Carriers Of Deleterious Mutations Research Articles

Inherited disorders of hemoglobin: A review of old and new diagnostic methods

The genetic regulation of hemoglobin is complex and there are a number of genetic abnormalities that result in clinically important hemoglobin disorders. Here, we review the molecular pathophysiology of hemoglobin disorders and review both old and new methods of diagnosing these disorders. Timely diagnosis of hemoglobinopathies in infants is essential to coordinate optimal life-saving interventions, and accurate identification of carriers of deleterious mutations allows for genetic counseling and informed family planning. The initial laboratory workup of inherited disorders of hemoglobin should include a complete blood count (CBC) and peripheral blood smear, followed by carefully selected tests based on clinical suspicion and available methodology. We discuss the utility and limitations of the various methodologies to fractionate hemoglobin, including cellulose acetate and citrate agar hemoglobin electrophoresis, isoelectric focusing, high-resolution high-performance liquid chromatography, and capillary zone electrophoresis. Recognizing that most of the global burden of hemoglobin disorders exists in low- and middle-income countries, we review the increasingly available array of point-of-care-tests (POCT), which have an increasingly important role in expanding early diagnosis programs to address the global burden of sickle cell disease, including Sickle SCAN, HemoTypeSC, Gazelle Hb Variant, and Smart LifeLC. A comprehensive understanding of the molecular pathophysiology of hemoglobin and the globin genes, as well as a clear understanding of the utility and limitations of currently available diagnostic tests, is essential in reducing global disease burden.

Physical Activity in Young BRCA Carriers and Reduced Risk of Breast Cancer

A systematic literature review was conducted to determine whether physical activity levels during adolescent and young adult years were associated with a reduced lifetime risk of breast cancer among carriers of deleterious mutations in BRCA1 and BRCA2 genes. Ovid/MEDLINE, Embase, CENTRAL, WOS, and CINAHL were searched for articles including information about adolescent and young adult physical activity and breast cancer incidence among women carrying deleterious BRCA1 and BRCA2 gene mutations (search was initiated in October 2019; last update and full analyses were in March 2021). Independent reviewers screened articles at the title/abstract and full-text levels, resolving differences by consensus with lead authors. The NIH Quality Assessment Tools were used to assess sources of bias. A total of 1,957 unique articles were identified; 5 met inclusion criteria. Samples size ranged from 68 to 1,185. All studies relied on self-reported adolescent and young adult physical activity. One study measured sports involvement; the others measured recreational activity. One large study was null, whereas 4 others showed a reduction in breast cancer incidence later in life with higher adolescent and young adult physical activity (p≤0.05). However, the protection was limited to premenopausal breast cancer in 1 of the studies (OR=0.62; 95% CI=0.40, 0.96; p-trend=0.01). In addition, adolescent and young adult physical activity was associated with older age at breast cancer diagnosis in 1 study (p=0.03). A limited number of studies suggest that adolescent and young adult physical activity may reduce or delay the risk of breast cancer incidence among carriers of deleterious mutations in BRCA1 and BRCA2 genes.

Generation and characterization of induced pluripotent stem cells from a family carrying the BRCA1 mutation c.3612delA.

How BRCA1 germline mutations predispose to cancer remains poorly understood. Induced pluripotent stem cells (iPSCs) represent an emerging model to investigate the molecular mechanisms underlying malignant transformation in primary cells from individuals who are carriers of deleterious mutations in the BRCA1 gene. Here we report the generation and characterization of iPSC lines from a female donor harboring a germline c.3612delA mutation in the BRCA1 gene and her daughter who does not carry the mutation. Skin fibroblasts were reprogrammed using non-integrative Sendai virus and characterized for their pluripotent properties. These iPSCs are a valuable cellular model for personalized pre-clinical research in the context of BRCA1 mutant hereditary cancers.

Mechanisms to increase cascade testing in hereditary breast and ovarian cancer: Impact of introducing standardized communication aids into genetic counseling.

