Expansion of Cancer Risk Profile for BRCA1 and BRCA2 Pathogenic Variants

Hereditary Gastric Cancer Is Linked With Hereditary Breast and Ovarian Cancer

Background

Helicobacter pylori (H. pylori), a bacterium which chronically infects the stomach of approximately half the world's population, is a risk factor for the development of gastric cancer (GC). However, the underlying mechanism whereby H. pylori infection induces GC development remains unclear. Intermittent injection of the H. pylori cytotoxin-associated gene A antigen (CagA) protein into its host cell inhibits nuclear translocation of BRCA1/BRCA2, DNA repair proteins involved in the development of breast cancer/ovarian cancer. Interestingly, hereditary breast and ovarian cancer (HBOC) syndrome is associated with GC development. Here, we aimed to clarify the molecular link between H. pylori infection, BRCA1/2 pathogenic variants (PVs), GC and higher GC incidence in HBOC families.

Methods

We retrospectively reviewed data from Japanese patients undergoing precision treatment using cancer genomic medicine.

Results

We found a higher GC incidence in HBOC families having germline pathogenic variants (GPVs) of BRCA1/2 (2.95% vs. 0.78% in non-HBOC families). Next, we found that 96.1% of H. pylori-infected patients received cancer genomic medicine for advanced GC, and > 16% advanced GC patients had gBRCA2 PVs. Furthermore, expressing wild-type BRCA1/2 in Gan mice (a mouse model of human GC) inhibited GC development. Thus, gBRAC1/2 PVs and H. pylori infection synergistically increase the risk of GC development.

Conclusion

Our study highlights the need to investigate the potential of therapeutic agents against BRCA1/2 PVs to avoid the development of GC in HBOC families. In addition, our results suggest that poly (ADP-ribose) polymerase (PARP) inhibitors could potentially inhibit GC development and progression with gBRCA1/2 PVs.

Prevalence of H. pylori and Gastric Intestinal Metaplasia in BRCA1 and BRCA2 Carriers

BRCA1 and BRCA2 carriers may be at increased risk for gastric cancer; however, the mechanisms of gastric carcinogenesis remain poorly understood. We sought to determine the prevalence of gastric cancer risk factors Helicobacter pylori (H. pylori) infection and gastric intestinal metaplasia (GIM) among BRCA1/2 carriers to gain insight into the pathogenesis of gastric cancer in this population. A total of 100 unselected BRCA1/2 carriers who underwent endoscopic ultrasound from March 2022 to March 2023 underwent concomitant upper endoscopy with nontargeted gastric antrum and body biopsies. The study population (70% women; mean age 60.1 years) included 66% BRCA2 carriers. H. pylori was detected in one (1%) individual, 7 (7%) had GIM, 2 (2%) had autoimmune atrophic gastritis, and no gastric cancers were diagnosed. Among BRCA1/2 carriers, H. pylori prevalence was low and GIM prevalence was similar to that in the general population; however, identification of H. pylori or GIM may help inform future gastric cancer risk management strategies in BRCA1/2 carriers. Prevention Relevance: Evaluating the burden of H. pylori infection and GIM among BRCA1/2 carriers is warranted to better understand the mechanisms of gastric carcinogenesis and to help inform risk management strategies for gastric cancer among this at-risk population.

ALDH2 mutations and defense against genotoxic aldehydes in cancer and inherited bone marrow failure syndromes

Reactive aldehydes, for instance, formaldehyde and acetaldehyde, are important endogenous or environmental mutagens by virtue of their abilities to produce a DNA lesion called interstrand crosslink (ICL). Aldehyde-metabolizing enzymes such as aldehyde dehydrogenases (ALDHs) and the Fanconi anemia (FA) pathway constitute the main defense lines against aldehyde-induced genotoxicity. Biallelic mutations of genes in any one of the FA complementation groups can impair the ICL repair mechanism and cause FA, a heterogeneous disorder manifested by bone marrow failure (BMF), congenital abnormality and a strong predisposition to cancer. The defective ALDH2 polymorphism rs671 (ALDH2*2) is a known risk and prognostic factor for alcohol drinking-associated cancers. Recent studies suggest that it also promotes BMF and cancer development in FA, and its combination with alcohol dehydrogenase 5 (ADH5) mutations causes aldehyde degradation deficiency syndrome (ADDS), also known by its symptoms as aplastic anemia, mental retardation, and dwarfism syndrome. ALDH2*2 and another pathogenic variant in the alcohol-metabolizing pathway, ADH1B1*1, is prevalent among East Asians. Also, other ALDH2 genotypes with disease-modifying potentials have lately been identified in different populations. Therefore, it would be appropriate to summarize current knowledge of genotoxic aldehydes and defense mechanisms against them to shed new light on the pathogenic effects of ALDH2 variants together with other genetic and environmental modifiers on cancer and inherited BMF syndromes. Lastly, we also presented potential treatment strategies for FA, ADDS and cancer based on the manipulation of aldehyde-induced genotoxicity.

Characteristics of Chinese breast cancer patients with double heterozygosity for BRCA1 and BRCA2 germline pathogenic variants

PURPOSE

Despite of very rare, breast cancer patients with double heterozygosity (DH) variants in BRCA1 and BRCA2 genes have been identified in other ethnic groups and seem to be associated with distinctive phenotypes. However, little is known about the frequency and clinical characteristics of Chinese breast cancer patients with BRCA1/2 DH variants.

METHODS

Four hundred and eleven unrelated patients with BRCA1 or BRCA2 pathogenic variants (PVs) were identified in a large series of unselected breast cancer patients. Another two siblings with metachronous bilateral breast cancer were referred for genetic counseling, after which BRCA1/2 DH variants were detected.

