What implications do the tolerability profiles of antiandrogens and other commonly used prostate cancer treatments have on patient care?

A novel selective androgen receptor modulator (SARM) MK-4541 exerts anti-androgenic activity in the prostate cancer xenograft R-3327G and anabolic activity on skeletal muscle mass & function in castrated mice

The androgen receptor (AR) is a member of the nuclear hormone receptor super family of transcription factors. Androgens play an essential role in the development, growth, and maintenance of male sex organs, as well as the musculoskeletal and central nervous systems. Yet with advancing age, androgens can drive the onset of prostate cancer, the second leading cause of cancer death in males within the United States. Androgen deprivation therapy (ADT) by pharmacologic and/or surgical castration induces apoptosis of prostate cells and subsequent shrinkage of the prostate and prostate tumors. However, ADT is associated with significant musculoskeletal and behavioral adverse effects. The unique pharmacological activity of selective androgen receptor modulator (SARM) MK-4541 recently has been reported as an AR antagonist with 5α-reductase inhibitor function. The molecule inhibits proliferation and induces apoptosis in AR positive, androgen dependent prostate cancer cells. Importantly, MK-4541 inhibited androgen-dependent prostate growth in male rats yet maintained lean body mass and bone formation following ovariectomy in female rats. In the present study, we evaluated the effects of SARM MK-4541 in the androgen-dependent Dunning R3327-G prostate carcinoma xenograft mouse model as well as on skeletal muscle mass and function, and AR-regulated behavior in mice. MK-4541 significantly inhibited the growth of R3327-G prostate tumors, exhibited anti-androgen effects on the seminal vesicles, reduced plasma testosterone concentrations in intact males, and inhibited Ki67 expression. MK-4541 treated xenografts appeared similar to xenografts in castrated mice. Importantly, we demonstrate that MK-4541 exhibited anabolic activity in androgen deficient conditions, increasing lean body mass and muscle function in adult castrated mice. Moreover, MK-4541 treatment restored general activity levels in castrated mice. Thus, MK-4541 exhibits an optimum profile as an adjuvant therapy to ADT which may provide potent anti-androgenic activity at the prostate yet protective activity on skeletal muscle and behavior in patients.

[Cardiovascular risks of androgen deprivation therapy for prostate cancer]

Androgen deprivation therapy (ADT) is the standard treatment for metastatic prostate cancer. It has increasingly been used in other stages of the disease as well. Besides well-known side effects caused by the lack of testosterone (impotency, osteoporosis, fatigue, loss of muscle mass), an increase of cardiovascular (CV) morbidity and mortality has recently been discussed in association with ADT. Cardiovascular side effects cannot be sufficiently explained by low testosterone levels. This review gives an overview of the recent literature, interprets the results, and offers clinical consequences.

Cancer treatment-related bone disease

Bone health may be impaired in many patients being treated for cancer. Primary tumors that reside in or form metastases to bone can result in compromised skeletal integrity. It has also been increasingly recognized that patients undergoing therapies for treatment of cancer are at higher risk of bone loss. These include androgen-deprivation therapy for prostate cancer and aromatase inhibitor therapy for breast cancer, among others. Hypogonadism induced by many of these cancer treatments results in bone loss and increases the risk of osteoporosis and fractures. Progress has been made in identifying the role of oral and intravenous bisphosphonates to prevent bone loss in these patients. This review discusses bone loss associated with cancer treatments, with a focus on breast cancer, prostate cancer, and survivors of childhood malignancies.

Attitudes of prostate cancer patients towards the diagnosis and treatment of their disease: findings from a multinational survey

OBJECTIVE

To explore the attitudes of patients with locally advanced or metastatic prostate cancer towards the diagnosis and treatment of their disease.

RESEARCH DESIGN AND METHODS

Patients who had been receiving hormonal therapy for > or = 1 year were recruited from France, Germany, Italy, Spain, the UK and the USA. All patients were required to complete a 10- to 15-minute fully structured questionnaire (either online or on paper) during September 2006.

RESULTS

A total of 382 patients completed the questionnaire. Patients were currently receiving luteinising hormone-releasing hormone agonist monotherapy (73%), antiandrogen monotherapy (10%), or combined androgen blockade (17%). Since diagnosis, while being treated with hormonal therapy, many patients felt that they had a more reasonable quality of life (36%) and were more able to lead an active life (36%). Although patients generally wanted to be involved in treatment decisions, many felt they had missed out on hormonal treatment options (26%) and/or were unaware of all the treatment options available (29%). Patients felt that information on hormonal treatments from their specialist physician could be trusted more than that from other sources. The most important factors for patients in terms of their treatment were disease control (39%) and outliving their disease (31%).

CONCLUSIONS

Patients can miss information regarding their disease and the hormonal treatments available. As patients place the most emphasis on disease control and outliving their disease, and may experience improved quality of life while on hormonal therapy, physicians should not exclude treatment options on the basis of potential side effects alone.