What is the Skin?
The skin is the body’s largest organ. It protects the body against infection and injury and helps regulate body temperature. The skin also stores water and fat and produces vitamin D.
The skin is made up of 3 main layers:
- The epidermis. The outer layer of skin.
- The dermis. The inner layer of skin.
- The hypodermis. The deep layer of fat.
What is Skin Cancer?
Cancer begins when healthy cells change and grow out of control, forming a mass called a tumour. A tumour can be cancerous or benign. A cancerous tumour is malignant, meaning it can grow and spread to other parts of the body. A benign tumour means the tumour can grow but will not spread.
Doctors diagnose skin cancer in more than 3 million Americans each year, making it the most common type of cancer. If skin cancer is found early, it can usually be treated with topical medications, procedures done in the office by a dermatologist, or outpatient surgery. A dermatologist is a doctor who specializes in diseases and conditions of the skin. As a result, skin cancer is responsible for less than 1% of all cancer deaths.
In some cases, skin cancer may be more advanced and require management by a multidisciplinary team that often includes a dermatologist, surgical oncologist, radiation oncologist, and a medical oncologist. These doctors will meet with a patient, and together they will recommend the best path forward to treat cancer.
Types of Skin Cancer
There are 4 main types of skin cancer:
Basal cell carcinoma
Basal cells are the round cells found in the lower epidermis. About 80% of skin cancers develop from this type of cell. These cancers are described as basal cell carcinomas. Basal cell carcinoma most often develops on the head and neck, although it can be found anywhere on the skin. It is mainly caused by sun exposure or develops in people who received radiation therapy as children. This type of skin cancer usually grows slowly and rarely spreads to other parts of the body.
Squamous cell carcinoma
Most of the epidermis is made up of flat, scale-like cells called squamous cells. Around 20% of skin cancers develop from these cells, and these cancers are called squamous cell carcinomas. Squamous cell carcinoma is mainly caused by sun exposure, so it may be diagnosed on many regions of the skin. It can also develop on skin that has been burned, damaged by chemicals, or exposed to x-rays. Squamous cell carcinoma is commonly found on the lips; at sites of a long-standing scar; and on the skin outside the mouth, anus, and vagina. About 2% to 5% of squamous cell carcinomas spread to other parts of the body.
Merkel cell cancer
Merkel cell cancer is a highly aggressive, or fast-growing, rare cancer. It starts in hormone-producing cells just beneath the skin and in the hair follicles. It is usually found in the head and neck region. Merkel cell cancer may also be called neuroendocrine carcinoma of the skin. Learn more about neuroendocrine tumours.
Melanoma
There are scattered cells called melanocytes where the epidermis meets the dermis. These cells produce the pigment melanin, which gives skin its color. Melanoma starts in melanocytes, and it is the most aggressive type of skin cancer. It accounts for about 1% of all skin cancers. For more information about melanoma, visit the melanoma section on this same website.
Risk Factors of Skin Cancer
The strongest risk factors for melanoma are a family history of melanoma, multiple benign or atypical nevi, and a previous melanoma. The list of additional risk factors includes immunosuppression, sun sensitivity, and exposure to ultraviolet (UV) radiation.
Familial factors
Approximately 10% of melanomas are familial. The higher risk of melanoma in these families may be attributed to both shared susceptibility genes and shared environment.
Nevi
Typical nevi are frequently precursors of melanoma, but more importantly, they are markers of increased risk. High common nevus counts (50 or more common nevi) account for 27% of melanoma cases, whereas individuals with few common nevi (0 to 10) account for only 4% of melanoma cases.
Exposure to sun and to UV radiation
It is known that UV radiation causes genetic changes in the skin, impairs cutaneous immune function, increases the local production of growth factors, and induces the formation of DNA-damaging reactive oxygen species that affect keratinocytes and melanocytes. Epidemiologic studies revealed that intermittent sun exposure and frequent sunburns, especially during childhood, increase the risk of melanoma. Chronic low-grade sun exposure may be protective, although data also show that higher total exposure to the sun is associated with a higher risk of melanoma among non-Hispanic White individuals.
