Twenty-two studies were included: one randomised controlled trial (463 participants) and 21 single arm (uncontrolled) phase II trials (1,642 participants, range 24 to 346).
Incidence of all-grade nail toxicity ranged from 5.7% to 48.1% and when data were pooled the overall incidence was 17.2% (95% CI 13.8% to 21.3%; 20 studies; random-effects model; Ι²=74%).
Incidence of high-grade nail toxicity ranged from 0.1% to 5.0% and when data were pooled the overall incidence was 1.4% (95% CI 0.9% to 2.1%; 22 studies; fixed-effect model; Ι²=0%).
Compared to controls that received best supportive care, the intervention group had a relative risk of all-grade nail toxicity of 0.77 (95% CI 0.41 to 1.45) and a relative risk of high-grade nail toxicity of 0.13 (95% CI 0.04 to 0.46).
Subgroup analyses showed no significant difference in nail toxicity between different types of epidermal growth factor receptor inhibitor.