Breast and ovarian cancer risks due to inherited mutations in BRCA1 and BRCA2

PARP inhibitors suppress tumours via centrosome error-induced senescence independent of DNA damage response

BACKGROUND

Poly(ADP-ribose) polymerase (PARP) inhibitors have emerged as promising chemotherapeutic drugs primarily against BRCA1/2-associated tumours, known as synthetic lethality. However, recent clinical trials reported patients' survival benefits from PARP inhibitor treatments, irrelevant to homologous recombination deficiency. Therefore, revealing the therapeutic mechanism of PARP inhibitors beyond DNA damage repair is urgently needed, which can facilitate precision medicine.

METHODS

A CRISPR-based knock-in technology was used to establish stable BRCA1 mutant cancer cells. The effects of PARP inhibitors on BRCA1 mutant cancer cells were evaluated by biochemical and cell biological experiments. Finally, we validated its in vivo effects in xenograft and patient-derived xenograft (PDX) tumour mice.

FINDINGS

In this study, we uncovered that the majority of clinical BRCA1 mutations in breast cancers were in and near the middle of the gene, rather than in essential regions for DNA damage repair. Representative mutations such as R1085I and E1222Q caused transient extra spindle poles during mitosis in cancer cells. PAR, which is synthesized by PARP2 but not PARP1 at mitotic centrosomes, clustered these transient extra poles, independent of DNA damage response. Common PARP inhibitors could effectively suppress PARP2-synthesized PAR and induce cell senescence by abrogating the correction of mitotic extra-pole error.

INTERPRETATION

Our findings uncover an alternative mechanism by which PARP inhibitors efficiently suppress tumours, thereby pointing to a potential new therapeutic strategy for centrosome error-related tumours.

FUNDING

Funded by National Natural Science Foundation of China (NSFC) (T2225006, 82272948, 82103106), Beijing Municipal Natural Science Foundation (Key program Z220011), and the National Clinical Key Specialty Construction Program, P. R. China (2023).

Clinicopathological features, prognostic factor analysis, and survival nomogram of patients with double primary cancers involving lung cancer

BACKGROUND

Although the incidence of double primary cancers (DPCs) involving lung cancer is rising, they have not been studied sufficiently. This study retrospectively analyzed the clinicopathological and prognostic characteristics of DPC patients with lung cancer and developed a survival nomogram to predict the individual OS rates.

METHODS

We included 103 DPC patients with lung cancer from Shengjing Hospital between 2016 and 2021. Based on the 6-month cancer occurrence interval, the cases were categorized as synchronous DPCs (sDPCs) or metachronous DPCs (mDPCs). Furthermore, the mDPCs were subdivided based on whether the lung cancer occurred first (LCF cohort) or the other cancer occurred first (OCF cohort).

RESULTS

Among the patients, 35 (33.98%) and 68 (66.02%) had sDPCs and mDPCs, respectively. In the mDPCs cohort, 18 (26.47%) belonged to the LCF cohort and 50 (73.53%) to the OCF cohort. The most frequent primary cancer sites were the breast (27.18%), colorectum (22.33%), and urinary system (18.45%). Independent risk factors for progression-free survival were Stage IV lung cancer (p = 0.008) and failure to undergo radical lung cancer surgery (p = 0.028). The risk factors for OS included squamous carcinoma (p = 0.048), Stage IV lung cancer (p = 0.001), single cancer resection plus drug therapy (p < 0.001), drug therapy alone (p = 0.002), failure to undergo radical lung cancer surgery (p = 0.014), and chemotherapy (p = 0.042). The median OS was 37 months, with 3- and 5-year rates of 50.9% and 35.9%, respectively.

CONCLUSION

DPCs involving lung cancer account for 1.11% of cases. The breast, colorectum, and urinary system were the most common extra-pulmonary sites, and mDPCs were more frequent than sDPCs. Radical lung cancer surgery significantly affects prognosis, and drug therapy alone may be preferable when only one tumor is operable. The developed nomogram can accurately predict individual 3-year and 5-year OS rates.

RAD51 separation of function mutation disables replication fork maintenance but preserves DSB repair

Homologous recombination (HR) protects replication forks (RFs) and repairs DNA double-strand breaks (DSBs). Within HR, BRCA2 regulates RAD51 via two interaction regions: the BRC repeats to form filaments on single-stranded DNA and exon 27 (Ex27) to stabilize the filament. Here, we identified a RAD51 S181P mutant that selectively disrupted the RAD51-Ex27 association while maintaining interaction with BRC repeat and proficiently forming filaments capable of DNA binding and strand invasion. Interestingly, RAD51 S181P was defective for RF protection/restart but proficient for DSB repair. Our data suggest that Ex27-mediated stabilization of RAD51 filaments is required for the protection of RFs, while it seems dispensable for the repair of DSBs.

2D graphene-based advanced nanoarchitectonics for electrochemical biosensors: Applications in cancer biomarker detection

Low-cost, rapid, and easy-to-use biosensors for various cancer biomarkers are of utmost importance in detecting cancer biomarkers for early-stage metastasis control and efficient diagnosis. The molecular complexity of cancer biomarkers is overwhelming, thus, the repeatability and reproducibility of measurements by biosensors are critical factors. Electrochemical biosensors are attractive alternatives in cancer diagnosis due to their low cost, simple operation, and promising analytical figures of merit. Recently graphene-derived nanostructures have been used extensively for the fabrication of electrochemical biosensors because of their unique physicochemical properties, including the high electrical conductivity, adsorption capacity, low cost and ease of mass production, presence of oxygen-containing functional groups that facilitate the bioreceptor immobilization, increased flexibility and mechanical strength, low cellular toxicity. Indeed, these properties make them advantageous compared to other alternatives. However, some drawbacks must be overcome to extend their use, such as poor and uncontrollable deposition on the substrate due to the low dispersity of some graphene materials and irreproducibility of the results because of the differences in various batches of the produced graphene materials. This review has documented the most recently developed strategies for electrochemical sensor fabrication. It differs in the categorization method compared to published works to draw greater attention to the wide opportunities of graphene nanomaterials for biological applications. Limitations and future scopes are discussed to advance the integration of novel technologies such as artificial intelligence, the internet of medical things, and triboelectric nanogenerators to eventually increase efficacy and efficiency.

Genetically driven predisposition leads to an unusually genomic unstable renal cell carcinoma

Renal cell carcinoma originates from the lining of the proximal convoluted renal tubule and represents the most common type of kidney cancer. Risk factors and comorbidities might be associated to renal cell carcinoma, while a small fraction of 2-3% emerges from patients with predisposing cancer syndromes, typically associated to hereditary mutations in VHL, folliculin, fumarate hydratase or MET genes. Here, we report a case of renal cell carcinoma in patient with concurrent germline mutations in BRCA1 and RAD51 genes. This case displays an unusual high mutational burden and chromosomal aberrations compared to the typical profile of renal cell carcinoma. Mutational analysis on whole genome sequencing revealed an enrichment of the MMR2 mutational signature, which is indicative of impaired DNA repair capacity. Overall, the tumor displayed a profile of unusual high genomic instability which suggests a possible origin from germline predisposing mutations in the DNA repair genes BRCA1 and RAD51. While BRCA1 and RAD51 germline mutations are well-characterised in breast and ovarian cancer, their role in renal cell carcinoma is still largely unexplored. The genomic instability detected in this case of renal cell carcinoma, along with the presence of unusual mutations, might offer support to clinicians for the development of patient-tailored therapies.

Protein-folding chaperones predict structure-function relationships and cancer risk in BRCA1 mutation carriers

Predicting the risk of cancer mutations is critical for early detection and prevention, but differences in allelic severity of human carriers confound risk predictions. Here, we elucidate protein folding as a cellular mechanism driving differences in mutation severity of tumor suppressor BRCA1. Using a high-throughput protein-protein interaction assay, we show that protein-folding chaperone binding patterns predict the pathogenicity of variants in the BRCA1 C-terminal (BRCT) domain. HSP70 selectively binds 94% of pathogenic BRCA1-BRCT variants, most of which engage HSP70 more than HSP90. Remarkably, the magnitude of HSP70 binding linearly correlates with loss of folding and function. We identify a prevalent class of human hypomorphic BRCA1 variants that bind moderately to chaperones and retain partial folding and function. Furthermore, chaperone binding signifies greater mutation penetrance and earlier cancer onset in the clinic. Our findings demonstrate the utility of chaperones as quantitative cellular biosensors of variant folding, phenotypic severity, and cancer risk.

Comprehensive germline profiling of patients with breast cancer: initial experience from a Familial Cancer Clinic

Introduction

Breast cancer is the most common cancer among Indian females. There is limited data on germline profiling of breast cancer patients from India.

Objective

The objective of the current study was to analyse the frequency and spectrum of germline variant profiles and clinicopathological characteristics of breast cancer patients referred to our Familial Cancer Clinic (FCC).

