Cancer risk associated with STK11/LKB1 germline mutations in Peutz-Jeghers syndrome patients: results of an Italian multicenter study

BACKGROUND: Germline mutations in the STK11/LKB1 gene cause Peutz-Jeghers syndrome, an autosomal-dominantly inherited condition characterized by mucocutaneous pigmentation, hamartomatous gastrointestinal polyposis, and an increased risk for various malignancies. We here report the results of the first Italian collaborative study on Peutz-Jeghers syndrome. AIMS: To assess cancer risks in a large homogenous cohort of patients with Peutz-Jeghers syndrome, carrying, in large majority, an identified STK11/LKB1 mutation. METHODS: One-hundred and nineteen patients with Peutz-Jeghers syndrome, ascertained in sixteen different Italian centres, were enrolled in a retrospective cohort study. Relative and cumulative cancer risks and genotype-phenotype correlations were evaluated. RESULTS: 36 malignant tumours were found in 31/119 (29 STK11/LKB1 mutation carriers) patients. The mean age at first cancer diagnosis was 41 years. The relative overall cancer risk was 15.1 with a significantly higher risk (p