Previous melanoma
The rate of a second primary cutaneous melanoma is 6% to 7%; the risk is higher among patients who initially presented with melanoma in situ than in those with invasive melanoma. The greatest risk is within the first 2 years, but it remains elevated for at least 20 years. Males, elderly patients, and individuals with the first melanoma on the face, the neck, and the trunk are at especially high risk. The incidence of a third primary melanoma from the time of second primary melanoma is 16% at 1 year and 31% at 5 years.
Occupational Exposure
Exposure to coal tar, pitch, creosote, arsenic compounds, or radium increases the risk of melanoma development.
Symptoms of Skin Cancer
- Warning signs of melanoma are as follows –
- Irregular borders.
- Changes in colour; pigmentation is not uniform.
- Diameter >6 mm.
- Enlarging or evolving lesion.
The changes in preexisting moles and the appearance of a new mole with these features are highly suspicious for melanoma. More than 50% of the cases arise in apparently normal areas of the skin. Ulceration or bleeding usually represents deeper lesions.
- In-transit lesions and skin metastases appear as skin or subcutaneous erythematous nodules between the primary tumour site and the regional nodal basin. The nodules do not have to be pigmented. As they grow, they can coalesce and ulcerate.
- Symptoms of the metastatic disease are related to the involved site.
Diagnoses of Skin Cancer
To diagnose skin cancer, a dermatologist will perform a physical examination of the affected area and may also use a dermatoscope to examine the skin in more detail. If the dermatologist suspects skin cancer, a skin biopsy will be performed. During a biopsy, the dermatologist will remove a small sample of skin and send it to a lab for analysis. If cancer cells are present, further tests may be needed to determine the extent of cancer and the best course of treatment.
Physical Examination:
A complete skin examination of the whole body should be performed, including scalp, axillae, genital area, interdigital webs, and mouth. Skin lesions that follow the “ugly duckling rule” (i.e., look different from other skin lesions, even if they do not fully follow the ABCDE rule) should be biopsied. Melanoma in men occurs more frequently on the trunk or head and neck, and in women on the back and legs, but it can arise from any site on the skin surface. Although most primary lesions are usually pigmented, frequently skin metastases are not pigmented, and they may appear as red or subcutaneous nodules.
Differential Diagnosis:
Compound nevi, halo nevi, dermal nevi, basal cell carcinoma, seborrheic keratosis, angiomas, and dermatofibromas may have features that suggest melanoma. Biopsy specimens of these lesions should be obtained. The precision of the diagnosis can be increased by the use of a dermatoscope, an instrument that magnifies pigmented lesions about 10 times. The dermatoscope is especially invaluable for the examination of flat to slightly raised pigmented lesions.
Biopsy:
Suspicious lesions should be biopsied and analyzed pathologically. A full-thickness excision with 1- to 3-mm margins should be performed if the tumour is highly suspected to be melanoma. Larger margins may interfere with planned sentinel lymph node biopsy (SNLB). Incisional biopsies (punch biopsy or tangential), where part of the pigmented lesion is sampled for pathologic diagnosis, may be used for very large lesions or lesions on the face, palmar surfaces of the hand, sole of the foot, ear, distal digits, genitalia, or under nails. Incisional biopsies may fail, however, to diagnose melanoma or result in a more favourable early staging impression owing to sampling error. If melanoma continues to be suspected or is diagnosed, the biopsy should be repeated or the lesion completely excised for pathologic reevaluation and staging. Incisional biopsies do not increase the chance of melanoma metastases.
Preventions and Treatments for Skin Cancer
Preventions to be considered are as follows
There are several measures you can take to reduce your risk of developing skin cancer. Here are some of the most effective preventive measures –
- Avoidance of exposure to the sun during the midday hours
- Wearing skin-protecting clothing, sunglasses
- Use of sunscreens with a sun protective factor (SPF) of 15 or higher
- Avoidance of sunburns and tanning beds are recommended as a primary prevention
- Patients with a family or personal history of melanoma should undergo at least one annual skin examination performed by a dermatologist as a secondary prevention
Treatments required for Skin Cancer
The treatment for skin cancer depends on the type, size, location, and stage of cancer, as well as the individual’s overall health. Here are some of the most common treatments for skin cancer –
Surgery is the removal of the tumour and surrounding tissue during a medical procedure. Many skin cancers can be removed from the skin quickly and easily during a simple surgical procedure. Often, no other treatment is needed.
