On the basis of the patient's physical examination, laboratory findings, and radiographic findings, a diagnosis of de novo metastatic prostate cancer is suspected and later confirmed by transrectal ultrasonography–guided needle biopsy of the prostate.
Prostate cancer is the most common cancer and the second most common cause of cancer-associated death in men in the United States. Among men diagnosed with prostate cancer in the United States, approximately three quarters have localized-stage disease at diagnosis; however, recent data show that an increasing number and percentage of men are being diagnosed with distant-stage prostate cancer. Despite advancements in treatment, less than one third of men survive 5 years after the diagnosis of distant-stage prostate cancer.
Prostate cancer frequently metastasizes to the bone. In fact, as many as 90% of patients with advanced prostate cancer have bone involvement. The morbidity from bone metastases is considerable and includes bone pain, immobility, pathologic fractures, hypercalcemia, hematologic disorders, and spinal cord compression. Bone metastases also have a considerable impact on mortality.
In patients with metastatic prostate cancer, determining the presence and extent of metastatic disease is essential for appropriate treatment to be selected. Studies have shown that the extent of metastatic disease affects treatment response. In a recent exploratory analysis of the STAMPEDE trial, survival benefit associated with prostate radiation therapy decreased continuously as the number of bone metastases rose, with the most benefit being seen in patients with up to three bone metastases.
Guidelines recommend that imaging studies be conducted in all patients with advanced prostate cancer. This may include conventional imaging (ie, CT, bone scan, and/or prostate MRI) and/or next-generation imaging (ie, PET, PET/CT, PET/MRI, whole-body MRI). In cases involving hormone-sensitive disease with obvious metastatic disease on conventional imaging at presentation, next-generation imaging may be useful for illuminating the disease burden and possibly shifting the treatment intent from multimodality management of oligometastatic disease to systemic anticancer therapy, either alone or in combination with targeted therapy for palliative purposes. However, prospective data on this are lacking.
Clinicians should also assess symptoms in patients with metastatic hormone-sensitive prostate cancer at presentation, because symptoms have been shown to have prognostic value. In addition, understanding symptoms related to cancer is essential for optimizing pain and other symptom management in addition to anticancer therapy.
Metastatic prostate cancer remains incurable. Immediate systemic treatment with androgen deprivation therapy (ADT) combined with abiraterone acetate plus prednisone or apalutamide or enzalutamide should be offered to symptomatic patients who have distant metastases on diagnosis, both to alleviate symptoms and to lessen the risk for potential serious complications, such as spinal cord compression. ADT combined with docetaxel can also be offered to patients who are able to tolerate docetaxel.
ADT combined with prostate radiation therapy may be offered to patients with distant metastases and low-volume disease. However, when patients present with high-volume disease, referral to a clinical trial is recommended.
Surgery and/or local radiation therapy can be considered for patients with distant metastases and evidence of impending complications (eg, spinal cord compression or pathologic fracture).