Men with locally advanced prostate cancer who undergo radiation plus long-term hormone treatment had their risk of dying cut in half, according to a new study by Swedish researchers. The study was published in the Dec. 16 online edition of The Lancet.

The new treatment is seen as a breakthrough in treating prostate cancer and could now become standard for men with locally advanced disease who are too ill to be cured.

Prostate cancer is diagnosed in approximately 220,000 US men annually and about 28,000 die of it, which makes it the most common cancer and second-leading cancer killer among men. Worldwide, 221,000 die every year while 679,000 new cases are diagnosed.

The study involved nearly 900 men (recruited from 47 centers in Norway, Sweden and Denmark) with “locally advanced” prostate tumors, which have emerged beyond the edge of the prostate gland, but haven’t yet invaded the lymph nodes or other organs.

Such tumors are hard to completely remove with surgery. That’s why doctors usually treat them with other therapies, Howard Sandler, a doctor and spokesman for the American Society of Clinical Oncology, who wasn’t involved in the study, said.

Hormone therapy is an option for people having this kind of tumors, although it has as most obvious side effect sexual dysfunction. Also, the therapy has been recently linked to greater risks such as diabetes, bone fractures, heart disease, reduced muscle mass, weight gain, hot flashes and decrease in mental acuity.

Half of the men involved in the study were given only hormone therapy, which cuts off the testosterone that fuels prostate tumors. The other half got hormones plus radiation treatments.

The study found that after 10 years, 12 percent of men given the combination therapy died of prostate cancer, compared to 24 percent of men who got hormones alone. Also, 30 percent of men given combination therapy died if any cause, compared to 39 percent of men who got hormones alone. Last but not least, after 10 years, prostate cancer recurred in 26 percent of men given combination therapy, compared to 75 percent of men given only hormones. But adding radiation to patients’ treatment did come at a cost. More exactly, after five years, men receiving hormones and radiation reported higher rates of side effects including fatigue, insomnia, and sexual problems.

However, lead author of the study Professor Anders Widmark, from Umea University in Sweden says the “significant superiority” of the combined treatment and its similar side effects suggest it “should be the new standard of care for these patients.”

Dr. Chris Parker and Dr. Alex Tan of Britain's Institute of Cancer Research in Sutton, Surrey, backed the same idea in a commentary accompanying the study in the journal The Lancet.