bims-lifras 2020-04-12 papers

bims-lifras

Biomed News

on Li-Fraumeni syndrome

Issue of 2020‒04‒12
eight papers selected by
Joanna Zawacka-Pankau

Characterization of therapy-related acute leukemia in hereditary breast-ovarian carcinoma patients: role of BRCA1 mutation and topoisomerase II-directed therapy.
Burden of hereditary cancer susceptibility in unselected patients with pancreatic ductal adenocarcinoma referred for germline screening.
Ovarian metastases from ileum cancer in a patient with germline EPCAM gene deletion successfully treated with surgical resection and CAPOX chemotherapy: a case report.
Germline mutations predisposing to melanoma.
Hereditary Trichilemmal Cysts are Caused by Two Hits to the Same Copy of the Phospholipase C Delta 1 Gene (PLCD1).
Molecular Trajectory of BRCA1 and BRCA2 Mutations.
NCCN Guidelines Insights: Genetic/Familial High-Risk Assessment: Breast, Ovarian, and Pancreatic, Version 1.2020.
Analysis of BRCA1 and RAD51C Promoter Methylation in Italian Families at High-Risk of Breast and Ovarian Cancer.

Med Oncol. 2020 Apr 10. 37(5): 48

Characterization of therapy-related acute leukemia in hereditary breast-ovarian carcinoma patients: role of BRCA1 mutation and topoisomerase II-directed therapy.

Bagal B, Kumar R, Gaur T, Talreja V, Bonda A, Patkar N, Shetty D, Kowtal P, Subramanian PG, Gupta S, Sarin R, Hasan SK.

  Therapy-related acute leukemias (t-ALs) represent approximately 10-20% of all acute leukemias, are frequently resistant to chemotherapy, and are associated with guarded outcomes. The national comprehensive cancer network data suggest that t-AL cases are diagnosed at increasing rates in breast cancer patients treated with chemotherapeutic agents targeting topoisomerase II. Two cases of BRCA1-mutated ovarian and breast carcinoma who developed therapy-related APL and ALL, respectively, following topoisomerase II-directed therapy were characterized. Genomic characterization of therapy-related acute promyelocytic leukemia (t-APL) revealed a unique RARA intron 2 breakpoint (Chr17: 40347487) at 3'-end of RARA corroborating breakpoint clustering in t-APL following topoisomerase II inhibition. Both cases of this series harbored germline BRCA1 mutations. The germline BRCA1 mutation in patient with t-APL was detected in exon 8 (HGVS nucleotide: c.512dupT). This mutation in t-APL is extremely rare. Interestingly, t-ALL patient in this series had a BRCA1 mutation (HGVS nucleotide: c.68_69delAG; BIC designation: 187delAG) identical to a previously reported case after the treatment of same primary disease. It is unlikely that two breast cancer patients with identical BRCA1 mutation receiving topoisomerase II-targeted agents for the primary disease developed t-AL by chance. This report highlights the development of t-AL in BRAC1-mutated hereditary breast and ovarian cancer patients and warrants further studies on functional consequences of topoisomerase inhibition in this setting.

Keywords:  Breast cancer; Germline BRCA1; Therapy-related leukemia; Topoisomerase II

DOI:  https://doi.org/10.1007/s12032-020-01371-z
Cancer Med. 2020 Apr 07.

Burden of hereditary cancer susceptibility in unselected patients with pancreatic ductal adenocarcinoma referred for germline screening.

Cremin C, Lee MK, Hong Q, Hoeschen C, Mackenzie A, Dixon K, McCullum M, Nuk J, Kalloger S, Karasinska J, Scudamore C, Kim PTW, Donnellan F, Lam ECS, Lim HJ, Neben CL, Stedden W, Zhou AY, Schaeffer DF, Sun S, Renouf DJ, Schrader KA.

