Many prostate cancer patients only go through chemotherapy treatment once their disease has progressed. Men who are newly diagnosed with hormone-sensitive prostate cancer are typically given androgen deprivation therapy (ADT) as standard first treatment and only begin chemotherapy once their tumor is no longer dependent on hormones but a new National Cancer Institute- funded study suggests that when paired with hormone treatment, chemotherapy can actually benefit prostate cancer patients.
For the study presented at the annual meeting of the American Society of Clinical Oncology (ASCO) in Chicago on June 1, Christopher Sweeney, from the Dana-Farber Cancer Institute in Boston, and colleagues, divided 790 men who were newly diagnosed with advanced prostate men into two groups.
The patients in one group were given ADT alone. ADT reduces androgen hormones, which help stimulate the growth of prostate cancer cells. The patients in the other group, on the other hand, received ADT and the chemotherapy drug docetaxel, which was given once every three weeks, over an 18-week period. Docetaxel, which is sold by under the brand name Taxotere and is also available in generic form, was approved as treatment for metastatic prostate cancer in 2004.
Two and a half year later, there were 136 deaths in the group of patients who only had hormone treatment, 35 more than the 101 deaths in the group of patients who both had hormone and chemotherapy drugs. The researchers also found that the average survival rate of men in the hormone therapy group was only 44 months compared with 67.6 in men who had docetaxel and ADT.
The use of docetaxel also appeared to have delayed the progression of the disease as the average time to progression after treatment in patients who received docetaxel and ADT was 49.2 months compared with only 32.2 in patients who only had hormone therapy.
"This is the first study to identify a strategy that prolongs survival in newly diagnosed, metastatic prostate cancer," Sweeney said. "The benefit is substantial and warrants this being a new standard treatment for men who have high-extent disease and are fit for chemotherapy."
Sweeney's hypothesis was that chemotherapy during hormone treatment can damage the tumor cells ability to repair themselves and this delays the development of resistance. Chemotherapy, however, is not for everyone given its side effects which include fatigue, reduced white blood cell count and numbness in fingers and toes. One of the participants in the study who received docetaxel has in fact died because of the treatment's side effects.