RESULTS

Four unrelated breast cancer patients with BRCA1/2 DH were identified in the cohort of 411 patients with BRCA1 or BRCA2 PVs, the frequency of BRCA1/2 DH was 0.97%. In total, six BRCA1/2 DH patients from five families were found in this study. In two families, the hereditary pattern of DH was speculated to have originated from both sides of the family. BRCA1/2 DH patients were more likely to have a family history of breast cancer than patients with a BRCA1 (100% vs. 29.2%, P = 0.004) or BRCA2 (100% vs. 29.6%, P = 0.004) single PV. BRCA1/2 DH patients were more likely to be triple-negative breast tumors than patients with single BRCA2 PVs (66.7% vs. 14.1%, P = 0.020), which was comparable to the findings in patients with single BRCA1 PVs (66.7% vs. 56.9%, P = 1.00).

CONCLUSION

Chinese patients with BRCA1/2 DH exhibit a high percentage of family history of breast cancer. The tumor pathological features of BRCA1/2 DH carriers are similar to those of BRCA1 PV carriers.

Ovarian surveillance including endometrial cytology for patients with hereditary breast and ovarian cancer before risk-reducing salpingo-oophorectomy: A retrospective analysis

AIM

Ovarian surveillance in women with hereditary breast and ovarian cancer who do not undergo risk-reducing salpingo-oophorectomy has been controversial. Therefore, this study aimed to demonstrate the clinical features of ovarian surveillance at our institution using a technique that combines serum cancer antigen 125 measurements, transvaginal ultrasonography, and uterine endometrial cytology.

METHODS

We retrospectively examined 65 women, who had not undergone risk-reducing salpingo-oophorectomy diagnosed with hereditary breast and ovarian cancer between 2000 and 2021 at our hospital. Clinical information was obtained and analyzed through a chart review. The details of the treatment course were reviewed for patients who had developed ovarian cancer.

RESULTS

Overall, 5 of the 65 women were diagnosed with ovarian cancer based on abnormal findings during periodic surveillance. All patients who developed ovarian cancer were asymptomatic, even if the cancer was at an advanced stage. Two of the 65 patients had endometrial cytology abnormalities, both of whom had ovarian cancer. All patients who developed ovarian cancer underwent primary debulking surgery, and complete gross resection was achieved. None of the patients experienced ovarian cancer recurrence.

CONCLUSIONS

The ovarian surveillance strategy at our institution for women with hereditary breast and ovarian cancer who do not undergo risk-reducing salpingo-oophorectomy can identify asymptomatic ovarian cancer and contribute to achieving complete gross resection during primary surgery. Ovarian surveillance may contribute to a reduction in ovarian cancer mortality.

Site-agnostic PARP-inhibitor maintenance therapy of advanced stage BRCA2-mutated gastric-type endocervical adenocarcinoma: A case report

•Gastric-type endocervical adenocarcinomas (GEA) are rare, aggressive cancers with limited therapeutic options. •Although therapeutic effects of PARP-inhibitors in non-BRCA-associated cancers might be limited, clinical data is sparse. •Given limited treatment options and poor prognosis of GEA, somatic BRCA mutation testing, and PARP-inhibitor maintenance can be considered.

Familial and hereditary pancreatic cancer in Japan

As in Western countries, familial pancreatic cancer accounts for 5-7% of pancreatic cancer (PC) in Japan. Opportunities for diagnosing hereditary pancreatic cancer (HPC) are increasing owing to the coverage of companion diagnostics and cancer genomic profiling by national health insurance in patients with unresectable or recurrent PC refractory to standard chemotherapies. HPC is recognized in 7% of PCs and 15% of familial pancreatic cancer, including germline variants of BRCA1/2, ATM, PALB2, APC, and mismatch repair genes. Individuals with 5-fold or greater inherited risks of PC are recommended to undergo pancreatic surveillance according to Japanese guidelines. The imaging modalities for this surveillance include endoscopic ultrasound, magnetic resonance cholangiopancreatography, abdominal ultrasound, and enhanced computed tomography. Currently, a nationwide prospective surveillance study is ongoing in Japan. Platinum-based chemotherapy is an effective pancreatic cancer treatment in patients with variants of homologous recombination repair genes (BRCA1/2 and PALB2); however, the use of platinum regimens solely based on familial/personal cancer history remains controversial. The efficacy of olaparib maintenance therapy, as confirmed by the POLO study, has significantly impacted the clinical treatment of advanced PC patients in Japan. Since the initiation of precision cancer medicine in 2019, genetic medicine for PC patients has expanded in Japan.

The response of pancreatic acinar cell carcinoma to platinum and olaparib therapy in a germline BRCA2 variant carrier: case report and literature review

A 73-year-old Japanese man with a history of distal biliary cancer treated by pancreatoduodenectomy developed pancreatic acinar cell carcinoma (PACC) treated by remnant pancreatectomy and adjuvant chemotherapy. Thirteen months after surgery, multiple liver metastases developed and FOLFOX chemotherapy was initiated. Based on the PACC diagnosis and a positive family history for breast and ovarian cancer genetic testing was performed which revealed a pathogenic germline BRCA2 variant (c.8629G > T, p.Glu2877Ter). Olaparib therapy was initiated and the metastases responded well (partial response). PACC is a BRCA2-associated cancer which may respond well to PARP inhibitors.

Germline Pathogenic Variants in Patients With Pancreatic and Periampullary Cancers

PURPOSE

Inherited cancer susceptibility is often not suspected in the absence of a significant cancer family history. Pathogenic germline variants in pancreatic cancer are well-studied, and routine genetic testing is recommended in the guidelines. However, data on rare periampullary cancers other than pancreatic cancer are insufficient. We compared the prevalence of germline susceptibility variants in patients with pancreatic cancer and nonpancreatic periampullary cancers.

