LOS ANGELES — Contrary to conventional wisdom among many urologists, brachytherapy is a good option for younger prostate cancer patients, according to investigators who reviewed outcomes for 1,763 men treated with radiation seed implants.
Five years after treatment, men 60 years of age and younger had “excellent” biochemical control rates that were comparable with those of older men, Dr. Alice Ho reported at the annual meeting of the American Society for Therapeutic Radiation and Oncology.
At a median follow-up of 59 months, 96% of younger men maintained biochemical freedom from failure (BFFF), she said. In comparison, men aged 61–75 had a control rate of 92% at 62 months of follow-up. For those 76 years of age and older, the rate was 88% at 54 months.
These differences were statistically significant on univariate analysis, but the outcomes became comparable when the investigators adjusted for such factors as risk, Gleason score, pretreatment prostate-specific antigen levels, additional radiation, stage, treatment era, use of hormonal therapy, and radiation dose.
“Age should not be a deterrent when considering radiation seed implantation for prostate cancer,” said Dr. Ho, a radiation oncologist at Memorial Sloan-Kettering Cancer Center in New York.
Dr. Ho did the research while a resident at Mount Sinai Medical Center, also in New York. She and her coauthors identified 2,850 patients who had been treated with radiation seed implantation from 1990 to 2005 at Mount Sinai Hospital. They included in the study only those who had clinically localized prostate cancer, had received low-dose brachytherapy with or without external beam radiation or hormone therapy, and had been followed for at least 2 years.
Nearly two-thirds of the patients studied, 1,142 men, were between the ages of 61 and 75 years. Another 400 men aged 60 and younger accounted for 23% of the sample. The remaining 221 men, 12%, were 76 years of age or older. Overall, the population had been followed for a median of 5 years.
The younger men were more likely to have low-risk disease (57% vs. 40% of the older groups) and to be treated after 1997 (72% vs. 60%)–two observations that were probably related, according to Dr. Ho. In addition, the younger men were more likely to receive a full biologically effective dose of radiation: 92% vs. 88% of the older groups.
“In earlier years, we were not even seeing younger men in our clinic,” she said at a press briefing. Later on, with improved [prostate-specific antigen] screening, urologists began diagnosing more prostate cancers in younger men. Radiation techniques also improved, she said, so that “it is very possible to deliver high radiation doses safely and effectively.”
“Radiation oncologists in prostate cancer … tend to get the patients who have the worse prognosis because the common belief always has been that surgery is better,” she said.
“When offering radiation to a younger population of patients, the risk of second malignancy is something that needs to be considered very carefully,” she said.