Pre-cancers and Actinic Keratosis
Author: Thomas C. Weiss : Contact: www.disabled-world.com
Published: 2010-12-03 : (Rev. 2020-04-10)
Synopsis and Key Points:
Actinic Keratosis may also be referred to as solar keratosis and is a crusty or scaly lesion or growth.
Photodynamic therapy or, 'PDT,' is a type of medical treatment that utilizes a photo-sensitizing drug and a light source to activate the drug.
PDT can be used to treat rosacea, sun damage, acne, oily skin, wrinkles, enlarged sebaceous glands, warts, psoriasis, hidradenitis suppurativa, and other skin conditions.
Actinic Keratosis may also be referred to as a, 'solar keratosis,' and is a crusty or scaly lesion or growth. The growth many times appears on a person's scalp, ears, lips, face, the backs or a person's forearms or hands, or their shoulders or neck.
The growth can also appear anywhere on a person's body that has been exposed to the sun. Many times you will find them referred to in the plural, 'keratoses,' due to the fact that people often experience more than just one. As actinic keratoses begin they are commonly small enough that they are recognized more by touch than visually. The keratoses feel similar to sandpaper as a person runs a finger of them. There are often several time the number of invisible lesions as ones that are visible on the person's skin.
In the majority of instances actinic keratoses start slowly, then develop to a size of between an eight of an inch and a quarter of an inch. In the early stages, actinic keratoses might disappear, then reappear later on. The majority of them become red in color, although some appear pin, light or dark tan, or a combination of these colors; some may be the same color as the person's skin. On occasion, actinic keratosis may present a tender or pricking sensation, or may itch. The presence of actinic keratoses indicates that a person has sustained sun damage the might develop any form of skin cancer; not merely squamous cell carcinoma.
Actinic Keratosis is the most common form of pre-cancer, with more than an estimated ten-million people in the United States affected by it. Persons who have a fair complexion, have red or blond hair, and green, gray, or blue eyes, have the highest potential of developing one or more forms of common pre-cancers if they spend a significant amount of time in the sun and live a reasonable length of time. The closer to the equator a person lives, the more likely they are to experience actinic keratoses.
The incidence of actinic keratosis is somewhat higher among men than women due to the fact that they may spend more time in the sun while tending to use less sun protection than women may. People of Asian, Hispanic, or African-American decent, as well as others with darker skin, are not as susceptible as people of Caucasian decent.
Some Cause for Concern
Actinic keratoses may be the initial step leading to squamous cell carcinoma; it is known as a, 'pre-cancer.' While the majority of actinic keratoses do remain benign, there have been studies demonstrating that up to ten-percent have the potential to advance to squamous cell carcinoma. The percentage may not sound large, but it does have a large impact. Where squamous cell carcinomas are concerned, forty to sixty-percent start as untreated actinic keratoses that might invade the person's surrounding tissues. Approximately two to ten-percent of squamous cell carcinomas spread to the person's internal organs and become life-threatening.
Another form of actinic keratosis is called, 'actinic cheilitis,' and develops on a person's lips. Actinic cheilitis can evolve into squamous cell carcinoma as well. The more keratoses a person has, the larger the chance that one or more of them may develop into skin cancer. Some scientists interpret actinic keratoses as the earliest form of squamous cell carcinoma.
Photodynamic therapy or, 'PDT,' is a type of medical treatment that utilizes a photo-sensitizing drug and a light source to activate the drug. A photo-sensitizing drug is one that becomes activated through exposure to light. The result is an activated oxygen molecule with the ability to destroy nearby cells. Precancerous cells, as well as specific types of cancer cells, may be treated with photodynamic therapy. The procedure can be performed in a doctor's office or in an outpatient setting.
PDT involves three steps:
- The first step involves a light-sensitizing cream, liquid, or intravenous drug that is either applied or administered.
- The second step involves an incubation period of between minutes to days.
- The third step involves the targeting of tissue, which is exposed to a particular wavelength of light that activates the photo-sensitizing drug.
While PDT was first used in the early 1900's, modern PDT is an evolving science. The current use of PDT involves a variety of incubation times for light-sensitizing drugs, as well as a variety of light sources, depending upon the target tissue. The basic premise of PDT is selective tissue destruction. Although the photo-sensitizing drug can be absorbed by a number of cells, cancerous or atypical cells intake more of the drug and retain it for a longer period of time than average cells.
At this time, the main limitation of PDT techniques available is the depth of penetration of the light and the ability to target cells no greater than one-third of an inch of the light source. Because of this, tumors and atypical growths need to be close to the surface of the person's skin or treatment surface in order for PDT to be effective. Medical fields currently using PDT include oncology, dermatology, as well as cosmetic surgery.
In the field of oncology, PDT is FDA-approved for esophageal cancer, non-small cell lung cancer, and precancerous changes of Barrett's esophagus. The treatment is also being investigated through clinical trials in general oncology in relation to conditions such as cancers of the cervix, brain, prostate gland, stomach, liver, and internal organs.
In the field of dermatology, PDT in conjunction with the photo-sensitizer delta-aminolevulinic acid HCI, is being used to treat pre-skin cancers such actinic keratosis. PDT was initially approved specifically for non-hyperkeratotic actinic keratosis of both the scalp and face with a specified fourteen to eighteen hour drug incubation time and one-thousand seconds of activation with a blue light source.
PDT is also being used to treat rosacea, sun damage, acne, oily skin, wrinkles, enlarged sebaceous glands, warts, psoriasis, hidradenitis suppurativa, and additional skin conditions. PDT is not used to treat either birthmarks or moles.
- 1 - Dry Skin: Causes : Prevention : Treatments : Disabled World (2009/08/06)
- 2 - Age Spots : Sun Spots : Liver Spots : Solar Lentigines : Thomas C. Weiss (2010/12/08)
- 3 - Clark's Nevus: Facts and Information : Thomas C. Weiss (2009/11/22)
- 4 - Moles, Dysplastic Nevi, Melanoma : Thomas C. Weiss (2010/10/14)
- 5 - Athlete's Foot : Causes Symptoms and Treatment : Disabled World (2009/04/14)
- 6 - Shingles - Herpes Zoster: Symptoms | Treatment | Prevention : Disabled World (2009/03/30)
- 7 - Pre-cancers and Actinic Keratosis : Thomas C. Weiss (2010/12/03)
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