  BACKGROUND: Recent guidelines recommend consideration of germline testing for all newly diagnosed pancreatic ductal adenocarcinoma (PDAC). The primary aim of this study was to determine the burden of hereditary cancer susceptibility in PDAC. A secondary aim was to compare genetic testing uptake rates across different modes of genetic counselling.PATIENTS AND METHODS: All patients diagnosed with PDAC in the province of British Columbia, Canada referred to a population-based hereditary cancer program were eligible for multi-gene panel testing, irrespective of cancer family history. Any healthcare provider or patients themselves could refer.
RESULTS: A total of 305 patients with PDAC were referred between July 2016 and January 2019. Two hundred thirty-five patients attended a consultation and 177 completed index germline genetic testing. 25/177 (14.1%) of unrelated patients had a pathogenic variant (PV); 19/25 PV were in known PDAC susceptibility genes with cancer screening or risk-reduction implications. PDAC was significantly associated with PV in ATM (OR, 7.73; 95% CI, 3.10 to 19.33, P = 6.14E-05) when comparing age and gender and ethnicity-matched controls tested on the same platform. The overall uptake rate for index testing was 59.2% and was significantly higher with 1-on-1 consultations and group consultations compared to telehealth consultations (88.9% vs 82.9% vs 61.8%, P < .001).
CONCLUSION: In a prospective clinic-based cohort of patients with PDAC referred for testing irrespective of family history, germline PV were detected in 14.1%. PV in ATM accounted for half of all PVs and were significantly associated with PDAC. These findings support recent guidelines and will guide future service planning in this population.

Keywords:  genetic consultation; hereditary cancer; pancreatic ductal adenocarcinoma

DOI:  https://doi.org/10.1002/cam4.2973
BMC Med Genet. 2020 Apr 09. 21(1): 76

Ovarian metastases from ileum cancer in a patient with germline EPCAM gene deletion successfully treated with surgical resection and CAPOX chemotherapy: a case report.

Iwata N, Shikama A, Takao W, Hosokawa Y, Itagaki H, Tasaka N, Akiyama A, Ochi H, Minaguchi T, Arita M, Noguchi E, Moriwaki T, Satoh T.

  BACKGROUND: Despite recent findings that epithelial cell adhesion molecule (EPCAM) deletions can cause Lynch syndrome (LS), its clinical characteristics are still unknown. We present the first case of ileum cancer in a patient with germline EPCAM gene deletion, which was discovered during ovarian tumor surgery.CASE PRESENTATION: A 59-year-old woman presented with a history of colon cancer occurring at 38 and 55 years old. Five of her siblings had a history of colon cancer, and an elder sister had confirmed LS. As imaging examination revealed an ovarian tumor, and we performed hysterectomy and bilateral salpingo-oophorectomy. Careful observation during surgery revealed a cherry-sized tumor in the ileum, prompting partial ileal resection. Pathological examination showed the ovarian tumor to be a metastasis of ileum cancer. Genetic testing with blood-relative information using multiplex ligation-dependent probe amplification showed EPCAM exons 8 and 9 deletions, confirming LS. The patient received adjuvant chemotherapy with CAPOX (capecitabine and oxaliplatin) and has remained disease-free for 24 months.
CONCLUSIONS: We were fortunate to identify ileum cancer that would have been difficult to find preoperatively through careful observation during ovarian tumor surgery and successfully treated the patient by using surgical resection and CAPOX chemotherapy. When treating patients with hereditary cancer syndromes including LS, we should keep all associated cancers in mind.

Keywords:  EPCAM; Ileum cancer; Lynch syndrome; Ovarian metastases

DOI:  https://doi.org/10.1186/s12881-020-01013-1
J Cutan Pathol. 2020 Apr 06.

Germline mutations predisposing to melanoma.

Toussi A, Mans N, Welborn J, Kiuru M.

