A qualitative study to understand the barriers and facilitators in smoking cessation practices among oncology health care practitioners in one health system.

INTRODUCTION: Despite the benefits of quitting smoking for those who have cancer, including improved health outcomes and reduced therapeutic toxicities, it is unclear how many people are supported in quit attempts during this time. Variations in the availability and provision of smoking cessation (SC) services are reported, with little understanding of the challenges and solutions. This co-designed study aimed to understand the perspectives of health care professionals (HCPs) working in oncology settings to engage in SC practices and identify recommendations for developing an SC pathway. METHODS: This was a qualitative study. Eighteen HCPs participated in semi-structured interviews from July 2021 to May 2022. We used thematic analysis approaches to code data and present four emergent themes and SC strategies at micro, meso and organizational levels. RESULTS: Four themes emerged specifically: 1) timing and knowledge, 2) building a relationship, 3) frequent asking with infrequent action, and 4) removing the barriers and tailoring the system. While HCPs discuss SC, there are variations in documentation and when conversations occur. Primarily, HCPs value the time to build therapeutic relationships with patients and thus may limit SC discussions in preference to treatment in clinical interactions. The role of structural barriers, including prescriptive authority for nurses, hinders active SC processes, as it is the lack of continuity and embedding of services supported by a clinical champion for SC. CONCLUSIONS: The study suggests re-evaluating the status quo in SC service, highlighting service gaps and suggesting opportunities at organizational levels to reduce structural barriers. IMPLICATIONS: Variations in smoking cessation services exist in designated cancer centres. The data from this study can be used to inform a real time health systems approach for SC services in oncology settings. Developing tailored smoking cessation services and interventions that are patient-centred and informed by their experiences are required. The data in this study suggests developing specialist education and training to upskill HCPs for equitable engagement if we are to meet EU and Moonshot goals for cancer reduction.

Real-World Analysis of the Clinical and Economic Impact of the 21-Gene Recurrence Score (RS) in Invasive Lobular Early-Stage Breast Carcinoma in Ireland.

Background: This study, using real-world data, assesses the impact of RS testing on treatment pathways and the associated economic consequences of such testing. This paper pertains to lobular breast cancer. Methods: A retrospective, observational study was undertaken between 2011 and 2019 on a cross-section of hormone receptor-positive (HR+), HER2-negative, lymph node-negative, early-stage breast cancer patients. All patients had ILC and had RS testing in Ireland. The patient population is representative of the national population. Patients were classified as low (RS ≤ 25) or high (RS > 25) risk. Patients aged ≤50 were stratified as low (RS 0-15), intermediate (RS 16-25), or high risk (RS > 25). Results: A total of 168 patients were included, most of whom had grade 2 (G2) tumors (n = 154, 92%). Overall, 155 patients (92.3%) had low RS (≤25), 12 (7.1%) had high RS (>25), and 1 (0.6%) had unknown RS status. In 29 (17.5%) patients aged ≤50 at diagnosis, RS was ≤15 in 16 (55%), 16-20 in 6 (21%), 21-25 in 5 (17%), >25 in 1 (3.5%), and unknown in 1 (3.5%). Post RS testing, 126 patients (78%) had a change in chemotherapy recommendation; all to hormone therapy. In total, only 35 patients (22%) received chemotherapy. RS testing achieved a 75% reduction in chemotherapy use, resulting in savings of €921,543.84 in treatment costs, and net savings of €387,283.84. Conclusions: The use of this test resulted in a 75% reduction in chemotherapy and a significant cost savings in our publicly funded health system.

Nodal positivity in patients with clinically and radiologically node-negative breast cancer treated with neoadjuvant chemotherapy: multicentre collaborative study.

