Introduction to the Stages of Skin Cancers - Melanoma and Nonmelanoma

You have just been diagnosed with precancerous keratinocyte carcinomas - and the doctor says he needs to do staging to determine the best course of treatment. What are the stages of skin cancer?

Types of Skin Cancers

For starters, there are two major classifications of skin cancers - melanomas, and non-melanoma skin cancer (also referred to as keratinocyte carcinoma). Staging is a tool for doctors to evaluate the severity of the cancer and to determine proper treatment methods.

Non-melanoma skin cancers can be either basal or squamous skin cancers. Most skin cancers are basal skin cancers, usually the result of overexposure to sun, and as a rule these cancers stay localized to their starting point. Because of the low risk of the cancer spreading to other parts of the body, basal skin cancers are not usually staged.

Squamous skin cancers are less common forms of cancer, but they carry the risk of spreading to fatty tissues like lymph nodes. Since this type of cancer may spread, staging to evaluate the growth of the cancer is essential to diagnosis and treatment.

Staging of Non-Melanoma Skin Cancer

Staging of skin cancer can be done by several methods. The most common method for staging non-melanoma cancers uses a rating system from 0 to 4. The lower number indicates less spread of the cancer, while the higher number indicates greater spread.

Stage 0 is referred to as "carcinoma in situ". This stage is characterized by the appearance of abnormal skin cells, with no noticeable spread. This precancerous group of cells is localized on the top layer of skin.

Stage 1 exhibits cancerous skin cells on the epidermis (top layer) of the skin. The tumor is about the size of a peanut, no more than 2 centimeters (less than 1").

Stage 2 is a worsening situation with the cancer spreading down from the epidermis to the dermis. Growth is larger than 2 centimeters.

Stage 3 is a serious condition with the cancer spreading invasively down through layers of skin into the subcutaneous tissues, and possibly into the lymph nodes or cartilage

Stage 4 is very dangerous with the cancer spreading, or metastasizing, throughout the body and invading the brain, lungs, or lymph nodes.

Melanoma cancers are staged according to clinical evaluation of visual examination, biopsy, and imaging tests. Pathological staging goes a step further to consider all of the above listed evaluations in conjunction with other biopsies.

Clark Level Staging Method

The Clark Level staging method for skin cancers works this way:

Level 1 - cancer is localized on epidermis.

Level 2 - cancer spreads to the upper dermis.

Level 3 - cancer has spread to most of the upper dermis.

Level 4 - cancer has spread to the lower dermis.

Level 5 - cancer has spread to the subcutaneous tissues.

Finally, there is the TNM method. The T refers to tumor size, N refers to nodes and the amount of invasion in nodes, and M refers to the rate of spread, also called metatasizing. In this system the capital letter of T, N, or M will be followed by a numerical indicator of severity.

Regardless of the staging method used, staging is a vital step in determining the proper course of treatment for skin cancer symptoms. Early detection is the key to giving your physician ample time to do proper staging and prescribe a treatment regimen.

Sources:

www.cancer.org/docroot/CRI/CRI_2_1x.asp

http://www.cancer.gov/cancertopics/pdq/treatment/skin/Patient/page2#Keypoint9

www.ehealthmd.com/library/skincancer/SC_stage.html