MATERIALS AND METHODS

Six hundred and eight patients who had undergone pancreaticoduodenal resection at a tertiary referral hospital were studied, including 213 with pancreatic ductal adenocarcinoma, 172 with ampullary cancer, 154 with distal common bile duct cancer, and 69 with duodenal adenocarcinoma. Twenty cancer susceptibility and candidate susceptibility genes were sequenced, and variant interpretation was assessed by interrogating ClinVar and PubMed.

RESULTS

Pathogenic or likely pathogenic, moderate- to high-penetrant germline variants were identified in 46 patients (7.7%), including a similar percentage of patients with pancreatic (8.5%) and nonpancreatic periampullary cancer (7.1%). Low-penetrant variants were identified in an additional 11 patients (1.8%). Eighty-nine percent of the moderate- to high-penetrant variants involved the major cancer susceptibility genes BRCA2, ATM, BRCA1, CDKN2A, MSH2/MLH1, and PALB2; the remaining 11% involved other cancer susceptibility genes such as BRIP1, BAP1, and MSH6. Almost all pathogenic variant carriers had a family history of cancer.

CONCLUSION

Patients with pancreatic and nonpancreatic periampullary cancer have a similar prevalence of pathogenic cancer susceptibility variants. Germline susceptibility testing should be considered for patients with any periampullary cancer.

High Frequency of BRCA2 c.5576_5579del Carriers in Kakogawa, Japan

Background/Aim

Certain germline pathogenic variants (PVs), known as founder mutations, have been frequently observed in specific regions and ethnic groups. In Japan, several pathogenic variants of BRCA1/2 have been identified as founder mutations, with their distribution varying across different regions. This retrospective study aimed to further investigate the detailed distribution and correlation between genotype and clinical features among breast cancer patients.

Patients and Methods

This study was conducted at Kobe University Hospital and three collaborating institutions. It included breast cancer patients who underwent BRCA1/2 genetic testing between July 1, 2018, and March 31, 2021, and were found to have germline PVs. Clinical characteristics and breast cancer subtypes were compared between carriers of BRCA2 c.5576_5579del and those with other PVs. Additionally, the detection rate of BRCA2 c.5576_5579del was compared with that observed in a previous report.

Results

A total of 38 breast cancer patients were included; PVs in BRCA1 and BRCA2 were detected in 12 and 26 patients, respectively, 12 of whom were BRCA2 c.5576_5579del carriers. BRCA2 c.5576_5579del carriers were more likely to develop triple negative breast cancers among all BRCA2 PV carriers. BRCA2 c.5576_5579del accounted for 30.8% of the PVs detected, with a particularly high frequency of 72.7% at Kakogawa Central City Hospital.

Conclusion

BRCA2 c.5576_5579del was detected with a particularly high frequency in Hyogo Prefecture, especially in Kakogawa city. In the future, a survey of the distribution of the BRCA2 c.5576_5579del carriers may provide more clarity regarding their localization.

The frequency and pathogenicity of BRCA1 and BRCA2 variants in the general Japanese population

Hereditary breast and ovarian cancer syndrome (HBOC) resulting from pathogenic variants of BRCA1 or BRCA2 is the most common and well-documented hereditary tumor. Although founder variants have been identified in population-based surveys in various countries, the types of variants are not uniform across races and regions. Recently, the Tohoku Medical Megabank Organization (ToMMo) released whole-genome sequence data including approximately 54,000 individuals from the general population of the Tohoku area in Japan. We analyzed these data and comprehensively identified the prevalence of BRCA1/2 pathogenic and truncating variants. We believe that an accurate understanding of the unique distribution and characteristics of pathogenic BRCA1/2 variants in Japan through this analysis will enable better surveillance and intervention for HBOC patients, not only in Japan but also worldwide.

Report of Cholangiocarcinoma With Transheterozygous BRCA1 and BRCA2 Co-mutation

Cholangiocarcinoma is an aggressive malignancy involving the epithelial cells of the intrahepatic, perihilar, or extrahepatic biliary tree. It is a disease that is often diagnosed late in its course and progresses quickly. Identifying genomic mutations may provide an important utility in predicting disease course and individualizing therapy for these patients. Mutations in BRCA1 or BCRCA2 genes have been increasingly documented in hepatobiliary malignancies, but they remain a relatively uncommon occurrence. Co-mutations in both BRCA1 and BRCA2 genes are even rarer, with no previously documented reports to our knowledge of BRCA co-positivity in a patient with a hepatobiliary malignancy. We present a case of a patient with cholangiocarcinoma found to have mutations in both BRCA1 and BRCA2 genes.

The Molecular Landscape of Gastric Cancers for Novel Targeted Therapies from Real-World Genomic Profiling

BACKGROUND

Panel-based comprehensive genomic profiling is used in clinical practice worldwide; however, large real-world datasets of patients with advanced gastric cancer are not well known.

OBJECTIVE

We investigated what differences exist in clinically relevant alterations for molecularly defined or age-stratified subgroups.

METHODS

This was a collaborative biomarker study of a real-world dataset from comprehensive genomic profiling testing (Foundation Medicine, Inc.). Hybrid capture was carried out on at least 324 cancer-related genes and select introns from 31 genes frequently rearranged in cancer. Overall, 4634 patients were available for analyses and were stratified by age (≥ 40/< 40 years), microsatellite instability status, tumor mutational burden status (high 10 ≥ /low < 10 Muts/Mb), Epstein-Barr virus status, and select gene alterations. We analyzed the frequency of alterations with a chi-square test with Yate's correction.