BACKGROUND: The necessity of performing a sentinel lymph node biopsy in patients with clinically and radiologically node-negative breast cancer after neoadjuvant chemotherapy has been questioned. The aim of this study was to determine the rate of nodal positivity in these patients and to identify clinicopathological features associated with lymph node metastasis after neoadjuvant chemotherapy (ypN+). METHODS: A retrospective multicentre study was performed. Patients with cT1-3 cN0 breast cancer who underwent sentinel lymph node biopsy after neoadjuvant chemotherapy between 2016 and 2021 were included. Negative nodal status was defined as the absence of palpable lymph nodes, and the absence of suspicious nodes on axillary ultrasonography, or the absence of tumour cells on axillary nodal fine needle aspiration or core biopsy. RESULTS: A total of 371 patients were analysed. Overall, 47 patients (12.7%) had a positive sentinel lymph node biopsy. Nodal positivity was identified in 22 patients (29.0%) with hormone receptor+/human epidermal growth factor receptor 2- tumours, 12 patients (13.8%) with hormone receptor+/human epidermal growth factor receptor 2+ tumours, 3 patients (5.6%) with hormone receptor-/human epidermal growth factor receptor 2+ tumours, and 10 patients (6.5%) with triple-negative breast cancer. Multivariable logistic regression analysis showed that multicentric disease was associated with a higher likelihood of ypN+ (OR 2.66, 95% c.i. 1.18 to 6.01; P = 0.018), whilst a radiological complete response in the breast was associated with a reduced likelihood of ypN+ (OR 0.10, 95% c.i. 0.02 to 0.42; P = 0.002), regardless of molecular subtype. Only 3% of patients who had a radiological complete response in the breast were ypN+. The majority of patients (85%) with a positive sentinel node proceeded to axillary lymph node dissection and 93% had N1 disease. CONCLUSION: The rate of sentinel lymph node positivity in patients who achieve a radiological complete response in the breast is exceptionally low for all molecular subtypes.

The accuracy of MRI in detecting pathological complete response following neoadjuvant chemotherapy in different breast cancer subtypes.

BACKGROUND: Pathological complete response (pCR) following neo-adjuvant chemotherapy (NACT) for breast cancer is associated with improved disease-free and overall survival in certain breast cancer subtypes. Magnetic Resonance Imaging (MRI) is increasingly used as standard to assess treatment response in patients receiving NACT. The aim of this study was to determine the clinical utility of MRI in accurately predicting pCR post-NACT. METHODS: A single-centre, retrospective study was conducted in breast cancer patients, who received NACT between 2013 and 2020. Patients who had an MRI before and after NACT were included. Pathological and MRI radiological response rates to NACT were analyzed and MRI accuracy assessed in detecting pCR according to breast cancer subtype. RESULTS: One hundred and sixty-seven patients were included in the study. Forty-one of the 167 patients achieved pCR (24.6 %), with the highest proportion in HR- HER2+ subgroup (58.3 %), followed by triple negative breast cancer (TNBC) (35 %). Only 22.2 % and 10.5 % of patients with HR + HER2+ and HR + HER2-respectively achieved pCR. The overall accuracy of MRI in predicting pCR after NACT was 77.3 %. The greatest accuracy was in TNBC (87.5 %) with a specificity and positive predictive value (PPV) of 100 % and the highest number of correctly diagnosed complete responses (14 of 40). MRI was less accurate in predicting response rates in HR + HER2- (PPV 91.2 %) and HR + HER2+ groups (PPV 90.5 %). MRI performed significantly better in predicting complete response in TNBC compared to HR + HER2-subtype (p = 0.0057). CONCLUSION: MRI is a clinically useful adjunct in assessing pCR following NACT and appears to predict pathological response more accurately in TNBC compared to HR + HER2-breast cancer subtypes. This has significant clinical implications in terms of surgical planning, adjuvant treatment options and prognosis.

A systematic review of oncological outcomes after nipple-sparing mastectomy for breast cancer.

Nipple-sparing mastectomy is an alternative to skin-sparing mastectomy in select patients. Increasing evidence supports its use in the setting of breast cancer, however concerns still exist regarding oncological safety. The aim of this systematic review was to evaluate long-term oncological outcomes of patients who underwent nipple-sparing mastectomy for breast cancer. A systematic review of the literature was performed to evaluate oncological outcomes in patients with breast cancer who underwent nipple-sparing mastectomy. Five major databases (PubMed, Embase, Scopus, Web of Science and Cochrane) were searched. The review included all original articles published in English reporting long-term oncological outcomes. 2334 studies were identified. After applying inclusion and exclusion criteria, 17 retrospective studies involving 7107 patients were included. The indication for nipple-sparing mastectomy was invasive carcinoma in 6069 patients (85.4%) and in situ disease in 1038 (14.6%). Median follow up was 48 months (range 25-94). The weighted mean rates of local recurrence and recurrence involving the nipple-areola complex were 5.4% (0.9-11.9) and 1.3% (0-4.9), respectively. The weighted mean distant failure rate was 4.8% (1.5-23.0). Therapeutic nipple-sparing mastectomy is oncologically safe in select patients with breast cancer.

