ANCHOR
ANCHOR Study: Anal Cancer/HSIL Outcomes Research Study (Treatment of Anal High-Grade Squamous Intraepithelial Lesions to Prevent Anal Cancer)
Phase 3N = 4,459NCT02135419
- Population
- People living with HIV aged 35 or older with HSIL (AIN grade 3 or p16-positive AIN grade 2) on at least one anal-canal or perianal biopsy read by a local pathology laboratory; people with a history of anal cancer or anal cancer found at screening were ineligible
- Design
- Randomised phase 3 trial at 25 US sites. People living with HIV aged 35 or older with biopsy-proven anal HSIL were randomised 1:1 (permuted blocks; stratified by site, nadir CD4 count 200 or lower vs above 200 cells per cubic millimetre, and lesion size 50% or less vs more than 50% of the anal canal or perianal region) to HSIL treatment or active monitoring without treatment. Primary outcome: progression to anal cancer in a time-to-event analysis; secondary outcome: safety of HSIL treatment. Screening for the trial ran from 24 September 2014 to 5 August 2021. The registry enrolment of 4446 equals the number analysed in the paper; 4459 were randomised.
- Primary endpoint
- Progression to anal cancer
- Arms
- Active monitoring (control, n = 2,222): No HSIL treatment; high-resolution anoscopy every 6 months with annual biopsy of visible lesions to confirm ongoing HSIL and exclude cancer; anal cancer diagnosed on biopsy ended trial participation and led to referral for therapy
- HSIL treatment (experimental, n = 2,237): Immediate treatment aiming to eradicate all HSIL, chosen from protocol options (ablation by infrared coagulation, electrocautery or laser; ablation or excision under anaesthesia; topical imiquimod or fluorouracil), then high-resolution anoscopy at least every 6 months once all HSIL was treated
- People
- Palefsky JM, ANCHOR Investigators Group
Δ 48-month Progression to anal cancer−0.9 points
Show the numbers
| Endpoint | Analysis | HSIL treatment | Active monitoring | Effect |
|---|---|---|---|---|
| Progression to anal cancerParticipants with at least one follow-up visit (4446 of 4459 randomised; 2227 treatment, 2219 active monitoring)Time from randomisation to diagnosis of anal cancer confirmed on central pathological review, with data censored at last follow-up or at non-adherence. The arm values are the cumulative incidence at 48 months reported in the full text. | primarymedian follow-up 25.8 monthsPalefsky 2022 | 0.9% at 4 y | 1.8% at 4 y | P=0.03Abstract: 9 cancers with treatment (173 per 100,000 person-years; 95% CI 90 to 332) and 21 with active monitoring (402 per 100,000 person-years; 95% CI 262 to 616); the rate was lower with treatment by 57% (95% CI 6 to 80), P = 0.03 by log-rank test. The paper reports this as a percentage difference in rates, not as a hazard ratio. No confidence intervals for the 48-month cumulative incidence appear in the text read. An analysis that did not censor active-monitoring participants at non-adherence gave the same conclusion (P = 0.03). |
| Endpoint | Analysis | HSIL treatment | Active monitoring | Effect |
|---|---|---|---|---|
| Progression to anal cancerParticipants with at least one follow-up visit (4446 of 4459 randomised; 2227 treatment, 2219 active monitoring)Time from randomisation to diagnosis of anal cancer confirmed on central pathological review, with data censored at last follow-up or at non-adherence. The arm values are the cumulative incidence at 48 months reported in the full text. | primarymedian follow-up 25.8 monthsPalefsky 2022 | 0.9% at 4 y | 1.8% at 4 y | P=0.03Abstract: 9 cancers with treatment (173 per 100,000 person-years; 95% CI 90 to 332) and 21 with active monitoring (402 per 100,000 person-years; 95% CI 262 to 616); the rate was lower with treatment by 57% (95% CI 6 to 80), P = 0.03 by log-rank test. The paper reports this as a percentage difference in rates, not as a hazard ratio. No confidence intervals for the 48-month cumulative incidence appear in the text read. An analysis that did not censor active-monitoring participants at non-adherence gave the same conclusion (P = 0.03). |