ESTRO meets Asia 2024 - Abstract Book

S290

Interdisciplinary – Urology

ESTRO meets Asia 2024

External beam radiation therapy (EBRT) is one of the recommended curative treatment options for localised prostate cancer (PCa). Radical EBRT with or without androgen deprivation therapy (ADT) has shown favourable long-term outcomes in terms of biochemical, local, and distant control. However, the interpretation of all these published studies is difficult due to the differences in methodology and heterogeneity in treatments. We evaluated the outcomes for patients with localised PCa treated with radical EBRT with or without ADT at Clinical Oncology Department, University Malaya Medical Centre (UMMC) between 2006 and 2017. We also looked at the factors affecting outcomes and treatment-related toxicities in our patient cohort in comparison to original studies or other real-world data.

Material/Methods:

A total of 97 patients with localised PCa treated with radical EBRT between 2006 and 2017, and fulfilled the inclusion and exclusion criteria were included for analysis. The primary endpoints are to analyse biochemical failure-free survival (BFFS), prostate cancer specific survival (PCSS) and overall survival (OS). Secondary endpoints are to identify factors affecting primary endpoints and also to evaluate treatment-related toxicities.

Results:

The 5 and 10-year BFFS was 85.9% and 75.6% respectively. The median BFFS was 151 months. The 5 and 10-year estimates of PCSS and OS were 92.6%, 89.4%, 76.8%, 66.3% respectively. The median time to PCSS and OS were not reached yet. In multivariate analysis, performance status, dose fractionation, nadir prostate specific antigen (nPSA), nPSA cut-off points of 0.5 nanograms per millilitre (ng/mL) and interval to biochemical failure (IBF) cut-off points of 18 months were statistically significant for BFFS. With regards to predictor of death, nPSA, nPSA cut-off points of 0.5 ng/mL and distant failure (DF) were statistically significant for both PCSS and OS. Genitourinary (GU) toxicities were the most common acute toxicities, followed by gastrointestinal (GI), lethargy, skin reaction and others. Late radiation proctitis and cystitis were rare, occurring in about 5% of patients.

Conclusion:

The outcomes in our patients treated with radical EBRT with or without ADT had achieved acceptable BFFS, PCSS and OS in comparison to randomised trials and real-world data. Treatment modalities and aims must be balanced against the possible increases in late treatment complications especially when life expectancy of men increases.

Keywords: localised, prostate, radiotherapy

References:

Pilepich M.V., et al., Phase III radiation therapy oncology group (RTOG) trial 86-10 of androgen deprivation adjuvant to definitive radiotherapy in locally advanced carcinoma of the prostate . Int J Radiat Oncol Biol Phys. 2001 Aug 1;50(5):1243-52. Denham J.W., et al., Short-term androgen deprivation and radiotherapy for locally advanced prostate cancer: results from the Trans-Tasman Radiation Oncology Group 96.01 randomised controlled trial . Lancet Oncol. 2005 Nov;6(11):841-50