Fertility treatment and breast-cancer incidence: meta-analysis.

BACKGROUND: The significance of exogenous hormone manipulation as part of fertility treatment and its relationship to the development of breast cancer remains uncertain. Several historical reviews have been performed with conflicting results. This study is an updated meta-analysis to determine whether there is a causal relationship between different fertility treatments and breast cancer. METHODS: The study report is based on the guidelines of PRISMA and Meta-Analysis of Observational Studies in Epidemiology. Studies published within the last 20 years were included to reflect up to date in vitro fertilization (IVF) practice. This study was prospectively registered on PROSPERO on 07/04/2021, registration identification CRD42021247706. The primary outcome of the study was to determine whether there is an increased incidence of breast cancer in women treated with hormonal fertility treatment. The secondary outcomes were to determine whether fertility treatments were individually associated with excess breast-cancer risk. RESULTS: Overall, 25 studies, including 617 479 participants, were eligible for inclusion. There was no significant breast-cancer risk association with fertility treatment (compared with general and subfertility reference groups). Summary odds ratio of all included studies was 0.97 (95 per cent c.i. 0.90 to 1.04). Women who received six or more IVF cycles did not have an increased risk of breast cancer. Similarly, there was no excess breast-cancer risk associated with clomiphene, human chorionic gonadotropin, gonadotropin analogues and progesterone when examined individually. Comparably, there was no significant association between fertility treatment and excess breast-cancer risk in patients with more than 10 years' follow-up. Summary odds ratio was 0.97 (95 per cent c.i. 0.85 to 1.12). CONCLUSION: This meta-analysis did not find a significant association between fertility treatments and excess breast-cancer risk. Women considering IVF should be informed that it does not appear to increase breast-cancer risk.

Clinical Treatment Score post-5 years as a predictor of late distant recurrence in hormone receptor-positive breast cancer: systematic review and meta-analysis.

BACKGROUND: The Clinical Treatment Score post-5 years (CTS5) integrates four clinicopathological variables to estimate the residual disease recurrence risk in hormone receptor-positive breast cancer patients who have been treated with five years of adjuvant endocrine therapy. This study aimed to determine the accuracy of the CTS5. METHODS: A systematic review was performed in accordance with the PRISMA statement. Studies relevant for inclusion in the current review were identified from The Cochrane Library, EBSCO, Ovid, PubMed, and Embase. RESULTS: Six papers reported on 30 354 postmenopausal patients (age range 42 to 91 years). The pooled hazard ratio (HR) of distant recurrence relative to the low-risk CTS5 category was 5.41 (95% c.i. 4.50 to 6.51; P < 0.05) for the high-risk CTS5 category and 2.32 (95% c.i. 1.90-2.84; P < 0.05) for the intermediate CTS5 category. Three papers reported on 10 425 premenopausal patients (age range 18 to 54 years). The pooled HR of distant recurrence relative to the low-risk CTS5 category was 5.42 (95% c.i. 2.26 to 13.01; P < 0.05) for the high-risk CTS5 category and 2.82 (95% c.i. 1.35 to 5.88; P < 0.05) for the intermediate CTS5 category. Relative to high-risk postmenopausal patients, the mean observed 10-year distant recurrence risk for the high CTS5 category was 13.83 per cent, which differs significantly from the CTS5 estimation of 10-year distant recurrence risk (20.3 per cent, 95% c.i. 17.2 to 24; P = 0.000). CONCLUSION: The CTS5 can predict late distant recurrence risk in pre- and postmenopausal hormone receptor-positive breast cancer patients. CTS5 overestimates the risk for high-risk patients and thus, its use in these patients warrants caution.

Optimal timing of surgery following breast cancer neoadjuvant chemotherapy: A systematic review and meta-analysis.

