Skin cancer is the most common cancer diagnosed in the United States, and most of it is preventable. Basal cell and squamous cell carcinomas are rarely fatal but can disfigure. Melanoma, though far less common, accounts for the majority of skin cancer deaths and can arise on skin that has never seen the sun. The tools to reduce risk are simple, cheap, and underused.
The evidence for daily photoprotection is strong and old. The debate is not whether it works, but how to make it consistent.
What counts as sun protection
Sunscreen is one part of a broader strategy. Clothing, shade, and timing are at least as important, and often more effective per dollar and per minute of effort.
- Broad-spectrum sunscreen covering both UVA and UVB, SPF 30 or higher, applied generously and reapplied every two hours in the sun and after swimming or sweating.
- UPF-rated clothing for extended outdoor time. A long-sleeved sun shirt outperforms sunscreen on the areas it covers.
- A wide-brimmed hat for the scalp, ears, and neck, which are common sites for skin cancer and often missed.
- Sunglasses with UV protection to reduce risk of cataracts and periocular skin cancer.
- Shade seeking during peak UV hours, typically 10 am to 4 pm at mid-latitudes.
The common failure mode is under-application. Studies consistently show that people apply roughly a quarter to half the amount used in SPF testing. A shot glass of sunscreen for full body exposure is the standard rule of thumb; a nickel-sized dab for the face and neck.
Mineral (zinc oxide, titanium dioxide) and chemical sunscreens are both effective. Mineral formulations are generally better tolerated by sensitive skin and start working immediately; chemical formulations tend to cosmetically outperform. The best sunscreen is the one you will actually apply.
Who is at higher risk
Skin cancer risk is not evenly distributed. Higher-risk features include:
- Fair skin, light hair, or light eyes
- Personal or family history of skin cancer
- History of blistering sunburns, particularly in childhood
- Many moles (more than 50) or atypical moles
- Immunosuppression, including organ transplantation
- Chronic occupational or recreational sun exposure
- History of tanning bed use, which the WHO classifies as a group 1 carcinogen
People with darker skin have lower overall risk but are more likely to be diagnosed at later stages, particularly with acral lentiginous melanoma, which can arise on palms, soles, and under the nails. Skin cancer awareness applies across skin tones.
Self-checks and professional exams
USPSTF has not issued a recommendation for routine whole-body skin cancer screening in average-risk asymptomatic adults, citing insufficient evidence. Dermatologic guidance is more permissive: periodic professional skin exams for people with the risk features above, and monthly self-examination for everyone else.
The ABCDE mnemonic remains useful for evaluating a mole or spot.
- Asymmetry
- Border irregularity
- Color variation within a single lesion
- Diameter greater than 6 mm
- Evolution over time
Any lesion that changes, itches, bleeds, or does not heal deserves evaluation. The ugly duckling sign, a spot that looks different from your other moles, is often more useful than a checklist.
The tumor you find on your own back next Tuesday is worth more than any theoretical debate about screening.
Where sunscreen debates get overheated
Periodically, headlines raise concerns about sunscreen ingredients or vitamin D. The evidence: FDA is studying systemic absorption of certain chemical filters, but no clinical harm has been demonstrated, and the population-level benefit of sun protection is not in question. Vitamin D concerns are largely addressable through diet or supplementation without abandoning photoprotection.
The bottom line
Cover up, seek shade, wear sunscreen, know your own skin, and get suspicious spots checked. Skin cancer is one of the few common cancers where daily habits meaningfully change lifetime risk, and the tools are cheap and well understood.