RESULTS

Genes with frequent alterations included TP53 (60.1%), ARID1A (19.6%), CDKN2A (18.2%), KRAS (16.6%), and CDH1 (15.8%). Differences in comprehensive genomic profiling were observed according to molecularly defined or age-stratified subgroups. Druggable genomic alterations were detected in 31.4% of patients; ATM (4.4%), BRAF V600E (0.4%), BRCA1 (1.5%), BRCA2 (2.9%), ERBB2 amplification (9.2%), IDH1 (0.2%), KRAS G12C (0.7%), microsatellite instability-high (4.8%), NTRK1/2/3 fusion (0.13%), PIK3CA mutation (11.4%), and tumor mutational burden-high (9.4%). CDH1 alterations and MET amplification were significantly more frequent in patients aged < 40 years (27.7 and 6.2%) than in those aged ≥ 40 years (14.7 and 4.0%).

CONCLUSIONS

Real-world datasets from clinical panel testing revealed the genomic landscape in gastric cancer by subgroup. These findings provide insights for the current therapeutic strategies and future development of treatments in gastric cancer.

Germline biallelic BRCA2 pathogenic variants and medulloblastoma: an international cohort study

Constitutional heterozygous pathogenic variants in genes coding for some components of the Fanconi anemia-BRCA signaling pathway, which repairs DNA interstrand crosslinks, represent risk factors for common cancers, including breast, ovarian, pancreatic and prostate cancer. A high cancer risk is also a main clinical feature in patients with Fanconi anemia (FA), a rare condition characterized by bone marrow failure, endocrine and physical abnormalities. The mainly recessive condition is caused by germline pathogenic variants in one of 21 FA-BRCA pathway genes. Among patients with FA, the highest cancer risks are observed in patients with biallelic pathogenic variants in BRCA2 or PALB2. These patients develop a range of embryonal tumors and leukemia during the first decade of life, however, little is known about specific clinical, genetic and pathologic features or toxicities. Here, we present genetic, clinical, pathological and treatment characteristics observed in an international cohort of eight patients with FA due to biallelic BRCA2 pathogenic variants and medulloblastoma (MB), an embryonal tumor of the cerebellum. Median age at MB diagnosis was 32.5 months (range 7-58 months). All patients with available data had sonic hedgehog-MB. Six patients received chemotherapy and one patient also received proton radiation treatment. No life-threatening toxicities were documented. Prognosis was poor and all patients died shortly after MB diagnosis (median survival time 4.5 months, range 0-21 months) due to MB or other neoplasms. In conclusion, MB in patients with biallelic BRCA2 pathogenic variants is a lethal disease. Future experimental treatments are necessary to help these patients.

Decoding triancestral origins, archaic introgression, and natural selection in the Japanese population by whole-genome sequencing

We generated Japanese Encyclopedia of Whole-Genome/Exome Sequencing Library (JEWEL), a high-depth whole-genome sequencing dataset comprising 3256 individuals from across Japan. Analysis of JEWEL revealed genetic characteristics of the Japanese population that were not discernible using microarray data. First, rare variant-based analysis revealed an unprecedented fine-scale genetic structure. Together with population genetics analysis, the present-day Japanese can be decomposed into three ancestral components. Second, we identified unreported loss-of-function (LoF) variants and observed that for specific genes, LoF variants appeared to be restricted to a more limited set of transcripts than would be expected by chance, with PTPRD as a notable example. Third, we identified 44 archaic segments linked to complex traits, including a Denisovan-derived segment at NKX6-1 associated with type 2 diabetes. Most of these segments are specific to East Asians. Fourth, we identified candidate genetic loci under recent natural selection. Overall, our work provided insights into genetic characteristics of the Japanese population.

Understanding familial risk of pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is a deadly disease that is the result of an accumulation of sequential genetic alterations. These genetic alterations can either be inherited, such as pathogenic germline variants that are associated with an increased risk of cancer, or acquired, such as somatic mutations that occur during the lifetime of an individual. Understanding the genetic basis of inherited risk of PDAC is essential to advancing patient care and outcomes through improved clinical surveillance, early detection initiatives, and targeted therapies. In this review we discuss factors associated with an increased risk of PDAC, the prevalence of genetic variants associated with an increased risk in patients with PDAC, estimates of PDAC risk in carriers of pathogenic germline variants in genes associated with an increased risk of PDAC. The role of common variants in pancreatic cancer risk will also be discussed.

HR-positive/HER2-negative breast cancer arising in patients with or without BRCA2 mutation: different biological phenotype and similar prognosis

Background

BRCA2 plays a key role in homologous recombination. However, information regarding its mutations in Chinese patients with breast cancer remains limited.

Objectives

This study aimed to assess the clinicopathological characteristics of BRCA2 mutation breast cancer and explore the mutation's effect on hormone receptor (HR)-positive/human epidermal growth factor receptor 2 (HER2)-negative breast cancer survival in China.

Design

This hospital-based cohort study prospectively included 629 women with breast cancer diagnosed from 2008 to 2023 at Zhejiang Cancer Hospital in China.

Methods

We compared the clinicopathological characteristics and metastatic patterns and analysed the invasive disease-free survival (iDFS), distant relapse-free survival (DRFS) and first-line progression-free survival (PFS1) of patients with HR-positive/HER2-negative breast cancer according to BRCA2 mutations.