BACKGROUND: Administration of chemotherapy before breast surgery has the potential to reduce the risk of distant recurrence by targeting micrometastasis as well as allowing a more minimalistic approach to surgical intervention. We performed a systematic review to determine the optimum timing of surgery post breast cancer neoadjuvant chemotherapy (NACT). METHODS: The primary outcome was to determine whether the timing of surgery post NACT impacted overall survival (OS) and disease-free survival (DFS). We compared patient outcomes between those who had surgery within 8 weeks of completion of NACT to those that had surgery after 8 weeks. An outcome comparison between <4 weeks and 4-8 weeks was also performed. Secondary outcome included complete pathological response (pCR) post NACT. A meta-analysis was performed using the Mantel-Haenszel method. RESULTS: Five studies, including 8794 patients were eligible for inclusion. Patients that had surgery within 8 weeks of completion of NACT had a statistically significant improved OS(OR 0.47, 95% c. i 0.34-0.65) and DFS(OR 0.71 (95% c. i 0.52-0.98, P = 0.04). There were no survival advantages associated with having surgery less than 4 weeks post completion of NACT (OR 0.78, 95% c. i 0.46-1.33, P = 0.37). There was no difference in pCR rate between those that had surgery <4 weeks and 4-8 weeks (OR 1.01, 95% c. i 0.80-1.28, P = 0.93). CONCLUSION: This meta-analysis shows that the optimum timing of surgery post completion of NACT is 4-8 weeks as it is associated with increased OS and DFS.

The Impact of Postoperative Wound Complications on Oncological Outcomes Following Immediate Breast Reconstruction for Breast Cancer: A Meta-analysis.

The association between immediate breast reconstruction (IBR)-related wound complications and breast cancer recurrence (BCR) remains uncertain. This study aimed to investigate the oncological outcomes in patients with wound complications following mastectomy and IBR. A comprehensive search was undertaken for all studies describing complications in patients with breast cancer following IBR. Studies were included if they reported on complications and investigated their relationship with BCR. A meta-analysis was performed using a random-effects model, with data presented as odds ratios and 95% confidence intervals. A total of 1418 patients from five studies were included in the final analysis. The mean age of patients included was 47.2 years. A total of 382 (26.9%) patients had postoperative complications following a majority of implant-based IBR (929/1418). A total of 158 (11.1%) recurrences, which included 63 locoregional and 106 distant recurrences, was noted at a mean follow-up of 66 months. Although there was an increase in recurrence rates in the complication group (n = 66/382; 17.3% vs. n = 92/1036; 8.9%), there was no significant association between complications and BCR (17.3% vs. 8.9%; P = .18) or mortality (3.6% vs. 2.3%; P = .15). Time to adjuvant therapy was significantly increased in patients with complications (mean difference, 8.69 days; range, 1.18-16.21 days; P = .02; I2 = 0.02). This meta-analysis demonstrated a higher incidence of wound complications following IBR and a statistically significant increased time to adjuvant therapy. However, this did not translate into adverse oncological outcomes in patients with breast cancer undergoing IBR.

Fibromatosis of the breast: a 10-year multi-institutional experience and review of the literature.

BACKGROUND: Breast fibromatosis is a rare clinical entity, but poses significant diagnostic and therapeutic challenges. In light of recent changes in management practices, the aim was to review our institutional experience of breast fibromatosis and provide a review of current available literature on such management. METHODS: A search of pathological databases within two tertiary institutions for all patients diagnosed with fibromatosis of the breast over a 10-year period (2007-2016) was performed. Clinicopathological characteristics and modes of treatment were recorded for each patient. Concurrently a comprehensive literature search was performed and studies relating to breast fibromatosis and its management were identified and reviewed. RESULTS: Sixteen patients were identified. Median age at diagnosis was 42 (range 21-70) and all patients were diagnosed with core biopsy. The most useful imaging modality in diagnosis was ultrasonography and magnetic resonance imaging. 13/16 were treated surgically whilst 3/16 were treated using a watch-and-wait approach. 6/13 (46%) required re-excision of margins and 2/13 (15%) had recurrence after surgery. On review of the literature, there is no dedicated guideline in place for the management of breast fibromatosis. Currently a 'watch and wait' approach is favoured over surgical intervention due to high levels of recurrence and associated surgical morbidity. All cases should be discussed at a sarcoma multidisciplinary team meeting and tyrosine kinase inhibitors should be considered in advanced cases. CONCLUSIONS: Breast fibromatosis is rare but affects young patients. Active surveillance is now favoured over surgical resection due to high recurrence rates and extensive morbidity. Dedicated guidelines are required to ensure best outcomes.