Precancer identification of women with hereditary breast and ovarian cancer (HBOC) could prevent 20% of these ovarian cancers. The objective was to determine whether standardized Facing Our Risk of Cancer Empowered (FORCE) materials are acceptable, improve knowledge of HBOC and increase disclosure to family members. A prospective cohort of women with breast or ovarian cancer was identified prior to genetic testing. Subjects completed a baseline knowledge survey and were provided three communication aids. Knowledge, acceptability and communication to family members were reassessed at 6 months and compared to a retrospective cohort who had undergone genetic testing for breast or ovarian cancer prior to the intervention. The primary outcome was increase in HBOC knowledge, requiring 20 pre- and postknowledge scores to detect a 10% difference. Forty women were enrolled. The median age at cancer diagnosis was 50 years and 55% had a family history of breast or ovarian cancer. Though subjects found the resources acceptable, knowledge scores did not improve after their use. Disclosure rates were of no different between cohorts (83% preintervention vs 77% postintervention, P = 0.26) though there was an increase in deleterious mutation carriers, 0% (0/6) preintervention vs 100% (22/22) postintervention. Rates of subsequent testing in relatives were low in both preintervention and postintervention cohorts (0% vs 4.5%). Inclusion of standardized communication tools is acceptable to patients. Knowledge did not improve after their use. In deleterious mutation carriers, disclosure rates increased postintervention.

Population-based targeted sequencing of 54 candidate genes identifies PALB2 as a susceptibility gene for high-grade serous ovarian cancer

PurposeThe known epithelial ovarian cancer (EOC) susceptibility genes account for less than 50% of the heritable risk of ovarian cancer suggesting that other susceptibility genes exist. The aim of this...

Spectrum of PALB2 germline mutations and characteristics of PALB2-related breast cancer: Screening of 16,501 unselected patients with breast cancer and 5890 controls by next-generation sequencing.

BackgroundPartner and localizer BRCA2 (PALB2) is a breast cancer predisposition gene, but the clinical relevance of PALB2 germline mutations in Chinese patients with breast cancer remains unknown. This study attempted to investigate the full prevalence and spectrum of PALB2 germline mutations in China and the associations between PALB2 germline mutations and breast cancer risk.MethodsA total of 21,216 unselected patients with breast cancer were enrolled from 10 provinces in China, and 5890 Chinese women without cancer were enrolled as healthy controls. PALB2 screening was based on next‐generation sequencing.ResultsA total of 16,501 BRCA1/2‐negative patients with breast cancer were analyzed. Deleterious PALB2 mutation carriers accounted for 0.97% (n = 160) in the breast cancer cohort and for 0.19% (n = 11) in the healthy control cohort. Forty‐one novel PALB2 germline mutations were identified. A high frequency of PALB2 c.751C>T was detected, and it accounted for 10.63% of the PALB2 germline mutations detected (17 of 160). PALB2 mutations were significantly associated with increased breast cancer risk (odds ratio [OR], 5.23; 95% confidence interval [CI], 2.84‐9.65; P < .0001), especially among women 30 years old or younger (OR, 10.09; 95% CI, 3.95‐25.79; P < .0001). Clinical characteristics, including a family history, bigger tumor size, triple‐negative breast cancer, positive lymph nodes, and bilateral breast cancer, were closely related to PALB2 mutations.ConclusionsThis study revealed a comprehensive spectrum of PALB2 germline mutations and characteristics of PALB2‐related breast cancer in China. PALB2 germline mutations confer a moderately increased risk for breast cancer but profoundly increase breast cancer risk for those 30 years old or younger in the Chinese population.

Abstract P2-09-03: Spectrum, prevalence and clinical outcomes of germline mutations in PALB2 genes in 16501 unselected BRCA1/2-negative breast cancer patients: A multi-center analysis

