Even as some across the United States are still experiencing snow flurries, May is the month when the majority of Americans are gearing up for the summer. As thoughts of time enjoying the warm weather and sunshine outdoors can provide a welcome distraction from the current state of the world — especially as many of us continue to shelter in place — it is important to also remember as we move into the summer season the danger sun exposure poses in relation to skin cancer.
May is also Skin Cancer Awareness Month, and thankfully while skin cancer is the most common type of malignancy Americans are diagnosed with, it is also one of the most preventable. Here, we explore below the three most common types of skin cancer, how to spot them, and what can be done to prevent them.
Basal Cell Carcinoma
Worldwide, the most common form of skin cancer is basal cell carcinoma. Thought to be caused by long-term exposure to ultraviolet (UV) radiation from sunlight, this type of cancer begins in a basal cell, which is a type of cell found at the bottom of the skin’s first layer known as the epidermis. The basal cells produce new skin cells, which pushes old skin cells to the surface allowing them to die off and be replaced by the newer cells. When a basal cell’s DNA mutates, it tells the basal cell to multiply rapidly and continue growing when it would normally die.
Eventually the accumulating abnormal cells may form a cancerous tumor — the lesion that appears on the skin.
It usually develops on parts of the body that are most-often exposed to the sun, such as the face, scalp, ears, chest, arms, back, and legs. Less often, basal cell carcinoma can occur on parts of the body that are usually protected by the sun such as the genitals. The tumor can have several different appearances, but the most common form found is a small dome-shaped bump with a pearly white color. It is often translucent and tiny blood vessels may be visible through the surface. It can also appear as a blue, brown or black lesion with a slightly raised translucent border. On the chest or back it may appear as a reddish scaly patch of raised skin that can grow quite large. It also can appear as a pimple-like growth that heals then reappears repeatedly. Least common, it can be a morpheaform which looks like a white or yellow waxy scar-like lesion without a clearly defined border.
Basal cell carcinoma has many drastically different appearances, which is why it is important to remain alert to any and all changes you notice on your skin, performing self-examinations at least monthly and visiting a board-certified dermatologist for an exam at least once a year, or anytime you notice something new, changing, or unusual.
If you are diagnosed with basal cell carcinoma, you should discuss the possible surgical options for treatment with your dermatologist. Alternatives include performing a simple surgical excision, to cut out the skin cancer and then sew the skin using dermatologic cosmetic techniques. Other treatment methods such as radiation therapy, cryosurgery, and laser therapy may also be used in certain circumstances. Some practices are capable of performing Mohs micrographic surgery, which is a specialized surgery in which a minimal amount of tissue is removed and all the edges of the removed specimen are carefully studied to ensure the complete removal of the cancerous cells. Most dermatologists agree that skin cancers that were previously treated and have come back, incompletely removed skin cancers, large skin cancers, and skin cancers in cosmetically important areas may benefit from the Mohs technique.
Squamous Cell Carcinoma
The second-most common type of skin cancer is squamous cell carcinoma. More than 250,000 new squamous cell carcinomas are diagnosed every year in the U.S., with middle-aged and elderly persons — especially those with fair complexions and frequent sun exposure — most likely to be affected. The squamous cells are flat, thin cells in the middle and upper layer of the epidermis, and like basal cell carcinoma the cancer is formed when the cell’s DNA mutates to begin growing cells out of control and continue living where normal cells would die. If treated in a timely manner, it is uncommon for squamous cell carcinoma to spread to other areas of the body, and also like basal cell carcinoma most of the DNA mutations in the squamous skin cells are caused by ultraviolet radiation found in sunlight and in commercial tanning lamps and tanning beds.
In terms of appearances, squamous cell carcinomas often arise from small sandpaper-like growths called solar or actinic keratoses on your scalp, the backs of your hands, your ears or your lips. It can also less commonly appear as a firm red nodule, a new sore or raised area on an old scar or ulcer, A rough, scaly patch on your lip that may evolve to an open sore, a red sore or rough patch inside your mouth, or a red, raised patch or wart-like sore on or in the anus or on your genitals. This type of skin cancer is usually localized in its destruction, and if left untreated can destroy much of the tissue surrounding the originating location of the tumor and may result in the loss of a nose or ear. Although not common, certain aggressive types of untreated squamous cell carcinomas can spread to the lymph nodes and other organs.