False-negative rate of ultrasound-guided fine-needle aspiration cytology for identifying axillary lymph node metastasis in breast cancer patients.

Axillary nodal status remains an important determinant of prognosis and of the therapeutic strategy in patients with a newly diagnosed breast cancer. The aim of this study was to assess the false-negative rate of ultrasound (US)-guided fine-needle aspiration cytology (FNAC) in axillary node staging at breast cancer diagnosis. All patients with a newly diagnosed breast cancer who had an indeterminate or suspicious axillary node sampled with an FNAC between 2007 and 2014 were included in the study. FNAC results were compared to the final histopathological results of surgically removed axillary lymph nodes. Patient demographics, tumor, and nodal characteristics were analyzed. Diagnostic accuracy tests were performed using IBM SPSS, version 22. A total of 3515 patients with breast cancer were identified, 675 of whom had ultrasound-guided FNAC of ipsilateral axillary lymph nodes (mean age: 55 years; Range: 26-84). A benign (C2) result was observed in 52% (n = 351) and a malignant (C5) result in 35% (n = 238). C1 was obtained in 11% (n = 76), C3 in 0.6% (n = 4), and C4 in 0.9% (n = 6). Of the 238 patients with a malignant (C5) FNAC, 99.6% had confirmed axillary lymph node metastatic disease on histopathology. Of the 351 patients with benign FNAC (C2), 31% (n = 108) of patients had a positive lymph node on histology. The false-negative rate of preoperative FNAC remains too high (31%) to omit definitive surgical staging of the axilla. The high diagnostic accuracy when a positive FNAC is obtained allows appropriate tailored decisions regarding definitive therapy.

Breast screening in symptomatic women over 35 years of age: improvements in service efficiency.

INTRODUCTION: The rationalization of cancer services in Ireland saw all women with symptomatic breast problems referred to one of the eight regional cancer centers. A pilot triaging system was introduced in St Vincent's University Hospital to streamline these services. Women over 35 years who do not meet urgent referral criteria are referred for a mammogram prior to a clinic appointment ("image first"). The aim of this study was to retrospectively determine the recall rates, biopsy rates, and rate of breast cancer identification within this cohort of patients. This was compared to a screening population of patients. METHODS: Patients triaged into the "image first" group within a one-year period were identified. Results of the initial mammogram, further imaging and subsequent biopsies were recorded. Data relating to number of recalls, number of patients biopsied and number of cancers identified within the Merrion Unit of the National Breastcheck Screening Program was obtained for comparison. RESULTS: One thousand six hundred eighty-eight referrals were triaged as "image first" over this period. 185 (11%) of patients required a biopsy of an identified lesion. Breast cancer was diagnosed in 65 patients (3.9%). During the same study period, of the 42,099 women who were screened for breast cancer, 496 (1.8%) underwent biopsy and 267 (0.63%) were diagnosed with breast cancer. CONCLUSION: Image first patients, who represent a cohort of "symptomatic" non-urgent women, have a greater rate of breast cancer detection than an asymptomatic screening population. This may have an impact on the appropriate triaging of symptomatic women in a national cancer center.

Change of paradigm in treating elderly with breast cancer: are we undertreating elderly patients?

Developed countries face significant population ageing in the near future. Within 20 years, the average age will approach 50 years and the largest population cohort will be those over 65 years. The incidence of breast cancer increases with age, with a risk in women of 0.44% by the age of 30, 3.82% by the age of 70 and 10% by the age of 80. Breast cancer is responsible for one out of every three cancer-related deaths. Elderly patients have higher mortality rates and most breast cancer-related deaths are observed in women over 65. There appears to be a trend that elderly patients with breast cancer receive less than the standard treatment compared to younger counterparts and this leads to poorer outcomes. The rationale for treating elderly breast cancer patients more conservatively is that breast cancers in this cohort are more commonly oestrogen receptor (ER) positive which gives the clinician the option to treat with hormonal manipulation alone. In addition, elderly patients present at a later stage compared to younger patients who frequently present with early (stages I and II) breast cancer. This review aims to give an overview of the diagnosis, treatment options and surveillance of breast cancer in elderly women (over 75 years) and to discuss the change in perception of the term 'elderly' and the reasons for undertreatment in the elderly patients.

