bims-lifras Biomed News
on Li-Fraumeni syndrome
Issue of 2020‒06‒07
sixteen papers selected by
Joanna Zawacka-Pankau

  1. J Clin Oncol. 2020 Jun 04. JCO1902760
    Qin N, Wang Z, Liu Q, Song N, Wilson CL, Ehrhardt MJ, Shelton K, Easton J, Mulder H, Kennetz D, Edmonson MN, Rusch MC, Downing JR, Hudson MM, Nichols KE, Zhang J, Robison LL, Yasui Y.
      PURPOSE: To investigate cancer treatment plus pathogenic germline mutations (PGMs) in DNA repair genes (DRGs) for identification of childhood cancer survivors at increased risk of subsequent neoplasms (SNs).METHODS: Whole-genome sequencing was performed on blood-derived DNA from survivors in the St Jude Lifetime Cohort. PGMs were evaluated in 127 genes from 6 major DNA repair pathways. Cumulative doses of chemotherapy and body region-specific radiotherapy (RT) were abstracted from medical records. Relative rates (RRs) and 95% CIs of SNs by mutation status were estimated using multivariable piecewise exponential models.
    RESULTS: Of 4,402 survivors, 495 (11.2%) developed 1,269 SNs. We identified 538 PGMs in 98 DRGs (POLG, MUTYH, ERCC2, and BRCA2, among others) in 508 (11.5%) survivors. Mutations in homologous recombination (HR) genes were significantly associated with an increased rate of subsequent female breast cancer (RR, 3.7; 95% CI, 1.8 to 7.7), especially among survivors with chest RT ≥ 20 Gy (RR, 4.4; 95% CI, 1.6 to 12.4), or with a cumulative dose of anthracyclines in the second or third tertile (RR, 4.4; 95% CI, 1.7 to 11.4). Mutations in HR genes were also associated with an increased rate of subsequent sarcoma among those who received alkylating agent doses in the third tertile (RR, 14.9; 95% CI, 4.0 to 38.0). Mutations in nucleotide excision repair genes were associated with subsequent thyroid cancer for those treated with neck RT ≥ 30 Gy (RR, 12.9; 95% CI, 1.6 to 46.6) with marginal statistical significance.
    CONCLUSION: Our study provides novel insights regarding the contribution of genetics, in combination with known treatment-related risks, for the development of SNs. These findings have the potential to facilitate identification of high-risk survivors who may benefit from genetic counseling and/or testing of DRGs, which may further inform personalized cancer surveillance and prevention strategies.
  2. Ann Gastroenterol Surg. 2020 May;4(3): 229-233
    Eguchi H, Kobayashi S, Gotoh K, Noda T, Doki Y.
      The incidence of pancreatic cancer is high among those in their sixties to seventies but low in those in their fifties or younger. Although there is no unified definition regarding the age of early-onset pancreatic cancer, previously published reports suggest that, compared to later-onset pancreatic cancer patients, early-onset pancreatic cancer patients tend to be detected at advanced stages and thus have poor prognoses, but they do not show significantly higher rates of patients with genetic factors. On the other hand, it has been reported that patients with familial pancreatic cancer and hereditary pancreatic cancer syndromes often develop pancreatic cancer at a young age. The broad definition of familial pancreatic cancer is pancreatic cancer in patients who have two or more first-degree relatives with pancreatic cancer; whereas the narrow definition of familial pancreatic cancer is the broad definition of familial pancreatic cancer, while excluding those with inherited tumor syndromes. Hereditary tumors developing pancreatic cancer include hereditary pancreatitis, hereditary breast and ovarian cancer, Peutz-Jeghers syndrome, familial atypical multiple mole melanoma syndrome, familial adenomatous polyposis, and hereditary non-polyposis colorectal cancer, all of which are autosomal dominant hereditary diseases. This study reviews the clinical characteristics of early-onset pancreatic cancer and its association with familial pancreatic cancer and hereditary pancreatic cancer syndromes.
