. 'We see that we can postpone more burdensome hormone therapy. In addition, PSMA therapy sometimes reduces the cancer enough for men to become once again eligible for targeted radiation. This may further contribute to delaying hormone treatment in the future.'

Source:

Radboud University Medical Center

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