  Nearly 15% of melanomas occur in patients with a family history and a subset of these patients have a germline mutation in a melanoma predisposing gene. CDKN2A mutations are responsible for the majority of hereditary melanoma, but many other susceptibility genes have been discovered in recent years, including CDK4, TERT, ACD, TERF2IP, POT1, MITF, MC1R, and BAP1. Additionally, melanoma risk is increased in mixed cancer syndromes caused by mutations in PTEN, BRCA2, BRCA1, RB1, and TP53. While early onset, multiple tumors, and family cancer history remain the most valuable clinical clues for hereditary melanoma, characteristic epithelioid cytology of melanocytic tumors may suggest an underlying BAP1 mutation. Herein, we review the clinical and histopathologic characteristics of melanocytic tumors associated with these germline mutations and discuss the role of genetic counseling. This article is protected by copyright. All rights reserved.

Keywords:  CDKN2A; Melanoma; germline mutation; hereditary; melanocytic nevus

DOI:  https://doi.org/10.1111/cup.13689
Sci Rep. 2020 Apr 07. 10(1): 6035

Hereditary Trichilemmal Cysts are Caused by Two Hits to the Same Copy of the Phospholipase C Delta 1 Gene (PLCD1).

Kolodney MS, Coman GC, Smolkin MB, Hagen R, Katzman JA, Katzman SN, Holliday AC, Kolodney JA.

The autosomal dominant presentation of trichilemmal cysts is one of the most common single gene familial diseases in humans. However, the genetic basis for the inheritance and genesis of these lesions has remained unknown. We first studied patients with multiple trichilemmal cysts using exome and Sanger sequencing. Remarkably, 21 of 21 trichilemmal cysts from 16 subjects all harbored a somatic p.S745L (c.2234 G > A) mutation in phospholipase C delta 1 (PLCD1), a proposed tumor suppressor gene. In addition to this specific somatic mutation in their tumors, 16 of the 17 subjects with multiple trichilemmal cysts were also heterozygous for a p.S460L (c.1379 G > A) germline variant in PLCD1 which is normally present in only about 6% of this population. The one patient of 17 that did not show the p.S460L germline variant had a germline p.E455K (c.1363 C > T) mutation in the same exon of PLCD1. Among 15 additional subjects, with a history suggesting a single sporadic trichilemmal cyst, six were likely familial due to the presence of the p.S460L germline variant. Of the remaining truly sporadic trichilemmal cysts that could be sequenced, only half showed the p.S745L somatic mutation in contrast to 100% of the familial cysts. Surprisingly, in contrast to Knudsen's two hit hypothesis, the p.S745L somatic mutation was always on the same chromosome as the p.S460L germline variant. Our results indicate that familial trichilemmal cysts is an autosomal dominant tumor syndrome resulting from two hits to the same allele of PLCD1 tumor suppressor gene. The c.1379 G > A base change and neighboring bases are consistent with a mutation caused by ultraviolet radiation. Our findings also indicate that approximately one-third of apparently sporadic trichilemmal cysts are actually familial with incomplete penetrance. Sequencing data suggests that the remaining, apparently sporadic, trichilemmal cysts are genetically distinct from familial cysts due to a lack of the germline mutations that underlie familial cysts and a decreased prevalence of the p.S745L somatic mutation relative to familial trichilemmal cysts.

DOI: https://doi.org/10.1038/s41598-020-62959-z
Front Oncol. 2020 ;10 361

Molecular Trajectory of BRCA1 and BRCA2 Mutations.

Hatano Y, Tamada M, Matsuo M, Hara A.

  Every cancer carries genomic mutations. Although almost all these mutations arise after fertilization, a minimal count of cancer predisposition mutations are already present at the time of genesis of germ cells. Of the cancer predisposition genes identified to date, BRCA1 and BRCA2 have been determined to be associated with hereditary breast and ovarian cancer syndrome. Such cancer predisposition genes have recently been attracting attention owing to the emergence of molecular genetics, thus, affecting the strategy of cancer prevention, diagnostics, and therapeutics. In this review, we summarize the molecular significance of these two BRCA genes. First, we provide a brief history of BRCA1 and BRCA2, including their identification as cancer predisposition genes and recognition as members in the Fanconi anemia pathway. Next, we describe the molecular function and interaction of BRCA proteins, and thereafter, describe the patterns of BRCA dysfunction. Subsequently, we present emerging evidence on mutational signatures to determine the effects of BRCA disorders on the mutational process in cancer cells. Currently, BRCA genes serve as principal targets for clinical molecular oncology, be they germline or sporadic mutations. Moreover, comprehensive cancer genome analyses enable us to not only recognize the current status of the known cancer driver gene mutations but also divulge the past mutational processes and predict the future biological behavior of cancer through the molecular trajectory of genomic alterations.

