What do systematic reviews say?

Vitamin A or retinoids (systemic or topical; incl. 13-cis-retinoic acid, acitretin) vs placebo or no treatment

It is very uncertain whether vitamin A or retinoids (systemic or topical; incl. 13-cis-retinoic… changes oral cancer development compared with placebo or no treatment (very low certainty).

• Interventions for treating oral leukoplakia to prevent oral cancer 2016 · Cochrane All outcomes

  24 months (treatment lasted 12 months)
  RR 0.11 [0.01, 2.05]
  1 study · 85 participants
  Very low

Vitamin A or retinoids (systemic or topical; incl. 13-cis-retinoic acid, acitretin) vs placebo or no treatment

• Interventions for treating oral leukoplakia to prevent oral cancer 2016 · Cochrane All outcomes

  4 to 12 months
  SoF 1, Clinical resolution (not completely resolved) at 4 to 12 months: 'Studies could not be combined in meta-analysis. One study evaluated topical treatment and did not find evidence of benefit; 3 studies of systemic…
  4 studies
  GRADE not reported

Vitamin A or retinoids (systemic or topical; incl. 13-cis-retinoic acid, acitretin) vs placebo or no treatment

Vitamin A or retinoids (systemic or topical; incl. 13-cis-retinoic… probably leads to lower improvement of histological features (not improved) compared with placebo or no treatment (moderate certainty).

• Interventions for treating oral leukoplakia to prevent oral cancer 2016 · Cochrane All outcomes

  3 months
  RR 0.43 [0.24, 0.76]
  1 study · 41 participants
  Moderate

Vitamin A or retinoids (systemic or topical; incl. 13-cis-retinoic acid, acitretin) vs placebo or no treatment

• Interventions for treating oral leukoplakia to prevent oral cancer 2016 · Cochrane All outcomes

  4 to 12 months
  SoF 1, Safety of the intervention at 4 to 12 months: '3 studies (1 each evaluating topical acitretin, topical 13-cis-retinoic acid, 200,000 IU per week of vitamin A) found no adverse effects. Systemic 13-cis-retinoic…
  4 studies
  GRADE not reported