Which surgical procedure is used depends on the type of skin cancer and the size and location of the lesion. Most of these procedures use a local anaesthetic to numb the skin first. They can be done by a dermatologist, surgical oncologist, general surgeon, plastic surgeon, nurse practitioner, or physician assistant in their clinic setting, outside of a hospital. Other procedures, such as more extensive wide excisions and sentinel lymph node biopsies, are performed in a hospital operating room with local and/or general anaesthesia. This is often done for Merkel cell cancer.
Surgeries and other procedures for non-melanoma skin cancer include:
- Curettage and electrodesiccation. During this common procedure, the skin lesion is removed with a curette, which is a sharp, spoon-shaped instrument. The area is then treated with an electric current that helps control bleeding and destroys any remaining cancer cells. This is called electrodesiccation. Many people have a flat scar after healing from this procedure.
- Mohs micrographic surgery. This technique, also known as complete margin assessment surgery, involves removing the visible tumour in addition to small fragments around the edge of the area where the tumour was located. Each small fragment is examined under a microscope until all of the cancer is removed. This is typically used for larger tumours, for those located in the head and neck region, and for cancers that have come back in the same place.
- Sentinel lymph node biopsy. This surgical procedure, also called SLNB, sentinel node biopsy, or SNB, is often used for Merkel cell cancer. It helps the doctor find out whether the cancer has spread to the lymph nodes. When cancer spreads from the place it started to the lymph nodes, it travels through the lymphatic system. A sentinel lymph node is the first lymph node into which the lymphatic system drains from the initial tumor site. Because cancer can start anywhere on the skin, the location of the sentinel lymph nodes will be different for each patient, depending on where the cancer started. To find the sentinel lymph node, a dye and a harmless radioactive substance is injected as close as possible to where the cancer started. The substance is followed to the sentinel lymph node. Then, the doctor removes 1 or more of these lymph nodes to check for cancer cells, leaving behind most of the other lymph nodes in that area. These are sent to a pathologist who analyzes the lymph nodes and then provides a report. If cancer cells are not found in the sentinel lymph node(s), no further lymph node surgery is needed. If the sentinel lymph node contains cancer cells, this is called a positive sentinel lymph node. This means the disease has spread, and further treatment, including additional surgery, may be recommended.
Radiation therapy is the use of high-energy rays or other particles to destroy cancer cells. A doctor who specializes in giving radiation therapy to treat cancer is called a radiation oncologist. Radiation therapy may be used instead of surgery for skin cancer that is located in a hard-to-treat place, such as on the eyelid, the tip of the nose, or the ear. It is also used by some people who would like to avoid scarring from surgery. Finally, radiation therapy may be recommended after surgery, especially for lymph nodes that are involved in cancer, to help prevent the skin cancer from coming back.
For Merkel cell cancer, radiation therapy is often given after surgery for stage I and II diseases. This is called adjuvant therapy.
The most common type of radiation treatment is called external-beam radiation therapy, which is radiation given from a machine outside the body. A radiation therapy regimen, or schedule, usually consists of a specific number of treatments given over a set period of time. Several treatments may be needed to eliminate cancer. A less common type of radiation treatment for skin cancer is brachytherapy. This involves placing the radiation source very close to or inside the skin cancer.
Radiation therapy is not recommended for people with nevoid basal cell carcinoma syndrome.
Immunotherapy uses the body’s natural defenses to fight cancer by improving your immune system’s ability to attack cancer cells.
There are 3 FDA-approved immunotherapy drugs for non-melanoma skin cancer.
- Cemiplimab (Libtayo): This immune checkpoint inhibitor targets the PD-1 pathway. It is approved to treat metastatic or locally advanced squamous cell carcinoma and metastatic or locally advanced basal cell carcinoma.
- Denvax Immunotherapy: Denvax is a treatment known as cancer immunotherapy. It boosts the immune system to fight against cancer, mostly solid tumours. Denvax is targeted therapy and comes under the 4th modality of cancer treatment called cancer Immunotherapy.
