bims-lifras 2020-08-09 papers

Cancer Sci. 2020 Aug 06.

Exon splicing analysis of intronic variants in multi-gene cancer panel testing for hereditary breast/ovarian cancer.

Jin-Sun Ryu, Hye-Young Lee, Eun Hae Cho, Kyong-Ah Yoon, Min-Kyeong Kim, Jungnam Joo, Eun-Sook Lee, Han-Sung Kang, Seeyoun Lee, Dong Ock Lee, Myong Cheol Lim, Sun-Young Kong.

The use of multi-gene panel testing for patients with a predisposition to breast/ovarian cancer is increasing as the identification of variants is useful for diagnosis and disease management. We identified pathogenic and likely pathogenic (P/LP) variants of high and moderate risk genes using a 23-gene germline cancer panel in 518 patients with hereditary breast and ovarian cancers (HBOC). The frequency of P/LP variants was 12.4% (64/518) for high and moderate penetrant genes, namely, BRCA2 (5.6%), BRCA1 (3.3%), CHEK2 (1.2%), MUTYH (0.8%), PALB2 (0.8%), MLH1 (0.4%), ATM (0.4%), BRIP1 (0.4%), TP53 (0.2%), and PMS2 (0.2%). Five patients possessed two P/LP variants in BRCA1/2 and other genes. We also compared the results from in silico splicing predictive tools and exon splicing patterns from patient samples by analyzing RT-PCR product sequences in six P/LP intronic variants and two intronic variants of unknown significance (VUS). Altered transcriptional fragments were detected for P/LP intronic variants in BRCA1, BRIP1, CHEK2, PARB2, and PMS2. Notably, we identified an in-frame deletion of the BRCT domain by exon skipping in BRCA1 c.5152+6T>C-as known VUS-indicating a risk for HBOC. Thus, exon splicing analysis can improve the identification of veiled intronic variants that would aid decision making and determination of hereditary cancer risk.

Keywords: Germline mutation; Hereditary breast and ovarian cancer syndrome; Next generation sequencing (NGS); Pathogenic/likely Pathogenic; RNA splicing

DOI: https://doi.org/10.1111/cas.14600

Lancet Oncol. 2020 Aug;pii: S1470-2045(20)30219-9. [Epub ahead of print]21(8): e386-e397

Hereditary diffuse gastric cancer: updated clinical practice guidelines.

Vanessa R Blair, Maybelle McLeod, Fátima Carneiro, Daniel G Coit, Johanna L D'Addario, Jolanda M van Dieren, Kirsty L Harris, Nicoline Hoogerbrugge, Carla Oliveira, Rachel S van der Post, Julie Arnold, Patrick R Benusiglio, Tanya M Bisseling, Alex Boussioutas, Annemieke Cats, Amanda Charlton, Karen E Chelcun Schreiber, Jeremy L Davis, Massimiliano di Pietro, Rebecca C Fitzgerald, James M Ford, Kimberley Gamet, Irene Gullo, Richard H Hardwick, David G Huntsman, Pardeep Kaurah, Sonia S Kupfer, Andrew Latchford, Paul F Mansfield, Takeshi Nakajima, Susan Parry, Jeremy Rossaak, Haruhiko Sugimura, Magali Svrcek, Marc Tischkowitz, Toshikazu Ushijima, Hidetaka Yamada, Han-Kwang Yang, Adrian Claydon, Joana Figueiredo, Karyn Paringatai, Raquel Seruca, Nicola Bougen-Zhukov, Tom Brew, Simone Busija, Patricia Carneiro, Lynn DeGregorio, Helen Fisher, Erin Gardner, Tanis D Godwin, Katharine N Holm, Bostjan Humar, Caroline J Lintott, Elizabeth C Monroe, Mark D Muller, Enrique Norero, Yasmin Nouri, Joana Paredes, João M Sanches, Emily Schulpen, Ana S Ribeiro, Andrew Sporle, James Whitworth, Liying Zhang, Anthony E Reeve, Parry Guilford.

