Metastasis from squamous cell skin cancer of the extremities.

In a series of patients with localized squamous cell skin cancer treated at a cancer center, the incidence of metastasis was 1.4%. A premalignant condition, including thermal burns and irradiation dermatitis, was found in 30% of those patients, and 28% had multiple primary skin cancers. Forty-two of the 106 patients with metastasis had experienced local treatment failures, suggesting that such patients may be at greater risk of metastasis. In all but one instance of metastasis occurring from squamous cell skin cancer of the extremities, the regional lymph nodes were involved. Despite aggressive therapy, the five-year survival of patients with nodal metastasis was only 39%. Extracapsular spread of nodal disease was of grave significance. Based on the experience with metastatic squamous cell skin cancer of the head and neck, it is proposed to evaluate the adjunctive use of preoperative or postoperative irradiation and surgery in the treatment of metastatic squamous cell cancer of the skin of the extremities. Careful follow-up of patients with squamous cell skin cancer is necessary, and the lethal potential for recurrence and regional metastasis must be recognized.