Materials and methods

It is a single-centre audit of patients with a confirmed diagnosis of breast carcinoma referred to our FCC from January 2017 to 2020. All patients underwent pretest counselling. Genetic testing was done by multigene panel testing by next-generation sequencing along with reflex multiplication ligation-dependent probe amplification for BRCA1 and 2. The variants were classified based on American College of Medical Genetics guidelines. Demographic and clinicopathological details were extracted from the case record files.

Results

One hundred and fifty-five patients were referred to the FCC and underwent pretest counselling. A total of 99 (63.9%) patients underwent genetic testing. Among them, 62 patients (62/99 = 62.6%) had a germline variant. A pathogenic/likely pathogenic (P/LP) germline variant was identified in 41 (41.4%) of the patients who underwent testing. Additional variants of unknown significance (VUS) were identified in seven patients who also carried a P/LP variant. VUS alone was detected in 21 patients (21/99 = 21.2%). Among the P/LP pathogenic variants (PV), BRCA 1 PV were seen in 27 patients (65.8%), BRCA 2 variants in 7 patients (17.1%), ATM variants in 3 patients (7.3%) and RAD51, TP53, CHEK2 and HMMR in 1 patient each. Variants were significantly more common in patients with a family history (FH) of malignancy than those without FH (58.5% versus 29.5%; p = 0.013). Age and triple-negative histology were not found to be significantly associated with the occurrence of P/LP PVs.

Conclusion

We report a 41% P/LP variant rate in our selected cohort of breast cancer patients, with variants in BRCA constituting 83% and non-BRCA gene variants constituting 17%.

Functional annotation of variants of the BRCA2 gene via locally haploid human pluripotent stem cells

Mutations in the BRCA2 gene are associated with sporadic and familial cancer, cause genomic instability and sensitize cancer cells to inhibition by the poly(ADP-ribose) polymerase (PARP). Here we show that human pluripotent stem cells (hPSCs) with one copy of BRCA2 deleted can be used to annotate variants of this gene and to test their sensitivities to PARP inhibition. By using Cas9 to edit the functional BRCA2 allele in the locally haploid hPSCs and in fibroblasts differentiated from them, we characterized essential regions in the gene to identify permissive and loss-of-function mutations. We also used Cas9 to directly test the function of individual amino acids, including amino acids encoded by clinical BRCA2 variants of uncertain significance, and identified alleles that are sensitive to PARP inhibitors used as a standard of care in BRCA2-deficient cancers. Locally haploid human pluripotent stem cells can facilitate detailed structure-function analyses of genes and the rapid functional evaluation of clinically observed mutations.

"There should be one spot that you can go:" BRCA mutation carriers' perspectives on cancer risk management and a hereditary cancer registry

Individuals who carry BRCA1 or BRCA2 pathogenic variants are recommended to have extensive cancer prevention screening and risk-reducing surgeries. Uptake of these recommendations is variable, and there remains room for improvement in the risk management of BRCA carriers. This paper explores female BRCA carriers' experiences with the current model of care and their perspectives on (and interest in) an inherited cancer registry. Findings can inform the development of a dedicated high-risk screening and management program for these patients. Quantitative and qualitative data were gathered through a provincial descriptive survey and semi-structured qualitative interviews to assess BRCA carriers' opinions toward risk management services in the province of Newfoundland and Labrador (NL), Canada. Survey (n = 69) and interview data (n = 15) revealed continuity and coordination challenges with the current system of care of high-risk individuals. Respondents suggested an inherited cancer registry would help identify high-risk individuals and provide a centralized system of risk management for identified carriers. Respondents identified concerns about the privacy of their registry data, including who could access it. Findings suggest BRCA carriers see great value in an inherited cancer registry. Specifically, participants noted it could provide a centralized system to help improve the coordination of burdensome, life-long risk management. Important patient concerns about protecting their privacy and their health data confidentiality must be addressed in patient and public information and informed consent documents about a registry.

Analysis of the indispensable RAD51 cofactor BRCA2 in Naganishia liquefaciens, a Basidiomycota yeast

The BRCA2 tumor suppressor plays a critical role in homologous recombination by regulating RAD51, the eukaryotic homologous recombinase. We identified the BRCA2 homolog in a Basidiomycota yeast, Naganishia liquefaciens BRCA2 homologs are found in many Basidiomycota species but not in Ascomycota species. Naganishia BRCA2 (Brh2, for BRCA2 homolog) is about one-third the size of human BRCA2. Brh2 carries three potential BRC repeats with two oligonucleotide/oligosaccharide-binding domains. The homolog of DSS1, a small acidic protein serving as an essential partner of BRCA2 was also identified. The yeast two-hybrid assay shows the interaction of Brh2 with both Rad51 and Dss1. Unlike human BRCA2, Brh2 is not required for normal cell growth, whereas loss of Dss1 results in slow growth. The loss of Brh2 caused pronounced sensitivity to UV and ionizing radiation, and their HR ability, as assayed by gene-targeting efficiency, is compromised. These phenotypes are indistinguishable from those of the rad51 mutant, and the rad51 brh2 double mutant. Naganishia Brh2 is likely the BRCA2 ortholog that functions as an indispensable auxiliary factor for Rad51.

A pancancer analysis of the clinical and genomic characteristics of multiple primary cancers

Multiple primary cancer (MPC) denotes individuals with two or more malignant tumors occurring simultaneously or successively. Herein, a total of 11,000 pancancer patients in TCGA database (1993-2013) were divided into MPC or non-MPC groups based on their history of other malignant tumors. The incidence of MPC has risen to 8.5-13.1% since 2000. Elderly individuals, males, early-stage cancer patients, and African Americans and Caucasians are identified as independent risk factors (p < 0.0001). Non-MPC patients exhibit significantly longer overall survival (OS) and disease-free survival (DFS) (p = 0.0038 and p = 0.0014). Age (p < 0.001) and tumor staging at initial diagnosis (p < 0.001) contribute to this difference. In our center, MPC was identified in 380 out of 801 tumor events based on SEER criteria. The peak occurrence of secondary primary was about 1-5 years after the first primary tumor, with a second small peak around 10-15 years. Multiple tumors commonly occur in the same organ (e.g., breast and lung), constituting 12.6%. Certain cancer types, notably skin cutaneous melanoma (SKCM), exhibit significantly higher tumor mutational burden (TMB) in the MPC group (17.31 vs. 6.55 mutations/MB, p < 0.001), with high TMB associated with improved survival (p < 0.001). High TMB in MPC may serve as a predictor for potential immunotherapy application.

Recurrent BRCA2 exon 3 deletion in Assyrian families

We identified six patients from five families with a recurrent mutation: NM_000059.3 (BRCA2) exon 3 deletion. All families self-identified as Assyrian. Assyrians are an ethnoreligious population of ancient Mesopotamia, now mostly living in modern day Iraq, Syria, Turkey and Iran. They are historically a socially isolated population with intermarriage within their community, living as a religious and language minority in mostly Muslim countries. The probands of each family presented with a classic BRCA2-associated cancer including early-onset breast cancer, epithelial serous ovarian cancer, male breast cancer and/or high-grade prostate cancer, and family history that was also significant for BRCA2-associated cancer. BRCA2 exon 3 deletion is classified as pathogenic and has been previously described in the literature, but it has not been described as a founder mutation in a particular population. We characterise this recurrent BRCA2 pathogenic variant in five Assyrian families in a single centre cohort.

Association Between Germline BRCA1/2 Gene Variants and Clinicopathological Features of Ovarian Cancer

Objective

To investigate the relationship between BRCA1/2 gene mutation and clinicopathological features in ovarian cancer patients, so as to develop precise individualized treatment plan for patients.

Methods

Patients diagnosed with ovarian cancer between January 2018 and July 2023 who underwent BRCA1/2 genetic testing were retrospectively analyzed. The clinicopathological characteristics (age, body mass index (BMI), family history of ovarian cancer, pregnancy history, menopause status, tumor size, histopathology, Federation of Gynecology and Obstetrics (FIGO) staging, and ascites) of non-carriers and BRCA1/2 variant carriers were compared. Logistic regression analysis was used to explore the relationship between BRCA1/2 variants and clinicopathological characteristics of ovarian cancer.

Results

A total of 284 ovarian cancer patients were collected, and the subjects were divided into two groups, 197 non-carriers and 87 BRCA1/2 variants carriers. The proportion of serous ovarian carcinoma in BRCA1/2 variant carriers is higher than that in non-BRCA variant carriers (78.2% vs 60.9%, p=0.015). There were 51 patients with BRCA pathogenic or likely pathogenic variant, 22 patients with BRCA likely benign variant, and 14 patients with BRCA variants of uncertain significance (VUS). The proportion of serous ovarian carcinoma in patients with BRCA pathogenic/likely pathogenic variant is higher than that in patients with BRCA likely benign variant and BRCA VUS (94.1% vs 50.0% and 64.3%. p<0.001). There were no statistically significant differences in BMI, family history of ovarian cancer, pregnancy history, menopause status, maximum diameter of the tumor lesion, FIGO stage, and ascites among patients with different grades of variants. Multivariate logistic regression analysis showed that serous ovarian carcinoma was related to BRCA mutation (Serous carcinoma vs non-serous carcinoma: OR 2.145, 95% CI: 1.044-4.407) (p=0.038).