Hereditary diffuse gastric cancer (HDGC) is an autosomal dominant cancer syndrome that is characterised by a high prevalence of diffuse gastric cancer and lobular breast cancer. It is largely caused by inactivating germline mutations in the tumour suppressor gene CDH1, although pathogenic variants in CTNNA1 occur in a minority of families with HDGC. In this Policy Review, we present updated clinical practice guidelines for HDGC from the International Gastric Cancer Linkage Consortium (IGCLC), which recognise the emerging evidence of variability in gastric cancer risk between families with HDGC, the growing capability of endoscopic and histological surveillance in HDGC, and increased experience of managing long-term sequelae of total gastrectomy in young patients. To redress the balance between the accessibility, cost, and acceptance of genetic testing and the increased identification of pathogenic variant carriers, the HDGC genetic testing criteria have been relaxed, mainly through less restrictive age limits. Prophylactic total gastrectomy remains the recommended option for gastric cancer risk management in pathogenic CDH1 variant carriers. However, there is increasing confidence from the IGCLC that endoscopic surveillance in expert centres can be safely offered to patients who wish to postpone surgery, or to those whose risk of developing gastric cancer is not well defined.

DOI: https://doi.org/10.1016/S1470-2045(20)30219-9

Cancers (Basel). 2020 Aug 03. pii: E2151. [Epub ahead of print]12(8):

Germline Genetic Findings Which May Impact Therapeutic Decisions in Families with a Presumed Predisposition for Hereditary Breast and Ovarian Cancer.

Carolina Velázquez, De Leeneer K, Eva M Esteban-Cardeñosa, Francisco Avila Cobos, Enrique Lastra, Luis E Abella, Virginia de la Cruz, Carmen D Lobatón, Kathleen B Claes, Mercedes Durán, Mar Infante.

In this study, we aim to gain insight in the germline mutation spectrum of ATM, BARD1, BRIP1, ERCC4, PALB2, RAD51C and RAD51D in breast and ovarian cancer families from Spain. We have selected 180 index cases in whom a germline mutation in BRCA1 and BRCA2 was previously ruled out. The importance of disease-causing variants in these genes lies in the fact that they may have possible therapeutic implications according to clinical guidelines. All variants were assessed by combined annotation dependent depletion (CADD) for scoring their deleteriousness. In addition, we used the cancer genome interpreter to explore the implications of some variants in drug response. Finally, we compiled and evaluated the family history to assess whether carrying a pathogenic mutation was associated with age at diagnosis, tumour diversity of the pedigree and total number of cancer cases in the family. Eight unequivocal pathogenic mutations were found and another fourteen were prioritized as possible causal variants. Some of these molecular results could contribute to cancer diagnosis, treatment selection and prevention. We found a statistically significant association between tumour diversity in the family and carrying a variant with a high score predicting pathogenicity (p = 0.0003).

Keywords: HBOC; clinical guidelines; family history; genetic testing; therapeutic selection; variant prioritisation

DOI: https://doi.org/10.3390/cancers12082151

Expert Rev Gastroenterol Hepatol. 2020 Aug 05. 1-14

Updates in the field of hereditary nonpolyposis colorectal cancer.

Paivi Peltomäki, Alisa Olkinuora, Taina T Nieminen.

INTRODUCTION: Up to one third of colorectal cancers show familial clustering and 5% are hereditary single-gene disorders. Hereditary non-polyposis colorectal cancer comprises DNA mismatch repair-deficient and -proficient subsets, represented by Lynch syndrome (LS) and familial colorectal cancer type X (FCCTX), respectively. Accurate knowledge of molecular etiology and genotype-phenotype correlations are critical for tailored cancer prevention and treatment.
AREAS COVERED: The authors highlight advances in the molecular dissection of hereditary non-polyposis colorectal cancer, based on recent literature retrieved from PubMed. Future possibilities for novel gene discoveries are discussed.
EXPERT COMMENTARY: LS is molecularly well established, but new information is accumulating of the associated clinical and tumor phenotypes. FCCTX remains poorly defined, but several promising candidate genes have been discovered and share some preferential biological pathways. Multi-level characterization of specimens from large patient cohorts representing multiple populations, combined with proper bioinformatic and functional analyses, will be necessary to resolve the outstanding questions.