Results

Among the 629 patients, 78 had BRCA2 mutations (12.4%) and 551 did not (87.6%). The mean age at diagnosis was lower in the BRCA2 mutation breast cancer group than in the non-mutation breast cancer group (38.91 versus 41.94 years, p = 0.016). BRCA2 mutation breast cancers were more likely to be lymph node-positive than non-mutation breast cancers (73.0% versus 56.6%, p = 0.037). The pathological grade was higher in 47.1% of BRCA2 mutation breast cancers than in 29.6% of non-mutation breast cancers (p = 0.014). The proportions of patients with BRCA2 mutations who developed contralateral breast cancer (19.2% versus 8.8%, p = 0.004), breast cancer in the family (53.8% versus 38.3%, p = 0.009) and ovarian cancer in the family (7.6% versus 2.4%, p = 0.022) were higher than those of patients without the mutation. The median follow-up time was 92.78 months. Multivariate analysis showed that BRCA2 mutation was not associated with poorer iDFS [hazard ratio = 0.9, 95% confidence interval (CI) = 0.64-1.27, p = 0.56] and poorer distant relapse-free survival (DRFS) (hazard ratio = 1.09, 95% CI = 0.61-1.93, p = 0.76). There was no significant difference between the two groups with regard to metastatic patterns in the advanced disease setting. In the first-line metastatic breast cancer setting, PFS1 expression was broadly similar between the two groups irrespective of chemotherapy or endocrine therapy.

Conclusion

HR-positive/HER2-negative breast cancer with BRCA2 mutations differs from those without mutations in clinical behaviour and reflects more aggressive tumour behaviour. Our results indicate that BRCA2 mutations have no significant effect on the survival of Chinese women with HR-positive/HER2-negative breast cancer.

Germline testing and genetic counseling in biliary tract cancer: an operative proposal to improve the state of art

INTRODUCTION

A genetic predisposition seems to be involved in biliary tract cancer, but the prevalence of germline mutations in BTC remains unclear, and the therapeutic role of the germline pathologic variants is still unknown.

AREA COVERED

The aim of the present work is to systematically review the data available on the hereditary predisposition of biliary tract cancer by a specific research on PubMed, in order to highlight the most important critical points and to define the current possible role of germinal testing and genetic counseling in this setting of patients.

EXPERT OPINION

Basing on data already available, we decided to start in our institution a specific genetic protocol focused on biliary tract cancer patients, which includes genetic counseling and, if indicated, germline test. The inclusion criteria are: 1) Patient with personal history of oncologic disease other than BTC, 2) Patient with familiar history of oncologic disease (considering relatives of first and second grade), 3) Patient with ≤ 50 years old, 4) Patient presenting a somatic mutation in genes involved in DNA damage repair pathways and mismatch repair. The aim of the presented protocol is to identify germline pathogenic variants with prophylactic and therapeutic impact, and to collect and integrate a significant amount of clinical, familial, somatic, and genetic data.

Risk-reducing decisions regarding germline BRCA pathogenic variant: focusing on the timing of genetic testing and RRSO

BACKGROUND

In Japan, the public insurance policy was revised in 2020 to cover hereditary breast and ovarian cancer (HBOC), including genetic testing and surveillance, for patients with breast cancer (BC). Consequently, the demand for risk-reducing salpingo-oophorectomy (RRSO) has increased. This study aimed to clarify the changes in the demand and timing of genetic testing and RRSO associated with public insurance coverage for HBOC in Japan.

METHODS

This retrospective analysis included 350 women with germline BRCA (gBRCA) pathogenic variants (PVs) who had visited gynaecologists; they received gBRCA genetic testing at 45.1±10.6 (20-74) years. The use of medical testing and preventive treatment was compared between the preinsurance and postinsurance groups using Mann-Whitney U and Fisher's exact tests.

RESULTS

The findings indicate that RRSO rates doubled from 31.4% to 62.6% among patients with gBRCA-PV. The implementation rate was 32.4% among unaffected carriers and 70.3% among BC-affected patients. Younger patients received genetic testing with significantly shorter intervals between BC diagnosis and genetic testing and between genetic testing and RRSO.

CONCLUSION

Overall, the insurance coverage for HBOC patients with BC has increased the frequency of RRSO in Japan. However, a comparison between the number of probands and family members indicated that the diagnosis among family members is inadequate. The inequality in the use of genetic services by socioeconomic groups is an issue of further concern.

Age-specific breast and ovarian cancer risks associated with germline BRCA1 or BRCA2 pathogenic variants - an Asian study of 572 families

Background

Clinical management of Asian BRCA1 and BRCA2 pathogenic variants (PV) carriers remains challenging due to imprecise age-specific breast (BC) and ovarian cancer (OC) risks estimates. We aimed to refine these estimates using six multi-ethnic studies in Asia.

Methods

Data were collected on 271 BRCA1 and 301 BRCA2 families from Malaysia and Singapore, ascertained through population/hospital-based case-series (88%) and genetic clinics (12%). Age-specific cancer risks were estimated using a modified segregation analysis method, adjusted for ascertainment.

Findings

BC and OC relative risks (RRs) varied across age groups for both BRCA1 and BRCA2. The age-specific RR estimates were similar across ethnicities and country of residence. For BRCA1 carriers of Malay, Indian and Chinese ancestry born between 1950 and 1959 in Malaysia, the cumulative risk (95% CI) of BC by age 80 was 40% (36%-44%), 49% (44%-53%) and 55% (51%-60%), respectively. The corresponding estimates for BRCA2 were 29% (26-32%), 36% (33%-40%) and 42% (38%-45%). The corresponding cumulative BC risks for Singapore residents from the same birth cohort, where the underlying population cancer incidences are higher compared to Malaysia, were higher, varying by ancestry group between 57 and 61% for BRCA1, and between 43 and 47% for BRCA2 carriers. The cumulative risk of OC by age 80 was 31% (27-36%) for BRCA1 and 12% (10%-15%) for BRCA2 carriers in Malaysia born between 1950 and 1959; and 42% (34-50%) for BRCA1 and 20% (14-27%) for BRCA2 carriers of the same birth cohort in Singapore. There was evidence of increased BC and OC risks for women from >1960 birth cohorts (p-value = 3.6 × 10-5 for BRCA1 and 0.018 for BRCA2).