Conclusion

Patients with BRCA1 variant develop ovarian cancer at a younger age than those with the BRCA2 variant. The proportion of FIGO stage III-IV in patients with BRCA pathogenic + likely pathogenic variant was significantly higher than those in patients with other variants. Germline BRCA1/2 variants were most frequently identified in serous ovarian carcinoma patients.

Anthracycline-related cardiotoxicity in patients with breast cancer harboring mutational signature of homologous recombination deficiency (HRD)

BACKGROUND

The BRCA proteins play a key role in the homologous recombination (HR) pathway. Beyond BRCA1/2, other genes are involved in the HR repair (HRR). Due to the prominent role in the cellular repair process, pathogenic or likely pathogenic variants (PV/LPVs) in HRR genes may cause inadequate DNA damage repair in cardiomyocytes.

PATIENTS AND METHODS

This was a multicenter, hospital-based, retrospective cohort study to investigate the heart toxicity from anthracycline-containing regimens (ACRs) in the adjuvant setting of breast cancer (BC) patients carrying germline BRCA PV/LPVs and no-BRCA HRR pathway genes. The left ventricular ejection fraction (LVEF) was assessed using cardiac ultrasound before starting ACR therapy and at subsequent time points according to clinical indications.

RESULTS

Five hundred and three BC patients were included in the study. We predefined three groups: (i) BRCA cohort; (ii) no-BRCA cohort; (iii) variant of uncertain significance (VUS)/wild-type (WT) cohort. When baseline (T0) and post-ACR (T1) LVEFs between the three cohorts were compared, pre-treatment LVEF values were not different (BRCA1/2 versus HRR-no-BRCA versus VUS/WT cohort). Notably, during monitoring (T1, median 3.4 months), patients carrying BRCA or HRR no-BRCA germline pathogenic or likely pathogenic variants showed a statistically significant reduction of LVEF compared to baseline (T0). To assess the relevance of HRR on the results, we included the analysis of the subgroup of 20 BC patients carrying PV/LPVs in other genes not involved in HRR, such as mismatch repair genes (MUTYH, PMS2, MSH6). Unlike HRR genes, no significant differences in T0-T1 were found in this subgroup of patients.

CONCLUSION

Our data suggest that deleterious variants in HRR genes, leading to impaired HR, could increase the sensitivity of cardiomyocytes to ACR in early BC patients. In this subgroup of patients, other measurements, such as the global longitudinal strain, and a more in-depth assessment of risk factors may be proposed in the future to optimize cardiovascular risk management and improve long-term survival.

Low Cancer Occurrence Rate following Prophylactic Nipple-Sparing Mastectomy

BACKGROUND

Nipple-sparing mastectomy (NSM) has become widely available for breast cancer prophylaxis. There are limited data on its long-term oncologic safety. The objective of this study was to determine the incidence of breast cancer in patients who underwent prophylactic NSM.

METHODS

All patients undergoing prophylactic NSM at a single institution from 2006 through 2019 were retrospectively reviewed. Patient demographic factors, genetic predispositions, mastectomy specimen pathology, and oncologic occurrences at follow-up were recorded. Descriptive statistics were performed where necessary to classify demographic factors and oncologic characteristics.

RESULTS

A total of 871 prophylactic NSMs were performed on 641 patients, with median follow-up of 82.0 months (standard error 1.24). A total of 94.4% of patients ( n = 605) underwent bilateral NSMs, although only the prophylactic mastectomy was considered. The majority of mastectomy specimens (69.6%) had no identifiable pathology. A total of 38 specimens (4.4%) had cancer identified in mastectomy specimens, with ductal carcinoma in situ being the most common (92.1%; n = 35). Multifocal or multicentric disease was observed in seven cases (18.4%) and lymphovascular invasion was identified in two (5.3%). One patient (0.16%), who was a BRCA2 variant carrier, was found to have breast cancer 6.5 years after prophylactic mastectomy.

CONCLUSIONS

Overall primary oncologic occurrence rates are very low in high-risk patients undergoing prophylactic NSM. In addition to reducing the risk of oncologic occurrence, prophylactic surgery itself may be therapeutic in a small proportion of patients. Continued surveillance for these patients remains important to assess at longer follow-up intervals.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, IV.

Prophylactic Interventions for Hereditary Breast and Ovarian Cancer Risks and Mortality in BRCA1/2 Carriers

BACKGROUND

Hereditary breast and ovarian cancers (HBOCs) pose significant health risks worldwide and are mitigated by prophylactic interventions. However, a meta-analysis of their efficacy and the impact of different genetic variants on their effectiveness is lacking.

METHODS

A systematic review and meta-analysis were conducted, adhering to Cochrane guidelines. The review encompassed studies that involved prophylactic interventions for healthy women with BRCA variants, focusing on cancer incidence and mortality outcomes. The Newcastle-Ottawa Scale was used for risk of bias assessment. We pooled the extracted outcomes using random effects models and conducted subgroup analyses stratified by intervention, variant, and cancer types.

RESULTS

A total of 21 studies met the inclusion criteria. The meta-analysis revealed that prophylactic interventions significantly reduced cancer risk and mortality. The subgroup analysis showed a greater protective effect for BRCA2 than BRCA1 variant carriers. Risk-reducing surgeries (RRS) were more effective than chemoprevention, with RRS notably reducing cancer risk by 56% compared to 39% for chemoprevention. Prophylactic oophorectomy significantly reduced HBOC risks, while the effect of prophylactic mastectomy and chemoprevention on mortality was less conclusive.

CONCLUSIONS

Prophylactic interventions significantly reduce the risk of HBOC and associated mortality. This comprehensive analysis provides insights for future economic evaluations and clinical decision-making in HBOC interventions.

Susceptibility Genes Associated with Multiple Primary Cancers

With advancements in treatment and screening techniques, we have been witnessing an era where more cancer survivors harbor multiple primary cancers (MPCs), affecting approximately one in six patients. Identifying MPCs is crucial for tumor staging and subsequent treatment choices. However, the current clinicopathological criteria for clinical application are limited and insufficient, making it challenging to differentiate them from recurrences or metastases. The emergence of next-generation sequencing (NGS) technology has provided a genetic perspective for defining multiple primary cancers. Researchers have found that, when considering multiple tumor pairs, it is crucial not only to examine well-known essential mutations like MLH1/MSH2, EGFR, PTEN, BRCA1/2, CHEK2, and TP53 mutations but also to explore certain pleiotropic loci. Moreover, specific deleterious mutations may serve as regulatory factors in second cancer development following treatment. This review aims to discuss these susceptibility genes and provide an explanation of their functions based on the signaling pathway background. Additionally, the association network between genetic signatures and different tumor pairs will be summarized.

Synchronous and Metachronous Breast and Ovarian Cancers: Experience from a Single Tertiary Care Cancer Centre in India

Women with either breast cancer (BC) or ovarian cancer (OC) have a 1.5-2 times higher risk of developing the other. Discerning discrete primaries versus metastases from either can be challenging. Clinico-pathological and outcome details of patients diagnosed with both BC and OC from December 1994 to August 2018 were retrospectively evaluated at a single tertiary cancer centre. We report the pattern of presentation and recurrences with case-based illustrations. Out of 139 patients, presentation was BC-first in 66.2%, OC-first in 24.5% and synchronous cancers (SC) in 9.3% of women. The median age at diagnosis in BC-first, OC-first and SC was 42 years, 48 years and 49 years, respectively. The most common histological subtype was invasive breast carcinoma-no special type (74.8%) in BC and serous cystadenocarcinoma (81.3%) in OC. BC presented at an early stage in 67.6% while OC presented at an advanced stage in 48.2% of patients. Germline mutation results were available in 82% with 61.4% of the cohort exhibiting a mutation- BRCA1 mutation being the most common. The median time to development of second cancer was 77.4 months and 39.4 months in BC-first and OC-first, respectively. At a median follow-up of 9.47 years, disease-free survival was 32.6%, 32.4% and 30.8% in BC-first, OC-first and SC, respectively (p < 0.001). In hereditary breast and ovarian cancer, BC-first patients have a better prognosis while synchronous malignancies have worse oncological outcomes. Deaths are mainly due to OC progression. Appropriate surveillance and prophylactic intervention in young patients with breast cancer may improve overall outcomes.

