Hormone and targeted therapy in the treatment of bone tumors in metastatic prostate cancer

The authors analyzed the effect of using hormone therapy and targeted therapy, in combination, to treat bone tumors in prostate cancer patients.

Hormone therapy is a common treatment for prostate cancer. It reduces the level of male sex hormones (e.g. testosterone) in the body or prevent them from affecting prostate cancer cells. Abiraterone acetate (Zytiga) is a common hormone therapy, used often in combination with prednisone (Deltacortil, Deltastab, Dilacort), to treat prostate cancer. In some cases, patients can become resistant to hormone therapy. This means patients will no longer respond to hormone therapy and will require a different treatment approach.

Patients resistant to hormone therapy can develop metastatic cancer (cancer that spreads out from the primary site). Metastatic cancer can affect other organs as well as the bones. Patients with bone tumors require specific targeted treatment (attack the specific site of cancer). A better understanding is required to determine the best treatment option for bone tumors in prostate cancer patients. 

The authors aimed to determine the effect of hormone therapy and targeted therapy in treating bone tumors in prostate cancer patients who never had chemotherapy.

353 patients were included in this study. Patients were divided into two groups. Group 1 received abiraterone acetate and prednisone. Group 2 received prednisone and a placebo. 34% of group 1 patients and 31% of group 2 patients received targeted treatment for bone tumors.The most common bone-targeted therapy (BTT) was zoledronic acid (Zometa, Zomera, Aclasta, Reclast – used to lower high levels of calcium).

Patients who received BTT had 25% reduced risk of dying from the treatment compared to the patients who did not receive targeted therapy.  Patients who received BTT, maintained their general well-being and had longer times from the treatment until cancer-related pain was experienced. Overall, the risk of weakening the general well-being was reduced by 25% and the risk of taking cancer-related pain medication was reduced by 20% for patients who received BTT. Abiraterone acetate showed favorable treatment results, regardless of whether targeted treatment was used in combination. Side effects to treatments were similar in patients who received both hormone therapy and BTT, compared to the hormone therapy alone. Less than 3% of patients experienced breakdown of the jawbone. 

The authors concluded that abiraterone acetate and prednisone used in combination with BTT were safe and well tolerated in prostate cancer patients. They also concluded that BTT increased the treatment benefit of abiraterone acetate. 

This study was carried out after the clinical trial was completed, so results may be biased. 

This study was carried out after the clinical trial was completed, so the results might not include other contributing factors that could have affected the outcomes.