In short. Photoprotection that genuinely works: sunscreen, clothing, shade and timing, plus an honest account of what prevention can and cannot undo once damage has accumulated.
Key points
- Consistent photoprotection lowers the rate at which new lesions and new skin cancers appear, and it is the single most useful thing a person with sun-damaged skin can do.
- It does not undo existing damage, it does not remove the risk created by previous skin cancers, and it does not replace surveillance.
- Someone who has had a melanoma remains at substantially elevated risk of a second one whatever they do next.
Ultraviolet radiation damages DNA in skin cells, and that damage accumulates over a lifetime. Prevention is therefore both simple and limited: the measures that reduce future damage are well established and genuinely effective, and none of them erases the exposure that has already happened. Understanding both halves of that sentence is what makes prevention advice realistic rather than moralising.
What works
Broad-spectrum sunscreen with a high protection factor, applied generously and reapplied every two hours and after swimming or sweating, reduces the formation of new actinic keratoses and new skin cancers in the people who use it consistently. Clothing is more reliable than any cream: densely woven fabric, long sleeves, a wide-brimmed hat that shades the ears and neck, and sunglasses that block ultraviolet light. Shade and timing matter too, because ultraviolet intensity peaks in the middle of the day, and much incidental exposure happens while driving or gardening rather than while deliberately sunbathing.
What does not work
A tan is not protection; it is evidence of damage, and it confers only the equivalent of a low protection factor. Sunbeds are not a safe way to tan and are a recognised cause of melanoma and squamous cell carcinoma. A single application of sunscreen in the morning does not last a day outdoors. And sunscreen does not make prolonged sun exposure safe — it reduces harm, it does not abolish it.
Reduced risk is not no risk
Consistent photoprotection lowers the rate at which new lesions and new skin cancers appear, and it is the single most useful thing a person with sun-damaged skin can do. It does not undo existing damage, it does not remove the risk created by previous skin cancers, and it does not replace surveillance. Someone who has had a melanoma remains at substantially elevated risk of a second one whatever they do next. Sunscreen changes the future; it does not rewrite the past.
What prevention cannot undo
Once keratinocytes have accumulated enough mutations, or a clone of melanocytes has begun to expand, protection does not reverse it. That is why prevention and surveillance are partners rather than alternatives: protection reduces the number of new problems, and surveillance catches the ones already in progress. It is also why a person who has had one skin cancer is not reassured by the fact that they now use sunscreen — the correct conclusion is continued skin checks.
Practical points
Vitamin D deserves a mention, because sun avoidance raises legitimate questions. Most people obtain adequate vitamin D from ordinary diet and brief incidental exposure, and where levels are low the answer is supplementation rather than deliberate tanning. Children and adolescents benefit most from protection, since sunburn early in life is strongly associated with later melanoma. People taking medicines that increase photosensitivity should ask about them, and anyone who works outdoors should treat protection as part of the job.
Seek review promptly if
- A new or changing lesion appears, even if you have been careful about sun protection since.
- You have had a skin cancer or melanoma before and notice any change in the treated area.
- A sun-damaged area develops a sore, a lump, or a patch that bleeds or will not heal.
Frequently asked questions
Does using sunscreen mean someone who has had skin cancer can relax?
No. Consistent photoprotection lowers the rate at which new lesions and new skin cancers appear, but it does not undo existing damage, it does not remove the risk created by previous skin cancers, and it does not replace surveillance. A person who has had a melanoma remains at substantially elevated risk of a second one.
Why is clothing considered more reliable than sunscreen?
Because sunscreen depends on generous application and reapplying every two hours and after swimming or sweating, which people often do not manage. Densely woven fabric, long sleeves, a wide-brimmed hat that shades the ears and neck, and sunglasses that block ultraviolet light do not depend on technique.
Is a tan a sign of healthy skin?
No. A tan is not protection; it is evidence of damage, and it confers only the equivalent of a low protection factor. Sunbeds are not a safe way to tan and are a recognised cause of melanoma and squamous cell carcinoma.
Risks & Limitations
- Incomplete excision, which may require a further operation to achieve clear margins.
- Recurrence of the skin cancer, and the need for surveillance for years afterwards.
- Scars are permanent. They mature and fade but never disappear.
- Problems with a graft or flap, including partial or complete loss, which may need further surgery.
- Numbness, altered sensation or nerve injury around the operated area.
- Melanoma carries a risk of spread that surgery cannot remove, even when the excision is complete.
- Pigment change, contour irregularity, or a scar that widens or thickens.
- Final assessment of the scar is made at 6–12 months, and surveillance continues longer.
When to Seek Care
- A lesion that changes in size, shape, colour or height, or that starts to bleed or itch.
- A new, rapidly growing nodule, or a sore that is not healing.
- A mole that becomes painful or bleeds.
- Swelling in a lymph node region — the neck, armpit or groin.
- A graft or flap that turns dark, cold or black, or a wound that opens or discharges.
- Fever above 38 °C, or spreading redness, warmth or pain around a wound.
References & Further Reading
- American Academy of Dermatology (AAD) — skin cancer diagnosis and treatment guidance
- American Cancer Society (ACS) — skin cancer types, staging and outlook
- Skin Cancer Foundation — prevention and skin self-examination resources
- American Society of Plastic Surgeons (ASPS) — reconstruction after skin cancer excision
- Cochrane Library — systematic reviews in skin cancer treatment and prevention
- Chinese Medical Association — clinical guidance for skin tumours and dermatologic surgery
This page is patient education, not medical advice, and it does not cite individual studies. Discuss your own case with a qualified clinician. To arrange an assessment at Chongqing West District Hospital, see Contact & Consultation.