An activity-based functional test for identifying homologous recombination deficiencies across cancer types in real time

Homologous recombination (HR)-mediated DNA repair is a prerequisite for maintaining genome stability. Cancer cells displaying HR deficiency (HRD) are selectively eliminated by poly(ADP-ribose) polymerase inhibitors (PARPis). To date, sequencing of HR-associated genes and analyzing genome instability have been used as clinical predictions for PARPi therapy. However, these genetic tests cannot reflect dynamic changes in the HR status. Here, we have developed a virus- and activity-based functional assay to quantify real-time HR activity directly. Instead of focusing on a few HR-associated genes, our functional assay detects endpoint HR activity and establishes an activity threshold for identifying HRD across cancer types, validated by PARPi sensitivity and BRCA status. Notably, this fluorescence-based assay can be applied to primary ovarian cancer cells from patients to reflect their level of HRD, which is associated with survival benefits. Thus, our work provides a functional test to predict the response of primary cancer cells to PARPis.

Genomic Profiling Reveals Germline Predisposition and Homologous Recombination Deficiency in Pancreatic Acinar Cell Carcinoma

PURPOSE

To determine the genetic predisposition underlying pancreatic acinar cell carcinoma (PACC) and characterize its genomic features.

METHODS

Both somatic and germline analyses were performed using an Food and Drug Administration-authorized matched tumor/normal sequencing assay on a clinical cohort of 28,780 patients with cancer, 49 of whom were diagnosed with PACC. For a subset of PACCs, whole-genome sequencing (WGS; n = 12) and RNA sequencing (n = 6) were performed.

RESULTS

Eighteen of 49 (36.7%) PACCs harbored germline pathogenic variants in homologous recombination (HR) and DNA damage response (DDR) genes, including BRCA1 (n = 1), BRCA2 (n = 12), PALB2 (n = 2), ATM (n = 2), and CHEK2 (n = 1). Thirty-one PACCs displayed pure, and 18 PACCs harbored mixed acinar cell histology. Fifteen of 31 (48%) pure PACCs harbored a germline pathogenic variant affecting HR-/DDR-related genes. BRCA2 germline pathogenic variants (11 of 31, 35%) were significantly more frequent in pure PACCs than in pancreatic adenocarcinoma (86 of 2,739, 3.1%; P < .001), high-grade serous ovarian carcinoma (67 of 1,318, 5.1%; P < .001), prostate cancer (116 of 3,401, 3.4%; P < .001), and breast cancer (79 of 3,196, 2.5%; P < .001). Genomic features of HR deficiency (HRD) were detected in 7 of 12 PACCs undergoing WGS, including 100% (n = 6) of PACCs with germline HR-related pathogenic mutations and 1 of 6 PACCs lacking known pathogenic alterations in HR-related genes. Exploratory analyses revealed that in PACCs, the repertoire of somatic driver genetic alterations and the load of neoantigens with high binding affinity varied according to the presence of germline pathogenic alterations affecting HR-/DDR-related genes and/or HRD.

CONCLUSION

In a large pan-cancer cohort, PACC was identified as the cancer type with the highest prevalence of both BRCA2 germline pathogenic variants and genomic features of HRD, suggesting that PACC should be considered as part of the spectrum of BRCA-related malignancies.

Prediction of breast cancer risk for sisters of women attending screening

BACKGROUND

Risk assessment is important for breast cancer prevention and early detection. We aimed to examine whether common risk factors, mammographic features, and breast cancer risk prediction scores of a woman were associated with breast cancer risk for her sisters.

METHODS

We included 53 051 women from the Karolinska Mammography Project for Risk Prediction of Breast Cancer (KARMA) study. Established risk factors were derived using self-reported questionnaires, mammograms, and single nucleotide polymorphism genotyping. Using the Swedish Multi-Generation Register, we identified 32 198 sisters of the KARMA women (including 5352 KARMA participants and 26 846 nonparticipants). Cox models were used to estimate the hazard ratios of breast cancer for both women and their sisters, respectively.

RESULTS

A higher breast cancer polygenic risk score, a history of benign breast disease, and higher breast density in women were associated with an increased risk of breast cancer for both women and their sisters. No statistically significant association was observed between breast microcalcifications and masses in women and breast cancer risk for their sisters. Furthermore, higher breast cancer risk scores in women were associated with an increased risk of breast cancer for their sisters. Specifically, the hazard ratios for breast cancer per 1 standard deviation increase in age-adjusted KARMA, Breast and Ovarian Analysis of Disease Incidence and Carrier Estimation Algorithm (BOADICEA), and Tyrer-Cuzick risk scores were 1.16 (95% confidence interval [CI] = 1.07 to 1.27), 1.23 (95% CI = 1.12 to 1.35), and 1.21 (95% CI = 1.11 to 1.32), respectively.

CONCLUSION

A woman's breast cancer risk factors are associated with her sister's breast cancer risk. However, the clinical utility of these findings requires further investigation.

Pancreatic cancer cluster region identified in BRCA2

Pancreatic cancer has a poor prognosis. Lack of diagnostic markers prevents its early diagnosis and treatment. Pathogenic germline variation in BRCA1 and BRCA2 (BRCA) is genetic predisposition for cancer. The location of variants in different regions in BRCA is non-randomly enriched in different types of cancer as shown by the breast cancer cluster region (BCCR), ovarian cancer cluster region (OCCR) and prostate cancer cluster region (PrCCR). Although pathogenic BRCA variation also contributes to pancreatic cancer, no pancreatic cancer cluster region (PcCCR) in BRCA1 or BRCA2 has been identified due to the relatively low incidence of pancreatic cancer and the lack of sufficient variation data from pancreatic cancer. Through comprehensive data mining, we identified 215 BRCA pathogenic variants (PVs) (71 in BRCA1 and 144 in BRCA2) from 27 118 pancreatic cancer cases. Through mapping the variants, we identified a region non-randomly enriched in pancreatic cancer between BRCA2 c.3515 and c.6787. This region contained 59 BRCA2 PVs and included 57% of pancreatic cancer cases (95% CI 43% to 70%). The PcCCR did not overlap with the BCCR and PrCCR but overlapped with the BRCA2 OCCR, highlighting that this region may play similar aetiological roles in pancreatic cancer and ovarian cancer.

The BRCA1/BARD1 complex recognizes pre-ribosomal RNA to facilitate homologous recombination

The BRCA1/BARD1 complex plays a key role in the repair of DNA double-strand breaks (DSBs) in both somatic cells and germ cells. However, the underlying molecular mechanism by which this complex mediates DSB repair is not fully understood. Here, we examined the XY body of male germ cells, where DSBs are accumulated. We show that the recruitment of the BRCA1/BARD1 complex to the unsynapsed axis of the XY body is mediated by pre-ribosomal RNA (pre-rRNA). Similarly, the BRCA1/BARD1 complex associates with pre-rRNA in somatic cells, which not only forms nuclear foci in response to DSBs, but also targets the BRCA1/BARD1 complex to DSBs. The interactions between the BRCT domains of the BRCA1/BARD1 complex and pre-rRNA induce liquid-liquid phase separations, which may be the molecular basis of DSB-induced nuclear foci formation of the BRCA1/BARD1 complex. Moreover, cancer-associated mutations in the BRCT domains of BRCA1 and BARD1 abolish their interactions with pre-rRNA. Pre-rRNA also mediates BRCA1-dependent homologous recombination, and suppression of pre-rRNA biogenesis sensitizes cells to PARP inhibitor treatment. Collectively, this study reveals that pre-rRNA is a functional partner of the BRCA1/BARD1 complex in the DSB repair.

Protein-Folding Chaperones Predict Structure-Function Relationships and Cancer Risk in BRCA1 Mutation Carriers

Identifying pathogenic mutations and predicting their impact on protein structure, function and phenotype remain major challenges in genome sciences. Protein-folding chaperones participate in structure-function relationships by facilitating the folding of protein variants encoded by mutant genes. Here, we utilize a high-throughput protein-protein interaction assay to test HSP70 and HSP90 chaperone interactions as predictors of pathogenicity for variants in the tumor suppressor BRCA1. Chaperones bind 77% of pathogenic BRCA1-BRCT variants, most of which engaged HSP70 more than HSP90. Remarkably, the magnitude of chaperone binding to variants is proportional to the degree of structural and phenotypic defect induced by BRCA1 mutation. Quantitative chaperone interactions identified BRCA1-BRCT separation-of-function variants and hypomorphic alleles missed by pathogenicity prediction algorithms. Furthermore, increased chaperone binding signified greater cancer risk in human BRCA1 carriers. Altogether, our study showcases the utility of chaperones as quantitative cellular biosensors of variant folding and phenotypic severity.

HIGHLIGHTS

Chaperones detect an abundance of pathogenic folding variants of BRCA1-BRCT.Degree of chaperone binding reflects severity of structural and phenotypic defect.Chaperones identify separation-of-function and hypomorphic variants. Chaperone interactions indicate penetrance and expressivity of BRCA1 alleles.

Characteristics of second primary breast cancer after ovarian cancer: a Korea central cancer registry retrospective study

Background

Second primary cancer has become an important issue among cancer survivors. This study sought to determine the differences in clinicopathologic outcomes between second primary breast cancer (SPBC) after ovarian cancer and primary breast cancer (PBC) in the Republic of Korea.

