Skin cancer occurs when there are abnormalities or uncontrolled growth of cells in the skin tissues. This uncontrolled growth is a result of mutations in otherwise healthy cells. Though skin carcinoma can occur at any location in the body, it is often found in parts that are exposed to the sun's ultraviolet rays, for example, the neck, face, arms, and legs.
As the name suggests, skin cancer refers to unwanted and uncontrolled changes in the healthy cells of the skin. The biggest risk factors for skin carcinoma include overexposure to the sun's UV rays, a weak immune system, and exposure to specific chemicals.
There are different types of skin cancer; some are common, while others are rare. Skin cancer is broadly classified into melanoma skin cancer and non-melanoma skin cancer, and non-melanoma type is further classified into basal cell carcinoma and squamous cell carcinoma.
Skin carcinoma is one of the top 20 cancers worldwide. It is not a very common type of cancer in India. Skin carcinoma can affect any age groups, however, its risk is found to increase with age. All the three main types of skin cancer are relatively more common among individuals aged above 50.
Here is detailed information on the different types of skin cancer:
There are three common types of skin cancer affecting patients: basal cell skin cancer, squamous cell skin cancer, and melanoma skin cancer.
Basal cell carcinoma, or BCC, is one of the most common skin cancer types that initiates in the epidermis' basal cells. The epidermis is the outermost layer of the human skin. BCCs are basically slow-growing tumors and rarely metastasize. However, it is important to receive appropriate treatment in order to reduce the risk of advanced-stage skin cancer. These cancerous cells appear as pinkish or flesh-colored skin patches and shiny sores, which do not heal easily.
The most effective way to reduce the risk of basal cell carcinoma is to protect the skin from sunburn.
Squamous cell carcinoma, or SCC, refers to a type of skin cancer that develops from squamous cells. These squamous cells are thin and flat in appearance and are found in the human skin's outermost layer.
This type of cancer is more aggressive than BCC and appears as crusty or scaly lesions on the skin. These lesions or sores can be pinkish or reddish in color and tend to grow on areas that are sun-exposed, such as the neck, arms, and back of the hands.
Also, squamous cell skin cancer grows more rapidly as compared to BCC cancer and, if left untreated, can spread to nearby body parts and lymph nodes.
Melanoma is another common skin cancer type that begins in melanocytes. The melanocytes are responsible for producing melanin in the skin. Melanin is a pigment that gives color to human skin.
When the DNA of the melanocyte cells is damaged, it leads to abnormal division of melanoma cells, which may, over time, lead to the formation of cancerous mass. Melanoma is an aggressive form of skin cancer.
Risk factors for the growth of this particular skin cancer include overexposure to the sun's ultraviolet rays, specific genetic conditions, a history of sunburns, and a weak immune system.
In addition to the common types of skin cancer, there are some rare skin cancer types as well, and these include:
A rare and aggressive form of skin carcinoma, Merkel cell carcinoma, initiates in the Merkel cells. Merkel cells are a type of nerve cell that is located at the end of the skin's nerve endings. This type of cancer appears as painless, red-colored or flesh-colored bumps that, if not treated on time, can grow quickly and spread to other essential body organs, such as the lungs, liver, etc.
Sebaceous gland carcinoma is a rare skin carcinoma type that originates in the sebaceous glands, or oil glands, in the skin. This type of cancer mostly affects people over the age of 60 and usually appears on the eyelids, scalp, and face.
Dermatofibrosarcoma protuberans is a rare and slow-moving cancer that grows in the body's connective tissues. This type of cancer is prevalent among people who are between the ages of 20 and 40.
Kaposi sarcoma is a type of skin carcinoma that develops in the blood vessels and lymphatic vessels. This type of cancer can occur in the mouth, internal organs, and skin, and it is connected with the infection caused by the human herpesvirus 8 (HHV-8).
Getting a clear picture of the extent of the spread of skin cancer is highly useful in arriving at a definitive diagnosis and treatment of the cancer. Here are the skin cancer stages as per the staging process.
An early-stage skin cancer, stage 0 skin cancer, is considered to be an 'in situ' cancer. This is the earliest stage of skin cancer, wherein cancerous cells are confined to the skin's top layer only. Surgery is often the main line of treatment for stage 0 skin cancer.
In stage 1 skin cancer, the cancerous cells break through the topmost layer of the skin, called the epidermis, and start growing into the dermis. The dermis is the skin's deeper layer. Though stage 1 is a little more advanced than stage 0, it is still considered one of the early-stage skin cancers.
In stage 2 skin cancer, the cancerous cells grow deeper into the skin and affect the nearby tissues. However, the cancer at this stage does not affect the lymph nodes or other essential organs.
Stage 3 skin cancer is an advanced stage in which the cancerous cells are known to move away from the cancer's original site and invade the nearby lymph nodes.
Stage 4 skin cancer is known to be the most advanced stage of skin carcinoma. In this stage, the cancer cells spread to other essential organs, such as the lungs, liver, and brain. The cancer at this stage is also known as metastatic skin cancer.
Skin cancer is one of the most common types of cancer and often requires immediate medical attention. Depending on the cell type that it originates from, skin cancer is classified into various types. Some skin cancer types are more aggressive than others. Thus, it is advisable to consult a doctor as soon as any of the symptoms of skin cancer appear.