Abstract Background: PALB2 (Partner and Localizer of BRCA2) is a breast cancer predisposition gene, which plays a critical role in homologous recombination via interacting with BRCA1/2 and RAD51 when DNA break. However, the clinical relevance of PALB2 germline mutations in Chinese breast cancer patients remains unknown. We attempted to illustrate the full prevalence and spectrum of PALB2 germline mutations in Chinese breast cancer population, and to investigate the clinical outcomes of PALB2 germline mutations. Patients and methods: A total of 21216 unselected breast cancer patients were enrolled from multiple clinical centers in China. After evaluation of the DNA quality and clinical information, 16501 eligible BRCA1/2-negative breast cancer patients were analyzed. A group of 5890 Chinese women without cancer was enrolled as healthy controls. PALB2 screening was based on next-generation sequencing, by screening complete coding sequence and intron-exon boundaries of PALB2. Clinical information was synchronously collected. Results: The 79 PALB2 deleterious germline mutations included 25 nonsense mutations, 47 frameshift mutations, and 7 splicing mutations. The hotspot region for PALB2 mutations was exon4. A total of 41 novel mutations were identified in PALB2. Among the 16501 BRCA1/2-negative breast cancer patients and 5890 healthy women, PALB2 deleterious mutation carriers account for 0.97% (n=160) and 0.19% (n=11) separately. PALB2 mutations were significantly associated with increased breast cancer risk (OR: 5.23, 95% CI 2.89-9.49; P&amp;lt;0.0001), and especially in women aged 30 or younger (OR: 11.97, 95% CI 3.76-34.39; P&amp;lt;0.0001). PALB2 mutation carriers were significantly more likely to be triple negative breast cancers and have bigger tumors, positive axillary lymph nodes, bilateral breast cancers, family history of breast and/or ovarian cancer and family history of any other cancer, than noncarriers. Conclusions: The PALB2 mutations confer a moderately increased breast cancer risk in women, but relatively highly increased breast cancer risk in those aged 30 or younger. PALB2 mutation status is associated with distinct clinical characteristics in breast cancer. Key words:PALB2, breast cancer, germline mutations, next-generation sequencing Citation Format: Jiaojiao Zhou, Honglian Wang, Fangmeng Fu, Zhanwen Li, Yun Liu, Qingjian Feng, Weizhu Wu, Hongxia Wang, Chuan Wang, Yiding Chen. Spectrum, prevalence and clinical outcomes of germline mutations in PALB2 genes in 16501 unselected BRCA1/2-negative breast cancer patients: A multi-center analysis [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P2-09-03.

Germline DNA damage repair gene alterations in Chinese prostate patients: More than HRR and MMR.

e13041 Background: Prostate cancer is a worldwide most occurred malignancy in male population. Genetic aberrations of homologous recombination repair (HRR) pathway were proved to be associated with aggressive disease and poorer outcome but may also lead cancer cells more vulnerable to PARP inhibitors. Other than HRR, germline variants in mismatch repair (MMR), nucleotide excision repair (NER) were also identified. Thus, it is important to clarify the distribution of germline alterations of DDR pathways in Chinese prostate cancer patients. Methods: Sixty-five prostate cancer patients unselected for family history, stage of disease, or age at diagnosis were collected. DNA from peripheral blood was extracted. Whole-exon was captured and sequenced subsequently using MGI-SEQ 2000 platform. A total of 229 DDR genes were selected for further analysis. Germline variants were determined to be deleterious according to the ACMG 2015 guidelines. Results: Ten of 65 patients (15.38%) had 7 pathogenic/likely pathogenic germline variants involving 5 different genes: FANCD2 (n = 5), BRCA2 (n = 3), CHEK2 (n = 1), ATM (n = 1) and RECQL (n = 1). Nine patients (13.84%) carried variants predicated to be deleterious via in silico predicators. Taken together, deleterious/potential deleterious germline variants were categorized into 5 DDR pathways which were Fanconi Anemia (9.2%), HRR (9.2%), MMR (4.6%), BER (4.6%) and NER (1.5%). Patients with pathogenic/likely pathogenic germline variants had tendency to be early-onset (mean age [range] at diagnosis, 52[43-67] versus 64[37-80] years, P = 0.001). PSA level at initial diagnosis and self-reported family history did not have significant difference between deleterious mutation carriers and non-carriers (P = 0.396 for PSA level, P = 0.753 for family history). Moreover, metastasis and Gleason score were not associated with deleterious germline variants. Conclusions: Our data showed approximately 52% DDR mutation occurred in other DNA repair pathways besides HRR and MMR, which was a unique spectrum of germline variants in Chinese prostate cancer patients. This indicated distinct genetic etiology and potential therapeutic targets of prostate cancer in Chinese population. Moreover, early-onset in patients with deleterious germline variants is an important clinical character. Whole DDR pathway genes’ testing and counseling should be considered for application for young individuals.