Again, early detection is the key to preventing the devastating spread of skin cancer, so keeping an eye out for any change in appearance to your skin is vital, especially if you work or are in the position where your sun exposure is above average. Dermatologists use a variety of different surgical treatment options depending on location of the tumor, size of the tumor, microscopic characteristics of the tumor, health of the patient, and other factors. Most treatment options are relatively minor office-based procedures that require only local anesthesia. Surgical excision to remove the entire cancer is the most commonly used treatment option. Mohs micrographic surgery can also be used to treat this form of cancer.”
Melanoma – the most serious type of skin cancer – is increasing in the United States rapidly. For someone born in 1930, the risk of developing malignant melanoma at some point in their lives was then 1 in 1500. A baby born today has a lifetime risk of 1 in 55. Like squamous cell and basal cell carcinoma, malignant melanoma develops in the epidermis layer of the skin, but unlike the other two it is more likely to grow and spread to other parts of the body if left untreated. Melanoma forms with a mutation of the DNA in melanocytes, cells that make the brown pigment called melanin which gives the skin and hair it’s tan or brown color.
Most often like the other skin cancers, melanoma forms where the skin has been most exposed to sun such as the back, arms, legs, and face. Because of its development in the skin cells that produce melanin, in these places melanoma most often occurs as a pigmented (tan or brown) area of skin. This is why it is especially important to check all existing moles — as well as any new ones that may pop up — for changes in size, color, shape, elevation, surface texture, surrounding skin, sensation, or consistency. However, melanoma can also occur in areas that don’t receive much sun exposure, such as the soles of your feet or palms of your hands. It can also occur under the nail bed, in the mucous membrane that lines the nose, mouth, esophagus, anus, urinary tract and vagina, and even in the eye.
It is now possible to predict with considerable accuracy which malignant melanomas are curable and which are not, with thickness of the tumor being a key factor. Malignant melanomas that are removed when they are less than 3/4 of a millimeter in thickness are cured in virtually all cases, as long-term follow-up has repeatedly confirmed. However, progressively thicker malignant melanomas have correspondingly poorer prognoses. Given these facts, it is essential that members of the medical profession, the allied health fields, and the public at large be able to recognize early malignant melanomas, which can be so successfully treated.
The best way to beat skin cancer is to avoid getting it in the first place. Sun avoidance is the best defense against skin cancer. Over-exposure to sunlight (including tanning) is the main cause of skin cancer especially when it results in sunburn and blistering. One can’t be expected to never go out in the the sun again though, so here are some of the most important steps to preventing sun exposure:
- Try to avoid being exposed to the sun during the time of day when the sun is highest in the sky (10:00am – 4:00p), or whenever your shadow is shorter than you are tall. This is important to remember even in the winter and when the sky is cloudy, as you can still receive harmful UV rays during both.
- Wear light-colored, protective clothing that is made of a tight weave. Clothing is more effective for skin protection than sunscreen as it completely covers your skin, and clothing with a UPF rating work particularly well.
- Apply sunscreen of at least SPF 30 whenever you will be exposed to the sun’s rays. This can even include being indoors, as UV rays are still easily able to travel through windows and cause damage. Sunscreen should be applied liberally and evenly to your body, and then reapplied every two hours, or more often if you get wet or sweat.
- Freedberg, et al. (2003). Fitzpatrick’s Dermatology in General Medicine. (6th ed.). McGraw-Hill. ISBN0-07-138076-0
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- Narayanan DL, Saladi RN, Fox JL (September 2010). “Ultraviolet radiation and skin cancer”. International Journal of Dermatology. 49 (9): 978–86
- Gandhi SA, Kampp J (November 2015). “Skin Cancer Epidemiology, Detection, and Management”. The Medical Clinics of North America. 99 (6): 1323–35