The Truth About Melanoma and Skin Cancer: Facts and Common Myths

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Often caused by excessive exposure to ultraviolet (UV) rays in sunlight, melanoma accounts for only 4 to 5 percent of skin cancer cases, but is responsible for most skin cancer-related deaths. As with many forms of cancer, melanoma is often misunderstood, and myths persist.

When detected and treated in its earliest stages, however, melanoma is often curable. The key is to avoid overexposure to UV rays – by limiting time outdoors during the peak hours of sunlight and wearing sun-protective clothing and sunscreen – and to be on the lookout for changes in moles and other blemishes that can be an early sign of the disease.

Jennifer Y. Lin, MD, of Dana-Farber Cancer Institute’s Melanoma Treatment Program, sets the record straight on five of the most common myths about melanoma.

Myth 1: A diagnosis of melanoma means that I have months to live.

There are four stages of melanoma — five if you include a form known as melanoma in situ, an early form of the disease that affects only the top layer of skin. Stage 1 melanomas, which are less than one millimeter thick and almost always have not spread beyond their original site, have an excellent prognosis and are generally cured by surgery. The depth of the original melanoma is critical to determining how it will be treated and how people with it are likely to fare. Although more melanomas are being diagnosed, the largest portion are made up of Stage 1 melanomas. Before worrying about the worst outcomes, speak with your doctor about what stage melanoma you have.

Myth 2: There is no difference between SPF 30 and SPF 100 sunscreen.

Although the baseline protection from SPF 30 and SPF 100 is not vastly different, the higher number provides longer coverage. (SPF stands for sun protection factor, or the amount of ultraviolet radiation the skin can absorb without burning while the sunscreen is on.)

If it normally takes you 10 minutes in the sun to burn, an SPF 30 sunscreen protects you for 300 minutes. An SPF 100 should, in theory, provide 1,000 minutes of coverage. If you are sweating and active, the sunscreen can rub off and should therefore be reapplied every two hours. When you are using a high SPF, there is a smaller likelihood of having a “missed spot.” A good way to know that you are applying enough sunscreen is to use the measurement of a shot glass of sunscreen for exposed sites.

Myth 3: If it is a cloudy day, I do not need to wear sunscreen.

About 80 percent of ultraviolet radiation reaches the earth even through clouds. Use a moisturizer with sunscreen daily, especially for areas that have high exposure, such as your face.

Myth 4: If I am low in vitamin D levels, I must get some sun exposure.

Although the skin is the most efficient site of vitamin D production, adequate amounts can be obtained from your diet and from supplements. Vitamin D helps you absorb calcium and build strong bones, so we frequently recommend supplements that include vitamin D and calcium.

Myth 5: If I have dark skin, I can’t burn and won’t get melanoma.

Even people with dark skin can burn if they’re exposed to the sun long enough. Although melanoma is much more rare in individuals of darker skin, it can occur. We recommend that darker-skinned individuals inspect their hands and feet once a month.

Learn more about skin cancer and melanoma from Dana-Farber Cancer Institute.

56 thoughts on “The Truth About Melanoma and Skin Cancer: Facts and Common Myths”

  1. My husband is 45 years old and thinks if he gets skin cancer it will be from overexposure to the sun as child and there is nothing he can do about it now. He has had lots of pre-cancer spots removed from his face as an adult. But he refuses to wear sunscreen because he doesn’t like how it feels.
    Is he right, or am I?

    • Most skin cancer is secondary to cumulative damage. The more sun protection he can get (especially at such a young age!) the better off he will be. Please continue to encourage him to use sun protection.

  2. my husband died from Melanoma and was going to the melanoma clinic every 6 months for almost 3 years but yet he still died!!! How was it possible that being seen my Melanoma Dr’s his was able to spread to his liver and lungs and within 6 months he was gone!!!!!

    • It depends on the individual case and stage. 5-6 visits over that length of time may not have been enough. The cancer could have progressed very rapidly in its final stage. My grandmother had a visit where she was at Stage III, and then less than a month later she died of very aggressive Stage IV. It simply moved that fast even though the doctors were doing good work. That’s the nature of melanoma and why it is so deadly.

      My sincere condolences for your loss.

  3. I would like to have seen some mention of tanning beds. Aren’t they dangerous as well? Much worse than sun, minute-for-minute exposure wise?

    • There is indeed much literature on the harmful effects of tanning bed usage. We are actively pursuing government regulation of tanning bed salons to protect our young patients from excessive exposure to ultraviolet radiation. There has been several articles suggesting that tanning bed use (and in general, UV exposure at a young age) is associated with increased risk of sun exposure

  4. The diagnosis of skin cancer is frightening. However early detection is key to a good outcome. The CDC shows that you have a one percent chance of getting skin cancer. However if you address it early you can lower your chances even more.

  5. my mom died in march of 1994 from a prolonged bout with melanoma. she was only 55 years old. she was first diagnosed in 1986 with a stage 4 mole on her upper thigh.
    she had surgery and went through intensive treatment. she was checked periodilly over the next five years and all looked good. about 3 months after the 5 yrs she was getting ready for bed and felt a lump in her groin. not good. it was back and had gotten into her lymph nodes. it was pure hell for the next 3 yrs and she battled mightly.
    what a horrible way to die. spread to her brain stem and finally to her liver. tumoers covered her upper leg amd groin area like barnicles on a rock. when i see young people going to tanning salons and getting sunburns at the beach i want to tear my hair out. if they only knew the long term affect. maybe i should show them pictures of my mom in her final days. keep up the good work, good luck and god bless.

    • I am so sorry to hear. I think that is why we are so committed to fighting melanoma because we see too many young people affected.

  6. Why are not more studies made on non melanoma cancer?
    It might not kill but leaves one terribly desfigured.

    • There is much interest in basal cell carcinoma and squamous cell carcinoma. Please see this Pubmed ID PMID: 19726763 [PubMed – indexed for MEDLINE] for the most recent studies on advanced stage basal cell carcinoma treatments.

    • Hi Rick,

      Thanks for your question about the effects of sunscreen on melanoma. In a recent Australian study, the regular use of sunscreen reduced the risk of all melanomas by 50% and invasive melanomas by 75%. The study also suggested that using sunscreen made people more likely to be aware of the importance of practicing sun safety in general, which likely contributed to the overall decline in melanoma risk. Here’s the research study abstract: http://www.ncbi.nlm.nih.gov/pubmed?term=21135266%20

      • I think the question might be regarding putting sunscreen on existing melanoma. My dermatologist and surgeon both told me the same — that once you have cancer, the only real solution is to stay out of the sun, because sunscreen won’t be effective enough. I also wear sun-protective clothing. Is there research on the efficacy of sunblock versus other methods post-diagnosis?

  8. How can you tell if you have a stage 1 melenoma>?
    Are there symptoms or visible signs?>

    • In general, we follow the ABCDE’s of melanoma:
      A for asymmetry
      B for border irregularity
      C for color – multiple colors, darker colors than other moles
      D for diameter (greater than 6mm)
      E for evolution which is probably the most important sign, if you have a mole that bleeds, a mole that is growing larger, please see a doctor.

      If at all concerned please see your primary care doctor or your dermatologist.

  9. When researchers say that melanoma is “often” the result of “too much” exposure to ultraviolet light, i would question what is meant by “often” and “too much”. I would be interested to see how many cancers can be correlated w/the effect of too little vitamin D / too little sun exposure.

  10. What is the evidence (literature citations) that wearing sunscreen protects against development of melanoma skin cancer?

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