Malignant Melanoma Trends Require Preventive Measures
Youth yield to tanning peer pressure at increasing risk
By Rachel Epstein, OMS IV, Nova Southeastern University
As I opened the door to one of the clinic rooms, I saw a beautiful young female with long blond hair. She was arguing with her mother who sat beside her about why she was in the doctor’s office on a Friday afternoon.
While tying the swim suit, her mother explained that when their family went boating over the past weekend, her daughter had asked her to tie her bikini top a little tighter prior to go waterskiing. While tying the swim suit, mother noticed a mole underneath the strap that appeared a little more colorful than what she remembered in the past. The daughter vehemently denied any changes in her skin.
This 16-year-old female hated putting on sunscreen because it “slowed down her tanning process” and she went to a tanning bed twice a week to soak up some more rays. She stated that she always wanted to look more tan because with a tan she looked healthier.
Little did she know that her mother had just saved her life. Just two weeks later, her whole future changed before her eyes – beauty queen, diagnosed with severe melanoma at just 16 years of age.
I could not believe it, one so young and innocent with no family history of skin cancer. I had never seen a patient this young with such an invasive disease and did not realize that melanoma could affect anyone at any age.
Like most teenagers, she was preoccupied with physical appearance and thought she was invincible. The majority of teenagers are embarrassed to see a physician, let alone have someone take a look at their blemishes, moles, birthmarks and freckles.
Malignant melanoma is the sixth most common malignancy in the United States.1 The incidence has continued to rise at a rate of four percent every year since 1973.1 To put that figure in perspective, there has been a 300 percent increase in melanoma over the past 40 years.
Statistics show that 1 in 59 individuals born today in the United States will be diagnosed with melanoma of the skin at some point in their life.1
If melanoma is localized to the epidermis, then the five-year survival rate is 100 percent. If this cancer invades deeper into the dermis layer, then the five-year survival rate drastically decreases.
So, the key to lowering the morbidity and mortality due to malignant melanoma is to screen patients early and educate them as to the risk factors involved.
One of the responsibilities of a primary care physician is to teach our patients how to examine their skin on a regular basis. More than 70 percent of melanomas actually arise in or near an existing lesion on the skin.
Educating patients about melanoma is as easy as ABCDE. If a patient notices any of these characteristics while examining their skin they should visit their doctor as soon as possible.
Other warning signs are when color spreads into the surrounding skin, swelling beyond the mole; pain, tenderness, itching, bleeding, oozing, ulcerating; and the appearance of a bump or nodule overlying the lesion or in the surrounding area.
The Sun’s Evil Rays
What are the risk factors for developing melanoma? Yes, the sun does play a role, but it is not the sole etiology. Two-thirds of melanomas may be attributed to excessive sunlight exposure.2,3 Both the dosage and the nature of exposure to ultraviolet radiation are risk factors.
Blistering sunburns in early childhood increase the risk as well as cumulative exposure to ultraviolet radiation. In fact, a 10 percent increase in average annual intensity of UVB exposure is associated with a 19 percent increase in an individual’s risk for melanoma in males and a 16 percent increase in females.4 Melanoma occurs most frequently after intermittent exposure to the solar rays and in people who are more prone to develop sunburns. Therefore, areas such as the back in men and the lower legs in women are the most common places to find malignant melanoma.5,6
These areas are very difficult to examine with one’s own eyes, and that is why individuals should use a full-length mirror in combination with a hand held mirror or ask another person to examine their skin, being sure to look at fingernails, toenails, soles of the feet, and intertriginous areas, as melanoma can be hiding out in these places.
Exposure to sun and the gradual development of a tan, however, can provide a protective shield.
Epidemiologic body site distribution of melanoma observations suggest that chronic, low-grade exposures to ultraviolet light induce protection against DNA damage, whereas intense, intermittent exposures cause genetic damage.3
One does not even have to be outside to be exposed to the UV rays. Tanning beds are an increasing source for these potentially deadly rays, especially among youth. This exposure in childhood is particularly detrimental. Just five or more severe sunburns in adolescence more than doubles the risk of developing melanoma.7
Primary prevention interventions, such as reducing exposure to the ultraviolet rays may reduce the incidence of this malignancy.2,3 Following the development of a melanoma, patients are 5-6 times more likely to develop a subsequent lesion.1 Multiple factors which have played a role in the dramatic increase in the incidence of melanoma are listed in Table 1.
