Extramammary Paget disease (EMPD) is a rare type of skin cancer that generally affects areas with abundant sweat glands, such as anogenital (areas surrounding the anusthe opening where solid waste (faeces or stool) exits the body and genitals) or axillary (the armpit area) skin. It is primarily an adenocarcinomacancer arising from mucus-producing glands in organs, which is cancera disease where abnormal cells split without control and spread to other nearby body tissue and/or organs originating in glandular tissuea group of cells that work together to perform a function. EMPD is different that mammary Paget disease, which has a similar appearance, but is found around the nipple and areolaarea of pigmented skin surrounding the nipple on the breast, and may be an indication of an underlying breast cancer.
EMPD can be classified into two categories, based on where the cancer originated from. The first is primary EMPD, which originates from the skin. The second category is secondary EMPD, which is associated with the metastasiswhen the cancer has spread to other parts of the body, also known as mets of a primary adenocarcinoma originating somewhere else in the body.
EMPD is most commonly diagnosed in people over 50 and is more prevalent in females. However, this disease can be developed at any age in any gender.
Treatment
If EMPD is detected, it will be staged and graded based on size, metastasis, and how the cancer cellsthe basic structural and functional unit of all living things look under the microscope. Stagingthe process of determining how big the cancer is, where it started and if it has spread to other areas and grading helps your doctors determine the best treatment for you.
Cancers can be staged using the TNM staging system:
- T (tumoura tissue mass that forms from groups of unhealthy cells) indicates the size and depth of the tumour.
- N (nodea small lump or mass of tissue in your body) indicates whether the cancer has spread to nearby lymph nodessmall bean-shaped structures that filters harmful substances from lymph fluid.
- M (metastasis) indicates whether the cancer has spread to other parts of the body.
This system can also be used in combination with a numerical value, from stage 0 – IV:
- Stage 0: this stage describes cancer cells in the place of origin (or ‘in situ’) that have not spread to nearby tissue.
- Stage I: cancer cells have begun to spread to nearby tissue. It is not deeply embedded into nearby tissue and has not spread to lymph nodes. This stage is also known as early-stage cancer.
- Stage II: cancer cells have grown deeper into nearby tissue. Lymph nodes may or may not be affected. This is also known as localisedaffecting only one area of body cancer.
- Stage III: the cancer has become larger and has grown deeper into nearby tissue. Lymph nodes are generally affected at this stage. This is also classified as localised cancer.
- Stage IV: the cancer has spread to other tissues and organs in the body. This is also known as advancedat a late stage, far along or metastatic cancer.
Cancers can also be graded based on the rate of growth and how likely they are to spread:
- Gradea description of how abnormal cancer cells and tissue look under a microscope when compared to healthy cells I: cancer cells present as slightly abnormal and are usually slow growing. This is also known as a low-grade tumour.
- Grade II: cancer cells present as abnormal and grow faster than grade I cancers. This is also known as an intermediate-grade tumour.
- Grade III: cancer cells present as very abnormal and grow quickly. This is also known as a high-grade tumour.
- Once your tumour has been staged and graded, your doctor may recommend genetic testinga procedure that analyses DNA to identify changes in genes, chromosomes and proteins, which can be used to analyse tumour DNA to help determine which treatment has the greatest chance of success, which analyses your tumour DNA and can help determine which treatment has the greatest chance of success. They will then discuss the most appropriate course of treatment for you.
Treatment is dependent on several factors, including location, stage of disease and overall health.
Treatment options for EMPD may include:
- Surgerytreatment involving removal of cancerous tissue and/or tumours and a margin of healthy tissue around it to reduce recurrence to remove as much of the tumour as possible, potentially including Mohs Micrographic surgeryspecialised surgery that removes thin layers of cancer in stages until completely removed.
- Radiation therapya treatment that uses controlled doses of radiation to damage or kill cancer cells.
- Chemotherapya cancer treatment that uses drugs to kill or slow the growth of cancer cells, while minimising damage to healthy cells.
- Clinical trialsresearch studies performed to test new treatments, tests or procedures and evaluate their effectiveness on various diseases.
- Palliative carea variety of practices and exercises used to provide pain relief and improve quality of life without curing the disease.
Risk factors
Because of how rare EMPD is, there has been limited research into the riskthe possibility that something bad will happen factors of this disease.
Symptoms
The symptoms of EMPD are often confused with other skin conditions, and as such is often misdiagnosed. The most common occurrence of EMPD is the vulva in women and on the scrotum or around the anus in men. Common symptoms of this disease are:
- Itchiness of the skin.
- Burning, pain, tenderness or irritation.
- Skin discolouration around the area.
- Crusting and/or scaling lesions of the skin.
- Weeping lesions of the skin.
Not everyone with the symptoms above will have cancer but see your general practitioner (GP) if you are concerned.
Diagnosis
If your doctor suspects you have an EMPD, they may order the following tests to confirm the diagnosisthe process of identifying a disease based on signs and symptoms, patient history and medical test results and refer you to a specialist for treatment:
- Physical examinationan examination of your current symptoms, affected area(s) and overall medical history.
- Imagingtests that create detailed images of areas inside the body tests, most commonly an ultrasounda type of medical imaging that uses soundwaves to create detailed images of the body .
- Blood teststesting done to measure the levels of certain substances in the blood.
- Endoscopya procedure that involves inserting a long, flexible tube with a light and small camera (endoscope) into the body to view internal organs, potentially including:
- Colonoscopyan examination of the large intestine/bowel with a small, flexible instrument known as a colonoscope (for perianalarea surrounding the anus EMPD).
- Cystoscopyan examination of the bladder and urethra with a small, flexible instrument known as a cystoscope (for EMPD of the urethrathe tube that carries urine from the bladder to outside of the body).
- Biopsyremoval of a section of tissue to analyse for cancer cells.