Germline TP53 mutation spectrum in Sudanese premenopausal breast cancer patients: correlations with reproductive factors

PurposeThe role of non-genetic factors as modifiers of TP53-related hereditary breast cancer (BC) risk is debated. In this regard, little is known about the impact of germline TP53 mutations on BC in sub-Saharan Africa, where the disease often presents in non-contraceptive multiparous premenopausal women with extended history of breastfeeding. Herein, we report the germline TP53 mutations found in a series of 92 Sudanese premenopausal BC patients characterized for reproductive history.MethodsThe entire TP53 coding sequence, including intron–exon boundaries and UTRs, was analyzed via DHPLC and direct sequencing, and the association of TP53 genotypes with BC risk and with individual lifetime exposures to reproductive factors was investigated with statistical tools.ResultsThe germline TP53 mutation spectrum comprised 20 variants, 15 in the non-coding and 5 in the coding region. The latter included a deleterious missense mutation, c.817C>T (p.Arg273Cys), in a unique patient, and the common and functionally relevant coding polymorphism at amino acid 72 [Pro72Arg (rs1042522)]. The non-coding mutations included c.919+1G>A, a known deleterious splice site mutation, also in a unique patient. Notably, the 2 carriers of deleterious TP53 mutations clustered in the subset of cases with stronger reproductive history relative to childbearing age. When analyzed in comparison to population controls, the codon 72 polymorphism did not reveal associations with BC.ConclusionsOur study suggests that the codon 72 Arg>Pro polymorphism is not implicated in premenopausal BC susceptibility, whereas multiparity and breastfeeding might be BC risk factors for carriers of deleterious TP53 mutations.

Association of glucocerebrosidase polymorphisms and mutations with dementia in incident Parkinson's disease

IntroductionBoth polymorphisms and mutations in glucocerebrosidase (GBA) may influence the development of dementia in patients with Parkinson's disease. MethodsFour hundred forty-two patients and 419 controls were followed for 7 years. Dementia was diagnosed using established criteria. Participants were analyzed for GBA genetic variants, including E326K, T369M, and L444P. Associations between GBA carrier status and dementia were assessed with Cox survival analysis. ResultsA total of 12.0% of patients with Parkinson's disease carried a GBA variant, and nearly half (22/53) of them progressed to dementia during follow-up. Carriers of deleterious GBA mutations (adjusted hazard ratio 3.81, 95% confidence interval 1.35 to 10.72; P = .011) or polymorphisms (adjusted hazard ratio 1.79; 95% confidence interval 1.07 to 3.00; P = .028) progressed to dementia more rapidly than noncarriers. DiscussionGBA variants are of great clinical relevance for the development of dementia in Parkinson's disease, especially due to the relatively higher frequency of these alleles compared with other risk alleles.

Breast Cancer Family History and Contralateral Breast Cancer Risk in Young Women: An Update From the Women's Environmental Cancer and Radiation Epidemiology Study.

Purpose The Women's Environmental Cancer and Radiation Epidemiology (WECARE) study demonstrated the importance of breast cancer family history on contralateral breast cancer (CBC) risk, even for noncarriers of deleterious BRCA1/2 mutations. With the completion of WECARE II, updated risk estimates are reported. Additional analyses that exclude women negative for deleterious mutations in ATM, CHEK2*1100delC, and PALB2 were performed. Patients and Methods The WECARE Study is a population-based case-control study that compared 1,521 CBC cases with 2,212 individually matched unilateral breast cancer (UBC) controls. Participants were younger than age 55 years when diagnosed with a first invasive breast cancer between 1985 and 2008. Women were interviewed about breast cancer risk factors, including family history. A subset of women was screened for deleterious mutations in BRCA1/2, ATM, CHEK2*1100delC, and PALB2. Rate ratios (RRs) were estimated using multivariable conditional logistic regression. Cumulative absolute risks (ARs) were estimated by combining RRs from the WECARE Study and population-based SEER*Stat cancer incidence data. Results Women with any first-degree relative with breast cancer had a 10-year AR of 8.1% for CBC (95% CI, 6.7% to 9.8%). Risks also were increased if the relative was diagnosed at an age younger than 40 years (10-year AR, 13.5%; 95% CI, 8.8% to 20.8%) or with CBC (10-year AR, 14.1%; 95% CI, 9.5% to 20.7%). These risks are comparable with those seen in BRCA1/2 deleterious mutation carriers (10-year AR, 18.4%; 95% CI, 16.0% to 21.3%). In the subset of women who tested negative for deleterious mutations in BRCA1/2, ATM, CHEK2*1100delC, and PALB2, estimates were unchanged. Adjustment for known breast cancer single-nucleotide polymorphisms did not affect estimates. Conclusion Breast cancer family history confers a high CBC risk, even after excluding women with deleterious mutations. Clinicians are urged to use detailed family histories to guide treatment and future screening decisions for young women with breast cancer.