Dendritic cells are cells of the immune system that help in the fight against cancer. Denvax treatment is customized dendritic cell-based cancer immunotherapy. Denvax shows the most promise at preventing a recurrence of cancer after surgery, chemotherapy or radiation because the immune system will need to recognize and attack a smaller number of cancer cells.
- Pembrolizumab (Keytruda): This is another immune checkpoint inhibitor that targets PD-1. It can be used to treat Merkel cell cancer that has spread or come back after treatment. Pembrolizumab can also be used to treat squamous cell carcinoma that is locally advanced, has spread, or has come back after treatment and cannot be treated with surgery or radiation therapy.
- Avelumab (Bavencio): Avelumab blocks the PD-L1 pathway. It can be used to treat people 12 and older with Merkel cell cancer that has spread to another part of the body.
Chemotherapy is the use of drugs to destroy cancer cells, usually by keeping the cancer cells from growing, dividing, and making more cells. In skin cancer treatment, these drugs are usually applied to the skin every day for several weeks. This is called topical treatment. These types of medications may cause the side effects of skin inflammation or irritation, which generally go away after treatment is finished.
Topical diclofenac (Solaraze), fluorouracil (multiple brand names), and ingenol mebutate (Picato) are approved for the treatment of precancerous actinic keratoses, with fluorouracil resulting in better results in terms of effectiveness and time until new precancers appear. All of these creams can cause irritation, burning, redness, and stinging during treatment. These symptoms usually go away soon after treatment has been completed. These creams do not cause scars, which is why many doctors use them to treat the face or other areas where a person’s appearance may be affected.
For small basal cell cancers not located on the face, topical imiquimod (Aldara, Zyclara), which stimulates the immune system, may be recommended. The cream must be applied once a day, 5 days a week, for 6 to 12 weeks. Topical fluorouracil is also approved by the U.S. Food and Drug Administration (FDA) to treat very thin basal cell carcinomas. It should be applied 2 times a day for 3 to 6 weeks. Some irritation and redness in the area of the basal cell carcinoma is expected with this treatment.
References:
- Manual of Clinical Oncology by Bartosz Chmeilowski and Mary Territo
- cancer.net
What is the Skin?
The skin is the body’s largest organ. It protects the body against infection and injury and helps regulate body temperature. The skin also stores water and fat and produces vitamin D.
The skin is made up of 3 main layers:
- The epidermis. The outer layer of skin.
- The dermis. The inner layer of skin.
- The hypodermis. The deep layer of fat.
What is Skin Cancer?
Cancer begins when healthy cells change and grow out of control, forming a mass called a tumour. A tumour can be cancerous or benign. A cancerous tumour is malignant, meaning it can grow and spread to other parts of the body. A benign tumour means the tumour can grow but will not spread.
Doctors diagnose skin cancer in more than 3 million Americans each year, making it the most common type of cancer. If skin cancer is found early, it can usually be treated with topical medications, procedures done in the office by a dermatologist, or outpatient surgery. A dermatologist is a doctor who specializes in diseases and conditions of the skin. As a result, skin cancer is responsible for less than 1% of all cancer deaths.
In some cases, skin cancer may be more advanced and require management by a multidisciplinary team that often includes a dermatologist, surgical oncologist, radiation oncologist, and a medical oncologist. These doctors will meet with a patient, and together they will recommend the best path forward to treat cancer.
Types of Skin Cancer
There are 4 main types of skin cancer:
Basal cell carcinoma
Basal cells are the round cells found in the lower epidermis. About 80% of skin cancers develop from this type of cell. These cancers are described as basal cell carcinomas. Basal cell carcinoma most often develops on the head and neck, although it can be found anywhere on the skin. It is mainly caused by sun exposure or develops in people who received radiation therapy as children. This type of skin cancer usually grows slowly and rarely spreads to other parts of the body.
Squamous cell carcinoma
Most of the epidermis is made up of flat, scale-like cells called squamous cells. Around 20% of skin cancers develop from these cells, and these cancers are called squamous cell carcinomas. Squamous cell carcinoma is mainly caused by sun exposure, so it may be diagnosed on many regions of the skin. It can also develop on skin that has been burned, damaged by chemicals, or exposed to x-rays. Squamous cell carcinoma is commonly found on the lips; at sites of a long-standing scar; and on the skin outside the mouth, anus, and vagina. About 2% to 5% of squamous cell carcinomas spread to other parts of the body.
