June 2024

The Focal Ablation Surgery for Selective Tumors (FASST) trial is a significant multinational study investigating the efficacy and safety of focal high-intensity focused ultrasound (HIFU) as a treatment for localized, low-to-intermediate-risk prostate cancer.

The FASST trial is designed as a prospective cohort study involving multiple international centers from Switzerland, Austria and Sweden. The primary endpoint of the trial is treatment failure, defined as the need for whole-gland salvage treatment due to cancer recurrence. Secondary endpoints include prostate-specific antigen (PSA) levels, MRI findings, biopsy results, and patient-reported outcomes on urinary and sexual function.

At baseline, mean (standard deviation) age was 64.14 (7.19) years, with the majority of patients showing T-stage 1 (73.9%) and International Society of Urological Pathology grading system Grade 2 (58.8%). PSA nadir (median, 1.70 ng/mL) was reached after 6 months. Of all patients recruited, 16% had clinically significant PCa, as confirmed by biopsy, of which 13.4% had TF. Notably, T-stage and number of positive cores at initial biopsy were independent predictors of TF during follow-up (HR [95% CI] 1.27 [1.02-1.59] and 5.02 [1.80-14.03], respectively). Adverse events were minimal (17% and 8% early and late adverse events, respectively), with stable or improved.

The FASST trial highlights the potential of focal HIFU as a less invasive, effective treatment for localized prostate cancer. By targeting only the cancerous tissue and sparing healthy surrounding tissue, focal HIFU may offer a better quality of life for patients with fewer side effects. Ongoing follow-up and further analysis of long-term data, specifically as it relates to oncological outcomes, are eagerly awaited to confirm these findings and establish focal HIFU as a standard treatment option.

More information in European Journal of Clinical Investigation:
https://doi.org/10.1111/eci.14192