Background Li-Fraumeni syndrome (LFS) is an autosomal dominant cancer predisposition syndrome characterized by very high lifetime cancer risk and early age at diagnosis of a wide cancer spectrum. Precise estimates for first and subsequent cancers risk are lacking. Methods The NCI’s LFS Study includes families meeting diagnostic criteria for LFS or Li-Fraumeni-like syndrome, and individuals with a germline TP53 mutation, choroid plexus carcinoma, adrenocortical carcinoma, or ≥3 cancers. We estimated cumulative risk and annual hazards for first and second cancer among TP53 mutation carriers (TP53+) using MATLAB. Results We evaluated 286 TP53+ individuals from 107 families. Cumulative cancer incidence was 50% by age 31 among TP53+ females and 46 among males, and nearly 100% by age 70 for both. Cancer risk was highest after age 20 for females, mostly due to breast cancer, while among males risk was higher in childhood and later adulthood. Among females, the cumulative incidence by age 70 for breast cancer, soft tissue sarcoma (STS), brain cancer, and osteosarcoma were 54%, 15%, 6%, and 5%, respectively. Among males, the incidence was 22%, 19%, and 11% for STS, brain cancer, and osteosarcoma. 49% of those with one cancer developed at least another cancer after a median of 10 years. Average age-specific risk of developing a second cancer was comparable to that of developing a first cancer. Conclusions Cumulative cancer risk in TP53+ individuals was high and varied by gender, age, and cancer type. Additional work, including prospective risk estimates, is needed to better inform personalized risk management.

Dyskeratosis congenita (DC) is an inherited bone marrow failure syndrome in which the known susceptibility genes (DKC1, TERC, and TERT) belong to the telomere maintenance pathway; patients with DC have very short telomeres. We used multicolor flow fluorescence in situ hybridization analysis of median telomere length in total blood leukocytes, granulocytes, lymphocytes, and several lymphocyte subsets to confirm the diagnosis of DC, distinguish patients with DC from unaffected family members, identify clinically silent DC carriers, and discriminate between patients with DC and those with other bone marrow failure disorders. We defined "very short" telomeres as below the first percentile measured among 400 healthy control subjects over the entire age range. Diagnostic sensitivity and specificity of very short telomeres for DC were more than 90% for total lymphocytes, CD45RA؉/CD20؊ naive T cells, and CD20؉ B cells. Granulocyte and total leukocyte assays were not specific; CD45RA؊ memory T cells and CD57؉ NK/NKT were not sensitive. We observed very short telomeres in a clinically normal family member who subsequently developed DC. We propose adding leukocyte subset flow fluorescence in situ hybridization telomere length measurement to the evaluation of patients and families suspected to have DC, because the correct diagnosis will substantially affect patient management. (Blood.

Summary Fanconi anaemia (FA), dyskeratosis congenita (DC), Diamond-Blackfan anaemia (DBA), and Shwachman-Diamond syndrome (SDS) comprise major inherited bone marrow failure syndromes (IBMFS). Adverse events include severe bone marrow failure (BMF), myelodysplastic syndrome (MDS), acute myeloid leukaemia (AML), and solid tumours (ST). The natural history of FA is well characterised; hazard rates in the other syndromes have not yet been quantified. An open cohort was established at the National Cancer Institute (NCI) in 2002. Patients enrolled prior to December, 2007 were followed up to December, 2008. Diagnoses were confirmed with standard tests. Age-associated risks of adverse events were calculated. Most patients in each syndrome survived to young adulthood. Patients with FA had earlier onset of cancers, need for stem cell transplant, and death; followed by DC; DBA and SDS were mildest. While FA and DC patients had markedly increased risks of cancer, AML and MDS, there were no cases of leukaemia in DBA or SDS patients. The NCI cohort provides the first direct quantitative comparison of timing and magnitude of cancer risk in the IBMFS. The findings demonstrate that both FA and DC are major cancer susceptibility syndromes. The IBMFS, historically considered paediatric disorders, have important management implications for physicians treating adult patients.