bims-lifras 2024-04-28 papers

Issue of 2024–04–28
four papers selected by
Joanna Zawacka, Karolinska Institutet

Cancer Prev Res (Phila). 2024 Apr 25.

Germline Testing identifies Pathogenic/Likely Pathogenic Variants in Patients with Pancreatic Neuroendocrine Tumors.

Chirayu Mohindroo, Seyda Baydogan, Parul Agarwal, Robin D Wright, Laura R Prakash, Maureen E Mork, Alison P Klein, Daniel A Laheru, Jessica E Maxwell, Matthew H G Katz, Arvind Dasari, Michael P Kim, Jin He, Florencia McAllister, Ana De Jesus-Acosta.

10% of pancreatic neuroendocrine tumors (pNETs) are related to inherited syndromes (MEN1, MEN4, VHL, NF1, TSC). Growing evidence suggests that clinically sporadic pNETs can also harbor germline pathogenic variants. In this study, we report the prevalence of pathological/likely pathological germline variants (P/LP) in a high-risk cohort and an unselected cohort. We collected clinical data of patients with pNETs seen at MD Anderson Cancer Center (MDACC) and Johns Hopkins Hospital (JHH). High-risk cohort included (n=132) patients seen at MDACC who underwent germline testing for high-risk criteria (early onset, personal or family history of cancer and syndromic features) between 2013-2019. Unselected cohort (n=106) patients seen at JHH who underwent germline testing following their diagnosis of pNETs between 2020 to 2022. In the high-risk cohort (n=132), 33% (n=44) had P/LP variants. The majority of the patients had P/LP variants in MEN1 56% (n=25), followed by DNA repair pathways 18% (n=8), and 7 %(n=3) in MSH2 (Lynch Syndrome). Patients with P/LP were younger (45 years vs 50 years; p=0.002). In the unselected cohort (n=106), 21% (n=22) had P/LP. The majority were noted in DNA repair pathways 40% (n=9) and MEN1 36% (n=8). Multifocal tumors correlated with the presence of P/LP (p=0.0035). MEN1 germline P/LP variants correlated with younger age (40 vs 56 years) (p=0.0012). presence of multifocal tumors (p<0.0001), and WHO grade 1 histology (p=0.0078). P/LP variants are prevalent in patients with clinically sporadic pNET irrespective of high-risk features. The findings support upfront universal germline testing in all pNET patients.

DOI: https://doi.org/10.1158/1940-6207.CAPR-23-0483

JAMA Netw Open. 2024 Apr 01. 7(4): e247862

CDH1 Genotype Exploration in Women With Hereditary Lobular Breast Cancer Phenotype.

Importance: Pathogenic or likely pathogenic (P/LP) germline CDH1 variants are associated with risk for diffuse gastric cancer and lobular breast cancer (LBC) in the so-called hereditary diffuse gastric cancer (HDGC) syndrome. However, in some circumstances, LBC can be the first manifestation of this syndrome in the absence of diffuse gastric cancer manifestation.
Objectives: To evaluate the frequency of germline CDH1 variants in women with the hereditary LBC (HLBC) phenotype, somatic CDH1 gene inactivation in germline CDH1 variant carriers' tumor samples, and the association of genetic profiles with clinical-pathological data and survival.
Design, Setting, and Participants: This single-center, longitudinal, prospective cohort study was conducted from January 1, 1997, to December 31, 2021, with follow-up until January 31, 2023. Women with LBC seen at the European Institute of Oncology were included. Testing for germline CDH1, BRCA1, and BRCA2 genes was performed. Somatic profiling was assessed for germline CDH1 carriers.
Main Outcomes and Measures: Accurate estimates of prevalence of germline CDH1 variants among patients with HLBC and the association of somatic sequence alteration with HLBC syndrome. The Kaplan-Meier method and a multivariable Cox proportional hazards regression model were applied for overall and disease-free survival analysis.
Results: Of 5429 cases of primary LBC, familial LBC phenotype accounted for 1867 (34.4%). A total of 394 women with LBC were tested, among whom 15 germline CDH1 variants in 15 unrelated families were identified. Among these variants, 6 (40.0%) were P/LP, with an overall frequency of 1.5% (6 of 394). Of the 6 probands with P/LP CDH1 LBC, 5 (83.3%) had a positive family history of BC and only 1 (16.7%) had sporadic juvenile early-onset LBC. No germline BRCA1 and BRCA2 variants were identified in CDH1 carriers. An inactivating CDH1 mechanism (second hit) was identified in 4 of 6 explored matched tumor samples (66.7%) in P/LP germline carriers. The P/LP CDH1 LBC variant carriers had a significantly lower age at diagnosis compared with the group carrying CDH1 variants of unknown significance or likely benign (42.5 [IQR, 38.3-43.0] vs 51.0 [IQR, 45.0-53.0] years; P = .03).
Conclusions and Relevance: In this cohort study, P/LP germline CDH1 variants were identified in individuals not fulfilling the classic clinical criteria for HDGC screening, suggesting that identification of these variants may provide a novel method to test women with LBC with early age at diagnosis and/or positive family history of BC.