Methods and materials

We searched the Korea Central Cancer Registry and identified 251,244 breast cancer cases that were diagnosed between 1999 and 2017. The incident rate and standardized incidence ratio (SIR) were calculated. Demographic and clinical characteristics and overall survival (OS) rates were estimated according to age, histological type, and cancer stage.

Results

Among the 228,329 patients included, 228,148 were patients with PBC, and 181 patients had SPBC diagnosed after ovarian cancer (OC). The mean ages at diagnosis were 56.09 ± 10.81 years for SPBC and 50.65 ± 11.40 years for PBC. Patients with SPBC were significantly less likely than patients with PBC to receive adjuvant radiotherapy (14.92% vs. 21.92%, p = 0.02) or adjuvant chemotherapy (44.75% vs. 55.69%, p < 0.01). Based on the age-standardized rate (ASR), the incidence of SPBC after OC was 293.58 per 100,000 ovarian cancer patients and the incidence of PBC was 39.13 per 100,000 women. The SIR for SPBC was 1.27 (1.09-1.46, 95% Confidence interval) in the patients overall. The 5-year OS rates were 72.88% and 89.37% for SPBC and PBC (p < 0.01). The OS rate in SPBC decreased significantly with advanced stage and older age.

Conclusion

The incidence of breast cancer is about 1.27 times higher in ovarian cancer patients than in healthy people. The survival outcomes were worse for SPBC than for PBC and were related to older age and advanced stage. Active screening for breast cancer is necessary in ovarian cancer patients.

A new wave of innovations within the DNA damage response

Genome instability has been identified as one of the enabling hallmarks in cancer. DNA damage response (DDR) network is responsible for maintenance of genome integrity in cells. As cancer cells frequently carry DDR gene deficiencies or suffer from replicative stress, targeting DDR processes could induce excessive DNA damages (or unrepaired DNA) that eventually lead to cell death. Poly (ADP-ribose) polymerase (PARP) inhibitors have brought impressive benefit to patients with breast cancer gene (BRCA) mutation or homologous recombination deficiency (HRD), which proves the concept of synthetic lethality in cancer treatment. Moreover, the other two scenarios of DDR inhibitor application, replication stress and combination with chemo- or radio- therapy, are under active clinical exploration. In this review, we revisited the progress of DDR targeting therapy beyond the launched first-generation PARP inhibitors. Next generation PARP1 selective inhibitors, which could maintain the efficacy while mitigating side effects, may diversify the application scenarios of PARP inhibitor in clinic. Albeit with unavoidable on-mechanism toxicities, several small molecules targeting DNA damage checkpoints (gatekeepers) have shown great promise in preliminary clinical results, which may warrant further evaluations. In addition, inhibitors for other DNA repair pathways (caretakers) are also under active preclinical or clinical development. With these progresses and efforts, we envision that a new wave of innovations within DDR has come of age.

Global trends in incidence, death, burden and risk factors of early-onset cancer from 1990 to 2019

Objective

This study aimed to explore the global burden of early-onset cancer based on the Global Burden of Disease (GBD) 2019 study for 29 cancers worldwid.

Methods and analysis

Incidence, deaths, disability-adjusted life years (DALYs) and risk factors for 29 early-onset cancer groups were obtained from GBD.

Results

Global incidence of early-onset cancer increased by 79.1% and the number of early-onset cancer deaths increased by 27.7% between 1990 and 2019. Early-onset breast, tracheal, bronchus and lung, stomach and colorectal cancers showed the highest mortality and DALYs in 2019. Globally, the incidence rates of early-onset nasopharyngeal and prostate cancer showed the fastest increasing trend, whereas early-onset liver cancer showed the sharpest decrease. Early-onset colorectal cancers had high DALYs within the top five ranking for both men and women. High-middle and middle Sociodemographic Index (SDI) regions had the highest burden of early-onset cancer. The morbidity of early-onset cancer increased with the SDI, and the mortality rate decreased considerably when SDI increased from 0.7 to 1. The projections indicated that the global number of incidence and deaths of early-onset cancer would increase by 31% and 21% in 2030, respectively. Dietary risk factors (diet high in red meat, low in fruits, high in sodium and low in milk, etc), alcohol consumption and tobacco use are the main risk factors underlying early-onset cancers.

Conclusion

Early-onset cancer morbidity continues to increase worldwide with notable variances in mortality and DALYs between areas, countries, sex and cancer types. Encouraging a healthy lifestyle could reduce early-onset cancer disease burden.

Identification and evaluation of a novel PARP1 inhibitor for the treatment of triple-negative breast cancer

Triple-negative breast cancer (TNBC) is a particularly invasive subtype of breast cancer and usually has a poor prognosis due to the lack of effective therapeutic targets. Approximately 25% of TNBC patients carry a breast cancer susceptibility gene1/2 (BRCA1/2) mutation. Clinically, PARP1 inhibitors have been approved for the treatment of patients with BRCA1/2-mutated breast cancer through the mechanism of synthetic lethality. In this study, we identified compound 6 {systematic name: 2-[2-(4-Hydroxy-phenyl)-vinyl]-3H-quinazolin-4-one} as a novel PARP1 inhibitor from established virtual screening methods. Compound 6 exerted stronger PARP1 inhibitory activity and anti-cancer activity as compared to olaparib in BRCA1-mutated TNBC cells and TNBC patient-derived organoids. Unexpectedly, we found that compound 6 also significantly inhibited cell viability, proliferation, and induced cell apoptosis in BRCA wild-type TNBC cells. To further elucidate the underlying molecular mechanism, we found that tankyrase (TNKS), a vital promoter of homologous-recombination repair, was a potential target of compound 6 by cheminformatics analysis. Compound 6 not only decreased the expression of PAR, but also down-regulated the expression of TNKS, thus resulting in significant DNA single-strand and double-strand breaks in BRCA wild-type TNBC cells. In addition, we demonstrated that compound 6 enhanced the sensitivity of BRCA1-mutated and wild-type TNBC cells to chemotherapy including paclitaxel and cisplatin. Collectively, our study identified a novel PARP1 inhibitor, providing a therapeutic candidate for the treatment of TNBC.

BRCA1 and NORE1A Form a Her2/Ras Regulated Tumor Suppressor Complex Modulating Senescence

BRCA1 is a tumor suppressor with a complex mode of action. Hereditary mutations in BRCA1 predispose carriers to breast cancer, and spontaneous breast cancers often exhibit defects in BRCA1 expression. However, haploinsufficiency or suppression of BRCA1 expression leads to defects in DNA repair, which can induce DNA damage responses, leading to senescence. Activating mutation or overexpression of the Her2 oncoprotein are also frequent drivers of breast cancer. Yet, over-activation of Her2, working through the RAS oncoprotein, can also induce senescence. It is thought that additional defects in the p53 and Rb tumor suppressor machinery must occur in such tumors to allow an escape from senescence, thus permitting tumor development. Although BRCA1 mutant breast cancers are usually Her2 negative, a significant percentage of Her2 positive tumors also lose their expression of BRCA1. Such Her2+/BRCA1- tumors might be expected to have a particularly high senescence barrier to overcome. An important RAS senescence effector is the protein NORE1A, which can modulate both p53 and Rb. It is an essential senescence effector of the RAS oncoprotein, and it is often downregulated in breast tumors by promotor methylation. Here we show that NORE1A forms a Her2/RAS regulated, endogenous complex with BRCA1 at sites of replication fork arrest. Suppression of NORE1A blocks senescence induction caused by BRCA1 inactivation and Her2 activation. Thus, NORE1A forms a tumor suppressor complex with BRCA1. Its frequent epigenetic inactivation may facilitate the transformation of Her2+/BRCA1- mediated breast cancer by suppressing senescence.

A bibliometric study of the top 100 most cited papers on aging and cancer

Cancer has been the major and increasing cause of premature death and years of life lost. Various studies suggested the correlation between the aging process and cancer genesis. To evaluate the performance of the articles and to identify and compare the top-cited articles on aging and cancer, a cross-sectional bibliometric analysis was performed. Top-cited articles that were indexed in the Core databases in Web of Science were utilized to identify articles published from inception to September 3, 2022. The top 100 most-cited articles on aging and cancer were evaluated for their specific characteristics. Both Microsoft Office Excel and Visual Basic for Applications were used to analyze the number of publications and scientific cooperations among authors over time. The query identified the top 100 most-cited articles from the 368,504 articles. The top cited articles accumulated 308,106 citations. The citations per article ranged from 39,141 to 1040. Thirty journals published these 100 articles, with the Ca-A Cancer Journal for Clinicians publishing the largest number. Most articles have focused on the trend analysis of incidence, survival outcomes, and prognosis of cancer from different origins. Co-authorship analysis revealed intense collaborative activity between United States authoritative academic institutions and scholars. The present study is the first to analyze most cited papers in "aging and cancer." The historical trends, current status, and future direction in the field of older patients with cancer are systematically summarized. The occurrence and development of cancer is correlated with aging.