Compliance with NCCN screening and chemoprevention recommendations among carriers of deleterious mutations in the adenomatous polyposis coli gene.

571 Background: Deleterious mutations in adenomatous polyposis coli gene (APC) lead to familial adenomatous polyposis [FAP] and attenuated FAP (aFAP) syndromes associated with hereditary colorectal cancer (CRC) and extra-colonic neoplasms. Reports suggest only two-third of such patients (pts) comply with recommended screening guidelines. The objective of this study was to assess compliance of FAP/aFAP pts with NCCN recommended guidelines of screening endoscopies and chemoprevention in our population. Methods: Retrospective review of clinical charts of pts with APC mutations, identified through multi-gene panel or single-gene testing, and seen in our NCI designated Comprehensive Cancer Center between 01/2013 and 09/2017. Results: Out of 53 pts with deleterious APC gene mutations, 31 pts (58.5%) had mutations associated with an FAP (27 pts; mean-age 31 years) or aFAP (4 pts, mean-age 33 years) phenotype and were included in analyses. Ten of these 31 pts (32.3%) were diagnosed with FAP after diagnosis of CRC; the rest had family history of FAP/aFAP. Documentation of total-colectomy was found in 17 pts (54.8%), 4 pts (12.9%) did not undergo colectomy and this information was unknown in 10 pts (32.3%). Colonoscopy/EGD after diagnosis of FAP/aFAP was documented in 22 pts (71.1%) while subsequent annual EGD/colonoscopy was documented only in 14 pts (45.1%); records were missing in 13 pts (41.9%). Extra-colonic secondary neoplasms such as duodenal polyps were documented in 8 pts, gastric polyps in 7 pts, desmoid tumor in 2 pts and malignant cancer of ampulla of Vater in 1 pt. Other malignant neoplasms, unrelated with FAP/aFAP, were reported in 3 pts (9.6%, 1 breast, 1 kidney and 1 endometrial cancer). Chemoprevention with sulindac was used in 3 pts (9.7%), 3 pts (9.7%) declined such treatment, 17 pts (54.8%) records were without evidence of this being discussed. Conclusions: The rate of compliance in FAP/aFAP pts with NCCN recommended screening and chemoprevention guidelines in our cohort was low but similar to prior literature. A multidisciplinary approach and interventions to improve compliance among pts are necessary to improve annual screening and chemoprevention rates.

Characterization of mutations in BRCA1/2 and the relationship with clinic-pathological features of breast cancer in a hereditarily high-risk sample of chinese population.

The database of BRCA1/2 mutations in Chinese population remains incomplete at present. Therefore, the present study aimed to report specific harmful BRCA1/2 mutations in the Chinese population and discuss the clinicopathological features in mutation carriers. BRCA1/2 germline mutation tests for 71 patients with breast cancer from a hereditarily high-risk Chinese population were performed using next-generation sequencing for identification of deleterious mutations. Furthermore, the clinicopathological features between BRCA1/2 mutation carriers and non-carriers were compared. A total of 13/71 (18.3%) patients carried a BRCA1 or BRCA2 mutation (7 BRCA1 and 6 BRCA2). The incidence of BRCA1/2 mutation in patients with bilateral breast cancer and patients with family history were 25, and 32.2%, respectively. Eleven pathogenic or likely pathogenic mutations were identified in 13 patients, among the mutation sites 7 were never reported before in Asian populations. The age at diagnosis of BRCA1/2 mutation carriers was older compared with non-mutation carriers (44.73 vs. 35.39 years; P=0.001) in this cohort. BRCA1/2 deleterious mutation carriers had a significantly lower chance of human epidermal growth factor receptor-2 (Her-2) positive status (P=0.010), higher tumor grade at diagnosis (P=0.009), higher probability to have a family history (P=0.016) and older age at diagnosis. Estrogen receptor (ER) and progesterone receptor (PR) status were significantly different between BRCA1, and BRCA2 mutation carriers (P=0.007). The current interpretation of BRCA1/2 status can only explain a small part of hereditary high-risk breast cancer. However, BRCA1/2 gene testing should still be recommended for women with a family history of breast cancer, as well as patients with breast cancer with specific pathologic types, which may be useful to make appropriate clinical decisions for treatment and prevention.