Impact of timing of trastuzumab initiation on long-term outcome of patients with early-stage HER2-positive breast cancer: the "one thousand HER2 patients" project.

BACKGROUND: The optimal timing of (neo)adjuvant trastuzumab initiation with respect to chemotherapy and surgery remains undefined. METHODS: Retrospective analysis of a large institutional database of HER2-positive patients who received anti-HER2 therapy. We included all Stage I to III patients treated with trastuzumab with a minimum follow up of 3 years. The date of first breast biopsy was recorded as initial diagnosis. RESULTS: A total of 506 patients [adjuvant: 386 (76%)-neo-adjuvant: 120 (24%)] were included. The median time-to-first-trastuzumab (TFT) from diagnosis was 12 weeks (range 1.9-122.3). Median follow-up is 73.3 months (range 1.4-176.3). TFT was significantly shorter in the neo-adjuvant than in the adjuvant cohort (median: 4.4 vs. 14 weeks, p < 0.00001). Despite the neo-adjuvant cohort having significantly more node-positive patients (75 vs. 53%, p < 0.0001), DFS rate (neo-adjuvant: 12.5 vs. adjuvant: 18%, p = 0.094) was numerically superior in neo-adjuvant patients. A TFT ≤ 12 weeks was associated with significantly superior DFS and OS over TFT > 12 weeks. Early concomitant regimens were associated with superior DFS over delayed-concomitant and sequential regimens. CONCLUSIONS: Initiating trastuzumab more than 12 weeks from diagnosis has a negative impact on clinical outcome. Neo-adjuvant anti-HER2 therapy could be the optimal strategy to treat early stage HER2-positive breast cancer.

Second international consensus guidelines for breast cancer in young women (BCY2).

The 2nd International Consensus Conference for Breast Cancer in Young Women (BCY2) took place in November 2014, in Dublin, Ireland organized by the European School of Oncology (ESO). Consensus recommendations for the management of breast cancer in young women (BCYW) were updated from BCY1 with incorporation of new evidence to inform the guidelines, and areas of research priorities were identified. This manuscript summarizes these international consensus recommendations, which are also endorsed by the European Society of Breast Specialists (EUSOMA).

Protein-truncating variants in moderate-risk breast cancer susceptibility genes: a meta-analysis of high-risk case-control screening studies.

Several "moderate-risk breast cancer susceptibility genes" have been conclusively identified. Pathogenic mutations in these genes are thought to cause a two to fivefold increased risk of breast cancer. In light of the current development and use of multigene panel testing, the authors wanted to systematically obtain robust estimates of the cancer risk associated with loss-of-function mutations within these genes. An electronic search was conducted to identify studies that sequenced the full coding regions of ATM, CHEK2, BRIP1, PALB2, NBS1, and RAD50 in a general and gene-targeted approach. Inclusion was restricted to studies that sequenced the germline DNA in both high-risk cases and geographically matched controls. A meta-analysis was then performed on protein-truncating variants (PTVs) identified in the studies for an association with breast cancer risk. A total of 10,209 publications were identified, of which 64 studies comprising a total of 25,418 cases and 52,322 controls in the 6 interrogated genes were eligible under our selection criteria. The pooled odds ratios for PTVs in the susceptibility genes were at least >2.6. Additionally, mutations in these genes have shown geographic and ethnic variation. This comprehensive study emphasizes the fact that caution should be taken when identifying certain genes as moderate susceptibility with the lack of sufficient data, especially with regard to the NBS1, RAD50, and BRIP1 genes. Further data from case-control sequencing studies, and especially family studies, are warranted.

Detection of novel germline mutations for breast cancer in non-BRCA1/2 families.

