KEY TAKEAWAYS
- The ASCaP observational trial aimed to investigate the efficacy of selective FT in extending AS and RP or RT for patients with PC.
- Researchers noticed a significant extension of AS and deferral of surgery or RT through the selective use of FT in PC management.
The goal of active surveillance (AS) is to avoid unnecessary treatment for prostate cancer (PC) patients with low-risk disease. However, a considerable proportion of individuals in AS eventually progress to undergo surgery (radical prostatectomy, RP) or radiation therapy (RT). Focal therapy (FT) has emerged as a potential strategy to address this challenge by selectively treating only the cancerous lesions while preserving surrounding healthy tissue.
Shannon Richardson and the team aimed to investigate whether the selective use of FT could extend the duration of AS and defer the need for surgery or radiation in eligible patients.
They performed an inclusive analysis of a prospective AS cohort comprising 1081 men enrolled in the UCLA AS program from 2010 to 2022. Inclusion criteria were met by 869 participants, characterized by baseline MRI-guided biopsy (MRGB), Grade Group (GG) ≤ 2, and ≥1 of follow-up (f/u). Baseline assessment was conducted at the time of the first MRGB, with 659 individuals having a previous positive TRUS biopsy. F/u examinations were conducted via MRGB, as documented by Jayadevan et al. in JAMA Open NW (2019).
When GG2 or GG3 was detected (n=401), FT was offered as a means to continue AS. Conversely, RP or RT was proposed for all men exhibiting an upgrade to GG3 (n=88), GG4 (n=23), or GG5 (n=21). FT techniques encompassed High-Intensity Focused Ultrasound (HIFU) (N=26) or Cryotherapy (N=76). Primary outcomes included RP/RT or progression to ≥ GG3 disease.
About 869 men accumulated over 3,500 person-years of f/u and underwent over 1,500 MRGBs throughout 12 years. The mean age was 65 years (SD 7.7), with 70% identified as White, 5% as Black, and 25% as other ethnicities. Upon initial MRGB, GG0 was in 22%, GG1 was in 58%, and GG2 was in 20%, respectively. Median progression-free survival (PFS) in AS was 5.8 years for men with GG2, contrasting with 10.2 years for GG0 and 8.7 years for GG1 (P<0.01). Individuals with GG1 or GG2 upon initial MRGB exhibited a higher rate of progression to GG3 or higher compared to those with GG0 (GG1 HR=2.9, 95% CI: 1.4-6.2; GG2 HR=7.1, 95% CI: 3.3-15.4).
Prostate-specific antigen (PSA) density emerged as an independent predictor of progression to GG3 or higher (reference: ≤ 0.15; HR=1.8, 95% CI: 1.2-2.8). FT was selected by 102 out of 869 men (12%), with 3 opting for FT at the first MRGB, while 99 chose FT after a f/u MRGB at a median of 3.2 years from baseline (IQR: 1.5-5.1). Among those who underwent FT, 72 were classified as GG2, 21 as GG3, and 2 as GG4. Men who did not undergo FT were twice as likely to undergo radical prostatectomy or RT compared to those who did (RR=2.2, 95% CI: 1.3-3.9). The 5-year probability of being free from radical prostatectomy or RT in the FT group stood at 0.90, in contrast to 0.76 in the no-FT cohort (P=0.01). This advantage persisted over a 9-year f/u.
The study concluded that selective employment of FT within an AS program holds promise for extending the duration of surveillance and postponing the necessity for surgery or RT in PC management.
The trial was sponsored by the Jonsson Comprehensive Cancer Center.
Source: https://www.auajournals.org/doi/10.1097/01.JU.0001008556.20565.76.09
Clinical Trial: https://clinicaltrials.gov/study/NCT00949819
Richardson S, Gonzalez S, Kwan L, et al. (2024). “IMPACT OF FOCAL THERAPY ON DEFERRAL OF SURGERY OR RADIATION DURING ACTIVE SURVEILLANCE OF PROSTATE CANCER.” Presented at AUA 2024 (Abstract PD26-09).
