A study published in the Journal of Clinical Oncology did not find a significant difference in overall survival between prostate cancer patients who received continuous versus intermittent androgen deprivation therapy (ADT). The study compiled data from nine clinical trials including more than 5,500 patients. Intermittent ADT was associated with fewer side effects, particularly for sexual function, and greater overall well-being. The authors hope this study will help support intermittent ADT for select prostate cancer patients.
Continuous androgen deprivation therapy (ADT) is the standard treatment for metastatic, hormone-sensitive prostate cancer. It can often be associated with side effects like erectile dysfunction, mental health disorders, and impaired physical functioning; most patients eventually develop resistance to the treatment, leading to castration-resistant prostate cancer (CRPC). A new study published in the New England Journal of Medicine compares intermittently dosed ADT to continuously dosed ADT. The findings suggest intermittent ADT decreases side effects up to 3 months of treatment and almost triples the time to developing CRPC; however, it decreases average survival by 0.7 years and may increase the risk of death by 20%.
Hussain M, Tangen CM, Berry DL, Higano CS, et al. The New England Journal of Medicine. Apr 4, 2013.
“Castration resistance occurs in most patients with metastatic hormone-sensitive prostate cancer who are receiving androgen-deprivation therapy. Replacing androgens before progression of the disease is hypothesized to prolong androgen dependence…”
A natural, nontoxic product called genistein-combined polysaccharide which is commercially available in health stores, could help lengthen the life expectancy of certain prostate cancer patients, UC Davis researchers have found. The findings hold promise for the product as a way to extend life expectancy of patients with low response to androgen-deprivation therapy. TThe product is a proprietary extract cultured from soybeans and shiitake mushrooms that was found to help block a key mechanism used by prostate cancer cells to survive in the face of testosterone deprivation.
A study based in Quebec, Canada, evaluated 630 patients undergoing hormone therapy for localized, high-risk prostate cancer. The study compared 18 months of hormone therapy to the standard treatment length of 36 months and found no significant difference in survival between the two treatment groups. Some researchers feel more data is necessary to draw a final conclusion.
In a phase I clinical trial, a new drug called ODM-201 was found to be effective and well tolerated by men with prostate cancer. Preclinical studies indicate that the androgen receptor-blocking drug may be more potent than the recently approved drug enzalutamide. The phase I clinical trial has been expanded and a phase II clinical trial is ongoing.
Results of a clinical trial that evaluated the prostate cancer vaccine Provenge have come under scrutiny. Questions arise regarding the reported 4-month survival benefit that ultimately led to FDA approval. Disputers suggest that a flaw in methods led to the survival benefit, but that the vaccine may actually cause harm.
A recent study evaluated the usefulness of surgery versus observation to treat localized prostate cancer. In the study, 731 men were followed for 10 years. Those treated with surgery did not have a significant decreased risk of death compared to those who were observed for advancing cancer.
A recent study weighed the benefits of yearly prostate cancer screening, finding that the potential disadvantages decrease the potential advantages by 23%. Harmful results of yearly prostate screening include negative prostate biopsies, radical prostatectomy, and radiation therapy.