Abstract The overall purpose of the study BRCAsearch is to evaluate a new method for offering mutation analysis of BRCA1 and BRCA2 to all patients with newly diagnosed breast cancer. Patients with breast cancer in southern Sweden are offered inclusion in the SCAN-B study at the time of diagnosis pre-surgery. If they consent, a part of the tumor is sent to a lab in Lund, Sweden, for research purposes (RNA sequencing etc.). Patients that are included in the SCAN-B study are eligible for inclusion in BRCAsearch. Summary of study procedure for BRCAsearch: 1.An envelope with written information is given to the patient at the visit to the surgeon the week after surgery. This envelope contains a written genetic counseling, information about the study, an informed consent form, psychosocial questionnaires and contact information to a genetic counsellor and psycisians responsible for the study (telephone, e-mail). The patient can contact a genetic counselor for pre-test telephone genetic counseling if she wishes to. 2.BRCA1 and BRCA2 are analyzed. 3.Non-carriers are informed about the test result with a letter. Mutation carriers and VUS (variants of uncertain significance) are telephoned and given a time for an appointment at the Department of Clinical Genetics. 4.Psychosocial self-reported questionnaires are delivered at 3 times over a year. Inclusion criteria (all): 1.The patient is included in the SCAN-B study. 2.The patient is recently diagnosed with an invasive breast cancer or a ductal cancer in situ. 3.The patient has signed an informed consent form for BRCAsearch. Exclusion criteria (any of): 1.The patient is unable to understand the written information in Swedish. 2.The patient is a psychological state, due to chronic och temporary reasons, where one could suspect that information about the study substantially could be detrimental to the psychological well-beeing. Primary outcome measures: • Prevalence of BRCA1/2 mutations in an unselected breast cancer cohort in southern Sweden • Uptake of genetic testing • Proportion of the mutation carriers that do not fulfil current criteria for genetic testing Secondary outcome measures: • How many of the patients that contact us for questions and what type of questions they have • How uptake of genetic testing varies with patient, treatment, and tumor characteristics • The patients' attitudes towards the method used for identifying mutation carriers • The economic cost per QALY (quality-adjusted life year) • Psychosocial comparisons between mutation carriers and non-carriers Targeted accrual is 500 patients included in the study, which is expected to be reached by the end of 2016. The study enrolls patients from two hospitals in southern Sweden: 1.Helsingborg Hospital (study start: Febuary 2, 2015) 2.Kristianstad Hospital (study start: March 2, 2015). Citation Format: Nilsson MP, Borg Å, Henriksson K, Kristoffersson U, Kvist A, Silfverberg B, Törngren T, Loman N. BRCAsearch: A population based prospective study on screening for BRCA1 and BRCA2 germline mutations in patients with newly diagnosed breast cancer treated in southern Sweden. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr OT2-05-01.
BRCA1 and BRCA2 screening in women at high-risk of breast cancer results in the identification of both unambiguously defined deleterious mutations and sequence variants of unknown clinical significance (VUS). We examined a population-based sample of young women with contralateral breast cancer (CBC, n=705) or unilateral breast cancer (UBC, n=1398). We identified 470 unique sequence variants, of which 113 were deleterious mutations. The remaining 357 VUS comprised 185 unique missense changes, 60% were observed only once, while 3% occurred with a frequency of >10%. Deleterious mutations occurred three times more often in women with CBC (15.3%) than in women with UBC (5.2%), whereas combined, VUS were observed in similar frequencies in women with CBC and UBC. A protein alignment algorithm defined 16 rare VUS, occurring at highly conserved residues and/or conferring a considerable biochemical difference, the majority located in the BRCA2 DNA-binding domain. We confirm a multiplicity of BRCA1 and BRCA2 VUS that occur at a wide range of allele frequencies. Although some VUS inflict chemical differences at conserved residues, suggesting a deleterious effect, the majority are not associated with an increased risk of CBC.
Basal-like breast cancer is an aggressive subtype generally characterized as poor prognosis and lacking the expression of the three most important clinical biomarkers, estrogen receptor, progesterone receptor, and HER2. Cell lines serve as useful model systems to study cancer biology in vitro and in vivo. We performed mutational profiling of six basal-like breast cancer cell lines (HCC38, HCC1143, HCC1187, HCC1395, HCC1954, and HCC1937) and their matched normal lymphocyte DNA using targeted capture and next-generation sequencing of 1,237 cancer-associated genes, including all exons, UTRs and upstream flanking regions. In total, 658 somatic variants were identified, of which 378 were non-silent (average 63 per cell line, range 37–146) and 315 were novel (not present in the Catalogue of Somatic Mutations in Cancer database; COSMIC). 125 novel mutations were confirmed by Sanger sequencing (59 exonic, 48 3'UTR and 10 5'UTR, 1 splicing), with a validation rate of 94% of high confidence variants. Of 36 mutations previously reported for these cell lines but not detected in our exome data, 36% could not be detected by Sanger sequencing. The base replacements C/G>A/T, C/G>G/C, C/G>T/A and A/T>G/C were significantly more frequent in the coding regions compared to the non-coding regions (OR 3.2, 95% CI 2.0–5.3, P<0.0001; OR 4.3, 95% CI 2.9–6.6, P<0.0001; OR 2.4, 95% CI 1.8–3.1, P<0.0001; OR 1.8, 95% CI 1.2–2.7, P = 0.024, respectively). The single nucleotide variants within the context of T[C]T/A[G]A and T[C]A/T[G]A were more frequent in the coding than in the non-coding regions (OR 3.7, 95% CI 2.2–6.1, P<0.0001; OR 3.8, 95% CI 2.0–7.2, P = 0.001, respectively). Copy number estimations were derived from the targeted regions and correlated well to Affymetrix SNP array copy number data (Pearson correlation 0.82 to 0.96 for all compared cell lines; P<0.0001). These mutation calls across 1,237 cancer-associated genes and identification of novel variants will aid in the design and interpretation of biological experiments using these six basal-like breast cancer cell lines.
