Different Skin Cancers
SKIN CANCER
There are many kinds of skin cancer but the vast majority fall into one of three categories: basal cell, squamous cell and melanoma. The first two are rarely life- threatening, while the last is one of the most dangerous of cancers known to man. Because of its conspicuous position, skin cancers provide great opportunities for early detection in some cases.
Cancers of the skin as a group are by far the commonest of cancers. In many cases, it is felt that chronic, cumulative exposure to solar radiation, especially in the ultraviolet category, is the main causative factor in all three types. X- rays, certain chemicals and some genetic diseases are additional causes in a minority of patients.
BASAL CELL CANCER
These are highly associated with sun exposure, and generally appear as raised, hard red bumps with a translucent quality to their surface. Characteristic locations are the scalp, forehead, cheeks, and nose. If untreated, they tend to develop ulceration of the central zone. A benign skin problem called an actinic keratosis is probably a precursor to an occasional cancer of the skin. It is a scaley raised area, with a characteristic appearance; most of them remain benign.
Definitive diagnosis is by biopsy under local anesthesia. However, many experienced physicians can accurately make the diagnosis of typical lesions by their appearance alone, and this is considered sufficient. Treatment is generally simple, and consists of surgical removal, radiation treatments, chemical destruction of the area with toxic chemical, electric cautery, or application of solutions of the anti-cancer drug fluorouracil. The choice of one of these methods depends on the location, local expertise, and presence or absence of other lesions to be treated. Each method leads to very high cure rates, and the occasional recurrence can be treated similarly. Observation should be quite intense indefinitely.
Occasionally, such a skin tumor can extend to underlying bone or cause considerable cosmetic deformity, especially if not treated early. In these cases, fairly considerable amounts of plastic and reconstructive surgery may be necessary. Metastasis is exceedingly rare, and cure rates should exceed 95% for smaller tumors.
SQUAMOUS CELL SKIN CANCER
Like basal cell cancer, squamous cell cancer often appears on sun exposed areas, but may occur anywhere. They tend to be scaley, with irregular borders, and have more of a tendency to ulcerate and form crusts. Biopsy is the means of definitive diagnosis. Local therapy is similar to that of basal cell cancer, but cure rates are slightly lower, in the 80% range. Recurrences are generally local, and can be readily treated.
Rarely, a squamous cancer will spread to other organs, and can become quite dangerous. This is the exception, but underlines the importance of not overlooking or underestimating skin cancers of this sort.
MELANOMA
Melanomas are cancers of the melanocytes or pigment forming cells of the skin. Common moles are also derived from melanocytes, and may be the source for the majority of melanomas.
Sun exposure plays a clear role in the causation of many but not all melanomas. Black people get melanomas very rarely, whereas the incidence in light skinned people is highest in equatorial locations. The incidence of this cancer is rising at an alarming rate, doubling every fifteen years or so.
SYMPTOMS
The earliest symptom of a melanoma is almost always a visible change in the appearance of an existing mole or an area of previously normal skin. Common clues are the occurrence of an enlarging irregular or notched border, the appearance of red, blue or white areas in a mole, itching or bleeding, or the appearance of a new mole in adulthood. Any such change, or any unexplained change of any sort in a skin area, should warrant prompt evaluation and probable simple biopsy under local anesthesia.
Diagnosis is based on the results of the biopsy. Staging and prognosis, as well as treatment is based upon the depth of invasion into the surrounding skin, among other things. A search for spread to other organs is warranted if symptoms are present or the tumor seems to have invaded deeply.
TREATMENT and PROGNOSIS
Local wide surgical removal of the original melanoma is the primary hope for cure, and for those which have invaded less than a millimeter or so, this is usually curative. In thicker melanomas, some of the nearby lymph nodes are often removed to check for spread.
If a melanoma has invaded deeply into the skin, chances of spread are great, and consideration is given to experimental modalities such as the infusion of anti-cancer drugs directly into the artery supplying the area of the melanoma, and chemotherapy. No known program has been of proven benefit for metastatic melanoma, and radiation has been similarly unsuccessful.
Recent research has explored the usefulness in advanced melanoma of immune stimulation of the patient’s system with vaccines used for tuberculosis, as well as with other agents, or with killed melanoma cells from another patient. These highly experimental treatments have produced no more than an occasional response. Malignant melanoma must be considered uncurable once it has spread beyond the skin, except in the most unusual case, with long- term survivals less than 25%.
Given the grim outlook of advanced melanoma as compared to the high cure rate of early lesions, it follows that prevention and early detection are key. Immediate attention for any suspicious skin changes is foremost. Prevention consists of sun avoidance for all light skinned people, except as is necessary. Sun screens of the highest protection factor (grade 15) can allow outdoor recreation with reduced risk for those who will not or cannot avoid long periods of sun exposure. The risks in this regard seem to be cumulative over a lifetime, so that the total risk increases with time, even if interval periods of no exposure have occurred. A very dangerous cancer, the melanoma incidence is rising sufficiently rapidly that many of us may soon be forced to re-evaluate our sun-worshipping way of life, or at least take consistent measures to minimize its risks.
