To investigate the effectiveness of external beam radiation therapy (EBRT) versus high-intensity focused ultrasound (HIFU) in treating patients with stage II prostate cancer and their oncological outcomes.

We performed a retrospective analysis of patients diagnosed with stage II prostate cancer using data from the Chang Gung Research Database between 2005 and 2022. To balance baseline characteristics, including age, PSA levels, CCI score, cancer stage, hypertension, coronary artery disease, and diabetes, we utilized the inverse probability of treatment weighting (IPTW) method. Oncological outcomes were evaluated through IPTW-adjusted Kaplan-Meier survival analysis.

The analysis identified 176 EBRT and 244 HIFU interventions. Following inverse probability of treatment weighting (IPTW) adjustment, the EBRT group exhibited elevated all-cause mortality (16.7% versus 9.2%; standardized difference 0.224) and increased cancer-specific mortality (9.2% versus 5.4%; standardized difference 0.144). Statistical analysis revealed a significant overall survival advantage in the HIFU-treated population across all stage II prostate carcinoma cases, with particularly pronounced benefit in the stage IIa subgroup post-IPTW adjustment (p=0.032). While cancer-specific survival data suggested a favorable trend toward the HIFU stage IIa subgroup following IPTW adjustment, this observation failed to achieve statistical significance (p=0.069).

HIFU shows a superior overall survival rate compared to EBRT in patients with stage II prostate cancer, especially in the stage IIa subgroup, after more than 10 years of follow-up. While cancer-specific survival marginally favors the HIFU stage IIa subgroup, the difference does not reach statistical significance.