A new prostate cancer medication is found to be effective at increasing length and quality of life
In a study involving 1088 men, all of whom had prostate cancer that had spread and was resistant to initial hormone therapy, researchers gave one group the new drug, called Zytiga, and a low dose of the steroid prednisone; the other group had a placebo. Halfway through the trial, however, the improvements were so significant in the Zytiga group that the placebo group were offered the medication too. The medication delayed the need for chemotherapy, improved survival rates and also quality of life. When compared to the placebo group, Zytiga slowed the spread of cancer from an average of eight months to about 16 months. These benefits led to the independent monitoring committee’s decision to recommend that all patients be offered the active drug. “The treatment of advanced prostate cancer is undergoing a rapid transformation,” said study author Dr Charles Ryan, of University of California San Francisco, “and this drug is a key component of that transformation.” Another form of treatment for prostate cancer – hormone therapy – has been found not to be effective if it is used only intermittently. Research funded by the National Cancer Institute has found that while hormone therapy can prevent further progression of the disease in men with newly diagnosed prostate cancer that has spread, those who do not take it continuously do not see the same benefits. The study was the largest to date looking specifically at hormone treatment – which deprives the body of male sex hormones – and metastatic hormone-sensitive prostate cancer.
The results showed that for some individuals intermittent therapy was not as effective as doing the treatment continuously. Patients may choose to take a break from the hormone therapy if they see positive results – where PSA (prostate-specific antigen) drops to low levels, for example – because their quality of life in terms of sexual function, physical function and energy levels can be adversely affected by hormone treatment.
Men on continuous therapy had an overall survival time of 5.8 years, with 29% surviving at least 10 years; men on intermittent therapy had an overall survival time of 5.1 years, with 23% surviving at least 10 years. However, the results were different when the type of prostate cancer was taken into account. Men with disease that had not spread beyond the lymph nodes or bones of the spine and pelvis (‘minimal disease’) did far better on continuous therapy compared to those on intermittent, but patients who had extensive disease, where the cancer had spread further, did as well on either type of treatment. This indicates that the decision whether or not to take a break from hormone treatment depends on how far the cancer has spread. For those with more extensive cancer, a break in treatment – and the better quality of life experienced in that time – may well be worth it.