DOI: https://doi.org/10.1001/jamanetworkopen.2024.7862

Exp Hematol. 2024 Apr 20. pii: S0301-472X(24)00076-6. [Epub ahead of print] 104217

Of gains and losses: SAMD9/SAMD9L and monosomy 7 in myelodysplastic syndrome.

Jörg Cammenga.

SAMD9 and SAMD9L are two interferon-regulated genes located adjacent to each other on chromosome 7q21.2. Germline gain-of-function mutations in SAMD9/SAMD9L are the genetic cause of MIRAGE syndrome, ataxia pancytopenia syndrome (ATXPC), myeloid leukemia syndrome with monosomy 7 (MLSM7), refractory cytopenia of childhood (RCC), transient monosomy 7 in children, SAMD9L-associated autoinflammatory disease (SAAD) and a proportion of inherited aplastic anemia and bone marrow failure syndromes.

Keywords: Genetic predisposition; SAMD9/SAMD9L; monosomy 7; myeloid neoplasms; somatic genetic compensation

DOI: https://doi.org/10.1016/j.exphem.2024.104217

Clin Genet. 2024 Apr 24.

Pediatric acute promyelocytic leukemia and Fanconi anemia: Case report and literature review.

Claire Freycon, Edith Sepulchre, Vincent-Philippe Lavallée, David Mitchell, Margaret L MacMillan, Catherine Vezina, Catherine Goudie.

Acute promyelocytic leukemia (APL) represents 5%-10% of childhood acute myeloid leukemia (AML) and is the most curable subtype of AML. Fanconi anemia (FA) is one of the most common inherited bone marrow failure syndromes caused by biallelic pathogenic variants (PV) in specific DNA-repair genes. Biallelic PVs in FANCD1/BRCA2 (FA-D1) account for 3% of FA and are associated with early-onset leukemia and a high risk of solid tumors. We report a 4 year-old boy from non-consanguineous parents diagnosed with standard risk APL. This child had café-au-lait spots and an extra thumb remnant. Genomic sequencing revealed two PV in FANCD1/BRCA2 confirming a diagnosis of FA-D1. Chromosomal breakage studies were compatible with FA. Each parent carried one variant and had no personal history of cancer. Morphological then molecular remissions were achieved with all-trans retinoic acid and Arsenic trioxide. This patient underwent haploidentical stem cell transplant. In addition to our patient, a literature search revealed four additional patients with APL/FA, with a total of three patients with FA-D1. This raises the possibility of an association between such rare disorders. Practical management of APL in the setting of FA-D1 is discussed with an overview of current evidence and knowledge gaps.

Keywords: Fanconi anemia; acute promyelocytic leukemia; cancer predisposition syndrome; cancer surveillance; stem cell transplant

DOI: https://doi.org/10.1111/cge.14537