Brachytherapy may provide an effective alternative treatment for younger men who are reluctant to undergo surgery for favorable risk prostate cancer, according to Canadian researchers.
Juanita Crook, MD, of the British Columbia Cancer Agency Center for the Southern Interior in Kelowna, British Columbia, and colleagues studied 94 men aged 55 years and younger with clinical stage T1-T2 prostate cancer. The men received 125iodine brachytherapy monotherapy. The men had a median age of 53 years and a minimum follow-up of 30 months. The investigators defined biochemical failure as the PSA nadir plus 2 mg/mL of PSA.
After a median follow-up of 63 months (range 30-108 months), all 94 subjects were alive, the investigators reported in Urology (2009; published online ahead of print). Only one patient experienced biochemical failure. The actuarial seven-year biochemical control rate was 98.9%. The median nadir, which was reached at a median of 48 months of follow-up, was 0.05 ng/mL. The overall survival rate was 100%.
The median five- and seven-year PSA levels were 0.09 and 0.06 ng/mL, respectively, according to the investigators. Grade 2 acute and late genitourinary (GU) toxicities rates were 9.8% and 10.6%, respectively. Grade 3 GU toxicity (urethral stricture) developed in three men; this was correct with urethral dilatation or transurethral resection. Two patients (2.2%) experienced grade 2 gastrointestinal toxicity (proctitis). Erectile function was preserved in 85 (93.4%) of 91 patients with good prior function. No patient was diagnosed with colorectal or bladder cancer.
The authors noted that the seven-year actuarial biochemical control rate compares favorably to previously reported studies, but they acknowledged that their definition of biochemical failure “may overestimate success rates as a slowly rising PSA in later years may show several incremental increases because being declared as a biochemical recurrence.”