Surgery versus 5% imiquimod for nodular and superficial basal-cell carcinoma: five year results of the SINS randomised controlled trial

Background: We previously reported modest clinical 3-year benefit for topical imiquimod compared with surgery for superficial or nodular basal cell carcinoma (sBCC, nBCC) at low risk sites in our non-inferiority randomised controlled SINS trial. Here we report 5-year data. Methods: Participants were randomised to imiquimod 5% cream once daily (sBCC, 6 weeks; nBCC, 12 weeks) or excisional surgery (4 mm margin). Primary outcome was clinical absence of initial failure or signs of recurrence at 3 year dermatology review. Five year success was defined as 3 year success plus absence of recurrences identified through hospital, histopathology and general practitioner records. Results: Of 501 participants randomised, 401 contributed to the modified intention-to-treat analyses at year 3 (primary outcome), 383 (96%) of whom had data at year 5. Five year success rates for imiquimod were 82·5% (170/206) compared to 97·7% (173/177) for surgery (relative risk of imiquimod success 0·84, 95% CI 0·77 to 0·91, p