    Keywords:  early‐onset pancreatic cancer; familial pancreatic cancer; hereditary; pancreatic cancer syndromes
  3. Curr Opin Hematol. 2020 Jun 01.
    Chen KZ, Kazi R, Porter CC, Qu CK.
      PURPOSE OF REVIEW: The purpose of this review is to summarize the current understanding of germline mutations as they contribute to leukemia development and progression. We also discuss how these new insights may help improve clinical management of germline mutations associated with leukemia.RECENT FINDINGS: Germline mutations may represent important initial mutations in the development of leukemia where interaction with somatic mutations provide further hits in leukemic progression. In addition, germline mutations may also contribute to leukemogenesis by impacting bone marrow stem-cell microenvironment and immune cell development and function.
    SUMMARY: Leukemia is characterized by the clonal expansion of malignant cells secondary to somatic or germline mutations in a variety of genes. Understanding somatic mutations that drive leukemogenesis has drastically improved our knowledge of leukemia biology and led to novel therapeutic strategies. Advances have also been made in identifying germline mutations that may affect leukemic development and progression. This review will discuss the biological and clinical relationship of germline mutations with clonal hematopoiesis, bone marrow microenvironment, and immunity in the progression of leukemia.
  4. J Pediatr Hematol Oncol. 2020 Jun 02.
    Wyatt KD, Kohorst MA, Coon LM, Hurley RM, van Dorland HA, Arndt CAS.
      Hereditary thrombotic thrombocytopenic purpura is an ultra-rare disorder caused by biallelic mutations in the ADAMTS13 gene. Because it can be difficult to diagnose, plasma ADAMTS13 activity assessment should be considered in patients with thrombocytopenia, anemia, and schistocytes on peripheral blood smear. We present the diagnostic evaluation of a patient with hereditary thrombotic thrombocytopenic purpura. Genetic testing revealed one known pathogenic mutation and one novel mutation of ADAMTS13 classified as likely pathogenic on the basis of parental genetic testing and in silico analyses. We further discuss off-label use of prophylactic plasma-derived Factor VIII (Koate-DVI) and the benefit of rare disease registries.
  5. Ann Surg Oncol. 2020 Jun 05.
    Rosenberger LH, Thomas SM, Nimbkar SN, Hieken TJ, Ludwig KK, Jacobs LK, Miller ME, Gallagher KK, Wong J, Neuman HB, Tseng J, Hassinger TE, Jakub JW.
      BACKGROUND: A paucity of data exists regarding inherited mutations associated with phyllodes tumors (PT); however, some are reported (TP53, BRCA1, and RB1). A PT diagnosis does not meet NCCN criteria for testing, including within Li-Fraumeni Syndrome (TP53). We sought to determine the prevalence of mutations associated with PT.METHODS: We performed an 11-institution review of contemporary (2007-2017) PT practice. We recorded multigenerational family history and personal history of genetic testing. We identified patients meeting NCCN criteria for genetic evaluation. Logistic regression estimated the association of select covariates with likelihood of undergoing genetic testing.
    RESULTS: Of 550 PT patients, 59.8% (n = 329) had a close family history of cancer, and 34.0% (n = 112) had ≥ 3 family members affected. Only 6.2% (n = 34) underwent genetic testing, 38.2% (n = 13) of whom had only BRCA1/BRCA2 tested. Of 34 patients tested, 8.8% had a deleterious mutation (1 BRCA1, 2 TP53), and 5.9% had a BRCA2 VUS. Of women who had TP53 testing (N = 21), 9.5% had a mutation. Selection for testing was not associated with age (odds ratio [OR] 1.01, p = 0.55) or PT size (p = 0.12) but was associated with grade (malignant vs. benign: OR 9.17, 95% CI 3.97-21.18) and meeting NCCN criteria (OR 3.43, 95% confidence interval 1.70-6.94). Notably, an additional 86 (15.6%) patients met NCCN criteria but had no genetic testing.
    CONCLUSIONS: Very few women with PT undergo germline testing; however, in those selected for testing, a deleterious mutation was identified in ~ 10%. Multigene testing of a PT cohort would present an opportunity to discover the true incidence of germline mutations in PT patients.