Interpretation

The absolute age-specific cancer risks of Asian carriers vary depending on the underlying population-specific cancer incidences, and hence should be customised to allow for more accurate cancer risk management.

Funding

Wellcome Trust [grant no: v203477/Z/16/Z]; CRUK (PPRPGM-Nov20∖100002).

A novel approach to evaluation of tumor response for advanced pulmonary adenocarcinoma using the intertumoral heterogeneity response score

Treatment response and prognosis estimation in advanced pulmonary adenocarcinoma are challenged by the significant heterogeneity of the disease. The current Response Evaluation Criteria in Solid Tumors (RECIST) criteria, despite providing a basis for solid tumor response evaluation, do not fully encompass this heterogeneity. To better represent these nuances, we introduce the intertumoral heterogeneity response score (THRscore), a measure built upon and expanding the RECIST criteria. This retrospective study included patients with 3-10 measurable advanced lung adenocarcinoma lesions who underwent first-line chemotherapy or targeted therapy. The THRscore, derived from the coefficient of variation in size for each measurable tumor before and 4-6 weeks posttreatment, unveiled a correlation with patient outcomes. Specifically, a high THRscore was associated with shorter progression-free survival, lower tumor response rate, and a higher tumor mutation burden. These associations were further validated in an external cohort, confirming THRscore's effectiveness in stratifying patients based on progression risk and treatment response, and enhancing the utility of RECIST in capturing complex tumor behaviors in lung adenocarcinoma. These findings affirm the promise of THRscore as an enhanced tool for tumor response assessment in advanced lung adenocarcinoma, extending the RECIST criteria's utility.

BRCA1/2 reversion mutations in a pan-cancer cohort

Tumor sensitivity to platinum (Pt)-based chemotherapy and poly(adenosine diphosphate ribose) polymerase (PARP) inhibitors is increased by homologous recombination deficiency-causing mutations; in particular, reversion mutations cause drug resistance by restoring protein function. Treatment response is predicted by breast cancer susceptibility gene 1/2 (BRCA1/2) mutations; however, BRCA1/2 reversion mutations have not been comprehensively studied in pan-cancer cohorts. We aimed to characterize BRCA1/2 reversion mutations in a large pan-cancer cohort of Japanese patients by retrospectively analyzing sequencing data for BRCA1/2 pathogenic/likely pathogenic mutations in 3738 patients with 32 cancer types. We identified somatic mutations in tumors or circulating cell-free DNA that could restore the ORF of adverse alleles, including reversion mutations. We identified 12 (0.32%) patients with somatic BRCA1 (n = 3) and BRCA2 (n = 9) reversion mutations in breast (n = 4), ovarian/fallopian tube/peritoneal (n = 4), pancreatic (n = 2), prostate (n = 1), and gallbladder (n = 1) cancers. We identified 21 reversion events-BRCA1 (n = 3), BRCA2 (n = 18)-including eight pure deletions, one single-nucleotide variant, six multinucleotide variants, and six deletion-insertions. Seven (33.3%) reversion deletions showed a microhomology length greater than 1 bp, suggesting microhomology-mediated end-join repair. Disease course data were obtained for all patients with reversion events: four patients acquired mutations after PARP-inhibitor treatment failure, two showed somatic reversion mutations after disease progression, following Pt-based treatment, five showed mutations after both treatments, one patient with pancreatic cancer and BRCA1 reversion mutations had no history of either treatment. Although reversion mutations commonly occur in BRCA-associated cancers, our findings suggest that reversion mutations due to Pt-chemotherapy might be correlated with BRCA1/2-mediated tumorigenesis even in non-BRCA-associated histologies.

Germline BRCA2 variant with low variant allele frequency detected in tumor-only comprehensive genomic profiling

Germline BRCA1/2 variants in comprehensive genomic profiling (CGP) often exhibit variant allele frequency (VAF) exceeding 50%. However, when genomic loss occurs at the ipsilateral allele, including the germline variant in tumor cells, the VAF is low. This case report presents a patient with uterine sarcoma with a pathogenic BRCA2 mutation and low VAF in tumor-only CGP, which was later identified as a germline variant. When genomic alterations in BRCA1/2 are identified in tumor-only CGP, the possible germline origin of the variants should be considered, even if their VAF is very low.

Brca2(p.T1942fs/+) dissipates ovarian reserve in rats through oxidative stress in follicular granulosa cells

Pathogenic variants of BRCA1/2 constitute hereditary breast and ovarian cancer (HBOC) syndrome, and BRCA1/2 mutant is a risk for various cancers. Whereas the clinical guideline for HBOC patients has been organized for the therapy and prevention of cancer, there is no recommendation on the female reproductive discipline. Indeed, the role of BRCA1/2 pathogenic variants in ovarian reserve has not been established due to the deficiency of appropriate animal models. Here, we used a rat model of Brca2(p.T1942fs/+) mutant of Sprague-Dawley strain with CRISPR-Cas9 editing to evaluate ovarian reserve in females. Fertility and ovarian follicles were evaluated and anti-Müllerian hormone (AMH) was measured at 8-32 weeks of age with a comparison between the wild-type and the mutant rats (MUT). MUT revealed a significantly smaller number of deliveries with fewer total pups. Furthermore, MUT showed a significant decrease in primordial follicles at 20 weeks and a low AMH level at 28 weeks. RNA-sequencing of the ovary at 10 weeks detected acceleration of the DNA damage repair pathway, which was accompanied by oxidative stress-induced DNA double-strand breaks, a decrease in PTEN, and an increase in mTOR in follicular granulosa cells. In conclusion, Brca2(p.T1942fs/+) dissipates primordial follicles via early activation of granulosa cells through oxidative stress, leading to earlier termination of fertility.

