Brachytherapy as effective in younger as in older men

LOS ANGELES—Compared with older men, younger men have a similarly high rate of biochemical control of localized prostate cancer when treated with brachytherapy and should therefore be offered this treatment option, Alice Y. Ho, MD, reported at ASTRO's 49th Annual Meeting (abstract 160).

"It is a common belief that younger patients with prostate cancer tend to have more aggressive disease than those patients who are older," said Dr. Ho, formerly of Mount Sinai Medical Center and currently at Memorial Sloan-Kettering Cancer Center.

To assess whether this perception is valid, she and her colleagues retrospectively reviewed the records of all men who were treated for clinically localized prostate cancer with low-dose-rate brachytherapy at Mount Sinai between 1990 and 2005 and who had at least 2 years of follow-up.

1,763 patients

Analyses were based on 1,763 patients, 23% of whom fell into the younger age group (aged 60 years or younger). Compared with their older counterparts, the younger men were more likely to have had low-risk disease (57% vs 40%), to have been treated after 1997 (72% vs 60%), and to have received hormonal therapy (60% vs 58%).

With a median follow-up of about 60 months, the estimated 5-year rate of prostate-specific antigen (PSA) control, based on the ASTRO consensus definition, was 90% for the population overall.

"When we compared PSA control rates in younger vs older men, there was no difference after treatment with seed implantation. In fact, both older and younger men had excellent 5-year PSA control rates after radiation," Dr. Ho said.

In univariate analysis, the rate was significantly higher in the younger group than in the older group (96% vs 89%). In multivariate analysis, age was not an independent predictor of PSA control, whereas treatment era (1998-2005 vs 1990-1997) and biologically effective dose (> 150 Gy vs ≤ 150 Gy) were.

"I think the main reason the younger patients did well in our study is because in the modern era, it is very possible to deliver a high radiation dose safely and effectively," Dr. Ho asserted.

She discounted a role for a selection bias in the study's findings by which younger men with a better prognosis underwent implantation. If anything, she noted, surgery tends to be offered upfront in this context, so that men eventually seen by radiation oncologists may, in fact, have a poorer prognosis.

"Age should not be a deterrent when considering seed implantation as a primary treatment option for younger patients," Dr. Ho concluded. "When younger men are diagnosed with localized prostate cancer, all of the treatment options—including a seed implant—should be presented to them by their physicians."

Choices artificially narrowed?

When it comes to cancer treatment, patients like to have a choice, said Anthony L. Zietman, MD, of Massachusetts General Hospital, who discussed the study at an ASTRO press briefing.

"Traditionally, it has been said that prostate cancer is a bit more aggressive in younger men, and therefore younger men need more aggressive therapy, which really means surgery, or that's how it has been perceived," Dr. Zietman said. "Now if that's the case, that's fine, and we can accept it. But if that's not the case, then patients are having their choices artificially narrowed by not being offered brachytherapy and other treatments."