A Narrative Review of Breastfeeding and Its Correlation With Breast Cancer: Current Understanding and Outcomes

Breastfeeding has been extensively studied in relation to breast cancer risk. The results of the reviewed studies consistently show a decreased risk of breast cancer associated with breastfeeding, especially for 12 months or longer. This protective effect is attributed to hormonal, immunological, and physiological changes during lactation. Breastfeeding also appears to have a greater impact on reducing breast cancer risk in premenopausal women and specific breast cancer subtypes. Encouraging breastfeeding has dual benefits: benefiting infants and reducing breast cancer risk long-term. Healthcare professionals should provide evidence-based guidance on breastfeeding initiation, duration, and exclusivity, while public health policies should support breastfeeding by creating enabling environments. This review examines the existing literature and analyzes the correlation between breastfeeding and breast cancer risk.

A transcription-independent mechanism determines rapid periodic fluctuations of BRCA1 expression

BRCA1 expression is highly regulated to prevent genomic instability and tumorigenesis. Dysregulation of BRCA1 expression correlates closely with sporadic basal-like breast cancer and ovarian cancer. The most significant characteristic of BRCA1 regulation is periodic expression fluctuation throughout the cell cycle, which is important for the orderly progression of different DNA repair pathways throughout the various cell cycle phases and for further genomic stability. However, the underlying mechanism driving this phenomenon is poorly understood. Here, we demonstrate that RBM10-mediated RNA alternative splicing coupled to nonsense-mediated mRNA decay (AS-NMD), rather than transcription, determines the periodic fluctuations in G1/S-phase BRCA1 expression. Furthermore, AS-NMD broadly regulates the expression of period genes, such as DNA replication-related genes, in an uneconomical but more rapid manner. In summary, we identified an unexpected posttranscriptional mechanism distinct from canonical processes that mediates the rapid regulation of BRCA1 as well as other period gene expression during the G1/S-phase transition and provided insights into potential targets for cancer therapy.

Peptide Vaccines as Therapeutic and Prophylactic Agents for Female-Specific Cancers: The Current Landscape

Breast and gynecologic cancers are significant global threats to women's health and those living with the disease require lifelong physical, financial, and social support from their families, healthcare providers, and society as a whole. Cancer vaccines offer a promising means of inducing long-lasting immune response against the disease. Among various types of cancer vaccines available, peptide vaccines offer an effective strategy to elicit specific anti-tumor immune responses. Peptide vaccines have been developed based on tumor associated antigens (TAAs) and tumor specific neoantigens which can also be of viral origin. Molecular alterations in HER2 and non-HER2 genes are established to be involved in the pathogenesis of female-specific cancers and hence were exploited for the development of peptide vaccines against these diseases, most of which are in the latter stages of clinical trials. However, prophylactic vaccines for viral induced cancers, especially those against Human Papillomavirus (HPV) infection are well established. This review discusses therapeutic and prophylactic approaches for various types of female-specific cancers such as breast cancer and gynecologic cancers with special emphasis on peptide vaccines. We also present a pipeline for the design and evaluation of a multiepitope peptide vaccine that can be active against female-specific cancers.

The postulated innocuity of lifetime exposure to aluminium should be reappraised

Because of its chemical versatility and abundance in nature, aluminium is employed in a myriad of frequently used products - including cosmetics and food additives - and applications - drinking water purification procedures being an example. Despite what its widespread use might suggest, aluminium's harmlessness is a matter of debate in the scientific community. In this article we trace the lines of a growing questioning about the potential mutagenic effects of this metal, due to the data produced over the recent years, and with an eye to the discussions currently underway in this regard between the scientific community, industry, and regulatory bodies.

Barriers to hormone therapy following prophylactic bilateral salpingo-oophorectomy in BRCA1/2 mutation carriers

OBJECTIVE

This study aimed to identify barriers to hormone therapy (HT) use among women with BRCA1/2 mutations after prophylactic bilateral salpingo-oophorectomy (BSO).

METHODS

A cross-sectional, electronic survey was conducted of BRCA1/2 mutation carriers at Women and Infants Hospital, Yale Medical Center, Hartford Healthcare, and Maine Medical Center. This study was a subanalysis of a subset of female BRCA1/2 mutation carriers who had undergone a prophylactic BSO. Data were analyzed using the Fisher's exact test or t test.

RESULTS

We performed a subanalysis of 60 BRCA mutation carriers who underwent a prophylactic BSO. Only 24 women (40%) reported ever using HT. HT use was higher in women who underwent their prophylactic BSO at age younger than 45 years (51% vs. 25%, P = 0.06). Among all women who had a prophylactic BSO, the majority (73%) reported that a provider talked to them about using HT. Two thirds reported having seen contradictory information in the media about long-term consequences of HT. Seventy percent listed their provider as the primary influence in their decision to start HT. The most common reasons for not starting HT included it not being recommended by their physician (46%) and that it was not necessary (37%).

CONCLUSIONS

BRCA mutation carriers frequently undergo prophylactic BSO at young ages, and less than half report using HT. This study highlights barriers to HT use, such as patient fears and physician discouragement, and identifies potential areas to improve educational efforts.

An overview of the research progress of BRCA gene mutations in breast cancer

The breast cancer susceptibility gene (BRCA) is an important tumor suppressor gene, including BRCA1 and BRCA2, a biomarker that assesses the risk of breast cancer and influences a patient's individualized treatment options. BRCA1/2 mutation (BRCAm) increases the risk of breast cancer. However, breast-conserving surgery is still an option for BRCAm, and prophylactic mastectomy and nipple-sparing mastectomy may also reduce the risk of breast cancer. BRCAm is sensitive to Poly (ADP-ribose) polymerase inhibitor (PARPi) therapy due to specific types of DNA repair defects, and its combination with other DNA damage pathway inhibitors and endocrine therapy and immunotherapy are also used for the treatment of BRCAm breast cancer. The current treatment and research progress of BRCA1/2 mutant breast cancer in this review provides a basis for the individualized treatment of patients with this type of breast cancer.

Molecular imaging of PARP in cancer: state-of-the-art

INTRODUCTION

Poly-ADP-ribose-polymerase inhibitors (PARPi), which exploit the processes of so-called 'synthetic lethality,' have been successfully implemented in oncological practice. However, not all patients respond to PARPi, and there is an unmet need for noninvasive biomarkers suitable for patient selection and monitoring during PARPi therapy.

AREAS COVERED

The first clinical applications of molecular imaging with positron emission tomography/computed tomography (PET/CT) with [18F]-FluorThanatrace ([18F]-FTT) and [18F]-PARPi, highly effective PARP-ligands, in patients with several malignancies (head and neck, ovarian, prostate, and breast cancer) are covered, with a particular focus on its potential for pre-treatment selection and follow-up.

EXPERT OPINION

By a search made on the most common database, such as PubMed and Google Scholar in a period from January 2010 and 2023, first clinical evidence suggests that PET/CT with [18F]-FTT and [18F]-PARPi might represent a reliable tool for in vivo imaging and quantification of PARP-1 expression in ovarian, prostate, breast, head, and neck cancer, supporting their potential usefulness for patient selection before PARPi-therapies. In addition, a reduction in [18F]-FTT uptake has been registered after therapy initiation and seems to be correlated with patient outcome after PARPi-based regimens. Further studies are needed to better address the value of PARPI-radiolabeled PET imaging in these clinical settings, especially as it concerns technical features such as optimal scan modality (dynamic vs. static) and timing.

Associations of height, body mass index, and weight gain with breast cancer risk in carriers of a pathogenic variant in BRCA1 or BRCA2: the BRCA1 and BRCA2 Cohort Consortium

INTRODUCTION

Height, body mass index (BMI), and weight gain are associated with breast cancer risk in the general population. It is unclear whether these associations also exist for carriers of pathogenic variants in the BRCA1 or BRCA2 genes.

PATIENTS AND METHODS

An international pooled cohort of 8091 BRCA1/2 variant carriers was used for retrospective and prospective analyses separately for premenopausal and postmenopausal women. Cox regression was used to estimate breast cancer risk associations with height, BMI, and weight change.

RESULTS

In the retrospective analysis, taller height was associated with risk of premenopausal breast cancer for BRCA2 variant carriers (HR 1.20 per 10 cm increase, 95% CI 1.04-1.38). Higher young-adult BMI was associated with lower premenopausal breast cancer risk for both BRCA1 (HR 0.75 per 5 kg/m2, 95% CI 0.66-0.84) and BRCA2 (HR 0.76, 95% CI 0.65-0.89) variant carriers in the retrospective analysis, with consistent, though not statistically significant, findings from the prospective analysis. In the prospective analysis, higher BMI and adult weight gain were associated with higher postmenopausal breast cancer risk for BRCA1 carriers (HR 1.20 per 5 kg/m2, 95% CI 1.02-1.42; and HR 1.10 per 5 kg weight gain, 95% CI 1.01-1.19, respectively).

CONCLUSION

Anthropometric measures are associated with breast cancer risk for BRCA1 and BRCA2 variant carriers, with relative risk estimates that are generally consistent with those for women from the general population.

