Metastatic prostate cancer patients who receive standard hormone treatment along with docetaxel chemotherapy may live up to two years longer, according to clinical trial results from an ongoing study.

Cardiff and Warwick University researchers used 2,692 participants in the study. The men in the study received four different types of treatment: Standard of Care (SOC), consisting of three years of androgen deprivation therapy with local radiation, SOC along with six doses of docetaxel, SOC with zoledronic acid for two years, and SOC with zoledronic acid and docetaxel. Sixty percent of patients in the study were metastatic, meaning that the cancer had spread from one organ to another.

When researchers conducted a median follow-up with patients after 42 months, they found 948 men had died. But in the overall study, the men who were given docetaxel along with SOC on average lived 10 months longer, whereas patients whose cancer had spread lived an average of 22 months longer. The zoledronic acid did not affect survival, which prompted researchers to conclude that it should no longer be given for future treatment. Researchers will present the findings at the annual meeting of the American Society of Clinical Oncology in Chicago on May 31.

"To see a 22-month survival advantage off six lots of treatment given several years earlier is a very big benefit. We are very pleased by it," said Professor Nicholas James, study researcher from Warwick University, the BBC reported.

The form of chemotherapy administered, docetaxel, is generally a drug given to patients after the normal hormone treatment has failed. Doxetaxel is relatively cheap because the drug is out of patent, which would bode well for patients who need it to prolong their lives. Researchers plan to monitor patients for any future side effects, which they said should be "manageable." While research is ongoing, they highlighted the need for the UK's National Health Service to take action.

"In prostate cancer it has been used at a much more advanced stage of the illness, for some years — now we know that this chemotherapy should be added earlier, in fact as soon as hormone therapy starts," said study researcher Professor Malcolm Mason, from Cardiff University.

The American Cancer Society estimates that in 2015, 220,800 new cases of prostate cancer will emerge. It's the second leading cause of cancer death in American men, following lung cancer. One in seven American men will get prostate cancer in their lifetime. However, it's a disease that doesn’t always claim its victims. In fact, more than 2.9 million prostate cancer survivors are still alive.