  6. Hum Mutat. 2020 Jun 02.
    Fortuno C, Mester J, Pesaran T, Weitzel JN, Dolinsky J, Yussuf A, McGoldrick K, Garber JE, Savage SA, Khincha PP, Gareth Evans D, Achatz MI, Nichols KE, Maxwell K, Schiffman JD, Sandoval R, , James PA, Spurdle AB.
      Early-onset breast cancer is the most common malignancy in women with Li-Fraumeni syndrome, caused by germline TP53 pathogenic variants. It has repeatedly been suggested that breast tumors from TP53 carriers are more likely to be HER2+ than those of non-carriers, but this information has not been incorporated into variant interpretation models for TP53. Breast tumor pathology is already being used quantitatively for assessing pathogenicity of germline variants in other genes, and it has been suggested that this type of evidence can be incorporated into current ACMG/AMP guidelines for germline variant classification. Here, by reviewing published data and using internal datasets separated by different age-groups, we investigated if breast tumor HER2+ status has utility as a predictor of TP53 germline variant pathogenicity, considering age at diagnosis. Overall, our results showed that the identification of HER2+ breast tumors diagnosed before the age of 40 can be conservatively incorporated into the current TP53-specific ACMG/AMP PP4 criterion, following a point system detailed in this manuscript. Further larger studies will be needed to re-assess the value of HER2+ breast tumors diagnosed at a later age. This article is protected by copyright. All rights reserved.
    Keywords:   TP53 ; ACMG; HER2; variant classification
  7. BMC Cancer. 2020 Jun 03. 20(1): 507
    Mohyuddin GR, Aziz M, Britt A, Wade L, Sun W, Baranda J, Al-Rajabi R, Saeed A, Kasi A.
      BACKGROUND: PARP inhibitors (PARPi) have recently been approved for various malignancies based on the results of several clinical trials. However, these trials have mostly recruited patients with germline BRCA mutations, and it is unclear whether PARPi have similar efficacy in patients with somatic BRCA mutations. Our study aimed to determine the efficacy of PARPi in patients with somatic BRCA mutations.METHODS: We performed a meta-analysis comparing overall response rate to PARPi in patients harboring somatic versus germline BRCA mutations. We looked at studies including somatic and germline mutations in BRCA patients that received PARPi.
    RESULTS: After screening and removing duplicates, 18 studies met our criteria for including both somatic and germline BRCA mutations. Only 8 studies reported response rates for both somatic and germline BRCA mutations. In those studies, 24 out of 43 patients with somatic BRCA mutations (55.8%), and 69 out of 157 (43.9%) patients with germline BRCA patients had a response to therapy to PARPi. This difference was not statistically significant (p = 0.399). In all five studies that reported progression-free survival, there was no obvious difference in outcomes between somatic versus germline BRCA patients, however a precise statistical analysis could not be performed.
    CONCLUSION: Our meta-analysis and systematic review of the literature indicates similar response rates of PARPi therapy in patients with somatic and germline BRCA mutations. Investigation of use of PARPi therapy in a broader patient population, and the inclusion of somatic BRCA mutations in further clinical trials is paramount in improving therapeutic options for our patients.
    Keywords:  BRCA; Germline; Meta-analysis; PARP inhibitors; Somatic
  8. Int J Mol Sci. 2020 May 28. pii: E3850. [Epub ahead of print]21(11):
    Santana Dos Santos E, Lallemand F, Petitalot A, Caputo SM, Rouleau E.
      Ovarian and breast cancers are currently defined by the main pathways involved in the tumorigenesis. The majority are carcinomas, originating from epithelial cells that are in constant division and subjected to cyclical variations of the estrogen stimulus during the female hormonal cycle, therefore being vulnerable to DNA damage. A portion of breast and ovarian carcinomas arises in the context of DNA repair defects, in which genetic instability is the backdrop for cancer initiation and progression. For these tumors, DNA repair deficiency is now increasingly recognized as a target for therapeutics. In hereditary breast/ovarian cancers (HBOC), tumors with BRCA1/2 mutations present an impairment of DNA repair by homologous recombination (HR). For many years, BRCA1/2 mutations were only screened on germline DNA, but now they are also searched at the tumor level to personalize treatment. The reason of the inactivation of this pathway remains uncertain for most cases, even in the presence of a HR-deficient signature. Evidence indicates that identifying the mechanism of HR inactivation should improve both genetic counseling and therapeutic response, since they can be useful as new biomarkers of response.