The identification of the breast cancer susceptibility genes BRCA1 and BRCA2 enhanced clinicians' ability to select high-risk individuals for aggressive surveillance and prevention, and led to the development of targeted therapies. However, BRCA1/2 mutations account for only 25% of familial breast cancer cases. To systematically identify rare, probably pathogenic variants in familial cases of breast cancer without BRCA1/2 mutations, we developed a list of 312 genes, and performed targeted DNA enrichment coupled to multiplex next-generation sequencing on 104 'BRCAx' patients and 101 geographically matched controls in Ireland. As expected, this strategy allowed us to identify mutations in several well-known high-susceptibility and moderate-susceptibility genes, including ATM (~ 5%), RAD50 (~ 3%), CHEK2 (~ 2%), TP53 (~ 1%), PALB2 (~ 1%), and MRE11A (~ 1%). However, we also identified novel pathogenic variants in 30 other genes, which, when taken together, potentially explain the etiology of the missing heritability in up to 35% of BRCAx patients. These included novel potential pathogenic mutations in MAP3K1, CASP8, RAD51B, ZNF217, CDKN2B-AS1, and ERBB2, including a splice site mutation, which we predict would generate a constitutively active HER2 protein. Taken together, this work extends our understanding of the genetics of familial breast cancer, and supports the need to implement hereditary multigene panel testing to more appropriately orientate clinical management.

Delineating transcriptional networks of prognostic gene signatures refines treatment recommendations for lymph node-negative breast cancer patients.

The majority of women diagnosed with lymph node-negative breast cancer are unnecessarily treated with damaging chemotherapeutics after surgical resection. This highlights the importance of understanding and more accurately predicting patient prognosis. In the present study, we define the transcriptional networks regulating well-established prognostic gene expression signatures. We find that the same set of transcriptional regulators consistently lie upstream of both 'prognosis' and 'proliferation' gene signatures, suggesting that a central transcriptional network underpins a shared phenotype within these signatures. Strikingly, the master transcriptional regulators within this network predict recurrence risk for lymph node-negative breast cancer better than currently used multigene prognostic assays, particularly in estrogen receptor-positive patients. Simultaneous examination of p16(INK4A) expression, which predicts tumours that have bypassed cellular senescence, revealed that intermediate levels of p16(INK4A) correlate with an intact pRB pathway and improved survival. A combination of these master transcriptional regulators and p16(INK4A), termed the OncoMasTR score, stratifies tumours based on their proliferative and senescence capacity, facilitating a clearer delineation of lymph node-negative breast cancer patients at high risk of recurrence, and thus requiring chemotherapy. Furthermore, OncoMasTR accurately classifies over 60% of patients as 'low risk', an improvement on existing prognostic assays, which has the potential to reduce overtreatment in early-stage patients. Taken together, the present study provides new insights into the transcriptional regulation of cellular proliferation in breast cancer and provides an opportunity to enhance and streamline methods of predicting breast cancer prognosis.

Gene analysis techniques and susceptibility gene discovery in non-BRCA1/BRCA2 familial breast cancer.

Breast cancer is the leading cause of cancer deaths in females worldwide occurring in both hereditary and sporadic forms. Women with inherited pathogenic mutations in the BRCA1 or BRCA2 genes have up to an 85% risk of developing breast cancer in their lifetimes. These patients are candidates for risk-reduction measures such as intensive radiological screening, prophylactic surgery or chemoprevention. However, only about 20% of familial breast cancer cases are attributed to mutations in BRCA1 and BRCA2, while a further 5-10% are attributed to mutations in other rare susceptibility genes such as TP53, STK11, PTEN, ATM and CHEK2. A multitude of genome wide association studies (GWAS) have been conducted confirming low-risk common variants associated with breast cancer in excess of 90 loci, which may contribute to a further 23% of the heritability. We currently find ourselves in "the next generation", with technologies offering deep sequencing at a fraction of the cost. Starting off primarily in a research setting, multi-gene panel testing is now utilized in the clinic to sequence multiple predisposing genes simultaneously (otherwise known as multi-gene panel testing). In this review, we focus on the hereditary breast cancer discoveries, techniques and the challenges we face in this complex disease, especially in the light of the vast amount of data we now have at hand. It has been 20 years since the first breast cancer susceptibility gene has been discovered and there has been substantial progress in unraveling the genetic component of the disease. However, hereditary breast cancer remains a challenging topic subject to common debate.