If you look into any educational website or information portal, you will see that there is a common rule associated with Melanoma known as ABCD.
• Asymmetry: The two halves of the mole are different from each other.
• Border irregularity: The spot has borders that are uneven or notched.
• Colour: The spot has several colours in an uneven pattern or differs a lot in colour from the rest of your moles.
• Diameter: The spot is larger than the size of a pencil eraser. The good thing about this cancer is that it is usually seen over skin (though mucous membranes like mouth, lips and rectum may also get involved, it is uncommon), which is easy to observe and thus we can detect the disease early, if you are aware of the disease.
At the same time, it needs to be understood that self-diagnosis is not possible. If you see a spot that looks as though it is new or changing, show it to a doctor. When it comes to spots on the skin, it is always better to be safe than sorry. However, not all spots are cancerous, and everybody gets spots on their skin. The older we are, the more spots we have. Hence it is important to note two things:
• Observe your skin (difficult-to-see parts should be seen with the help of a mirror)
• In case of doubt immediately consult a doctor
The disease confirmation is done by examining the concern-causing spot and doing a biopsy. Once this is done, the physician will usually go for prognostication (how good or bad the disease is) of the disease, which includes staging and biological characters of disease.
The following tests and procedures may be used in the staging process:
• Wide local excision: A surgical procedure to remove some of the normal tissue surrounding the area where melanoma was found, to check for cancer cells.
• Lymph node mapping and sentinel lymph node biopsy: Procedures in which a radioactive substance and/or blue dye is injected near the tumour. The substance or dye flows through lymph ducts to the sentinel node or nodes (the first lymph node or nodes where cancer cells are likely to have spread). The surgeon removes only the nodes with the radioactive substance or dye. A pathologist then checks the sentinel lymph nodes for cancer cells. If no cancer cells are detected, it may not be necessary to remove additional nodes.
PET scan (Positron Emission Tomography scan):
A procedure to find malignant tumour cells in the body. A small amount of radioactive glucose (sugar) is injected into a vein. The PET scanner rotates around the body and makes a picture of where glucose is being used in the body. Malignant tumour cells show up brighter in the picture because they are more active and take up more glucose than normal cells do. This will be done because the melanoma can spread in predominantly three ways:
• Through tissue
• Through the lymph system
• Through the blood
Once the staging is done, the pathologist will give the extent of disease. For broad understanding the disease if of three types:
• Superficial spreading melanoma: It the most common of all (70 per cent), and usually occurs in women on the legs, and in men on the back, in between the ages of 30 and 50. These melanomas are often barely raised and have a variety of colours. Such melanomas evolve over one to five years and can be readily caught at an early stage if they are detected and removed.
• Nodular melanoma: It is the next common variant (20 per cent) and usually begins as deeper, blue-black to purplish lumps. They evolve faster and may also be more likely to spread.
• Lentigo maligna: It is the rarest of all and occurs in rare locations like the face,which are exposed to the sun constantly. The most useful criterion for determining prognosis along with stage is tumour thickness. If tumours measure less than one mm, they have excellent cure rates.
In general, melanoma is treated by surgery alone. Doctors have learned that surgery does not need to be as extensive as was thought years ago. When treating many early melanomas, for instance, surgeons only remove one cm (less than half inch) of the normal tissue around the melanoma. Deeper and more advanced cancers may need more extensive surgery.
Surgery for the removal of nearby lymph glands depends on various considerations such as tumour thickness, body location, age, etc. For advanced disease, such as when the melanoma has spread to other parts of the body, treatments like immunotherapy or radiation are sometimes recommended. However once the disease is extensive or comes back, the best attempts are to reduce the suffering (palliation, which is best done by multidisciplinary team with the help of some immunotherapy, or newer tablets which selectively target these cancer cells like tyrosine kinase inhibitors.)
The three golden rules to prevent this dreaded disease are:
• Reducing sun exposure
• Early detection
• Screening of high-risk individuals, such as anyone with a close relative who has melanoma.
Though not so common in India, malignant melanoma needs special attention as once you miss the bus it is gone forever, meaning that if you delay the diagnosis and it crosses the lymph nodes, cure is almost impossible.