There are many different types of skin cancer, and the treatment for each can be very different also. As far as a time line, a cancer growth can excellerate at a different rate in each person, so this is also a variable. The best way to judge the stage that it is in is by the skin biopsy.
Types of Nonmelanoma Skin Cancer
Skin cancers are divided into 2 general types: nonmelanoma and melanoma. Nonmelanoma skin cancers are the most common cancers of the skin. They are called nonmelanoma because this group of cancers includes all skin cancers except one – malignant melanoma. Cancers that develop from melanocytes, the pigment-producing cells of the skin, are called melanoma. Melanocytes can also form benign growths called moles. Melanoma and benign moles are discussed in a separate document called "Melanoma Skin Cancer."
There are many types of nonmelanoma skin cancers, but 2 types are most common – basal cell carcinoma and squamous cell carcinoma. These 2 types are also known as keratinocyte carcinomas.
Basal cell carcinoma: Basal cell carcinoma begins in the lowest layer of the epidermis, called the basal cell layer. About 70% to 80% of all skin cancers in men and 80% to 90% in women are basal cell carcinomas. They usually develop on sun-exposed areas, especially the head and neck. Basal cell carcinoma was once found almost exclusively in middle-aged or older people. Now it is also being seen in younger people, probably because they are spending more time in the sun with their skin exposed.
Basal cell carcinoma is slow growing. It is highly unusual for a basal cell cancer to spread to lymph nodes or to distant parts of the body. However, if a basal cell cancer is left untreated, it can grow into nearby areas and invade the bone or other tissues beneath the skin.
After treatment, basal cell carcinoma can recur (come back) in the same place on the skin. Also, new basal cell cancers can start elsewhere on the skin. Thirty-five to 50% of people diagnosed with one basal cell cancer develop a new skin cancer within 5 years of the first diagnosis.
Squamous cell carcinoma: Squamous cell carcinomas account for about 10% to 30% of all skin cancers. They commonly appear on sun-exposed areas of the body such as the face, ear, neck, lip, and back of the hands. They can also develop within scars or skin ulcers elsewhere. They sometimes start in actinic keratoses. Less often, they form in the skin of the genital area.
Squamous cell carcinomas tend to be more aggressive than basal cell cancers. They are more likely to invade tissues beneath the skin, and slightly more likely to spread to lymph nodes and/or distant parts of the body, although this is still uncommon.
Less common types of nonmelanoma skin cancer: Other nonmelanoma skin cancers include:
- Kaposi sarcoma
- cutaneous lymphoma
- skin adnexal tumors
- various types of sarcomas
- Merkel cell carcinoma
Together, these types account for less than 1% of nonmelanoma skin cancers.
For More information read more here:
http://www.cancer.org/docroot/cri/content/cri_2_4_1x_what_is_skin_cancer_51.asp?sitearea=
Examination of the Skin Biopsy
Measuring the size and thickness of a melanoma under a microscope is believed to be the best way to determine a patient's prognosis.
The pathologist examining the skin biopsy specimen measures the thickness of the melanoma under the microscope with a device called a micrometer, which is like a small ruler. This technique is called the Breslow measurement. The thinner the melanoma, the better the prognosis. In general, melanomas less than 1 millimeter (mm) in depth (about 1/25 of an inch or the diameter of a period or a comma) have a very small chance of spreading. As the melanoma becomes thicker, it has a greater chance of spreading. The thickness of the melanoma also guides the choice of treatment.
Another system, called the Clark level, describes the thickness of a melanoma in relation to its penetration into the skin instead of actually measuring it. The Clark level of a melanoma uses a scale of I to V (with higher numbers indicating a deeper melanoma) to describe whether:
- the cancer stays in the epidermis (Clark level I)
- the cancer has begun to penetrate to the upper dermis (Clark level II)
- the cancer involves most of the upper dermis (Clark level III)
- the cancer has penetrated to the lower dermis (Clark level IV)
- the cancer has penetrated very deeply to the subcutis (Clark level V)
Recently, the Breslow measurement of thickness has been found more useful than the Clark level of penetration in determining a patient’s prognosis. This is because the thickness measurement is easier to measure and depends less on the pathologist's judgment. Sometimes, however, the Clark level shows that a melanoma is more advanced than doctors may think it is from the Breslow measurement. The Clark level is now used only to stage thin melanomas (T1; see below).
In either system, the melanoma is said to have a worse prognosis if the pathologist says it is ulcerated (outermost covering layer of skin is absent).
T staging: The possible values for T are:
T0: No evidence of primary tumor
Tis: Melanoma in situ (not invading)
T1a: The melanoma is less than or equal to 1.0 mm thick (1.0 mm = 1/25 or .04 inches), without ulceration and Clark level II or III (see Ta and Tb below; there is an exception made for T1 depending on the Clark level).
T2: The melanoma is between 1.01 and 2.0 mm thick with or without ulceration.
T3: The melanoma is between 2.01 and 4.0 mm thick with or without ulceration.
T4: The melanoma is thicker than 4.0 mm with or without ulceration.
Any Ta = not ulcerated
Any Tb = ulcerated
__________________
I hope to enhance the lives of those I touch, one moment at a time. Thank you for allowing me to assist you today.
Sincerely,
Roxanna (momceo111)
