Accuray Incorporated announced positive data for CyberKnife stereotactic body radiation therapy (SBRT) for the treatment of cancer confined to the prostate. Several studies indicate that SBRT is as effective and possibly less toxic than traditional radiotherapy. Treatment with SBRT was effective with far fewer treatment sessions than are often required with traditional radiotherapy.
The FDA has approved a new chemical, choline C 11, to be used at the Mayo Clinic to help detect recurrent prostate cancer. The chemical will be used with PET imaging and may help detect recurrent prostate cancer much earlier than current methods. The chemical is not known to cause any significant side effects.
A recent study evaluated the use of sildenafil (Viagra) for preventing sexual side effects when taken after radiation therapy for prostate cancer. Participants were treated with sildenafil for 6 months and evaluated for 2 years. Erectile function questionnaire scores were significantly higher in the group who received sildenafil, suggesting an overall improvement in sexual satisfaction in these individuals.
In a phase III clinical trial, a new drug called enzalutamide (Xtandi) increased survival from 13.6 to 18.4 months in patients with castration-resistant prostate cancer (CRPC). Early-stage prostate cancer is often treated with medications known as androgen receptor blockers, but patients may eventually stop responding to these drugs and progress to an advanced stage known as CRPC. Enzalutamide is a more potent androgen receptor blocker and may offer an additional treatment option for patients with CRPC.
Primary source: http://www.nejm.org/doi/full/10.1056/NEJMoa1207506
Anti-androgen drugs block the effects of male hormones on the prostate gland and slow cancer growth. However, in a small number of individuals, these medications lead to an advanced stage known as castration-resistant prostate cancer (CRPC). Researchers at the Dana-Farber Cancer Institute and Harvard Medical School recently conducted a mouse study that suggests that genetic mutations, perhaps in the PTEN gene, may be responsible for worsening prostate cancer in individuals with CRPC and that they may benefit from gene targeted therapy.
Primary source: http://cancerdiscovery.aacrjournals.org/content/3/1/44.full
Two studies evaluated the potential side effects of proton therapy for prostate cancer using quality-of-life scores. Urinary and bowel scores were similar to those of healthy men and satisfaction rates were high. Sexual function was affected, but results may be related to other factors.
A recent study evaluated the molecular urine test PROGENSA PCA3 as a prostate cancer screening tool. The test is currently approved in conjunction with PSA testing to determine the need for repeat biopsies in individuals with a prior negative biopsy. The study found that when PROGENSA PCA 3 was used with prostate-specific antigen (PSA) testing in individuals without a prior biopsy, unnecessary biopsies were avoided for 20% of the patients.
A recent clinical study compared therapy with 50 mg of docetaxel administered every 2 weeks versus standard therapy of 75 mg every 3 weeks for the treatment of castration-resistant prostate cancer (CRPC). Treatment failure occurred later and was associated with less frequent side effects in study participants receiving the drug every 2 weeks.
A recent study found a genetic change, or ‘signature,’ in cancer cells from 13 patients with metastatic prostate cancer. The signature, which is not a DNA sequence mutation, but still alters the function of a gene, was found consistently throughout an individual’s metastatic tumors and was unique to each individual. The researchers hope to use epigenetic ‘marks’ as biomarkers to identify cancer.