Merkel cell cancer
Merkel cell cancer is a highly aggressive, or fast-growing, rare cancer. It starts in hormone-producing cells just beneath the skin and in the hair follicles. It is usually found in the head and neck region. Merkel cell cancer may also be called neuroendocrine carcinoma of the skin. Learn more about neuroendocrine tumours.
Melanoma
There are scattered cells called melanocytes where the epidermis meets the dermis. These cells produce the pigment melanin, which gives skin its color. Melanoma starts in melanocytes, and it is the most aggressive type of skin cancer. It accounts for about 1% of all skin cancers. For more information about melanoma, visit the melanoma section on this same website.
Risk Factors of Skin Cancer
The strongest risk factors for melanoma are a family history of melanoma, multiple benign or atypical nevi, and a previous melanoma. The list of additional risk factors includes immunosuppression, sun sensitivity, and exposure to ultraviolet (UV) radiation.
Familial factors
Approximately 10% of melanomas are familial. The higher risk of melanoma in these families may be attributed to both shared susceptibility genes and shared environment.
Nevi
Typical nevi are frequently precursors of melanoma, but more importantly, they are markers of increased risk. High common nevus counts (50 or more common nevi) account for 27% of melanoma cases, whereas individuals with few common nevi (0 to 10) account for only 4% of melanoma cases.
Exposure to sun and to UV radiation
It is known that UV radiation causes genetic changes in the skin, impairs cutaneous immune function, increases the local production of growth factors, and induces the formation of DNA-damaging reactive oxygen species that affect keratinocytes and melanocytes. Epidemiologic studies revealed that intermittent sun exposure and frequent sunburns, especially during childhood, increase the risk of melanoma. Chronic low-grade sun exposure may be protective, although data also show that higher total exposure to the sun is associated with a higher risk of melanoma among non-Hispanic White individuals.
Previous melanoma
The rate of a second primary cutaneous melanoma is 6% to 7%; the risk is higher among patients who initially presented with melanoma in situ than in those with invasive melanoma. The greatest risk is within the first 2 years, but it remains elevated for at least 20 years. Males, elderly patients, and individuals with the first melanoma on the face, the neck, and the trunk are at especially high risk. The incidence of a third primary melanoma from the time of second primary melanoma is 16% at 1 year and 31% at 5 years.
Occupational Exposure
Exposure to coal tar, pitch, creosote, arsenic compounds, or radium increases the risk of melanoma development.
Symptoms of Skin Cancer
- Warning signs of melanoma are as follows –
- Irregular borders.
- Changes in colour; pigmentation is not uniform.
- Diameter >6 mm.
- Enlarging or evolving lesion.
The changes in preexisting moles and the appearance of a new mole with these features are highly suspicious for melanoma. More than 50% of the cases arise in apparently normal areas of the skin. Ulceration or bleeding usually represents deeper lesions.
- In-transit lesions and skin metastases appear as skin or subcutaneous erythematous nodules between the primary tumour site and the regional nodal basin. The nodules do not have to be pigmented. As they grow, they can coalesce and ulcerate.
- Symptoms of the metastatic disease are related to the involved site.
Diagnoses of Skin Cancer
To diagnose skin cancer, a dermatologist will perform a physical examination of the affected area and may also use a dermatoscope to examine the skin in more detail. If the dermatologist suspects skin cancer, a skin biopsy will be performed. During a biopsy, the dermatologist will remove a small sample of skin and send it to a lab for analysis. If cancer cells are present, further tests may be needed to determine the extent of cancer and the best course of treatment.
Physical Examination:
A complete skin examination of the whole body should be performed, including scalp, axillae, genital area, interdigital webs, and mouth. Skin lesions that follow the “ugly duckling rule” (i.e., look different from other skin lesions, even if they do not fully follow the ABCDE rule) should be biopsied. Melanoma in men occurs more frequently on the trunk or head and neck, and in women on the back and legs, but it can arise from any site on the skin surface. Although most primary lesions are usually pigmented, frequently skin metastases are not pigmented, and they may appear as red or subcutaneous nodules.
