Chemoprevention for keratinocytic (pre)cancers: balancing the risks and benefits.

QUESTION: Can celecoxib reduce the incidence of actinic keratoses (AKs) and keratinocytic cancers?

DESIGN

Randomized, double-blind, placebo-controlled phase 2-3 clinical trial.

SETTING

Eight centers in the United States participated and included 240 patients from January 2001 to November 2006, when the Food and Drug Administration requested termination of this trial after the worldwide withdrawal of rofecoxib.

PATIENTS: The study population comprised individuals 18 years or older with Fitzpatrick skin type I to III, with 10 to 40 AKs on the upper extremities, neck, face, and scalp at baseline and a previous histological diagnosis of a keratinocytic (pre)malignant neoplasm.

INTERVENTION: Celecoxib (200 mg) or placebo twice daily.

MAIN OUTCOME MEASURE: The ratio of new AKs per patient at completion of the study to the number of AKs at randomization. EXPLORATORY POST HOC ANALYSIS: The mean cumulative number of keratinocytic skin cancers per patient.

RESULTS

There was no difference in the incidence of AKs between the 2 groups at month 9 after randomization. The adjusted rate ratios for the celecoxib arm compared with the placebo arm were 0.41 (95% CI, 0.23-0.72) for keratinocytic skin cancers, 0.40 (95% CI, 0.18-0.93) for basal cell carcinomas (BCCs), and 0.42 (95% CI, 0.19-0.93) for squamous cell carcinomas (SCCs).

CONCLUSION

Celecoxib might be effective for prevention of keratinocytic cancers but not for actinic keratoses.