Part One: The Skin Cancer Epidemic
This is part one of a three part series addressing the skin cancer problem in America. Our next 2 issues will deal with treatment methods and then prevention of skin cancer.
By Sherrif Ibrahim, M.D., PhD
The incidence of skin cancer in this country has reached nothing short of epidemic proportions with no sign of relent. Recent analyses estimate that the number of skin cancers treated annually in the United States approaches 3,000,000, far exceeding that of all other human malignancies combined and these numbers continue to rise dramatically. To put these figures in perspective, this translates to a 1 in 3 lifetime risk of developing skin cancer for fair-skinned Americans. The cost to the health care system ranks skin cancer 5th among human cancers, which is remarkable given that these are treated in an outpatient setting without expensive hospital, operating room, laboratory, or radiological costs, and without the use of traditional chemotherapy.
Contrary to the assumption that northern latitudes are not affected by this epidemic, the Greater Rochester Area has not been spared from the inundation of skin cancer. Our population of farmers, golfers, and snowbirds contributes to an abundance of skin cancer that keeps local dermatology offices quite busy. In fact, the University of Rochester Medical Center Department of Dermatology has two offices dedicated solely to the treatment of skin cancer.
What skin cancer looks like:
There are three main types of skin cancer: basal cell cancer (BCC), squamous cell cancer (SCC), and melanoma. Contrary to what most people think, skin cancers are not typically big black ugly marks on the skin. When BCCs and SCCs show up, they commonly appear as a small dome-shaped papule, or a flat scaly pink area of skin located on sun exposed areas of fair-skinned individuals. They occasionally bleed, scab, or become crusted.The first time someone has a skin cancer usually the last thing on their mind is that this is something serious. What usually brings someone into the dermatology office is that this spot that looks like a pimple or small scab just does not go away and slowly keeps getting bigger. If something is bleeding and you do not remember cutting yourself, or you see blood on your pillow from a spot on the back of your ear or on your scalp, there is a good chance that this is a small, growing skin cancer that needs treatment.
What is skin cancer?
Remember that our skin is our first line of defense against invading micro-organisms like bacteria and viruses as well as our shield from harmful ultraviolet rays from the sun (and from artificial sources such as tanning beds). When skin cells accumulate damage from a lifetime of sun exposure, they can begin to grow abnormally and at an uncontrolled rate. These cells do not grow properly and do not attach to one another the way skin cells do normally. If you imagine normal skin to look like a nice organized brick wall of individual cells, cancer cells are disorganized and piled up upon one another in a heap. These cells divide faster than the normal surrounding skin, and as they grow, they invade the surrounding skin and underlying structures such as muscle, bone, and cartilage. As the cancer continues to grow it can potentially spread into blood vessels and lymph channels. Once this happens, then cancer cells have access to other parts of the body and can spread, or metastasize, to other organs. Luckily, the most common types of skin cancer rarely metastasize in otherwise healthy individuals. However, melanoma does have a high propensity of spreading to different organs and once this occurs, current treatment options are very limited.
Types of Skin cancer:
Basal Cell Carcinoma (BCC): Basal cell cancer is by far the most common type of skin cancer, accounting for about 80% of all cases in the United States. The name “basal cell” comes from the type of cell that these cancers originate from – the basal cells are the bottom row of cells in the outermost layer of the skin (the epidermis). BCCs can appear in the skin as a small red or pink dome, a small thin scaly area of skin, or a spot that scabs over repeatedly but never heals. These cancers can be tender, bleed, change color, itch or cause crusting of the skin. BCC’s grow very slowly and almost never spread to other areas of the body. However, although they typically do not spread to different organs and are rarely, if ever, life threatening, they can cause a great deal of damage by being locally destructive and ‘eating away’ at whatever they grow into. BCCs continue to grow and grow and cause a great deal of damage and destruction. Remember that these cancers occur in sun exposed areas (80% on the head and neck), which means that they are most commonly found on areas such as the nose, lips, ears, or eyelids, and surgery to these areas to remove BCCs can often be extensive if they are not treated early.
Squamous cell carcinoma (PRON: skway-mus): SCCs are the second most common type of skin cancer, accounting for about 15% of all cases. Because, like BCCs, they start in the outer layer of skin, the two often can look very similar in appearance – small crusted or scaly growths in sun exposed areas that bleed easily and never go away. SCCs differ from BCCs in that on rare occasions, they can invade the blood or lymph vessels in the skin and metastasize to other organs, most commonly lymph nodes in the neck. Once this occurs, additional and often extensive surgery and radiation is needed to control the cancer.With both SCCs and BCCs the portion of the tumor that is visible on the skin may only partially represent the true extent of the cancer, as they often have roots or fingerlike projections that can extend outwards or downwards.
Although melanoma is nowhere near as common as BCC and SCC, it carries a much more serious prognosis. Suprising to most people, melanoma accounts for only 4% of skin cancer but we hear about it so much because it causes about 80% of deaths due to skin cancer. The cells that produce the color, or pigment, in our skin are called melanocytes, and when cancer develops in these cells, it is known as melanoma. In the United States, one person dies from melanoma every hour. It is the seventh most common type of cancer amongst American women, however, it is the most common cause of death due to cancer in younger women and the incidence of this disease continues to increase tremendously. Melanoma is a completely different entity than BCC or SCC and cancers of one type cannot transform in to the other types. Melanoma has a different appearance on the skin than BCC or SCC. These lesions are often irregularly shaped dark (or hyperpigmented) spots that can be either flat or raised. They can but do not necessarily bleed, scab, or crust. A mnemonic exists to help remember the concerning features of a melanoma: ABCDE. A: Asymmetry, B: Border Irregularity, C: Color variation (different colors and shades within the same spot), D: Diameter greater than 6 mm (about the size of a pencil eraser), E: Evolution – has the spot been changing? Areas on the skin that meet these criteria can be a sign for concern and should prompt a visit to a local dermatologist. As with any cancer, the earlier melanoma is discovered, the better the chances are for survival. Research has shown that the best predictor for how a patient will fare is how thick the melanoma is when it is measured by the pathologist. Thin melanomas carry a very good prognosis and have a very low chance of spreading to other parts of the body. Once melanomas have the chance to grow thicker, the chances for metastasis increase. If the cancer spreads to other organs, our current treatment options are very poor and chances for survival decrease.
Know your body: Change is everything
With any of the three main types of skin cancer, changes in the skin are most important. Because the skin is on the outside of the body, we have the advantage of being able to see and examine it without the need for x-rays or other medical tests. Being familiar with your skin and detecting new or changing areas is very important for the early detection of areas suspicious for skin cancer. Small bumps that continue to enlarge, sometimes bleed and never heal completely should prompt a visit to the dermatologist. New irregular dark moles or changes to existing moles that meet the ABCDE criteria are also reasons for a skin check. Suspicious lesions can be biopsied by your doctor and evaluated by a pathologist. Those that are confirmed as skin cancer will need additional treatment and these options will be discussed in Part II of this series. In the meantime, the best advice is to get to know your skin so that if any potential skin cancers appear, you will spot them early and have them looked at.
Next Month: Part Two-Treatment of Skin Cancer: Mohs Surgery
Sherrif Ibrahim, MD PhD is Assistant Professor of the URMC Department of Dermatology and the Wilmot Cancer Center. His practice is focused on procedural and surgical dermatology including the management of skin cancer with Mohs surgery.