    Keywords:  BRCA1; BRCA2; DNA repair; breast cancer tumorigenesis; hereditary breast cancer; hereditary ovarian cancer; homologous recombination deficiency; ovarian cancer tumorigenesis
  9. Clin Gastroenterol Hepatol. 2020 May 31. pii: S1542-3565(20)30761-8. [Epub ahead of print]
    Mehta NA, Shah RS, Yoon JY, O'Malley M, LaGuardia L, Mankaney G, Bhatt A, Burke CA.
      BACKGROUND & AIMS: Ampullary and duodenal cancer are the leading causes of death in patients with familial adenomatous polyposis (FAP) after colectomy has been performed. Risk of duodenal cancer is determined based on Spigelman stage (SS) of duodenal polyposis. Guidelines recommend endoscopic surveillance of the duodenum and visualization of the papilla to stage duodenal polyposis. There is no consensus on whether biopsies should be routinely collected from duodenal papilla and findings included in SS. Additionally, there are no data on the risk of pancreatitis after biopsy collection from papilla of patients with FAP. We studied the incidence of pancreatitis after biopsy of the papilla in patients with FAP and effects of biopsy findings on SS.METHODS: We identified consecutive patients with FAP at a single center from January 2011 through December 2018 with >1 endoscopy with biopsy of the papilla. Patients with history of foregut surgery were excluded. We identified 273 patients with FAP who had biopsies collected from papilla over 792 EGDs, with 1-8 independent exams with biopsy per patient. We collected demographic, endoscopic, and histology data from patients and calculated SS with vs without biopsy findings. Post-procedural pancreatitis was defined by 2 of the following: abdominal pain, lipase level 3-fold the upper limit of normal, or radiography findings consistent with pancreatitis within 7 days of esophagogastroduodenoscopy (EGD).
    RESULTS: Pancreatitis developed in 2 patients (0.73%): 1 after biopsy of a normal-appearing papilla and 1 after biopsy of an abnormal appearing papilla. Inclusions of biopsy data increased SS in 36 patients (13.2%), with consideration of prophylactic duodenectomy for 3.3%.
    CONCLUSIONS: Pancreatitis after biopsy of the duodenal papilla is rare. Histology data obtained from biopsy of the papilla in patients with FAP can change SS and affect patient management.
    Keywords:  acute pancreatitis; gastrointestinal neoplasia; hereditary cancer syndromes; prognostic factor
  10. Breast J. 2020 Jun 04.
    Bayraktar S, Zhou JZ, Bassett R, Gutierrez Barrera AM, Layman RM, Valero V, Arun B.
      Germline variations in genes coding for proteins involved in the oxidative stress and DNA repair greatly influence drug response and toxicity. Because BRCA1 and BRCA2 proteins play a role in DNA damage repair, we postulated that taxane-related toxicity is potentially higher and clinical outcome in different in patients with BRCA pathogenic variants (PV). Seven hundred nineteen women who underwent BRCA genetic testing and were treated with taxane-containing chemotherapy for early-stage breast cancer between 1997 and 2018 were included in the study. Patients with BRCA variants of uncertain significance were excluded. The Kaplan-Meier product-limit method was used to estimate recurrence-free survival (RFS) and overall survival (OS) rates. Logistic regression models were used to assess the association between chemotherapy toxicity and factors of interest. Cox regression models were used to assess the association between RFS and OS and factors of interest. Ninety-four (13%) and 54 (7%) patients had BRCA1 and BRCA2-PVs, respectively. While anemia (P = .0025) and leukopenia (P = .001) were more frequently seen in BRCA noncarriers, there was no difference in regards to peripheral neuropathy or other toxicities between the groups. Increasing doses of taxane were associated with increased risk of neutropenia, stomatitis, nausea, vomiting, acne/rash, and peripheral neuropathy across all groups. In a multivariate logistic regression model, BRCA2 status remained as an independent significant predictor for decreased hematologic toxicity (HR: 0.36; 95% CI: 0.20-0.67; P = .001) and increased gastrointestinal toxicity (HR: 1.93; 95% CI: 1.02-3.67; P = .04). Being overweight, obese and African-American race were significant predictors for peripheral neuropathy (P = .04; P = .03; P = .06, respectively). Total taxane dose received did not have any impact on survival outcomes. Our study demonstrates that taxane-containing chemotherapy regimens do not increase risk of peripheral neuropathy or hematologic toxicity in patients with BRCA PVs. The mechanisms for this finding need to be further investigated as it may provide an opportunity to combine taxanes with other agents, such as platinum salts or PARP inhibitors, with less anticipated toxicity.