Purpose To describe a snapshot of international genetic testing practices, specifically regarding the use of multigene panels, for hereditary breast/ovarian cancers. We conducted a survey through the Evidence-Based Network for the Interpretation of Germline Mutant Alleles (ENIGMA) consortium, covering questions about 16 non- BRCA1/ 2 genes. Methods Data were collected via in-person and paper/electronic surveys. ENIGMA members from around the world were invited to participate. Additional information was collected via country networks in the United Kingdom and in Italy. Results Responses from 61 cancer genetics practices across 20 countries showed that 16 genes were tested by > 50% of the centers, but only six ( PALB2, TP53, PTEN, CHEK2, ATM, and BRIP1) were tested regularly. US centers tested the genes most often, whereas United Kingdom and Italian centers with no direct ENIGMA affiliation at the time of the survey were the least likely to regularly test them. Most centers tested the 16 genes through multigene panels; some centers tested TP53, PTEN, and other cancer syndrome–associated genes individually. Most centers reported (likely) pathogenic variants to patients and would test family members for such variants. Gene-specific guidelines for breast and ovarian cancer risk management were limited and differed among countries, especially with regard to starting age and type of imaging and risk-reducing surgery recommendations. Conclusion Currently, a small number of genes beyond BRCA1/ 2 are routinely analyzed worldwide, and management guidelines are limited and largely based on expert opinion. To attain clinical implementation of multigene panel testing through evidence-based management practices, it is paramount that clinicians (and patients) participate in international initiatives that share panel testing data, interpret sequence variants, and collect prospective data to underpin risk estimates and evaluate the outcome of risk intervention strategies.
Skipping of BRCA2 exon 3 (∆E3) is a naturally occurring splicing event, complicating clinical classification of variants that may alter ∆E3 expression. This study used multiple evidence types to assess pathogenicity of 85 variants in/near BRCA2 exon 3. Bioinformatically predicted spliceogenic variants underwent mRNA splicing analysis using minigenes and/or patient samples. ∆E3 was measured using quantitative analysis. A mouse embryonic stem cell (mESC) based assay was used to determine the impact of 18 variants on mRNA splicing and protein function. For each variant, population frequency, bioinformatic predictions, clinical data, and existing mRNA splicing and functional results were collated. Variant class was assigned using a gene-specific adaptation of ACMG/AMP guidelines, following a recently proposed points-based system. mRNA and mESC analysis combined identified six variants with transcript and/or functional profiles interpreted as loss of function. Cryptic splice site use for acceptor site variants generated a transcript encoding a shorter protein that retains activity. Overall, 69/85 (81%) variants were classified using the points-based approach. Our analysis shows the value of applying gene-specific ACMG/AMP guidelines using a points-based approach and highlights the consideration of cryptic splice site usage to appropriately assign PVS1 code strength.
Adoptive T-cell therapy (ACT) is a highly intensive immunotherapy regime that has yielded remarkable response rates and many durable responses in clinical trials in melanoma; however, 50-60% of the patients have no clinical benefit. Here, we searched for predictive biomarkers to ACT in melanoma. Whole exome- and transcriptome sequencing and neoantigen prediction were applied to pre-treatment samples from 27 patients recruited to a clinical phase I/II trial of ACT in stage IV melanoma. All patients had previously progressed on other immunotherapies. We report that clinical benefit is associated with significantly higher predicted neoantigen load. High mutation and predicted neoantigen load are significantly associated with improved progression-free and overall survival. Further, clinical benefit is associated with the expression of immune activation signatures including a high MHC-I antigen processing and presentation score. These results improve our understanding of mechanisms behind clinical benefit of ACT in melanoma.
Linkage analysis, positional cloning, candidate gene mutation scanning and genome-wide association study approaches have all contributed significantly to our understanding of the underlying genetic architecture of breast cancer. Taken together, these approaches have identified genetic variation that explains approximately 30% of the overall familial risk of breast cancer, implying that more, and likely rarer, genetic susceptibility alleles remain to be discovered.
'%3e%3cpath fill='%23012169' d='M0 0v30h60V0z'/%3e%3cpath stroke='%23fff' stroke-width='6' d='m0 0 60 30m0-30L0 30'/%3e%3cpath stroke='%23C8102E' stroke-width='4' d='m0 0 60 30m0-30L0 30' clip-path='url(%23b)'/%3e%3cpath stroke='%23fff' stroke-width='10' d='M30 0v30M0 15h60'/%3e%3cpath stroke='%23C8102E' stroke-width='6' d='M30 0v30M0 15h60'/%3e%3c/g%3e%3c/svg%3e)
