Andrew Siegel MD 11/16/19
Prostate cancer — in and of itself — as well as its treatment can affect bone health. Last week I reviewed bone health, which segues to today’s entry that addresses maintaining bone vitality and minimizing the risk of fracture and other skeletal related events in prostate cancer patients.
Author of image above: Виталий Смолыгин (publicdomainpictures.net)
Patients with prostate cancer are often older, a population at risk for less dense and more fragile bones. Additionally, prostate cancer patients are often treated with androgen deprivation therapy (ADT) that further accelerates bone demineralization. Furthermore, patients who have advanced prostate cancer often have bone metastases that interfere with bone integrity and can give rise to pain, pathological fractures and spinal cord compression. Aging, ADT and bony metastases create a perfect storm for poor bone health and bone-related skeletal events. Some men with advanced prostate cancer are on steroids in conjunction with chemotherapeutic agents (e.g., men on abiraterone and taxotere) that further increases their risk for bone demineralization.
Bone metastases from prostate cancer are a state of increased bone turnover that involves the action of osteoblasts that form bone and osteoclasts that erode bone. Metastases largely consist of woven bone, which is structurally frail and increases one’s risk of fracture. More than 80% of men with metastatic castrate resistant prostate cancer have bone metastases detectible on imaging tests. Metastases more typically involve the “axial “skeleton—vertebra, skull, ribs and pelvis—as opposed to the “appendicular” skeleton, which includes the long bones. Metastases to the vertebra can give rise to compression fracture and spinal cord compression as well as nerve root compression. Bone metastases can be evaluated with nuclear bone scans, although bone scans are non-specific and can “light up” for other reasons including old trauma, fractures, inflammation, infections and arthritis. The newer sodium fluoride (Na-F-18) PET/CT has been shown to be far more accurate than standard nuclear bone scanning.
Testing bone integrity
Bone mineral density can be measured and monitored using dual energy X-ray absorptiometry (DEXA) scanning, which uses a small dose of radiation to produce images of the lower spine and hips to quantitate bone loss. DEXA scanning is useful to diagnose osteoporosis and assess risk for fracture. Results are reported as T-score, the number of standard deviations from the mean that the measured bone loss differs from that of the mean of a young, normal population.
Bone-directed therapy
Men with bony metastatic castrate resistant prostate cancer are at increased risk for skeletal related events, including pathological fracture and spinal cord or nerve compression.
Prolia 60 mg every six months is used to help maintain bone integrity and limit loss of bone mass in men on ADT.
Xgeva 120 mg every four weeks is used for men with rising PSA despite ADT or in metastatic castrate resistant prostate cancer patients to prevent skeletal related events. It decreases the risk of fractures and bone pain and delays the time to bone metastases.
Prolia and Xgeva are the same drug, which works by inhibiting osteoclast activity. On rare occasions, it can cause osteonecrosis of the jaw, so a dental checkup is mandatory to ensure oral health before embarking on treatment with these medications.
Xofigo is a radiopharmaceutical drug used to treat minimally symptomatic or symptomatic metastatic castrate resistant prostate cancer requiring opioid or analgesic medication in men who have no significant lymph node enlargement and no spread to visceral organs. It mimics calcium and forms complexes at areas of increased bone turnover. It is given intravenously every 4 weeks, for a total of 6 doses. It contains the radioactive material radium 223, which works at the site of bone metastases, emitting radiation that has an anti-cancer effect and prolongs the time to the first skeletal related event. Xofigo can be absorbed by other organs, particularly those that are metabolically active, including bone marrow and the digestive system, which can result in anemia, low white blood cell count, low platelet count, bone pain, nausea, vomiting, diarrhea and swelling of the extremities.
Palliative radiotherapy can be used to relieve pain from metastases in metastatic spinal cord compression and in those with impending pathological fractures.
Surgical decompression occasionally needs to be used to manage metastatic spinal cord compression. Surgical stabilization occasionally needs to be used for patients with bone metastases who have a high risk of fracture.
Maintaining bone health in prostate cancer patients
Prostate cancer patients need safeguards to avoid the increased risk of bone fracture and other skeletal related events. Although genetics, aging and gender are factors beyond one’s control, intake of bone-building nutrients (calcium and vitamin D) and exercise are modifiable factors. All men on ADT should at minimum use a calcium and vitamin D supplement at the following recommended daily dose: 1200 mg calcium and 800-1000 Units vitamin D3. Urologists often recommend Prosteon for men on ADT, a non-prescription supplement consisting of vitamin D3, vitamin K1, calcium citrate, magnesium oxide, strontium citrate and sodium borate (available through Theralogix.com). Sunlight exposure in moderation and pursuing weight-bearing exercises and ball sports are helpful to maintain bone health and integrity in all people, including men with prostate cancer.
Wishing you the best of health,
A new blog is posted weekly. To receive a free subscription with delivery to your email inbox visit the following link and click on “email subscription”: www.HealthDoc13.WordPress.com
Dr. Andrew Siegel is a physician and urological surgeon who is board-certified in urology as well as in female pelvic medicine and reconstructive surgery. He is an Assistant Clinical Professor of Surgery at the Rutgers-New Jersey Medical School and is a Castle Connolly Top Doctor New York Metro Area, Inside Jersey Top Doctor and Inside Jersey Top Doctor for Women’s Health. His mission is to “bridge the gap” between the public and the medical community. He is a urologist at New Jersey Urology, the largest urology practice in the United States.
The content of this entry is excerpted from his new book, PROSTATE CANCER 20/20: A Practical Guide to Understanding Management Options for Patients and Their Families
Video trailer for Prostate Cancer 20/20
Preview of Prostate Cancer 20/20
Andrew Siegel MD Amazon author page
Prostate Cancer 20/20 on Apple iBooks
PROSTATE CANCER 20/20: A Practical Guide to Understanding Management Options for Patients and Their Families is now on sale at Audible, iTunes and Amazon as an audiobook read by the author (just over 6 hours).
Dr. Siegel’s other books:
PROMISCUOUS EATING— Understanding and Ending Our Self-Destructive Relationship with Food
MALE PELVIC FITNESS: Optimizing Sexual and Urinary Health
THE KEGEL FIX: Recharging Female Pelvic, Sexual, and Urinary Health
Tags: Andrew Siegel MD, androgen deprivation therapy, bone health, bone metastases, bone mineral density, Prolia, prostate cancer, Prosteon, Xgeva, Xofigo
Our Greatest Wealth Is Health 
Leave a Reply