    Keywords:  BRCA; breast cancer; chemotherapy toxicity; peripheral neuropathy; taxanes
  11. Curr Oncol. 2020 Apr;27(2): e182-e190
    Aronson M, Swallow C, Govindarajan A, Semotiuk K, Cohen Z, Kaurah P, Velsher L, Ambus I, Buckley K, Forster-Gibson C, Meschino WS, Blumenthal A, Kim RH, Brar S.
      Background: CDH1 pathogenic variants (pvs) cause most cases of inherited diffuse gastric cancer (dgc), but have low detection rates and vary geographically. In the present study, we examined hereditary causes of dgc in patients in Ontario.Methods: CDH1 testing through single-site or multi-gene panels was conducted for patients with dgc meeting the 2015 International Gastric Cancer Linkage Consortium (igclc) criteria, or with isolated dgc at less than 50 years of age, or with a strong family history of cancer identified at the Zane Cohen Centre (zcc). All CDH1-positive patients at zcc, regardless of cancer history, were summarized.
    Results: In 15 of 85 patients with dgc (17.6%), a pv or likely pv was identified through CDH1 single-site (n = 43) or multi-gene panel (n = 42) testing. The detection rate was 9.4% overall (8 of 85) and 11% using igclc criteria (7 of 65). No CDH1 pvs were identified in patients with isolated dgc at less than 40 years of age, but 1 pv was identified in a patient with isolated dgc at less than 50 years of age. Multi-gene panels identified 9 pvs (21.4%), including CDH1, STK11, ATM, BRCA2, MLH1, and MSH2. Review of 81 CDH1 carriers identified 10% with dgc (median age: 48 years; range: 38-59 years); 41% were unaffected (median age: 53 years; range: 26-89 years). Observed malignancies other than dgc or lobular breast cancer (lbc) included colorectal, gynecologic, kidney or bladder, prostate, testicular, and ductal breast cancers. Lobular-breast cancer was seen only in 3 families.
    Conclusions: In Ontario, the detection rate of CDH1 pvs in patients with dgc was low: no pvs were identified in patients with isolated dgc at less than 40 years of age, and 1 was identified in a patient with isolated dgc at less than 50 years of age. Isolated lbc with no dgc was observed in CDH1-positive families, as were pathology-confirmed nondgc or non-lbc malignancies, which had not previously been reported. Given a phenotype that overlaps with other hereditary conditions, multi-gene panels are recommended for all patients with dgc at less than 50 years of age and for those meeting igclc criteria.
    Keywords:  Hereditary diffuse gastric cancer; breast cancer, lobular; early-onset disease; hdgc
  12. J Clin Med. 2020 Jun 01. pii: E1664. [Epub ahead of print]9(6):
    Snowsill TM, Ryan NAJ, Crosbie EJ.