Implant-Based Breast Reconstruction after Risk-Reducing Mastectomy in BRCA Mutation Carriers: A Single-Center Retrospective Study

Women with BRCA gene mutations have a higher lifetime risk of developing breast cancer. Furthermore, cancer is usually diagnosed at a younger age compared to the wild-type counterpart. Strategies for risk management include intensive surveillance or risk-reducing mastectomy. The latter provides a significant reduction of the risk of developing breast cancer, simultaneously ensuring a natural breast appearance due to the preservation of the skin envelope and the nipple-areola complex. Implant-based breast reconstruction is the most common technique after risk-reducing surgery and can be achieved with either a submuscular or a prepectoral approach, in one or multiple stages. This study analyzes the outcomes of the different reconstructive techniques through a retrospective review on 46 breasts of a consecutive, single-center case series. Data analysis was carried out with EpiInfo version 7.2. Results of this study show no significant differences in postoperative complications between two-stage tissue expander/implant reconstruction and direct-to-implant (DTI) reconstruction, with DTI having superior aesthetic outcomes, especially in the prepectoral subgroup. In our experience, the DTI prepectoral approach has proven to be a safe and less time-consuming alternative to the submuscular two-stage technique, providing a pleasant reconstructed breast and overcoming the drawbacks of subpectoral implant placement.

No Cancer Occurrences in 10-year Follow-up after Prophylactic Nipple-sparing Mastectomy

Prophylactic nipple-sparing mastectomies (NSM) have become increasingly common, although there is little long-term data on its efficacy in prevention of breast cancer. The objective of this study was to assess the incidence of breast cancer in a cohort of patients undergoing prophylactic NSM with a median follow-up of 10 years.

Methods

Patients receiving prophylactic NSM at a single institution from 2006 to 2019 were included in a retrospective nature. Patient demographics, genetic mutations, operative details, and specimen pathology were recorded, and all postoperative patient visits and documentation were screened for cancer occurrence. Descriptive statics were performed where appropriate.

Results

Two hundred eighty-four prophylactic NSMs were performed on 228 patients with a median follow-up of 120.5 ± 15.7 months. Roughly, a third of patients had a known genetic mutation, with 21% BRCA1 and 12% BRCA2. The majority (73%) of prophylactic specimens had no abnormal pathology. The most commonly observed pathologies were atypical lobular hyperplasia (10%) and ductal carcinoma in situ (7%). Cancer was identified in 10% of specimens, with only one case of lymphovascular invasion. Thus far, there have been no incidences of locoregional breast cancer occurrence in this cohort.

Conclusions

The long-term breast cancer occurrence rate in this cohort of prophylactic NSM patients at the time of this study is negligible. Despite this, continued surveillance of these patients is necessary until lifetime risk of occurrence following NSM has been established.

New, fast and cheap prediction tests for BRCA1 gene mutations identification in clinical samples

Despite significant progress in cancer therapy, cancer is still the second cause of mortality in the world. The necessity to make quick therapeutic decisions forces the development of procedures allowing to obtain a reliable result in a quick and unambiguous manner. Currently, detecting predictive mutations, including BRCA1, is the basis for effectively treating advanced breast cancer. Here, we present new insight on gene mutation detection. We propose a cheap BRCA1 mutation detection tests based on the surface plasmon resonance (SPR) or quartz crystal microbalance with energy dissipation (QCM-D) response changes recorded during a hybridization process of an oligonucleotide molecular probe with DNA fragments, with and without the BRCA1 mutation. The changes in the morphology of the formed DNA layer caused by the presence of the mutation were confirmed by atomic force microscopy. The unique property of the developed SPR and QCM tests is really short time of analysis: ca. 6 min for SPR and ca. 25 min for QCM. The proposed tests have been verified on 22 different DNA extracted from blood leukocytes collected from cancer patients: 17 samples from patients with various BRCA1 gene mutation variants including deletion, insertion and missense single-nucleotide and 5 samples from patients without any BRCA1 mutation. Our test is a response to the need of medical diagnostics for a quick, unambiguous test to identify mutations of the BRCA1 gene, including missense single-nucleotide (SNPs).

Inhibitors of Rho kinases (ROCK) induce multiple mitotic defects and synthetic lethality in BRCA2-deficient cells

The trapping of Poly-ADP-ribose polymerase (PARP) on DNA caused by PARP inhibitors (PARPi) triggers acute DNA replication stress and synthetic lethality (SL) in BRCA2-deficient cells. Hence, DNA damage is accepted as a prerequisite for SL in BRCA2-deficient cells. In contrast, here we show that inhibiting ROCK in BRCA2-deficient cells triggers SL independently from acute replication stress. Such SL is preceded by polyploidy and binucleation resulting from cytokinesis failure. Such initial mitosis abnormalities are followed by other M phase defects, including anaphase bridges and abnormal mitotic figures associated with multipolar spindles, supernumerary centrosomes and multinucleation. SL was also triggered by inhibiting Citron Rho-interacting kinase, another enzyme that, similarly to ROCK, regulates cytokinesis. Together, these observations demonstrate that cytokinesis failure triggers mitotic abnormalities and SL in BRCA2-deficient cells. Furthermore, the prevention of mitotic entry by depletion of Early mitotic inhibitor 1 (EMI1) augmented the survival of BRCA2-deficient cells treated with ROCK inhibitors, thus reinforcing the association between M phase and cell death in BRCA2-deficient cells. This novel SL differs from the one triggered by PARPi and uncovers mitosis as an Achilles heel of BRCA2-deficient cells.

Deregulated Metabolic Pathways in Ovarian Cancer: Cause and Consequence

Ovarian cancers are tumors that originate from the different cells of the ovary and account for almost 4% of all the cancers in women globally. More than 30 types of tumors have been identified based on the cellular origins. Epithelial ovarian cancer (EOC) is the most common and lethal type of ovarian cancer which can be further divided into high-grade serous, low-grade serous, endometrioid, clear cell, and mucinous carcinoma. Ovarian carcinogenesis has been long attributed to endometriosis which is a chronic inflammation of the reproductive tract leading to progressive accumulation of mutations. Due to the advent of multi-omics datasets, the consequences of somatic mutations and their role in altered tumor metabolism has been well elucidated. Several oncogenes and tumor suppressor genes have been implicated in the progression of ovarian cancer. In this review, we highlight the genetic alterations undergone by the key oncogenes and tumor suppressor genes responsible for the development of ovarian cancer. We also summarize the role of these oncogenes and tumor suppressor genes and their association with a deregulated network of fatty acid, glycolysis, tricarboxylic acid and amino acid metabolism in ovarian cancers. Identification of genomic and metabolic circuits will be useful in clinical stratification of patients with complex etiologies and in identifying drug targets for personalized therapies against cancer.

Use of Arabidopsis thaliana as a model to understand specific carcinogenic events: Comparison of the molecular machinery associated with cancer-hallmarks in plants and humans

Model organisms are fundamental in cancer research given that they rise the possibility to characterize in a quantitative-objective fashion the organisms as a whole in ways that are infeasible in humans. From this perspective, model organisms with short generation times and established protocols for genetic manipulation allow the understanding of basic biology principles that might guide carcinogenic onset. The cancer-hallmarks (CHs) approach, a modular perspective for cancer understanding, stands that underlying the variability among different cancer types, critical events support the carcinogenic origin and progression. Thus, CHs as interconnected genetic circuitry, have a causal effect over cancer biogenesis and might represent a comparison scaffold among model organisms to identify and characterize evolutionarily conserved modules to understand cancer. Nevertheless, the identification of novel cancer regulators by comparative genomics approaches relies on selecting specific biological processes or related signaling cascades that limit the type of detected regulators, even more, holistic analysis from a systemic perspective is absent. Similarly, although the plant Arabidopsis thaliana has been used as a model organism to dissect specific disease-associated mechanisms, given the evolutionary distance between plants and humans, a general concern about the utility of using A. thaliana as a cancer model persists. In the present research, we take advantage of the CHs paradigm as a framework to establish a functional systemic comparison between plants and humans, that allowed the identification not only of specific novel key genetic regulators, but also, biological processes, metabolic systems, and genetic modules that might contribute to the neoplastic transformation. We propose five cancer-hallmarks that overlapped in conserved mechanisms and processes between Arabidopsis and human and thus, represent mechanisms which study can be prioritized in A. thaliana as an alternative model for cancer research. Additionally, derived from network analyses and machine learning strategies, a new set of potential candidate genes that might contribute to neoplastic transformation is described. These findings postulate A. thaliana as a suitable model to dissect, not all, but specific cancer properties, highlighting the importance of using alternative complementary models to understand carcinogenesis.

Quantifying the effects of risk-stratified breast cancer screening when delivered in real time as routine practice versus usual screening: the BC-Predict non-randomised controlled study (NCT04359420)

BACKGROUND

Risk stratification as a routine part of the NHS Breast Screening Programme (NHSBSP) could provide a better balance of benefits and harms. We developed BC-Predict, to offer women when invited to the NHSBSP, which collects standard risk factor information; mammographic density; and in a sub-sample, a Polygenic Risk Score (PRS).