Consensus Clustering Analysis Based on Enhanced-CT Radiomic Features: Esophageal Squamous Cell Carcinoma patients' 3-Year Progression-Free Survival

RATIONALE AND OBJECTIVES

To assess the efficacy of consensus cluster analysis based on CT radiomics in stratifying risk and predicting postoperative progression-free survival (PFS) in patients diagnosed with esophageal squamous cell carcinoma (ESC).

MATERIALS AND METHODS

We conducted a retrospective study involving 546 patients diagnosed with ESC between January 2016 and March 2021. All patients underwent preoperative enhanced CT examinations. From the enhanced CT images, radiomics features were extracted, and a consensus clustering algorithm was applied to group the patients based on these features. Statistical analysis was performed to examine the relationship between the clustering results and gene protein expression, histopathological features, and patients' 3-year PFS. We applied the Kruskal-Wallis test for continuous data, chi-square or Fisher's exact tests for categorical data, and the log-rank test for PFS.

RESULTS

This study identified four groups: Cluster 1 (n = 100, 18.3%), Cluster 2 (n = 197, 36.1%), Cluster 3 (n = 205, 37.5%), and Cluster 4 (n = 44, 8.1%). The cancer gene Breast Cancer Susceptibility Gene 1 (BRCA1) was most highly expressed in Cluster 4 (75%), showing significant differences between the four subtypes with a P-value of 0.035. The expression of programmed death-1 (PD-1) was highest in Cluster 1 (51%), with a P-value of 0.022. Vascular invasion occurred most frequently in Cluster 2 (28.9%), with a P-value of 0.022. The majority of patients with stage T3-4 were in Cluster 2 (67%), with a P-value of 0.003. Kaplan-Meier survival analysis revealed significant differences in PFS between the four groups (P = 0.013). Among them, patients in Cluster 1 had the best prognosis, while those in Cluster 2 had the worst.

CONCLUSION

This study highlights the effectiveness of consensus clustering analysis based on enhanced CT radiomics features in identifying associations between radiomics features, histopathological characteristics, and prognosis in different clusters. These findings provide valuable insights for clinicians in accurately and effectively evaluating the prognosis of esophageal cancer.

Clinical characterization of patients with gBRCA1/2 mutation-positive unresectable pancreatic cancer: a multicenter prospective study

BACKGROUND

Accumulating evidence has demonstrated platinum-based chemotherapy followed by maintenance therapy with a poly Adenosine diphosphate (ADP)-ribose polymerase inhibitor (olaparib) show benefits in unresectable pancreatic cancer with a germline (g)BRCA1/2 mutation. Evaluation of the germline BRCA1 and BRCA2 mutation is essential for making decisions on a treatment strategy for patients with unresectable pancreatic cancer. However, the detection rates of germline BRCA1 and BRCA2 mutations and efficacy of maintenance with olaparib remain undetermined, prospectively, in Japan.

METHODS & RESULTS

In this prospective analysis, the rate of germline BRCA1 and BRCA2 mutations and efficacy of chemotherapy were analyzed in 136 patients with pancreatic cancer who underwent BRACAnalysis® (85 patients) or FoundationOne® CDx (51 patients) between January 2020 and July 2022. A total of six patients (4.4%) had a germline BRCA1 and BRCA2 mutation. Five patients were treated with modified FOLFIRINOX and one with fluorouracil and oxaliplatin. All patients continued platinum-based chemotherapy for ˃4 months and were subsequently treated with olaparib as a maintenance therapy. The response rate to platinum-based chemotherapy in the germline BRCA1 and BRCA2 mutation-positive group was significantly better than that of the germline BRCA1 and BRCA2 mutation-negative group (66% vs 23%, P = 0.04). All patients harbouring a germline BRCA1 and BRCA2 mutation were able to switch to olaparib. The median progression-free survival using olaparib was 5.7 months (range 3.0-9.2).

CONCLUSIONS

The rate of germline BRCA1 and BRCA2 mutations found in patients with unresectable pancreatic cancer was comparable to those of previous studies.An analysis of germline BRCA1 and BRCA2 mutations has benefits for all patients with unresectable pancreatic cancer with regard to decisions on therapeutic strategies in a clinical practice setting.

Clinical features of germline BRCA1/2 or ATM pathogenic variant positive pancreatic cancer in Japan

BACKGROUND

There has been increasing interest into the role of germline BRCA1/2 pathogenic variants (gBRCA PV) and gATM PV and likely PV (PV and LPV; PV + LPV) in the carcinogenesis and treatment of pancreatic cancer (PC), but the clinical features have not been well described.

METHODS

Patients with confirmed gBRCA PV and gATM PV + LPV PC treated at our hospital between April 2016 and December 2021, were retrospectively evaluated for clinical characteristics and outcomes.

RESULTS

Twenty-two patients harbored gBRCA PV and three patients harbored gATM PV + LPV. Of the gBRCA PV patients, 81.8 % received platinum-based chemotherapy with favorable treatment outcomes with an objective response rate of 50.0 % (95 % CI: 23.0-77.0), median progression free survival (PFS) of 334 days, and median overall survival (OS) of 926 days from the initiation of first-line chemotherapy. The annual number of patients with gBRCA PV was two patients per year before January 2021 (when BRACAnalysis became available in Japan), and ten patients during the 10 months thereafter. Four patients (20 %) with gBRCA PV developed soft-tissue metastasis with progression. Two patients with gATM PV + LPV received platinum-based chemotherapy and the best response of those patients was partial response and stable disease and their OS from the initiation of first-line chemotherapy was 1192 and 989 days, and PFS was 579 and 140 days, respectively.

