tretinoin and Adenomatous-Polyps

A boy showing symptoms of a Turcot-like childhood cancer syndrome together with stigmata of neurofibromatosis type I is reported. His brother suffers from an infantile myofibromatosis, and a sister died of glioblastoma at age 7. Another 7-year-old brother is so far clinically unaffected. The parents are consanguineous. Molecular diagnosis in the index patient revealed a constitutional homozygous mutation of the mismatch repair gene PMS2. The patient was in remission of his glioblastoma (WHO grade IV) after multimodal treatment followed by retinoic acid chemoprevention for 7 years. After discontinuation of retinoic acid medication, he developed a relapse of his brain tumour together with the simultaneous occurrence of three other different HNPCC-related carcinomas. We think that retinoic acid might have provided an effective chemoprevention in this patient with homozygous mismatch repair gene defect. We propose to take a retinoic acid chemoprevention into account in children with proven biallelic PMS2 mismatch repair mutations being at highest risk concerning the development of a malignancy.

Topics: Adenomatous Polyps; Adenosine Triphosphatases; Alleles; Base Pair Mismatch; Brain Neoplasms; Child; Colorectal Neoplasms; DNA Repair Enzymes; DNA-Binding Proteins; Female; Germ-Line Mutation; Glioblastoma; Homozygote; Humans; Magnetic Resonance Imaging; Male; Microsatellite Instability; Microsatellite Repeats; Mismatch Repair Endonuclease PMS2; Mutation; Neoplasm Recurrence, Local; Syndrome; Tretinoin