SKIN CANCER
There are many kinds of skin cancer but the vast majority fall into one of three categories: basal cell, squamous cell and melanoma. The first two are rarely life- threatening, while the last is one of the most dangerous of cancers known to man. Because of its conspicuous position, skin cancers provide great opportunities for early detection in some cases.
Cancers of the skin as a group are by far the commonest of cancers. In many cases, it is felt that chronic, cumulative exposure to solar radiation, especially in the ultraviolet category, is the main causative factor in all three types. X- rays, certain chemicals and some genetic diseases are additional causes in a minority of patients.
BASAL CELL CANCER
These are highly associated with sun exposure, and generally appear as raised, hard red bumps with a translucent quality to their surface. Characteristic locations are the scalp, forehead, cheeks, and nose. If untreated, they tend to develop ulceration of the central zone. A benign skin problem called an actinic keratosis is probably a precursor to an occasional cancer of the skin. It is a scaley raised area, with a characteristic appearance; most of them remain benign.
Definitive diagnosis is by biopsy under local anesthesia. However, many experienced physicians can accurately make the diagnosis of typical lesions by their appearance alone, and this is considered sufficient. Treatment is generally simple, and consists of surgical removal, radiation treatments, chemical destruction of the area with toxic chemical, electric cautery, or application of solutions of the anti-cancer drug fluorouracil. The choice of one of these methods depends on the location, local expertise, and presence or absence of other lesions to be treated. Each method leads to very high cure rates, and the occasional recurrence can be treated similarly. Observation should be quite intense indefinitely.
Occasionally, such a skin tumor can extend to underlying bone or cause considerable cosmetic deformity, especially if not treated early. In these cases, fairly considerable amounts of plastic and reconstructive surgery may be necessary. Metastasis is exceedingly rare, and cure rates should exceed 95% for smaller tumors.
SQUAMOUS CELL SKIN CANCER
Like basal cell cancer, squamous cell cancer often appears on sun exposed areas, but may occur anywhere. They tend to be scaley, with irregular borders, and have more of a tendency to ulcerate and form crusts. Biopsy is the means of definitive diagnosis. Local therapy is similar to that of basal cell cancer, but cure rates are slightly lower, in the 80% range. Recurrences are generally local, and can be readily treated.
Rarely, a squamous cancer will spread to other organs, and can become quite dangerous. This is the exception, but underlines the importance of not overlooking or underestimating skin cancers of this sort.
MELANOMA
Melanomas are cancers of the melanocytes or pigment forming cells of the skin. Common moles are also derived from melanocytes, and may be the source for the majority of melanomas.
Sun exposure plays a clear role in the causation of many but not all melanomas. Black people get melanomas very rarely, whereas the incidence in light skinned people is highest in equatorial locations. The incidence of this cancer is rising at an alarming rate, doubling every fifteen years or so.
SYMPTOMS
The earliest symptom of a melanoma is almost always a visible change in the appearance of an existing mole or an area of previously normal skin. Common clues are the occurrence of an enlarging irregular or notched border, the appearance of red, blue or white areas in a mole, itching or bleeding, or the appearance of a new mole in adulthood. Any such change, or any unexplained change of any sort in a skin area, should warrant prompt evaluation and probable simple biopsy under local anesthesia.
Diagnosis is based on the results of the biopsy. Staging and prognosis, as well as treatment is based upon the depth of invasion into the surrounding skin, among other things. A search for spread to other organs is warranted if symptoms are present or the tumor seems to have invaded deeply.
TREATMENT and PROGNOSIS
Local wide surgical removal of the original melanoma is the primary hope for cure, and for those which have invaded less than a millimeter or so, this is usually curative. In thicker melanomas, some of the nearby lymph nodes are often removed to check for spread.
If a melanoma has invaded deeply into the skin, chances of spread are great, and consideration is given to experimental modalities such as the infusion of anti-cancer drugs directly into the artery supplying the area of the melanoma, and chemotherapy. No known program has been of proven benefit for metastatic melanoma, and radiation has been similarly unsuccessful.
Recent research has explored the usefulness in advanced melanoma of immune stimulation of the patient’s system with vaccines used for tuberculosis, as well as with other agents, or with killed melanoma cells from another patient. These highly experimental treatments have produced no more than an occasional response. Malignant melanoma must be considered uncurable once it has spread beyond the skin, except in the most unusual case, with long- term survivals less than 25%.
Given the grim outlook of advanced melanoma as compared to the high cure rate of early lesions, it follows that prevention and early detection are key. Immediate attention for any suspicious skin changes is foremost. Prevention consists of sun avoidance for all light skinned people, except as is necessary. Sun screens of the highest protection factor (grade 15) can allow outdoor recreation with reduced risk for those who will not or cannot avoid long periods of sun exposure. The risks in this regard seem to be cumulative over a lifetime, so that the total risk increases with time, even if interval periods of no exposure have occurred. A very dangerous cancer, the melanoma incidence is rising sufficiently rapidly that many of us may soon be forced to re-evaluate our sun-worshipping way of life, or at least take consistent measures to minimize its risks.