      Lynch syndrome (LS) is a hereditary cancer syndrome responsible for 3% of all endometrial cancer and 5% in those aged under 70 years. It is unclear whether universal testing for LS in endometrial cancer patients would be cost-effective. The Manchester approach to identifying LS in endometrial cancer patients uses immunohistochemistry (IHC) to detect mismatch repair (MMR) deficiency, incorporates testing for MLH1 promoter hypermethylation, and incorporates genetic testing for pathogenic MMR variants. We aimed to assess the cost-effectiveness of the Manchester approach on the basis of primary research data from clinical practice in Manchester. The Proportion of Endometrial Tumours Associated with Lynch Syndrome (PETALS) study informed estimates of diagnostic performances for a number of different strategies. A recent microcosting study was adapted and was used to estimate diagnostic costs. A Markov model was used to predict long-term costs and health outcomes (measured in quality-adjusted life years, QALYs) for individuals and their relatives. Bootstrapping and probabilistic sensitivity analysis were used to estimate the uncertainty in cost-effectiveness. The Manchester approach dominated other reflex testing strategies when considering diagnostic costs and Lynch syndrome cases identified. When considering long-term costs and QALYs the Manchester approach was the optimal strategy, costing £5459 per QALY gained (compared to thresholds of £20,000 to £30,000 per QALY commonly used in the National Health Service (NHS)). Cost-effectiveness is not an argument for restricting testing to younger patients or those with a strong family history. Universal testing for Lynch syndrome in endometrial cancer patients is expected to be cost-effective in the U.K. (NHS), and the Manchester approach is expected to be the optimal testing strategy.
    Keywords:  Lynch syndrome; cost-effectiveness analysis; decision analytic model; endometrial cancer; reflex testing
  13. Fam Cancer. 2020 Jun 06.
    Scott AJ, Tokaz MC, Jacobs MF, Chinnaiyan AM, Phillips TJ, Wilcox RA.
      Clinical tumor sequencing protocols often depend on obtaining germline DNA from patients to aid in the identification of de novo variants in the tumor, and therefore come with the possibility for the incidental discovery of germline variants. Ninety-one adult patients with lymphoma were consented and enrolled in MIONCOSEQ, an IRB-approved tumor profiling protocol that utilizes an exome sequencing platform. Charts were retrospectively reviewed for germline variants from sequencing results, personal and/or family history of cancer and genetic counseling referral. After review of the 91 lymphoma cases, seven (8%) cases revealed germline variants. Only one of these, CHEK2 p.I157T, has been previously recovered as a germline variant in lymphoma. Two of the seven patients received genetic counseling, two died before genetic counseling could be arranged and three did not follow-up with a genetics provider. None of the patients had a personal or family history that would have otherwise suggested an indication for cancer genetics referral, especially notable as lymphoma is not traditionally associated with inherited cancer syndromes. Importantly, as only two of seven patients had appropriate genetic counseling for their variant, timely genetic counseling should be a critical part of all tumor profiling platforms that use non-tumor DNA.
    Keywords:  Genetic counseling; Germline variants; Lymphoma; Precision medicine
  14. Breast Cancer Res Treat. 2020 Jun 02.
    Alter BP, Best AF.
      PURPOSE: Germline pathogenic variants in BRCA1 (FANCD1) and BRCA2 (FANCS) do not explain all familial or sporadic cases with breast cancer. Several reports indicate a role for pathogenic variants in other genes in the Fanconi anemia/breast cancer DNA repair pathway; the strengths of these associations vary widely. Publications from 2006 through 2017 were reviewed to provide a better estimate of the role of pathogenic variants in genes in this pathway in breast cancer.METHODS: We identified cohorts and case-control reports describing heterozygous pathogenic variants in Fanconi anemia genes in breast cancer cases with high risk of a germline pathogenic variant in a non-BRCA1/2 breast cancer susceptibility gene ("familial"), and cases unselected for family history ("unselected"). Meta-analysis and meta-regression were used to estimate the frequencies of pathogenic variants in cohorts and the odds ratios (OR) in case-control studies.
    RESULTS: Meta-analysis of more than 100 reports of FANCN/PALB2 in familial breast cancer cases provided an overall pathogenic variant prevalence of 1.29% and an OR of 8.45. The prevalence in unselected cohorts was 0.64%, and the OR was 4.76. Pathogenic variants in FANCJ/BRIP1 had a prevalence of 0.5% in familial cases, and an OR of 1.62; their prevalence in unselected cases was 0.39%. FANCO/RAD51C, FANCP/SLX4, FANCU/XRCC2, FANCD2, and other FA-related genes all had prevalences of ≤ 0.5% among familial cases, and even lower in unselected cases.
