An in-depth report on the causes, diagnosis, treatment, and prevention of melanoma.
Skin cancer; Squamous cell cancer; Basal cell cancer; Actinic keratosis
Although any diagnosis of cancer is frightening, very few people die of nonmelanoma skin cancers. They are generally slow-growing and very curable. A number of options are available for treating these skin problems, including surgery, cryosurgery, phototherapy, radiation, and topical 5-fluorouracil. Few comparison studies have been performed to see which procedures are most effective for these skin problems .
For any skin cancer and for some keratoses that require removal, surgery is the first treatment. It is usually one of the following:
Excisional Surgery. This is the surgical removal of the cancerous lesion.
Curettage and Electrodesiccation. This procedure involves scraping away of the cancerous tissue followed by electric cauterization to stop the bleeding.
Mohs Micrographic Surgery. Mohs surgery is a meticulous procedure used for skin cancers at high risk for recurrence or becoming invasive. Studies indicate patients with the following skin cancers are among the good candidates for this procedure:
This procedure involves the following:
Mohs surgery saves more healthy tissue than other procedures and is highly effective. It results in a 99% cure rate for primary tumors and a 95% cure rate for recurrent ones. It can be safely performed in the doctor's office. Complications are uncommon but can include bleeding and infection.
Lasers. Laser surgery may be useful for certain basal cells and for keratoses that appear on the lips, although it is not clear whether lasers offer any advantages over other surgical treatments. Lasers do not appear to be very effective for thick or tough squamous cell carcinomas.
Cryosurgery removes skin cancer cells or actinic keratoses by freezing the affected tissue with liquid nitrogen (a technique known as cryosurgery). Studies report the following:
Cryotherapy achieves good cosmetic results for many patients. However, it may cause blistering and ulceration, leading to pain and infection, as well as harmless, but undesirable, skin-color changes.
In unusual cases where the carcinoma may be in an inoperable position (such as the eyelid or the tip of the nose) or if cancer has recurred multiple times, radiation therapy may be indicated. Radiation is directed at the tumor. It may take one to four weeks with treatments performed several times a week. One technique being investigated for basal and squamous cell carcinoma uses radiation implants (brachytherapy) and custom-made molds to specifically target the radiation. Studies suggest that this treatment is very effective with few complications.
Topical phototherapy with aminolevulinic acid (ALA) is a nonsurgical method that is proving to be a good choice for treating actinic keratoses and some nonmelanoma skin cancers (Bowen's disease and basal cell carcinoma). It employs blue light administered after that patient has taken aminolevulinic acid (Levulan, Karastik). ALA accumulates in the skin cells and when exposed to intense light, the chemical causes these cells to die. This approach allows precise targeting of one or more lesions, leaving healthy skin unaffected.
It does not penetrate deeper than the epidermis (the top layer of the skin), so it does not produce scarring or changes in skin color, as cryotherapy or other more invasive treatments do.
It can cause pain, irritation, including stinging, itching, and burning, but in one study only 3% of patients stopped using it for this reason. In a 2002 study, the procedure was more painful for patients with actinic keratoses than for those with nonmelanoma skin cancers. It was also painful when large areas were affected, and men experienced more pain than women.
ALA Phototherapy for Actinic Keratoses. Phototherapy is showing very good results for actinic keratoses. It works best on flat lesions performed in two treatments, and is more effective for clearing lesions on the face than those on the scalp. Phototherapy can also treat multiple lesions at the same time instead of sequentially, as in cryotherapy. Studies to date suggest that it may be as effective as cryotherapy and achieve better cosmetic results. (More patients report burning and itching with phototherapy, however.) Phototherapy is also equal to topical 5-fluorouracil in effectiveness and achieving a satisfactory appearance.
ALA Phototherapy for Nonmelanoma Skin Cancers. In patients with squamous cell carcinoma-in-situ (Bowen's disease) and basal cell carcinoma, phototherapy has been equal to cryotherapy, with superior healing and appearance afterward. A 2003 study reported that it was more effective than topical 5-FU for patients with Bowen's disease and there were fewer side effects.
Nevertheless, two 2001 studies reported that despite initial good results, about 10% of patients using phototherapy experienced a recurrence within 1 year. These recurrence rates are higher than with surgery and other standard treatments. Longer-term studies are required before ALA phototherapy can be recommended for most patients with nonmelanoma skin cancers.
Chemical peeling, or exfoliation, is useful for solar keratoses on the face, especially in people with fair, dry skin. Alpha-hydroxy acids, for example, are being investigated for keratoses. Dermabrasion, which "sands" the skin, may also be effective although scarring is possible. A 2002 study found laser resurfacing to treat severe sun damage on the face; however, it may not prevent nonmelanoma skin cancers.
A number of medications are being used for keratoses and some may be helpful for skin cancers as well. Besides cryotherapy, 5-fluorouracil is the other most commonly used treatment for actinic keratoses. Other medications are also available.
Medications for Keratoses and Common Skin Cancers |
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| Medication | Skin Conditions Affected | Oral or Topical | Comments | ||
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5-Fluorouracil |
Actinic keratoses, Bowen's disease and small nonmelanoma skin cancers. |
Topical cream (Efudex, Fluoroplex) or injected gel containing 5-FU and epinephrine (AccuSite). |
5-Fluorouracil (5-FU) removes actinic keratoses and is useful for some patients with a large number of lesions. It requires twice daily application for 3 to 4 weeks. It can cause significant redness, irritation, swelling, and crusting, which takes 2 to 4 weeks to heal. Newer preparations are reducing these side effects. It is still unclear if this medication protects against recurrent keratoses or future skin cancer. Of concern is the possibility that (5-FU) will clear the top of a skin cancer and obscure the rest of the cancer that lies beneath the surface of the skin. A 10-year 2003 study of patients with Bowen's disease reported that 5-FU was safe and effective, with only 2 out of 26 cancers recurring. |
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Masoprocol (Actinex) |
Actinic keratoses. |
Topical cream applied twice a day. |
Actinic keratoses have cancer-fighting properties. Side effects, including itching and redness, can be as severe as those from 5-fluorouracil. |
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Diclofenac and hyaluronan (Solaraze) |
Actinic keratoses (approved). Investigated for basal cell. |
Topical gel applied twice a day. |
Diclofenac is a nonsteroidal anti-inflammatory drug (NSAID). When used to treat actinic keratoses, it is delivered to the skin with hyaluronan, a water-seeking molecule that helps maintain skin tension. Healing may not be evident until a month after treatment ends. It has modest effects and when healing occurs, it may not be evident for at least a month after treatment ends. However, it causes less irritation than 5-FU and may be useful for some people. |
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Imiquimod (Aldara) |
Approved by the FDA in July 2004 for treating superficial basal cell carcinoma (BCC). Previously approved for treating actinic keratoses. Investigated for Bowen's disease and squamous cell cancer. Aldara should only be used when surgery for BCC is inappropriate. It is not approved for use on the face. |
Imiquimod is a topical cream. |
Imiquimod (Aldara) induces production of immune factors that help fight cell proliferation. It has good cosmetic results and is showing promise for actinic keratoses and for basal cell carcinoma (BCCs). One study, in fact, suggested it may prove to be an alternative to surgery for small, low-risk BCCs. However, long-term cure rates are not known. |
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Alpha-Interferons |
Basal cell carcinoma, squamous cell carcinoma. |
Require injections administered three times a week. |
Interferons are immune factors that are being used to treat a number of serious conditions. Alpha-interferon injections may be effective against skin cancers that are hard to treat using conventional surgical measures. Cosmetic results reported to be good or very good by 83% of patients. |
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