Keywords:  BRCA1; BRCA2; breast; cancer predisposition gene; mutational signature; ovary; pancreas; prostate

DOI:  https://doi.org/10.3389/fonc.2020.00361
J Natl Compr Canc Netw. 2020 04;pii: jnccnGLINS1804. [Epub ahead of print]18(4): 380-391

NCCN Guidelines Insights: Genetic/Familial High-Risk Assessment: Breast, Ovarian, and Pancreatic, Version 1.2020.

Daly MB, Pilarski R, Yurgelun MB, Berry MP, Buys SS, Dickson P, Domchek SM, Elkhanany A, Friedman S, Garber JE, Goggins M, Hutton ML, Khan S, Klein C, Kohlmann W, Kurian AW, Laronga C, Litton JK, Mak JS, Menendez CS, Merajver SD, Norquist BS, Offit K, Pal T, Pederson HJ, Reiser G, Shannon KM, Visvanathan K, Weitzel JN, Wick MJ, Wisinski KB, Dwyer MA, Darlow SD.

The NCCN Guidelines for Genetic/Familial High-Risk Assessment: Breast, Ovarian, and Pancreatic provide recommendations for genetic testing and counseling for hereditary cancer syndromes, and risk management recommendations for patients who are diagnosed with syndromes associated with an increased risk of these cancers. The NCCN panel meets at least annually to review comments, examine relevant new data, and reevaluate and update recommendations. These NCCN Guidelines Insights summarize the panel's discussion and most recent recommendations regarding criteria for high-penetrance genes associated with breast and ovarian cancer beyond BRCA1/2, pancreas screening and genes associated with pancreatic cancer, genetic testing for the purpose of systemic therapy decision-making, and testing for people with Ashkenazi Jewish ancestry.

DOI: https://doi.org/10.6004/jnccn.2020.0017
Cancers (Basel). 2020 Apr 08. pii: E910. [Epub ahead of print]12(4):

Analysis of BRCA1 and RAD51C Promoter Methylation in Italian Families at High-Risk of Breast and Ovarian Cancer.

Tabano S, Azzollini J, Pesenti C, Lovati S, Costanza J, Fontana L, Peissel B, Miozzo M, Manoukian S.

  Previous studies on breast and ovarian carcinoma (BC and OC) revealed constitutional BRCA1 and RAD51C promoter hypermethylation as epigenetic alterations leading to tumor predisposition. Nevertheless, the impact of epimutations at these genes is still debated. One hundred and eight women affected by BC, OC, or both and considered at very high risk of carrying BRCA1 germline mutations were studied. All samples were negative for pathogenic variants or variants of uncertain significance at BRCA testing. Quantitative BRCA1 and RAD51C promoter methylation analyses were performed by Epityper mass spectrometry on peripheral blood samples and results were compared with those in controls. All the 108 analyzed cases showed methylation levels at the BRCA1/RAD51C promoter comparable with controls. Mean methylation levels (± stdev) at the BRCA1 promoter were 4.3% (± 1.4%) and 4.4% (± 1.4%) in controls and patients, respectively (p > 0.05; t-test); mean methylation levels (± stdev) at the RAD51C promoter were 4.3% (± 0.9%) and 3.7% (± 0.9%) in controls and patients, respectively (p > 0.05; t-test). Based on these observations; the analysis of constitutional methylation at promoters of these genes does not seem to substantially improve the definition of cancer risks in patients. These data support the idea that epimutations represent a very rare event in high-risk BC/OC populations.

Keywords:  BRCA1; RAD51C; breast carcinoma; germline epigenetic defects; ovarian carcinoma; promoter methylation

DOI:  https://doi.org/10.3390/cancers12040910