What About Genes?
Although anyone’s genetic makeup can potentially predispose them to developing melanoma, there are certain polymorphisms that place one at a higher risk. Light-skinned and redheaded individuals often carry a germ-line polymorphism in the MC1R (melanocortin receptor 1) gene that has been found to reduce activity of this receptor.8,9 These lighter skinned individuals have an increased susceptibility to melanoma due to a genetic impairment in the production of melanin.
Melanin is the main defense of melanocytes against UV radiation. Many other genes play an important role in melanoma including p16/INK4a and BRAF- kinase. P16/INK4a, which encodes for tumor suppressors, is the most frequently mutated gene in malignant familial melanoma. BRAF-kinase is the most frequently mutated gene in acquired melanoma and nevi.
Patients who have these genetic polymorphisms need to be more cognizant about making an effort to reduce the risk factors for developing melanoma. A list of preventative measures that should be implemented on a daily basis are listed below.
Melanoma Progression
It is important to understand the progression and classifications of melanoma in order to educate your patients about their diagnosis and prognosis.
Dr. Clark defined the progression of melanoma in terms of two phases, a radial and a vertical growth phase. Once the vertical growth phase is reached and the melanoma invades the papillary dermis, the melanocytes have access to lymphatics and are capable of metastasizing. These levels of invasion correlate well with survival. Table 2 defines the levels of invasion, according to Dr. Clark.
Dr. Breslow defined a method of measuring melanoma tumor thickness by using a calibrated micrometer, and found that the depth of the tumor correlated with survival. Tumor thickness is the most important risk factor in determining survival for level I melanoma.
The second most important factor for survival relates to the presence or absence of ulceration. Melanomas that ulcerate are more aggressive compared to those that do not ulcerate.
The incidence of malignant melanoma has increased in all ages and in both females and males from 1975 until 2003, and still continues to rise.10 Currently melanoma is responsible for 80 percent of deaths from skin cancer. Melanoma among adolescents is on the rise, most likely due to perceived social norms among this population.
Most young adults have the attitude that a tan is both healthy and attractive. This attitude alone predicts a lower use of sun protection.11 Until this perspective is modified, we are likely to witness a continued increase in the incidence of malignant melanoma. One of most important roles of a family physician is to educate the general public about the signs of melanoma and the consequences of excess exposure to ultraviolet rays.
A decrease in the incidence of melanoma has been evident in Australia, where melanoma affects one out of 17 males and one out of 14 females.12 Educating children with the Slip-Slap-Slop Program (slipping on a shirt, slapping on a hat and slopping on sunscreen) has been effective in Australia and has contributed to the national decline in incidence of malignant melanoma.12
Primary prevention such as the Slip-Slap-Slop Program and the ABCDE’s during routine skin screenings should be implemented in the United States. These processes will allow for detection of this cancer early or in the preinvasive stage, before it is too late. Self skin examinations should be performed every six to eight weeks. This helps to find suspicious moles or other irregular lesions early and bring them to the attention of their physicians.
Children and adolescents should be encouraged by their physicians, as well as their parents, to wear sunscreen and avoid excess sun exposure. Protecting the skin during the first 18 years of life can reduce the risk of skin cancer by up to 78 percent.1 If melanoma is caught early on it will only be skin deep.
Dr. Rachel Epstein is a recent graduate of Nova Southeastern University, Fort Lauderdale, Florida. She currently is an intern at Sun Coast Hospital in Largo, Florida.
References:
High Risk |
Intermediate Risk (~10-fold increase in risk) |
Low Risk (2-4-fold increase in risk) |
| >50 nevi ≥ 2mm in diameter | Family history of melanoma | Sun sensitivity |
| Clinically atypical moles with a family history of melanoma | Congenital nevi "birthmarks" | Excess exposure to UV rays |
| Persistently changing mole | Sporadically changing atypical moles | Immunosuppression |
| White ethnicity, expecially fair skin with blue/green eyes and blonde/red hair | ||
| Personal history of melanoma | ||
| Adapted from AR Rhodes et al: JAMA 258:3146, 1987 | ||