Radiation therapy for high-risk squamous cell carcinomas in patients with xeroderma pigmentosum: report of two cases and review of the literature.

Radiation therapy (RT) represents an important adjuvant treatment modality for high-risk squamous cell carcinomas (SCCs). Despite the frequency of aggressive cutaneous and extracutaneous malignancies, there have been relatively few reports of RT in individuals with xeroderma pigmentosum (XP). We describe 2 adolescent boys with XP and high-risk SCCs of the skin that were treated with standard RT regimens without acute or chronic complications. After follow-up periods of 2 and 7 years, both of these patients had developed fewer skin cancers on the treated side of the face. A review of reported cases revealed that XP patients generally have normal cellular and clinical responses to ionizing radiation, which reflects the specificity of their nucleotide excision repair defect for ultraviolet radiation-induced DNA damage.