    CONCLUSIONS: Heterozygous pathogenic variants in FANCN/PALB2 and possibly FANCJ/BRIP1 may account for 1-2% of familial non-BRCA1/2 breast cancer cases and 0.5-1% of unselected cases. Genetic counseling and testing may be suggested for unaffected relatives.
    Keywords:  BRIP1; Breast cancer; Fanconi anemia; Germline pathogenic variants; Meta-analysis; Meta-regression; PALB2
  15. Cancers (Basel). 2020 Jun 01. pii: E1441. [Epub ahead of print]12(6):
    Srivastava A, Miao B, Skopelitou D, Kumar V, Kumar A, Paramasivam N, Bonora E, Hemminki K, Försti A, Bandapalli OR.
      Non-medullary thyroid cancer (NMTC) is a common endocrine malignancy with a genetic basis that has yet to be unequivocally established. In a recent whole-genome sequencing study of five families with occurrence of NMTCs, we shortlisted promising variants with the help of bioinformatics tools. Here, we report in silico analyses and in vitro experiments on a novel germline variant (p.V29L) in the highly conserved oligonucleotide/oligosaccharide binding domain of the Protection of Telomeres 1 (POT1) gene in one of the families. The results showed a reduction in telomere-bound POT1 levels in the mutant protein as compared to its wild-type counterpart. HEK293T cells carrying POT1 p.V29L showed increased telomere length in comparison to wild-type cells, suggesting that the mutation causes telomere dysfunction and may play a role in predisposition to NMTC in this family. While one germline mutation in POT1 has already been reported in a melanoma-prone family with prevalence of thyroid cancers, we report the first of such mutations in a family affected solely by NMTCs, thus expanding current knowledge on shelterin complex-associated cancers.
    Keywords:  POT1; familial non-medullary thyroid cancer; germline variant; non-syndromic; shelterin complex; telomere length; whole-genome sequencing
  16. Cancer Sci. 2020 Jun 03.
    Yoshihara K, Enomoto T, Aoki D, Watanabe Y, Kigawa J, Takeshima N, Inomata H, Hattori K, Jinushi M, Tsuda H, Sugiyama T.
      Whether germline (g) breast cancer susceptibility gene (BRCA) mutations are located within or outside the ovarian cancer cluster region (OCCR; 1380-4062 bp for gBRCA1, and between 3249-5681 bp and 6645-7471 bp for gBRCA2) may influence risk variations for ovarian cancers. This ad hoc analysis of the CHARLOTTE epidemiological study in Japan assessed the distribution of gBRCA1/2 mutations in patients with newly diagnosed ovarian cancer, and investigated an association between gBRCA1/2 mutation locations and ovarian cancer risk. Differences in patient background and clinical characteristics in subgroups stratified by gBRCA1/2 mutation locations were also evaluated. We analyzed the data of 93 patients (14.7%) from the CHARLOTTE study who were positive for gBRCA1/2 mutations. After excluding 16 cases with L63X founder mutation, 28 (65.1%) of gBRCA1 mutations were within the OCCR. Of 30 gBRCA2 mutations, 15 (50.0%) were within the OCCR. Of 27 patients (one patient excluded for unknown family history) with gBRCA1 mutations located in the OCCR, 11 (40.7%) had a family history of ovarian cancer; the proportion of patients with a family history of ovarian cancer and gBRCA1 mutations outside the OCCR was lower (13.3%). Sixty percent of patients with gBRCA1 mutations outside the OCCR had a family history of breast cancer; the proportion of patients with a family history of breast cancer and gBRCA1 mutations within the OCCR was relatively lower (33.3%). Understanding the mutation locations may contribute to more accurate risk assessments of susceptible individuals and early detection of ovarian cancer among gBRCA mutation carriers.
    Keywords:  BRCA1 gene; BRCA2 gene; Mutation; Ovarian cancer; Ovarian cancer cluster region