Keywords: DNA mismatch repair; Hereditary non-polyposis colorectal cancer; constitutional epimutation; familial colorectal cancer type X; genomic instability; germline mutation; lynch syndrome

DOI: https://doi.org/10.1080/17474124.2020.1782187

Expert Opin Ther Targets. 2020 Aug 01.

Fumarate hydratase as a therapeutic target in renal cancer.

Priyanka Kancherla, Michael Daneshvar, Rebecca A Sager, Mehdi Mollapour, Gennady Bratslavsky.

INTRODUCTION: Renal cell carcinoma (RCC) is a heterogeneous group of cancers that can occur sporadically or as a manifestation of various inherited syndromes. Hereditary leiomyomatosis and renal cell carcinoma (HLRCC) is one such inherited syndrome that predisposes patients to HLRCC-associated RCC. These tumors are notoriously aggressive and often exhibit early metastases. HLRCC results from germline mutations in the FH gene, which encodes the citric acid cycle enzyme fumarate hydratase (FH). FH loss leads to alterations in oxidative carbon metabolism, necessitating a switch to aerobic glycolysis, as well as a pseudohypoxic response and consequent upregulation of various pro-survival pathways. Mutations in FH also alter tumor cell migratory potential, response to oxidative stress, and response to DNA damage.
AREAS COVERED: We review the mechanisms by which FH loss leads to HLRCC-associated RCC and how these mechanisms are being rationally targeted.
EXPERT OPINION: FH loss results in activation of numerous salvage pathways for tumor cell survival in HLRCC-associated RCC. Tumor heterogeneity requires individualized characterization via next-generation sequencing, ultimately resulting in HLRCC-specific treatment regimens. As HLRCC-associated RCC represents a classic Warburg tumor, targeting aerobic glycolysis is particularly promising as a future therapeutic avenue.

Keywords: FH; Fumarate hydratase; HLRCC; Hereditary leiomyomatosis and renal cell carcinoma; Renal cell carcinoma

DOI: https://doi.org/10.1080/14728222.2020.1804862

Pediatr Blood Cancer. 2020 Aug 02. e28633

Medical radiation exposure and risk of sporadic retinoblastoma.

Omar Shakeel, Nelson Pace, Tiffany M Chambers, Michael E Scheurer, Arupa A Ganguly, Philip J Lupo, Greta R Bunin.

BACKGROUND: While there is evidence that parental exposure to medical radiation is associated with increased risk of sporadic bilateral retinoblastoma in offspring, this association has not been confirmed. Additionally, the relationship between paternal and maternal exposures and sporadic unilateral retinoblastoma has not been fully investigated.
PROCEDURE: Data were obtained from two large multicenter case-control studies of retinoblastoma. For the paternal analyses, 268 bilateral cases, 155 unilateral cases, and 358 controls were included. For the maternal analyses, 298 bilateral cases, 184 unilateral cases, and 404 controls were included. Logistical regression models were used to estimate odds ratios (OR) and 95% confidence intervals (CI) to evaluate the associations between parental exposures to medical radiation and sporadic retinoblastoma, while adjusting for potential confounders.
RESULTS: Paternal exposure to medical radiation was not significantly associated with sporadic bilateral retinoblastoma in offspring. However, increasing paternal exposure to gonadal radiation was associated with increased risk of unilateral retinoblastoma (P-trend = .03). Maternal history of upper and lower gastrointestinal (GI) series was associated with bilateral retinoblastoma (OR = 1.9, 95% CI: 1.1-3.2 and OR = 6.9, 95% CI: 2.9-16.4, respectively). However, there was no association between maternal exposure to medical radiation and unilateral retinoblastoma in offspring.
CONCLUSION: Our investigation adds to the evidence that medical radiation exposure in fathers as well as mothers prior to pregnancy may increase the risk of germline alterations leading to the development of retinoblastoma in their offspring. However, our findings could point to a more complex etiological framework for this important pediatric malignancy.

Keywords: de novo germline alteration; epidemiology; gonadal radiation; sporadic retinoblastoma

DOI: https://doi.org/10.1002/pbc.28633