Xeroderma pigmentosum: spinal cord astrocytoma with 9-year survival after radiation and isotretinoin therapy.

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.