A federally funded phase III study found that adding docetaxel chemotherapy to standard hormone and radiation therapy reduces the risk of death for men with high-risk, localised prostate cancer.

At an average follow-up of 5.5 years, four-year overall survival rates were 89% in the standard therapy group vs. 93% in the docetaxel group.

According to the authors, as many as 33,000 men are diagnosed with high-risk, localised prostate cancer in the United States every year.

“This study is the first indication that chemotherapy has a role in the adjuvant treatment of localised prostate cancer, and we also expect to see an even bigger survival advantage over time,” said lead study author Howard Sandler, MD, a professor of radiation oncology at the Cedars Sinai Medical Center in Los Angeles, USA.

“This finding could improve outcomes for thousands of men. At the same time, chemotherapy carries a modest increase in side effects, so it is
important that physicians discuss the balance of benefits and risks with their patients.”

Adjuvant therapy is additional treatment that is given after patients complete the primary treatment for their tumour, such as surgery or radiation.

The goal of adjuvant therapy is to lower the risk of recurrence and improve overall survival.

Among the most common cancers – lung, breast, colorectal, and prostate – prostate cancer is the only disease without an established adjuvant chemotherapy regimen.

In the study, 562 men with high-risk, locally advanced prostate cancer were randomly assigned to treatment with standard therapy (radiation therapy plus two years of hormone therapy) or standard therapy followed with docetaxel chemotherapy.

Docetaxel was given for 18 weeks, starting a month after radiation therapy.

After an average follow-up period of 5.5 years, 52 deaths occurred in the standard therapy group compared to only 36 deaths in the docetaxel group.

The four-year overall survival rates were 89% in the standard therapy group compared to 93% in the docetaxel group.

Docetaxel also reduced the risk of relapse ─ the five-year disease-free survival rates were 66% in the standard therapy group vs. 73% in the docetaxel group. 

Patient follow-up will continue to determine the long-term benefit of adjuvant chemotherapy in this setting, and an analysis of quality of life data will be performed at a later time.

Dr Sandler noted that future studies will explore the impact of adjuvant therapies among men with high-risk, localised prostate cancer.

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Source: ASCO