KEY POINTS
- This single-centre retrospective cohort included 226 men aged at least 75 years treated between 2012 and 2021. Median age was 79 years, median Charlson Comorbidity Index was 4, and 53% had high- or very-high-risk prostate cancer.
- Patients received prostate radiotherapy of 32.5–36.25 Gy in five alternate-day fractions. A simultaneous integrated boost of 37.5–40 Gy to the dominant intraprostatic lesion was delivered in 43.4%, while elective pelvic lymph nodes were not treated.
- Androgen-deprivation therapy was prescribed to 165 patients (73%), with a median duration of 12 months. Treatment use and duration were individualized according to disease risk, age, performance status and comorbidities rather than assigned according to a standardized protocol.
- After a median follow-up of 2.3 years, 44 of 217 evaluable patients (20%) developed biochemical recurrence. One-, two- and three-year biochemical relapse-free survival was 98%, 88% and 82%, respectively.
- Clinical progression followed biochemical recurrence in 31 of 44 patients (70%). Three-year clinical progression-free survival was 86%; 61% of clinical progressions were oligoprogressive, and nine occurred within the treated field.
- Neither androgen-deprivation therapy, its duration, simultaneous integrated boosting nor the analysed prostate doses were significantly associated with biochemical or clinical progression. However, among the 14 patients receiving 32.5 Gy, 7 developed biochemical recurrence and 4 clinical progression, suggesting possible underdosing that could not be tested reliably.
- No acute grade 3 or higher gastrointestinal toxicity occurred. Two patients developed acute grade 3 or higher genitourinary toxicity, one developed late grade 3 proctitis, and no late grade 3 or higher genitourinary event was reported. Older age and higher comorbidity burden predicted acute genitourinary toxicity, while larger prostate volume was associated with acute gastrointestinal toxicity.
CLINICAL TAKEAWAY
Prostate-only radiotherapy in five fractions appears feasible for carefully selected elderly and comorbid patients who might otherwise be denied curative treatment. The study does not justify reducing or omitting guideline-recommended androgen-deprivation therapy: allocation was non-randomized, follow-up was short and the low-dose subgroup showed a concerning recurrence signal.