Germline BRCA2 mutations drive prostate cancers with distinct evolutionary trajectories

Germline mutations in the BRCA2 tumour suppressor are associated with both an increased lifetime risk of developing prostate cancer (PCa) and increased risk of aggressive disease. To understand this aggression, here we profile the genomes and methylomes of localized PCa from 14 carriers of deleterious germline BRCA2 mutations (BRCA2-mutant PCa). We show that BRCA2-mutant PCa harbour increased genomic instability and a mutational profile that more closely resembles metastastic than localized disease. BRCA2-mutant PCa shows genomic and epigenomic dysregulation of the MED12L/MED12 axis, which is frequently dysregulated in metastatic castration-resistant prostate cancer (mCRPC). This dysregulation is enriched in BRCA2-mutant PCa harbouring intraductal carcinoma (IDC). Microdissection and sequencing of IDC and juxtaposed adjacent non-IDC invasive carcinoma in 10 patients demonstrates a common ancestor to both histopathologies. Overall we show that localized castration-sensitive BRCA2-mutant tumours are uniquely aggressive, due to de novo aberration in genes usually associated with metastatic disease, justifying aggressive initial treatment.

Impact that Timing of Genetic Mutation Diagnosis has on Surgical Decision Making and Outcome for BRCA1/BRCA2 Mutation Carriers with Breast Cancer.

Deleterious BRCA mutation carriers with breast cancer are at increased risk for additional breast cancer events. This study evaluated the impact that timing of identification of BRCA+ status has on surgical decision and outcome. The authors reviewed all BRCA carriers at their institution whose breast cancer was diagnosed between January 1996 and June 2015. Patient surveys, medical records, and institutional databases were used to collect data. Differences in surgical choice were analyzed using the chi-square test, and rates of subsequent breast cancer events were estimated using the Kaplan-Meier method. The study investigated 173 BRCA carriers with breast cancer (100 BRCA1, 73 BRCA2). Of the women with known BRCA mutation before surgery and unilateral stages 0 to 3 breast cancer (n=63), 12.7% underwent lumpectomy, 4.8% underwent unilateral mastectomy (UM), and 82.5% underwent bilateral mastectomy (BM). These surgical choices differed significantly (p<0.0001) from those of patients unaware of their mutation at the time of surgery (n=93) (51.6% had lumpectomy, 19.4% had UM, 29% had BM). Of the patients with BRCA mutation identified after surgery who underwent lumpectomy or UM, 36 (59%) of 66 underwent delayed BM. The patients with BRCA+ known before diagnosis presented with significantly lower-stage disease (p=0.02) at diagnosis (69% stage 0 or 1) than those whose BRCA mutation was identified after cancer diagnosis (40% stage 0 or 1). The study findings showed that BRCA mutation status influences surgical decision. The rates of BM were higher for the patients with BRCA mutation known before surgery. Identification of BRCA mutation after surgeryfrequently leads to subsequent breast surgery. Genetic testing before surgery is important for patients at elevated risk for BRCA mutation.

Incidence of BRCA1 somatic mutations and response to neoadjuvant chemotherapy in Chinese women with triple-negative breast cancer

BackgroundThe prevalence of BRCA1 somatic mutations status in triple-negative breast cancer (TNBC) has not been well documented. The aims of this study were to determine the frequency of BRCA1 somatic mutations and to investigate the association between BRCA1 deleterious somatic mutation status and response to neoadjuvant chemotherapy in women with TNBC. MethodsTwo hundred and five TNBC patients without BRCA1 germline mutations were enrolled in this study. Fresh tumor tissues were available for this cohort of 205 patients, including 112 patients with fresh core needle biopsy tumor tissues before treatment and 93 patients with fresh tumor tissues procured after surgery. BRCA1 somatic mutations were determined in the tumor samples using PCR-direct sequencing assay. Among the 112 patients with core needle biopsy samples, 97 patients received neoadjuvant chemotherapy. ResultsEight patients (3.9%) carried a BRCA1 pathogenic somatic mutation in this cohort of 205 TNBC patients. These eight BRCA1 deleterious somatic mutations included five frameshift or nonsense mutations (c.191_212del22, c.1664delA, c.4674_4675+17del, c.3671_3672insTTCC, c.1162A>T), one splicing site mutation (c.134+2T>G) and two missense mutations (c.5511G>C and c.286G>A). No significant differences in tumor characteristics between BRCA1 deleterious somatic mutation carriers and non-carriers were observed. The pCR (pathologic complete response) rate was 32.0% in the 97 patients who received neoadjuvant chemotherapy. BRCA1 deleterious somatic mutation carriers (n=5) had a higher pCR rate than did non-carriers (n=92) (BRCA1 carriers vs non-carriers, 60.0% vs 30.4%, P=0.32), although it did not reach a significance due to a small sample size. ConclusionsA small subset of TNBC patients carried a BRCA1 deleterious somatic mutation; BRCA1 somatic mutation carriers are likely to respond to neoadjuvant chemotherapy.

