Routine screening and removal of precursor lesions can significantly reduce the risk of anal cancer by nearly 60%, a world-first randomised controlled trial has found. 

The finding, from the Anal Cancer-HSIL Outcomes Research (ANCHOR) trial, suggests a test-and-treat approach should be the standard of care for high-risk groups, such as people living with HIV, the researchers say. 

Professor Joel Palefsky, from the University of California San Francisco, and colleagues conducted the phase III study among 10,000 people over 35 living with HIV at 25 sites across the US.

Some 4400 of them who were found to have biopsy-proven anal high-grade squamous intraepithelial lesions (HSILs) were then randomised to either HSIL treatment or active monitoring without treatment.