Melanoma is a serious form of skin cancer originating in melanocytes, the cells responsible for producing skin pigment. This type of cancer is particularly dangerous due to its potential for rapid growth and spread if not addressed promptly. Leaving melanoma untreated can lead to severe and life-threatening consequences, underscoring the importance of early detection and intervention.
How Melanoma Progresses
Untreated melanoma progresses, initially growing on the skin’s surface before extending deeper. The initial phase involves radial growth, where the cancer spreads horizontally, followed by a vertical growth phase where it penetrates into deeper layers of the skin. A critical measurement at this stage is Breslow thickness, which quantifies the tumor’s depth in millimeters from the skin’s surface to its deepest point. Thicker melanomas are associated with a higher likelihood of spreading and a less favorable outlook. Ulceration, a breakdown of the skin over the melanoma, also indicates a more serious condition with an increased risk of spread.
As melanoma progresses, its cells can detach from the primary tumor and spread through the lymphatic system. This network of vessels and nodes filters fluids throughout the body, but cancer cells can exploit it as a pathway for dissemination. The first lymph node to which melanoma cells typically travel is known as the sentinel lymph node. Involvement of these regional lymph nodes indicates a more advanced stage of the disease. This regional spread signifies that the cancer has moved beyond its original site, making treatment more complex.
If untreated, cancer cells can continue through the lymphatic system or enter the bloodstream, leading to distant metastasis. This means cancer spreads to organs and tissues far from the original tumor. Common sites for distant metastases include the lungs, liver, brain, and bones, as well as distant skin areas or other lymph nodes. This stage is classified as stage 4, the most advanced form of the disease.
Systemic Impact and Complications
Untreated melanoma spreading to distant sites leads to various health problems depending on the organs affected. When melanoma metastasizes to other areas of the skin or soft tissues, new tumors may appear, which can ulcerate, bleed, and cause pain. Involvement of lymph nodes can result in noticeable swelling and discomfort in the affected areas, potentially leading to obstruction of lymphatic flow.
Metastasis to the lungs, a common site for distant spread, can cause respiratory symptoms such as a persistent cough, shortness of breath, and chest pain. Fluid accumulation around the lungs may also occur, impeding breathing. Liver spread can cause symptoms like jaundice (yellowing of skin and eyes), abdominal pain, fatigue, and unintended weight loss. Nausea and malaise are also possible with liver involvement.
Brain metastases are a concerning complication of advanced melanoma. These can lead to severe headaches, seizures, and neurological deficits like weakness, speech difficulties, or vision changes. Personality changes may also occur. When melanoma spreads to the bones, it commonly causes localized pain and increases fracture risk. This can also lead to hypercalcemia (elevated blood calcium), causing fatigue, confusion, and kidney problems.
Beyond organ-specific complications, untreated metastatic melanoma can lead to general systemic effects impacting overall health and quality of life. These include unexplained weight loss, persistent fatigue, and recurrent fevers. These complications cumulatively lead to a decline in well-being.
Prognosis Without Treatment
Untreated melanoma carries a grave prognosis, with progression leading to increasingly poor outcomes. If left without intervention, melanoma is almost always fatal because of its ability to spread aggressively throughout the body. The likelihood of survival decreases significantly as the disease advances through its stages.
For melanoma detected while still localized to the skin, the estimated five-year survival rate is very high, approaching 99%. However, once melanoma cells spread to nearby lymph nodes, the five-year survival rate drops to around 71%. When the cancer has metastasized to distant organs, the prognosis becomes considerably worse. Historically, the five-year survival rate for distant metastatic melanoma was as low as 15% to 20%, though newer treatments have shown improvements in select groups.
Early detection and timely treatment are the only effective means to achieve a cure or long-term survival for melanoma. The success of treatment is directly linked to how early the cancer is found and removed. Any suspicious changes in the skin, such as a new mole or a change in an existing one, warrant immediate medical attention to ensure the best possible outcome.