Endocrine therapies such as gonadotropin releasing hormone agonists, surgical treatments (bilateral orchiectomy) and certain chemotherapy meds (anthracyclines, alkylating agents, and antimicrotubule agents) can lead to hypogonadism - one of the most common causes of secondary osteoporosis.
The American Society of Clinical Oncology (ASCO) recommends total daily intake of at least 600 IU vitamin D and </= 1200 mg calcium from dietary sources for men with prostate cancer.
However, change to 1000-1500 mg elemental calcium and 400-800 IU vitamin D daily for men with prostate cancer receiving hormone therapy.
Circulating estrogen levels in men are extremely low, but estrogen is produced by the aromatization of testosterone to estradiol. Surgical or chemical ADT used for treatment locally advanced or metastatic prostate cancer significantly reduces plasma androgen levels, leading to severe hypogonadism. Reduction in testosterone levels decreases the amount of circulating estrogen as well, thus contributing to the loss of bone mineral density and increased fracture risk.
Men undergoing ADT may lose bone mineral density at femoral neck and lumbar spine.
Higher calcium intake has been identified as a potential risk factor for prostate cancer. A significantly higher risk in advanced and fatal cancer with dietary calcium intake of >/= 2000 mg. Even modest intake of calcium may increase risk, particularly among smaller men (BMI < 23)
Supplemental calcium can increase serum ionized calcium levels which may increase risk through stimulation of the calcium sensing receptor and calcium dependent voltage gated channels expressed by prostate cancer cells. May promote growth of prostate cancer cells.
Goal: obtain sufficient calcium through dietary sources and limit supplements to those who just cannot meet needs through diet alone. Also promote other bone health activities such as resistance and weight bearing exercise. Test vitamin D and correct deficiencies as needed.
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