Melanoma Prognosis Calculator

The Melanoma Prognosis Calculator estimates survival outcomes and recurrence risk for cutaneous melanoma based on the key pathological and staging factors identified in the AJCC (American Joint Committee on Cancer) 8th Edition melanoma staging system. Melanoma prognosis is primarily determined by tumor characteristics at diagnosis, making accurate pathological assessment essential for treatment planning.

Melanoma is the most lethal form of skin cancer, accounting for approximately 75% of all skin cancer deaths despite representing only 1% of skin cancer diagnoses. Worldwide, over 300,000 new melanoma cases are diagnosed annually, with approximately 100,000 in the United States. Early-stage melanoma is highly curable, but advanced melanoma has historically carried a very poor prognosis, though this has improved dramatically with modern immunotherapy and targeted therapy.

The Breslow thickness is the single most important prognostic factor in primary melanoma. Measured in millimeters from the granular layer of the epidermis to the deepest point of tumor invasion, it directly correlates with both survival and metastatic potential. Melanomas less than 1 mm thick have 10-year survival rates exceeding 90%, while those over 4 mm have rates below 60%.

Ulceration is the second most important pathological prognostic factor. Ulcerated melanomas have significantly worse outcomes than non-ulcerated melanomas of the same thickness. In the AJCC 8th edition, ulceration upstages melanoma within each T category (e.g., T2a becomes T2b with ulceration). The mechanism is believed to relate to more aggressive tumor biology and increased propensity for metastasis.

Sentinel lymph node (SLN) status is the most important staging factor after T-stage. Positive sentinel nodes indicate regional metastasis (Stage III disease) and dramatically affect prognosis. SLN biopsy is recommended for melanomas greater than 0.8 mm thick, and results guide decisions about adjuvant therapy, completion lymph node dissection, and follow-up intensity.

In the era of modern adjuvant therapy, patients with Stage III melanoma may receive immune checkpoint inhibitors (nivolumab, pembrolizumab) or targeted therapy (dabrafenib/trametinib for BRAF-mutant melanoma) after surgery. These adjuvant treatments have significantly improved recurrence-free survival and are changing the prognostic landscape. Stage and recurrence risk assessment guides the risk-benefit discussion for adjuvant therapy.