Background: Patients with xeroderma pigmentosum (XP) frequently develop sunlight-induced skin cancer. Infrequently, internal neoplasms may also occur. A 21-year-old patient with XP, who had many skin cancers, developed a rare internal tumour - a grade II diffuse fibrillary spinal cord astrocytoma - during a break in a therapeutic trial of isotretinoin for skin cancer prevention. Treatment of neoplasms in XP patients presents special difficulties because of their defect in DNA repair.
Objective: The study objective was to raise awareness of the cancer surveillance process in XP patients and the concerns involved in choice of therapy.
Methods: Since the spinal cord tumour was inoperable, the patient was treated with x-radiation, continued on isotretinoin treatment and was followed closely for tumour response.
Results: Despite sensitivity to sunlight, the patient had a normal acute response to the x-ray treatment without excessive skin reaction. Serial examinations by magnetic resonance imaging (MRI) starting 8 months after x-ray treatment was initiated, showed a marked gadolinium enhancement followed by regression. This clearing was first seen at 2 years after biopsy and persisted to at least 9 years after treatment.
Conclusion: In contrast to the exaggerated sensitivity to UV radiation, XP patients may tolerate therapeutic doses of x-radiation. Isotretinoin treatment may have contributed to the good response of this spinal cord astrocytoma.