METHODS

Risk prediction was estimated primarily from self-reported questionnaires and mammographic density using the Tyrer-Cuzick risk model. Women eligible for NHSBSP were recruited. BC-Predict produced risk feedback letters, inviting women at high risk (≥8% 10-year) or moderate risk (≥5-<8% 10-year) to have appointments to discuss prevention and additional screening.

RESULTS

Overall uptake of BC-Predict in screening attendees was 16.9% with 2472 consenting to the study; 76.8% of those received risk feedback within the 8-week timeframe. Recruitment was 63.2% with an onsite recruiter and paper questionnaire compared to <10% with BC-Predict only (P < 0.0001). Risk appointment attendance was highest for those at high risk (40.6%); 77.5% of those opted for preventive medication.

DISCUSSION

We have shown that a real-time offer of breast cancer risk information (including both mammographic density and PRS) is feasible and can be delivered in reasonable time, although uptake requires personal contact. Preventive medication uptake in women newly identified at high risk is high and could improve the cost-effectiveness of risk stratification.

TRIAL REGISTRATION

Retrospectively registered with clinicaltrials.gov (NCT04359420).

Variant-specific Mendelian Risk Prediction Model

Many pathogenic sequence variants (PSVs) have been associated with increased risk of cancers. Mendelian risk prediction models use Mendelian laws of inheritance to predict the probability of having a PSV based on family history, as well as specified PSV frequency and penetrance (agespecific probability of developing cancer given genotype). Most existing models assume penetrance is the same for any PSVs in a certain gene. However, for some genes (for example, BRCA1/2), cancer risk does vary by PSV. We propose an extension of Mendelian risk prediction models to relax the assumption that risk is the same for any PSVs in a certain gene by incorporating variant-specific penetrances and illustrating these extensions on two existing Mendelian risk prediction models, BRCAPRO and PanelPRO. Our proposed BRCAPRO-variant and PanelPRO-variant models incorporate variant-specific BRCA1/2 PSVs through the region classifications. Due to the sparsity of the variant information we classify BRCA1/2 PSVs into three regions; the breast cancer clustering region (BCCR), the ovarian cancer clustering region (OCCR), and an other region. Simulations were conducted to evaluate the performance of the proposed BRCAPRO-variant model compared to the existing BRCAPRO model which assumes the penetrance is the same for any PSVs in BRCA1 (and respectively BRCA2). Simulation results showed that the BRCAPRO-variant model was well calibrated to predict region-specific BRCA1/2 carrier status with high discrimination and accuracy on the region-specific level. In addition, we showed that the BRCAPRO-variant model achieved performance gains over the existing risk prediction models in terms of calibration without loss in discrimination and accuracy. We also evaluated the performance of the two proposed models, BRCAPRO-variant and PanelPRO-variant, on a cohort of 1,961 families from the Cancer Genetics Network (CGN). We showed that our proposed models provide region-specific PSV carrier probabilities with high accuracy, while the calibration, discrimination and accuracy of gene-specific PSV carrier probabilities were comparable to the existing gene-specific models. As more variant-specific PSV penetrances become available, we have shown that Mendelian risk prediction models can be extended to integrate the additional information, providing precise variant or region-specific PSV carrier probabilities and improving future cancer risk predictions.

BRCA1 and BRCA2 germline mutation analysis from a cohort of 1267 patients at high risk for breast cancer in Brazil

We determined the frequency and mutational spectrum of BRCA1 and BRCA2 in a series of patients at high risk for developing breast cancer from Brazil. A total of 1267 patients were referred for BRCA genetic testing, and no obligation of fulfilling criteria of mutation probability methods for molecular screening was applied. Germline deleterious mutations in BRCA1/2 (i.e., pathogenic/likely pathogenic variants) were identified in 156 out of 1267 patients (12%). We confirm recurrent mutations in BRCA1/2, but we also report three novel mutations in BRCA2, not previously reported in any public databases or other studies. Variants of unknown significance (VUS) represent only 2% in this dataset and most of them were detected in BRCA2. The overall mutation prevalence in BRCA1/2 was higher in patients diagnosed with cancer at age > 35 years old, and with family history of cancer. The present data expand our knowledge of BRCA1/2 germline mutational spectrum, and it is a valuable clinical resource for genetic counseling and cancer management programs in the country.

Deoxycytidine kinase (dCK) inhibition is synthetic lethal with BRCA2 deficiency

BRCA2 is a well-established cancer driver in several human malignancies. While the remarkable success of PARP inhibitors proved the clinical potential of targeting BRCA deficiencies, the emergence of resistance mechanisms underscores the importance of seeking novel Synthetic Lethal (SL) targets for future drug development efforts. In this work, we performed a BRCA2-centric SL screen with a collection of plant-derived compounds from South America. We identified the steroidal alkaloid Solanocapsine as a selective SL inducer, and we were able to substantially increase its potency by deriving multiple analogs. The use of two complementary chemoproteomic approaches led to the identification of the nucleotide salvage pathway enzyme deoxycytidine kinase (dCK) as Solanocapsine's target responsible for its BRCA2-linked SL induction. Additional confirmatory evidence was obtained by using the highly specific dCK inhibitor (DI-87), which induces SL in multiple BRCA2-deficient and KO contexts. Interestingly, dCK-induced SL is mechanistically different from the one induced by PARP inhibitors. dCK inhibition generates substantially lower levels of DNA damage, and cytotoxic phenotypes are associated exclusively with mitosis, thus suggesting that the fine-tuning of nucleotide supply in mitosis is critical for the survival of BRCA2-deficient cells. Moreover, by using a xenograft model of contralateral tumors, we show that dCK impairment suffices to trigger SL in-vivo. Taken together, our findings unveil dCK as a promising new target for BRCA2-deficient cancers, thus setting the ground for future therapeutic alternatives to PARP inhibitors.

Obesity promotes breast epithelium DNA damage in women carrying a germline mutation in BRCA1 or BRCA2

Obesity, defined as a body mass index (BMI) ≥ 30, is an established risk factor for breast cancer among women in the general population after menopause. Whether elevated BMI is a risk factor for women with a germline mutation in BRCA1 or BRCA2 is less clear because of inconsistent findings from epidemiological studies and a lack of mechanistic studies in this population. Here, we show that DNA damage in normal breast epithelia of women carrying a BRCA mutation is positively correlated with BMI and with biomarkers of metabolic dysfunction. In addition, RNA sequencing showed obesity-associated alterations to the breast adipose microenvironment of BRCA mutation carriers, including activation of estrogen biosynthesis, which affected neighboring breast epithelial cells. In breast tissue explants cultured from women carrying a BRCA mutation, we found that blockade of estrogen biosynthesis or estrogen receptor activity decreased DNA damage. Additional obesity-associated factors, including leptin and insulin, increased DNA damage in human BRCA heterozygous epithelial cells, and inhibiting the signaling of these factors with a leptin-neutralizing antibody or PI3K inhibitor, respectively, decreased DNA damage. Furthermore, we show that increased adiposity was associated with mammary gland DNA damage and increased penetrance of mammary tumors in Brca1+/- mice. Overall, our results provide mechanistic evidence in support of a link between elevated BMI and breast cancer development in BRCA mutation carriers. This suggests that maintaining a lower body weight or pharmacologically targeting estrogen or metabolic dysfunction may reduce the risk of breast cancer in this population.

Diagnosis, Management, and Surveillance for Patients With PALB2, CHEK2, and ATM Gene Mutations

BACKGROUND

This study aims to capture clinical and surgical practice patterns of patients with deleterious mutations in partner and localizer of BRCA2 (PALB2), checkpoint kinase 2 (CHEK2) and ataxia telangiesctasia mutated (ATM) genes.

MATERIALS AND METHODS

This study is a retrospective chart review of patients with PALB2, CHEK2 or ATM mutations. Patient demographics, testing indications, management decisions, and surveillance strategies were recorded.

RESULTS

Sixty-two patients were found to have deleterious mutations: 14 (23%) with a PALB2 mutation, 30 (48%) with a CHEK2 mutation, and 18 (29%) patients with an ATM mutation. Thirty-one (50%) patients have a history of breast cancer. Twenty-three patients were diagnosed and treated prior to genetic testing while 8 patients learned of their mutation status and breast cancer diagnosis simultaneously. Of these 8 patients, 4 sought treatment at our institution, 3 underwent bilateral mastectomy, and 1 patient opted for lumpectomy and surveillance. Thirty-one patients had no history of breast cancer. After genetic diagnosis, 3 of the 9 patients who continued clinical follow-up proceeded with bilateral prophylactic mastectomy within 2 years. Clinical surveillance continued for 23 months on average.

CONCLUSION

Most patients who learned of their genetic and breast cancer diagnoses simultaneously underwent bilateral mastectomy, whereas only a third of patients without cancer opted for bilateral prophylactic mastectomy.