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

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”

    • Dear Pat —
      Thank you for your comment and for reading Insight. Experts recommend using the “ABCDE rule” to help determine when a physician should see a mole or skin change:

      A for asymmetry: One half is differently shaped than the other
      B for border irregularity: Jagged or blurred edges
      C for color: The pigmentation is not consistent
      D for diameter: Moles greater than six millimeters (the size of a pencil eraser)
      E for evolving: A mole changing in size, shape or color

      Other symptoms of melanoma can include satellite moles (new moles that grow near an existing mole), or areas that ooze, bleed, or are ulcerated.

      I hope this is helpful! More information about skin cancer screening recommendations is available here.

  1. I had a biopsy last week; the result was the scary word, Melanoma. Yesterday, I had more taken from the area, well outside of the margins. I should hear the results from this next week. My question: Should I make an appointment with an oncologist? I will be seeing my Dermotologist every 3 months for two years and every 6 months after that; in addition, I don’t know if I should see an oncologist too.
    Thank you

    • Dear Tammy–
      I am sorry to hear about your recent health concerns. Unfortunately, we cannot give out medical advice on this blog or over email. It is best to discuss your questions and concerns with your physician or dermatologist – they will be able to recommend any next steps you should take.
      Wishing you all the best.

  2. Why is there a difference in opinion in the medical field whether melanoma in situ is considered cancer or not? I was diagnosed two weeks ago and referred to a plastic surgeon by my dermatologist to remove the rest of the “spot” since it is on my face. I’m having to wait another two weeks to see the plastic surgeon for a “consultation,” then who knows how much longer it will be. I NEVER spent a lot of time outdoors (don’t like the blistering sun), never went to a tanning salon and the “spot” does not have the characteristics of the ABCDE’s. I went to the dermatologist to have a couple of skin tags, and what I thought was either an age spot or freckle, removed (which I had for three years), for cosmetic reasons. She was suspicious of the “spot” (which was flat and light brown) because I had no other similarities on my face and suggested a biopsy, to which I agreed.

  3. One clarification please: if I put on a 30+ sunscreen before I apply make up at say 8 am, then am in an office until noon, do I have to reapply it before I go out for a lunch time walk? Does the reapply rule assume that the wearer is in the sun and active for those two hours. To be honest, I would like to avoid the hassle of reapplying the sunscreen, make up etc.

  4. I have recently been diagnosed with Stage IV Melanoma, Unknown Primary Tumor. The metastasis on my left calf has been removed and I am currently NED. Surgery and observation is current treatment plan; I have not had a recurrence as of my original diagnosis (2 months). Are there any clinical trials available for my situation?

    • Dear Mary —
      Thank you for connecting with us and reading Insight. We are so sorry to hear about your recent diagnosis.

      Unfortunately, we cannot give out specific medical advice on this blog or over email. However, the links below provide a list of clinical trials both at Dana-Farber and across the country.

      Dana-Farber Clinical Trials

      We hope this is helpful and wish you all the best.

  5. 60 year old male, melanoma site on back removed. Sentinel lymph nodes biopsy indicates 3 of 4 nodes clean. 1 lymph node had 3 spots of micro cell melanoma. diagnosed with melanoma stage IIIA. Receiving treatment at MGH. The initial spot on my back looked like a bug bite. It was itchy and a pink spot, I initially thought it was a tick bite. All the doctors said it was very unusual, I would be happy to share the photo so that others may get some benefit from recognizing early onset of a unique melanoma. Awaiting results of lymph nodes pathology from regional lymphadenectomy.

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