Favorable Efficacy (RCT)

Celecoxib for skin cancer prevention

Celecoxib 200 mg twice daily vs. Placebo · for Nonmelanoma skin cancer (high-risk, actinic damage) · real-time analysis of 1 studies · updated 2026-05-29

In a small trial of patients with extensive actinic keratoses, the COX-2 inhibitor celecoxib roughly halved new nonmelanoma skin cancers, including both squamous- and basal-cell carcinomas—but cardiovascular safety concerns limit its use as a preventive.

Efficacy (RCT): Efficacy evidence on clinical outcomes. Effects are risk ratios with number-needed-to-treat where a baseline risk is available. Glossary →

Interpretation & tips

Roughly halved skin cancers in high-risk patients, so NNTs are low. The limit is safety, not efficacy: COX-2 inhibitors carry cardiovascular risk, and this was a small, short trial—so celecoxib is not used routinely for prevention.

57% lower risk of nonmelanoma skin cancer
Pooled RR 0.43 (95% CI 0.24–0.76) across 1 studies, 240 patients (random-effects, I² 0%).
0.43
Pooled RR
0.24–0.76
95% CI
1
Studies
240
Patients
6
NNT

Forest plot—Nonmelanoma skin cancer

Elmets 2010 0.43 [0.24–0.75] Pooled (RE) 0.43 [0.24–0.76] 0.1 0.25 0.5 1 2 4 ← favors treatment favors control →

Study results—Nonmelanoma skin cancer

Study Design Dose / regimen Treatment Control RR [95% CI] Improvement NNT Weight
Elmets 2010 note DB-RCT Celecoxib 200 mg BID 0.43 [0.24–0.75] 57% 6 100%

RR < 1 favors treatment for outcomes where lower is better. Rows in gray have a confidence interval crossing 1 (individually inconclusive). “~” marks effects reported as OR/HR and treated as RR-approximations. “excl” = excluded from pooling (e.g. reviews).

Notes & interpretation

  • Elmets 2010—Nonmelanoma skin cancer rate ratio (P=0.003).

Background

A randomized, double-blind, placebo-controlled trial of 240 patients with actinic keratoses treated celecoxib 200 mg twice daily for 9 months, with skin cancers counted at 11 months.

Topic methodology & caveats

Tumor rate ratios with 95% CIs; control lesion rates are the NNT baseline. Single small trial (n=240, ~11 months).

Studies