Treatment for Metastatic Prostate Cancer

Hormone Therapy: The First Line of Defense

Prostate cancer cells grow in response to male hormones, so hormone therapy (also known as androgen deprivation therapy) is crucial in systemic treatment. It works by counteracting the effect of male hormones on prostate cancer cells, helping control the disease.

Upon diagnosis of metastatic prostate cancer, traditional hormone therapy is typically effective for a significant period, known as the "hormone-sensitive" phase. Eventually, resistance develops, leading to the "hormone-refractory" phase. Until the early 2000s, there were limited treatment options for this stage, but significant advancements have been made in the last two decades.

What to Do When Hormone Therapy Fails?

Currently effective treatments include chemotherapy, new-generation hormone therapies, radium-223 therapy, targeted drugs, and lutetium-177 therapy.

Chemotherapy

Historically, the 2004 clinical studies showed that Docetaxel was the first chemotherapy drug to extend survival in hormone-refractory metastatic prostate cancer. Later, Cabazitaxel, a new-generation taxane, also proved beneficial for patients unresponsive to Docetaxel.

Docetaxel is administered via injection every three weeks, or weekly for older or frailer patients. Side effects may include mild gastrointestinal discomfort and fatigue, which typically improve over time. About one to two weeks post-injection, patients may experience decreased blood cell counts and weakened immunity, necessitating precautions such as avoiding public places, wearing masks, and maintaining high-protein diets. Abnormal fever or chills during treatment should prompt immediate medical attention. Standard treatment involves six cycles, with hair loss, neuropathy, or edema as potential side effects, which usually subside after completion.

New-Generation Hormone Therapy

Abiraterone (Zytiga) and Enzalutamide (Xtandi) are two oral medications effective in extending survival. Covered by insurance for one treatment option, continuous daily intake is required if effective. Treatment suitability should be discussed with a doctor.

Targeted Therapy

PARP inhibitors, such as Olaparib and Rucaparib, prevent DNA repair in cancer cells with HRR gene mutations, leading to cell death. Approved by the FDA for metastatic prostate cancer with BRCA mutations, these drugs can cause anemia, nausea, and fatigue.

Radium-223 Therapy

Radium-223, a radiopharmaceutical, targets bone metastases, reducing pain, delaying complications, and extending survival. It circulates through the bloodstream, localizing in bone metastases to release energy and kill cancer cells.

Lutetium-177 Therapy

Similar to Radium-223, Lutetium-177 targets cancer cells throughout the body by binding to PSMA molecules. Effective against metastases in any organ, it kills cancer cells upon binding.

Choosing the Right Treatment

These treatments are effective for metastatic prostate cancer, but there is no standard sequence. Doctors will tailor treatment plans based on individual patient conditions. Recent studies suggest combination therapies may outperform single treatments, but side effects and costs are considerations. Patients should discuss with their doctors to choose the most appropriate treatment.

Early Use of Treatments

Since 2015, combining treatments during the hormone-sensitive phase has been explored. For high-risk patients, combining traditional hormone therapy with Docetaxel or new-generation hormone drugs (Abiraterone, Enzalutamide, Apalutamide) can extend survival. Research shows that combining traditional hormone therapy with Docetaxel and a new-generation hormone drug can be effective but is not widely accepted due to side effects and costs. Detailed discussions with doctors are essential to understand the benefits, side effects, and costs of each treatment option.