Abstract P1-08-10: Clinicopathological characteristics and clinical outcome in Egyptian female breast cancer patients with and without BRCA1/2 mutations

Abstract Background: Germline mutations in BRCA1 and BRCA2 genes confer high risk of developing breast cancer. We sought to examine for the first time in the Egyptian population, which has witnessed the world's oldest recorded breast cancer case, whether the clinicopathological characteristics and the clinical outcome differ in patients with and without BRCA mutations. Patients and Methods: A series of 103 Egyptian female patients diagnosed with breast cancer before 2008 were recruited from Breast Cancer Unit, Clinical Oncology Department, Ain Shams University, Egypt. The enrolled patients, unselected for age of onset or family history, were tested for BRCA1/2 mutations using HRM analysis and direct sequencing. The clinical and pathological features of the patients were retrospectively assessed and comparisons were made between BRCA mutation carriers and non-carriers, respectively, using Chi-square. Disease free survival (DFS) was estimated by Kaplan–Meier method and compared in the two groups with log-rank. Survival Cox proportional hazards models were fit to determine the independent association of mutation status with outcome. Results: The overall rate of BRCA1/2 mutations was 44% (46/103). Novel deleterious mutations were detected and submitted to NCBI Clinvar database. Deleterious mutations were identified in 29 cases and unclassified variants in 32 cases, 15 of which had a co-occuring deleterious mutation. Patients with BRCA mutations tended to have early onset breast cancer compared to non-carriers (P=0.002), more often premenopausal (P=0.006), with a familial history of breast cancer as well as other cancers (P=0.005). BRCA-related breast cancers were more likely to have T3-T4 stage than wild type (41% versus 28%, P=0.02), positive lymph node involvement (78 versus 53%, P=0.007) and develop bilateral breast cancers (24% versus 9%, P =0.007). Grade and histology were not associated with mutation status. The incidence of ER negative and PR negative tumors was higher in BRCA carriers, but not statistically significant (P=0.17 and 0.15, respectively). No difference in HER-2/neu status was observed (P=0.25). Multivariate logistic regression model showed that early age at onset, positive lymph node involvement, family history of any cancer (P=0.047, 0.05 and 0.05, respectively) are independent predictive factors for occurrence of BRCA1/2 mutations. Carriers of BRCA2 deleterious mutations were more likely to report positive family history of cancer other than breast compared to non-carriers (P=0.001). The median follow-up time for the cohort was 5.53 years (ranged from 4.7 to 20.4 years). Patients with BRCA mutations had poorer 5-year DFS compared to non-carriers (47.7% versus 67.4%, P=0.041); but Cox regression analysis failed to demonstrate a significant independent influence of BRCA mutation status on DFS. Conclusion: This is the first study in the Middle East to show that BRCA-related breast cancers in the Egyptian population have distinctive clinical and tumor features as well as outcome. Early onset breast cancer, family history of cancer and positive lymph node involvement are predictors for BRCA mutation in this Egyptian cohort. This data has important health implications for guiding cancer control policies. Citation Format: AbdelHamid SG, El-Mesallamy HO, AbdelAziz HM, Zekri A-RN. Clinicopathological characteristics and clinical outcome in Egyptian female breast cancer patients with and without BRCA1/2 mutations. [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 P1-08-10.

Epidemiology of Patients with Ovarian Cancer with and Without a BRCA1/2 Mutation.