Differential Diagnosis:
Compound nevi, halo nevi, dermal nevi, basal cell carcinoma, seborrheic keratosis, angiomas, and dermatofibromas may have features that suggest melanoma. Biopsy specimens of these lesions should be obtained. The precision of the diagnosis can be increased by the use of a dermatoscope, an instrument that magnifies pigmented lesions about 10 times. The dermatoscope is especially invaluable for the examination of flat to slightly raised pigmented lesions.
Biopsy:
Suspicious lesions should be biopsied and analyzed pathologically. A full-thickness excision with 1- to 3-mm margins should be performed if the tumour is highly suspected to be melanoma. Larger margins may interfere with planned sentinel lymph node biopsy (SNLB). Incisional biopsies (punch biopsy or tangential), where part of the pigmented lesion is sampled for pathologic diagnosis, may be used for very large lesions or lesions on the face, palmar surfaces of the hand, sole of the foot, ear, distal digits, genitalia, or under nails. Incisional biopsies may fail, however, to diagnose melanoma or result in a more favourable early staging impression owing to sampling error. If melanoma continues to be suspected or is diagnosed, the biopsy should be repeated or the lesion completely excised for pathologic reevaluation and staging. Incisional biopsies do not increase the chance of melanoma metastases.
Preventions and Treatments for Skin Cancer
Preventions to be considered are as follows
There are several measures you can take to reduce your risk of developing skin cancer. Here are some of the most effective preventive measures –
- Avoidance of exposure to the sun during the midday hours
- Wearing skin-protecting clothing, sunglasses
- Use of sunscreens with a sun protective factor (SPF) of 15 or higher
- Avoidance of sunburns and tanning beds are recommended as a primary prevention
- Patients with a family or personal history of melanoma should undergo at least one annual skin examination performed by a dermatologist as a secondary prevention
Treatments required for Skin Cancer
The treatment for skin cancer depends on the type, size, location, and stage of cancer, as well as the individual’s overall health. Here are some of the most common treatments for skin cancer –
Surgery is the removal of the tumour and surrounding tissue during a medical procedure. Many skin cancers can be removed from the skin quickly and easily during a simple surgical procedure. Often, no other treatment is needed.
Which surgical procedure is used depends on the type of skin cancer and the size and location of the lesion. Most of these procedures use a local anaesthetic to numb the skin first. They can be done by a dermatologist, surgical oncologist, general surgeon, plastic surgeon, nurse practitioner, or physician assistant in their clinic setting, outside of a hospital. Other procedures, such as more extensive wide excisions and sentinel lymph node biopsies, are performed in a hospital operating room with local and/or general anaesthesia. This is often done for Merkel cell cancer.
Surgeries and other procedures for non-melanoma skin cancer include:
- Curettage and electrodesiccation. During this common procedure, the skin lesion is removed with a curette, which is a sharp, spoon-shaped instrument. The area is then treated with an electric current that helps control bleeding and destroys any remaining cancer cells. This is called electrodesiccation. Many people have a flat scar after healing from this procedure.
- Mohs micrographic surgery. This technique, also known as complete margin assessment surgery, involves removing the visible tumour in addition to small fragments around the edge of the area where the tumour was located. Each small fragment is examined under a microscope until all of the cancer is removed. This is typically used for larger tumours, for those located in the head and neck region, and for cancers that have come back in the same place.
- Sentinel lymph node biopsy. This surgical procedure, also called SLNB, sentinel node biopsy, or SNB, is often used for Merkel cell cancer. It helps the doctor find out whether the cancer has spread to the lymph nodes. When cancer spreads from the place it started to the lymph nodes, it travels through the lymphatic system. A sentinel lymph node is the first lymph node into which the lymphatic system drains from the initial tumor site. Because cancer can start anywhere on the skin, the location of the sentinel lymph nodes will be different for each patient, depending on where the cancer started. To find the sentinel lymph node, a dye and a harmless radioactive substance is injected as close as possible to where the cancer started. The substance is followed to the sentinel lymph node. Then, the doctor removes 1 or more of these lymph nodes to check for cancer cells, leaving behind most of the other lymph nodes in that area. These are sent to a pathologist who analyzes the lymph nodes and then provides a report. If cancer cells are not found in the sentinel lymph node(s), no further lymph node surgery is needed. If the sentinel lymph node contains cancer cells, this is called a positive sentinel lymph node. This means the disease has spread, and further treatment, including additional surgery, may be recommended.
