FOCAL MICROSATELLITE MUTATIONS IN RELATIVES WITH PROSTATIC ADENOCARCINOMA

Instability of short tandem repeat sequences, microsatellite instabili ty (MI), has been reported to play an important role in the tumorigene sis of various adenocarcinomas, including prostatic adenocarcinoma. Al though prostate cancer is not widely recognized as a heriditary cancer , familial clustering is well known. To investigate the frequency of m icrosatellite instability in familial prostatic adenocarcinomas we ana lyzed archival tumor tissue from seven paired first degree relatives w ith prostatic adenocarcinoma. Twelve dinucleotide, nine trinucleotide, six tetranucleotide repeats and the CAG repeat of the androgen recept or gene were screened for MI. Solitary mutations were observed in four separate cases (28.6%) and widespread somatic alterations were not id entified. No statistical correlation to pathological characteristics w as determined. Our. data indicate that microsatellite instability is a n uncommon phenomenon in prostatic adenocarcinoma within first degree relatives. Those changes present appeal to manifest as focal mutations in contrast to the more global changes seen in MI.