Ovarian cancer survival rates have improved only slightly in recent decades; however, treatment of this disease is expected to undergo rapid change as strategies incorporating molecular-targeted therapies enter clinical practice. Carriers of deleterious mutations (defined as a harmful mutation) in either the BRCA1 or BRCA2 gene (BRCAm) have a significantly increased risk of developing ovarian cancer. Epidemiology data in large (>500 patients) unselected ovarian cancer populations suggest that the expected incidence rate for BRCAm in this population is 12-14%. Patients with a BRCAm are typically diagnosed at a younger age than those without a BRCAm. Associations with BRCAm vary according to ethnicity, with women of Ashkenazi Jewish descent being 10 times more likely to have a BRCAm than the general population. In terms of survival, patients with invasive epithelial ovarian cancer who have a BRCAm may have improved overall survival compared with patients who do not carry a BRCAm. Although genetic testing for BRCAm remains relatively uncommon in ovarian cancer patients, testing is becoming cheaper and increasingly accessible; however, this approach is not without numerous social, ethical and policy issues. Current guidelines recommend BRCAm testing in specific ovarian cancer patients only; however, with the emergence of treatments that are targeted at patients with a BRCAm, genetic testing of all patients with high-grade serous ovarian cancer may lead to improved patient outcomes in this patient population. Knowledge of BRCAm status could, therefore, help to inform treatment decisions and identify relatives at increased risk of developing cancer.

Deleterious Germline BLM Mutations and the Risk for Early-onset Colorectal Cancer

Bloom syndrome is an autosomal recessive disorder characterized by chromosomal instability and increased cancer risk, caused by biallelic mutations in the RECQL-helicase gene BLM. Previous studies have led to conflicting conclusions as to whether carriers of heterozygous BLM mutations have an increased risk to develop colorectal cancer (CRC). We recently identified two carriers of a pathogenic BLM mutation in a cohort of 55 early-onset CRC patients (≤45 years of age), suggesting an overrepresentation compared to the normal population. Here, we performed targeted sequencing using molecular inversion probes to screen an additional cohort of 185 CRC patients (≤50 years of age) and 532 population-matched controls for deleterious BLM mutations. In total, we identified three additional CRC patients (1.6%) and one control individual (0.2%) that carried a known pathogenic BLM mutation, suggesting that these mutations are enriched in early-onset CRC patients (P = 0.05516). A comparison with local and publically available databases from individuals without suspicion for hereditary cancer confirmed this enrichment (P = 0.003534). Analysis of family members of the five BLM mutation carriers with CRC suggests an incomplete penetrance for CRC development. Therefore, these data indicate that carriers of deleterious BLM mutations are at increased risk to develop CRC, albeit with a moderate-to-low penetrance.

Endometrial cancers in mutation carriers from hereditary breast ovarian cancer syndrome kindreds: report from the Creighton University Hereditary Cancer Registry with review of the implications.

The aim of this study was to categorize and report endometrial cancers in mutation carriers from hereditary breast ovarian cancer families. Our Hereditary Cancer Registry was searched for gynecologic and peritoneal cancers linked to mutations in BRCA1 or BRCA2. Invasive cancers were registered in 101 mutation carriers with complete pathology reports. Efforts were made to secure diagnostic surgical pathology tissues for review. All records and available diagnostic slides were meticulously studied, and primary cancers were classified. Eight malignancies were classified as primary endometrial cancers. Five of these were low- or intermediate-grade endometrioid carcinomas, and 3 were pure serous carcinomas or contained serous carcinoma elements mixed with high-grade endometrioid carcinoma. Breast cancers were diagnosed in 5 patients before and in 1 patient after endometrial carcinoma. Three endometrioid carcinomas were preceded by estrogen treatment, 2 for many years and the other for only 2 months, and 2 of the patients with serous carcinoma had been treated with tamoxifen. The finding that 8 of gynecologic and peritoneal cancers in 101 mutation carriers were endometrial cancers with a smaller proportion of endometrioid carcinomas than reported in general populations is added to the current controversial literature on endometrial cancer, particularly regarding serous carcinomas, in hereditary breast ovarian cancer syndrome. Well-designed prospective programs for standardized surgical and pathologic handling, processing, and reporting are essential for working out the pathogenesis, true risks, and best management of this disease in carriers of deleterious BRCA1 and BRCA2 germline mutations.