KEY POINTS
- The PLATO platform included 706 evaluable patients from 36 UK centres across three risk-adapted trials. Patient-reported outcome consent was 98.9%, and questionnaire completion remained 86.0% at six months.
- ACT3 included 39 patients observed after local excision and 44 receiving 41.4 Gy in 23 fractions. ACT4 included 105 patients receiving 41.4 Gy in 23 fractions and 55 receiving 50.4 Gy in 28 fractions.
- ACT5 included 463 patients with T3–4 or node-positive disease: 154 received 53.2 Gy, 155 received 58.8 Gy, and 154 received 61.6 Gy, all in 28 fractions with concurrent mitomycin and capecitabine or fluorouracil.
- ACT5 participants entered treatment with clinically worse scores—defined as differences exceeding 10 points—for social and role functioning, bowel symptoms, pain, toilet dependency, fatigue, appetite loss, constipation, and several daily-life activities.
- Nearly all treated groups reported clinically meaningful deterioration at treatment completion, including bowel, urinary, pain, fatigue, sexual, and global quality-of-life domains. Most problems improved substantially between six weeks and six months.
- At six months, ACT5 participants continued to report absolute scores more than 10 points worse than ACT3 and ACT4 for bowel function, toilet dependency, and the need to clean themselves more frequently.
- Male and female sexual-function scores remained more than 10 points below baseline after ACT4 standard-dose treatment and across all ACT5 dose groups. Scores returned close to baseline after ACT4 reduced-dose treatment, but the study was not powered for formal comparisons between arms.
CLINICAL TAKEAWAY
Most acute quality-of-life effects of anal cancer chemoradiotherapy improve within six months, but patients with locally advanced disease continue to carry a substantial bowel and functional burden. The apparent sexual-function advantage with reduced-dose ACT4 treatment is clinically relevant but remains exploratory until longer follow-up and formal comparative analyses are available.