Men with locally advanced prostate cancer who are treated with just 6 months of hormone therapy combined with radiotherapy halve their chances of dying from the disease compared with patients who receive radiation alone, according to the long-term (10 year) results of the Trans-Tasman Radiation Oncology Group (TROG) 96.01 trial published in The Lancet Oncology. Importantly, these findings also show that 6 months of hormone therapy has few of the adverse side-effects associated with prolonged hormone treatment.

Androgen deprivation therapy (ADT), also known as hormone therapy, is used to treat prostate cancer by lowering the levels of male hormones that can promote the growth of prostate cancer. Supplementary (adjuvant) ADT has been shown to prolong survival in men with locally advanced disease. However, prolonged use of ADT might be associated with significant side-effects which include erectile dysfunction, hot flashes, fatigue, osteoporosis, high cholesterol, anaemia, and cardiac death.

In 2005, initial (5 year) results from the TROG 96.01 trial suggested that short-term neoadjuvant (given before and during radiotherapy) ADT (NADT) significantly improved on the outcome achieved by radiotherapy alone. The trial included 802 men with locally advanced disease who were randomly assigned to prostate external beam radiation alone or with 3 or 6 months of NADT plus radiotherapy.

5 years later, there is still no agreement on the optimum duration of treatment with NADT and clinical practice varies widely.

In this new study, a team from New Zealand and Australia led by Jim Denham from the University of Newcastle, New South Wales, Australia present the long-term outcomes (median follow-up 10.6 years) of the TROG 96.01 trial to establish the size of the benefits from 3 months and 6 months of NADT.

6 months of NADT combined radiotherapy was associated with a significantly lower 10-year prostate-cancer death rate compared with radiation treatment alone (11% vs 22%), and the chances of death due to any cause were reduced by a third (29% vs 43%).

However, 3 months of NADT had no effect on the 10-year rates of distant cancerous spread, prostate-cancer death, or death due to any cause compared with radiation alone.

The authors conclude: "The TROG 96.1 trial...shows that a large proportion of men with locally advanced prostate cancer can be treated successfully, with few late side-effects, with as little as 6 months of NADT (and a relatively low dose of radiation). We believe that 6 months of NADT in combination with contemporary radiation techniques and doses will remain an effective treatment option in the next decade, particularly in men without nodal metastases or pre-existing metabolic comorbidities that could be exacerbated by prolonged androgen deprivation."

Commenting on the article Chris Parker from The Royal Marsden Hospital, UK says: "TROG 96.01 is an important trial, and has two clear messages for current clinical practice. First, it confirms that NADT significantly reduces mortality after radiotherapy for high-risk prostate cancer, and is a standard of care. Second, it helps to resolve the uncertainty regarding NADT duration, and strongly suggests that men receiving NADT should have at least 6 months treatment."

Source: Lancet Oncology

Article: http://www.thelancet.com/journals/lanonc/article/PIIS1470-2045(11)70063-8/abstract