Among the major skin cancers, which is the most lethal?

• A. Melanoma
• B. Basal cell carcinoma
• C. Squamous cell carcinoma
• D. Actinic keratosis

Answer: (A)

Melanoma is the most lethal because its biology favors early and unpredictable spread to distant sites. It arises from pigment-producing melanocytes and tends to invade blood and lymphatic channels quickly, so even a small or seemingly thin lesion can seed metastases to the lymph nodes, liver, lungs, brain, and other organs. Once distant spread occurs, prognosis worsens substantially, making melanoma responsible for the majority of skin cancer deaths despite not being the most common skin cancer.

In contrast, basal cell carcinoma grows slowly and almost never metastasizes; it’s highly curable with local treatment and carries very low mortality. Squamous cell carcinoma can metastasize and cause significant morbidity, but overall its death rate is lower than that of melanoma, especially when treated early. Actinic keratosis is a precancerous lesion with a low immediate risk of death because it’s not malignant itself and only a minority progress to squamous cell carcinoma.

So, the higher risk of death with melanoma comes from its aggressive potential to spread and the resulting difficulty in treating advanced disease.