Radiation therapy is the use of high-energy rays or other particles to destroy cancer cells. A doctor who specializes in giving radiation therapy to treat cancer is called a radiation oncologist. Radiation therapy may be used instead of surgery for skin cancer that is located in a hard-to-treat place, such as on the eyelid, the tip of the nose, or the ear. It is also used by some people who would like to avoid scarring from surgery. Finally, radiation therapy may be recommended after surgery, especially for lymph nodes that are involved in cancer, to help prevent the skin cancer from coming back.
For Merkel cell cancer, radiation therapy is often given after surgery for stage I and II diseases. This is called adjuvant therapy.
The most common type of radiation treatment is called external-beam radiation therapy, which is radiation given from a machine outside the body. A radiation therapy regimen, or schedule, usually consists of a specific number of treatments given over a set period of time. Several treatments may be needed to eliminate cancer. A less common type of radiation treatment for skin cancer is brachytherapy. This involves placing the radiation source very close to or inside the skin cancer.
Radiation therapy is not recommended for people with nevoid basal cell carcinoma syndrome.
Immunotherapy uses the body’s natural defenses to fight cancer by improving your immune system’s ability to attack cancer cells.
There are 3 FDA-approved immunotherapy drugs for non-melanoma skin cancer.
- Cemiplimab (Libtayo): This immune checkpoint inhibitor targets the PD-1 pathway. It is approved to treat metastatic or locally advanced squamous cell carcinoma and metastatic or locally advanced basal cell carcinoma.
- Denvax Immunotherapy: Denvax is a treatment known as cancer immunotherapy. It boosts the immune system to fight against cancer, mostly solid tumours. Denvax is targeted therapy and comes under the 4th modality of cancer treatment called cancer Immunotherapy.
Dendritic cells are cells of the immune system that help in the fight against cancer. Denvax treatment is customized dendritic cell-based cancer immunotherapy. Denvax shows the most promise at preventing a recurrence of cancer after surgery, chemotherapy or radiation because the immune system will need to recognize and attack a smaller number of cancer cells.
- Pembrolizumab (Keytruda): This is another immune checkpoint inhibitor that targets PD-1. It can be used to treat Merkel cell cancer that has spread or come back after treatment. Pembrolizumab can also be used to treat squamous cell carcinoma that is locally advanced, has spread, or has come back after treatment and cannot be treated with surgery or radiation therapy.
- Avelumab (Bavencio): Avelumab blocks the PD-L1 pathway. It can be used to treat people 12 and older with Merkel cell cancer that has spread to another part of the body.
Chemotherapy is the use of drugs to destroy cancer cells, usually by keeping the cancer cells from growing, dividing, and making more cells. In skin cancer treatment, these drugs are usually applied to the skin every day for several weeks. This is called topical treatment. These types of medications may cause the side effects of skin inflammation or irritation, which generally go away after treatment is finished.
Topical diclofenac (Solaraze), fluorouracil (multiple brand names), and ingenol mebutate (Picato) are approved for the treatment of precancerous actinic keratoses, with fluorouracil resulting in better results in terms of effectiveness and time until new precancers appear. All of these creams can cause irritation, burning, redness, and stinging during treatment. These symptoms usually go away soon after treatment has been completed. These creams do not cause scars, which is why many doctors use them to treat the face or other areas where a person’s appearance may be affected.
For small basal cell cancers not located on the face, topical imiquimod (Aldara, Zyclara), which stimulates the immune system, may be recommended. The cream must be applied once a day, 5 days a week, for 6 to 12 weeks. Topical fluorouracil is also approved by the U.S. Food and Drug Administration (FDA) to treat very thin basal cell carcinomas. It should be applied 2 times a day for 3 to 6 weeks. Some irritation and redness in the area of the basal cell carcinoma is expected with this treatment.
References:
- Manual of Clinical Oncology by Bartosz Chmeilowski and Mary Territo
- cancer.net
