ADT plus radiotherapy superior to radiotherapy alone in localized prostate cancer

Radiotherapy combined with androgen deprivation therapy appears to yield better outcomes than radiotherapy alone among men with small, localized prostate cancer at risk for progression or recurrence.

“Although we need longer follow-up to assess the impact on these men's overall survival, these findings need to be taken into account in daily clinical practice,” Michel Bolla, MD, professor of radiation oncology at Grenoble University Hospital in France, said in a press release. “They show that three-dimensional conformal radiotherapy, whether intensity modulated or not, and regardless of the dose level, has to be combined with short-term androgen deprivation therapy in order to obtain a significant decrease in the risk of relapse.”

In a randomized, multicenter clinical trial, Bolla and colleagues evaluated 819 men with early stage prostate tumors who were at moderate-to-high risk for metastasis as determined by biopsy and levels of PSA. Patients were randomly assigned to undergo treatment regimens with radiotherapy alone (n= 407) or radiotherapy and two injections of luteinizing hormone-releasing hormone analogues (n=403).

The injections, each of which lasted 3 months, were administered on the first day of irradiation and 3 months after irradiation. Patients underwent radiotherapy at either 70 Gy, 74 Gy or 78 Gy. The patients were followed for an average of 7.2 years.

According to study results, the men who had been treated with radiotherapy combined with hormone analogues had approximately half the risk (47%) of cancer recurrence or progression than those treated with radiotherapy alone.

In the combined group, 118 men had a biochemical disease progression vs. 201 in the radiotherapy only group. At 5 years after treatment, 17.5% of the men in the combined treatment group had experienced disease progression vs. 30.7% receiving radiotherapy alone.

“During multidisciplinary team meetings to discuss a patient’s treatment, this combined treatment approach should be one of the options proposed for men with localized prostate cancer that has an intermediate or high risk of growing and spreading,” Bolla said.

Adverse effects pertained primarily to problems with urination and were seen in 5.9% of patients on the combined regimen vs. 3.6% of patients on radiotherapy alone. Problems with sexual function also were more prevalent in the combined group (27%) than in the radiotherapy-only group (19.4%).

“These results show that, in men with localized prostate cancer that is at risk of recurring and spreading, the addition of 6 months of hormonal treatment to radiotherapy improves the time these men survive without their disease progressing,” Bolla said. “It is important to ensure that the radiation treatment is of the best quality; further clinical research is required to optimize radiation techniques and to find new hormonal treatments.”

For more information:

Bolla M. Presented at: European Society for Radiotherapy and Oncology (ESTRO) 33 Congress; April 4-8, 2014; Vienna.

Disclosure: The researchers report no relevant financial disclosures.