Key Clinical Summary: Navigating Treatment Decisions in Metastatic Prostate Cancer

This is a micro-learning module summary of the Prostate Cancer Education session which you can find here.

Before participating please read our CME and disclosure information which can be found here. This program was supported by an independent medical education grant from Merck. This content is intended for US Healthcare Professionals only.

Introduction:

This educational summary provides an overview of the contemporary management of metastatic prostate cancer, emphasizing a patient-centered approach. Through two distinct clinical cases—one with oligometastatic disease and another with a high metastatic burden—it highlights the importance of articulating complex clinical data to facilitate shared decision-making. The management of advanced prostate cancer has evolved significantly, incorporating multi-specialty collaboration and a combination of treatment modalities. A holistic approach, which considers the patient's overall health, lifestyle, and care goals, is crucial for tailoring therapy.

Case 1: Early (Oligometastatic) Prostate Cancer

This section focuses on a patient who is in good overall health and has a limited number of metastases. The treatment strategy for this patient population has been shaped by several key clinical trials.

• Multimodality Treatment is Key: For patients with oligometastatic disease, the best outcomes are often achieved with a combination of therapies.
• ADT as a Foundation: Lifelong Androgen Deprivation Therapy (ADT) is a foundational treatment for these patients.
• The Role of Prostate Radiation: The STAMPEDE trial (Arm H) demonstrated that adding radiation therapy to the prostate for patients with a low metastatic burden improved overall survival and other cancer-related outcomes. This benefit was not observed in patients with a high metastatic burden.
• Intensifying Systemic Therapy: The LATITUDE trial showed that adding abiraterone and prednisone to ADT increased overall survival and reduced the risk of disease progression in men with newly diagnosed metastatic prostate cancer.
• Targeting Metastases: The ORIOLE trial revealed that treating metastatic sites directly with Stereotactic Ablative Body Radiotherapy (SABR) improved cancer outcomes, even without concurrent ADT. Some men remained progression-free for up to two years with this approach.
• Integrated Treatment Recommendation: Based on these trials, a comprehensive treatment plan for a patient like Mr. Smith would involve ADT, abiraterone, and radiation to the prostate, pelvic lymph nodes, and metastatic sites.

Case 2: Widespread (High-Burden) Metastatic Prostate Cancer

This section addresses a patient with multiple chronic health conditions and widespread bony metastases.

• Chemotherapy's Role: For patients with a high metastatic burden, the STAMPEDE trial showed that adding docetaxel chemotherapy to ADT improves overall survival compared to ADT alone.
• Palliative Radiation: In this context, external radiation is typically reserved for palliating painful bone metastases. Research indicates that about 75% of patients experience at least partial pain relief, and about a third achieve a complete pain response.
• Managing Treatment Resistance: When the cancer becomes castrate-resistant (no longer responds to ADT), further options are considered.
• Targeted Radionuclide Therapy: The VISION trial showed that for men with metastatic castration-resistant prostate cancer, adding Lutetium-177 vipivotide tetraxetan (a targeted radiopharmaceutical) to standard care prolonged both progression-free and overall survival.

Shared Decision-Making and Managing Side Effects

A crucial part of patient-centered care is a thorough discussion of potential treatment side effects to align therapy with the patient's goals and quality of life.

• Androgen Deprivation Therapy (ADT): While foundational, ADT can lead to sexual side effects like loss of libido and erectile dysfunction, as well as physiological changes such as weight gain and loss of bone density. Importantly, it carries an increased risk of cardiovascular disease and diabetes, often requiring a cardiac evaluation before initiation.
• Radiation Therapy: As a local treatment, its side effects are specific to the treated area.
• Prostate/Pelvis: Acute effects can include urinary frequency, urgency, and bowel changes. Late effects, though rare, can include chronic urinary or bowel issues.
• Bone: Can cause a temporary increase in pain and carries a long-term increased risk of fracture in the treated bone.

Conclusion:

The management of metastatic prostate cancer is increasingly personalized, driven by the extent of the disease and the patient's individual health status and preferences. For oligometastatic disease, an aggressive, multimodal approach combining systemic therapies and targeted radiation offers the best chance for long-term control. In high-burden disease, the focus shifts to extending survival with therapies like chemotherapy and managing symptoms with palliative radiation. Effective, patient-centered communication is paramount to navigate these complex treatment options, manage side effects, and ensure that the chosen therapeutic path aligns with the patient's life goals.