Prostate Cancer Bone Metastases

Prostate cancer is the leading cancer diagnosis in American men, with 1 in 8 being diagnosed in their lifetime. In 2022, it is estimated that there will be 268,490 new cases of prostate cancer and an estimated 34,500 people will die of this disease. Though many prostate cancers are clinically inconsequential due to their indolent nature, it remains the third leading cause of cancer-related death in the United States [1]. Bone is the most common site of distant involvement, which is present in up to 90% of men who die of this disease and has a profound impact on quality of life [2]. “Skeletal-related event” (SRE) is a defined term that has been adopted by the oncologic community and is useful in comparing the efficacy of therapies and impact on quality of life in research studies. The National Comprehensive Cancer Network (NCCN) task force defines SREs as “a constellation of skeletal complications, including fracture, need for surgery on bone, need for radiation to bone, spinal cord compression, and hypercalcemia of malignancy” [3]. Androgen-deprivation therapy (ADT) remains the cornerstone of systemic therapy by starving prostate cancer cells of testosterone, an essential growth factor. The castrate environment induced by ADT is defined as a serum testosterone concentration maintained below 50 ng/dL or 1.7 nmol/dL. Disease that responds to ADT is referred to as “castrate-sensitive,” while disease that has not responded to or progressed on ADT is referred to as “castrate-resistant.” Contemporary research has dramatically expanded the availability of therapies with activity in both castrate-sensitive and castrate-resistant prostate cancer, many of which prolong life and reduce the incidence of SREs. This chapter does not attempt to reiterate the general management of bone tumors explained elsewhere in the book. It focuses on the elements that are specific to prostate cancer, with an emphasis on adenocarcinoma, which accounts for over 95% of diagnoses.