From the Guidelines
Smoking is a significant risk factor for both actinic keratosis and skin cancer, and quitting smoking is essential to reduce this risk. According to the most recent and highest quality study, cigarette smoking contains numerous carcinogens that can damage skin cells and impair the body's natural repair mechanisms 1. Smokers have approximately a 50% higher risk of developing squamous cell carcinoma (a type of skin cancer) compared to non-smokers. The chemicals in tobacco smoke generate free radicals that damage DNA and proteins in skin cells, accelerating photoaging and increasing susceptibility to UV radiation damage.
Key Points to Consider
- Smoking suppresses the immune system, reducing the body's ability to identify and destroy abnormal cells before they become cancerous.
- Smoking decreases blood flow to the skin, limiting the delivery of oxygen and nutrients needed for healthy cell function and repair.
- For skin health, complete smoking cessation is recommended, along with other protective measures like daily sunscreen use, wearing protective clothing, and regular skin examinations by a healthcare provider.
- Public health campaigns and sun avoidance may also have an impact on reducing the risk of development of AKs and skin cancer, although more studies are needed to confirm this 1.
Recommendations for Patients
- Quit smoking to reduce the risk of actinic keratosis and skin cancer.
- Use daily sunscreen with a Sun Protection Factor (SPF) of at least 30, and reapply every 2 hours or after swimming or sweating.
- Wear protective clothing, such as a wide-brimmed hat and long-sleeved shirt, when spending time outdoors.
- Get regular skin examinations by a healthcare provider to detect any potential skin cancers early.
From the Research
Risk Factors for Actinic Keratosis and Skin Cancer
- Smoking is a potential risk factor for certain types of skin cancer, including squamous cell carcinoma (SCC) 2, 3.
- Studies have found that current smokers have a higher risk of SCC compared to never smokers, with a hazard ratio of 2.3 (95% confidence interval = 1.5-3.6) 2.
- However, the relationship between smoking and basal cell carcinoma (BCC) is less clear, with one study finding that current smokers had a lower risk of BCC (hazard ratio = 0.6; 95% confidence interval = 0.4-0.9) 2.
- Another study found that ever smokers had an elevated crude odds ratio (OR=1.99; 95% CI: 1.02-3.88, p=0.043) for SCC compared to non-smokers, but this association was not dose-dependent 3.
Actinic Keratosis Treatment and Prevention
- Actinic keratosis (AK) is a precursor to SCC and can be treated with various topical therapies, including 5-fluorouracil and imiquimod 4, 5, 6.
- A study comparing the effectiveness of 5-fluorouracil and imiquimod found that 5-fluorouracil reduced the short-term incidence of subsequent AKs, but there was no statistically significant evidence of a long-term decreased risk 6.
- Another study found that AK can undergo spontaneous regression, stable existence, or malignant transformation to cutaneous SCC, with progression rates to SCC ranging from 0% to 0.5% per lesion-year 5.