CONCLUSION

The diagnosis of gBRCA PV-positive PC has increased revealed in recent years. These tumors appear to be sensitive to platinum-based chemotherapy, with long term survival observed in gATM PV + LPV-positive patients.

Low-grade appendiceal mucinous neoplasm encountered during risk-reducing salpingo-oophorectomy: A case of laparoscopic surgery

Low-grade appendiceal mucinous neoplasm (LAMN) is a rare epithelial malignancy of the appendix. If it perforates the abdominal cavity, it can cause a serious clinical syndrome called pseudomyxoma peritonei. In the present case, we laparoscopically removed a LAMN encountered during risk-reducing salpingo-oophorectomy (RRSO). The patient was a 53-year-old woman who was diagnosed with hereditary breast and ovarian cancer syndrome. RRSO was planned, and magnetic resonance imaging revealed a large cystic tumor in the right lower abdomen. We expected an ovarian cyst; however, it was a primary tumor of the appendix. Partial cecal resection was performed laparoscopically by a surgical oncologist. The pathological diagnosis was LAMN. Gynecologists may encounter this disease incidentally. Mucinous appendiceal neoplasm (MAN) may be encountered during RRSO. If a right lower abdominal mass is found near a normal ovary preoperatively, gynecologists should consider MAN as well as paraovarian cyst.

Pathogenic Germline Variants in BRCA1/2 and p53 Identified by Real-world Comprehensive Cancer Genome Profiling Tests in Asian Patients

Cancer genome profiling (CGP) occasionally identifies pathogenic germline variants (PGV) in cancer susceptibility genes (CSG) as secondary findings. Here, we analyzed the prevalence and clinical characteristics of PGVs based on nationwide real-world data from CGP tests in Japan. We analyzed the genomic information and clinical characteristics of 23,928 patients with solid cancers who underwent either tumor-only (n = 20,189) or paired tumor-normal (n = 3,739) sequencing CGP tests between June 2019 and December 2021 using the comprehensive national database. We assigned clinical significance for all variants and highlighted the prevalence and characteristics of PGVs. Our primary analysis of the tumor-normal sequencing cohort revealed that 152 patients (4.1%) harbored PGVs in 15 CSGs. Among 783 germline variants, 113 were annotated as PGVs, 70 as benign variants, and 600 as variants of uncertain significance. The number of PGVs identified was highest in BRCA1/2, with 56, followed by TP53, with 18. PGVs were the most prevalent in ovarian and peritoneal cancers, including among cancer types common in Asia. In the tumor-only sequencing cohort, of the 5,184 pathogenic somatic variants across 26 CSGs, 784 (15.1%) were extracted according to the European Society for Medical Oncology recommendations for germline-focused tumor analysis. The prevalence of PGVs was similar to that previously reported in Europe and the United States. This is the largest analysis based on real-world tumor-normal sequencing tests in Asia. The more widespread use of the tumor-normal sequencing CGP test could be reasonable for evaluating PGVs.

SIGNIFICANCE

We analyzed real-world data from over 23,000 patients in Japan, revealing 4.1% harbored PGVs, particularly in BRCA1/2 and TP53, in CSGs. It highlights the prevalence of PGVs in Asian populations and supports the broader adoption of tumor-normal sequencing CGP tests for PGV evaluation.

Male awareness of prostate cancer risk remains poor in relatives of women with germline variants in DNA-repair genes

Abstract.

Objective

The aim of this study is to evaluate male awareness of developing prostate cancer (PCa) in families with germline DNA-repair genes (DRG) variants.

Materials and methods

Data were collected from a prospective, monocentric cohort study. The study was conducted in a university hospital with a multidisciplinary approach to the patient (collaboration of the Departments of Oncology, Urology, Pathology, Radiology, and Medical Genetics Laboratory). We recruited healthy males, relatives of families of women with breast or ovarian cancer who tested positive for pathogenic variants (PVs) or likely pathogenic variants (LPVs) in DRGs. A dedicated PCa screening was designed and offered to men aged 35 to 69 years, based on early visits with digital rectal examination (DRE), prostate health index (PHI) measurement, multiparametric magnetic resonance imaging (mpMRI) and, if necessary, targeted/systematic prostate biopsies. The primary endpoint was to evaluate the willingness of healthy men from families with a DRG variants detected in female relatives affected with breast and/or ovarian cancer to be tested for the presence of familial PVs. The secondary endpoints were the acceptance to participate if resulted positive and compliance with the screening programme.

Results

Over 1256 families, of which 139 resulted positive for PVs in DRGs, we identified 378 'healthy' men aged between 35 and 69 years old. Two hundred sixty-one (69.0%) refused to be tested for DRG variants, 66 (17.5%) declared to have been previously tested, and 51 (13.5%) males were interested to be tested. Between those previously tested and those who accepted to be tested, 62 (53.0%) were positive for a DRG variant, and all of them accepted to participate in the subsequent surveillance steps. The main limitation is that is a single-centre study and a short follow-up.

Conclusions

All men tested positive for a DRG variants agreed to go under the surveillance scheme. However, only 31% of 'men at risk' (i.e., relative of a DRG variant carrier) expressed their willingness to be tested for the familial DRG variant. This observation strongly supports the urgent need to implement awareness of genetic risk for PCa within the male population.

Personalized medicine with germline pathogenic variants: Importance of population- and region-wide evidence

Rare germline pathogenic variants in cancer-predisposing genes have a high impact and potential for clinical utility. In the last 30 years, based on evidence of cancer risk associated with germline pathogenic variants, several measures have been suggested for personalized medicine, including the development of novel treatments, treatment stratification, risk reduction by surgical measures, chemoprevention, removal of environmental factors, and surveillance for early detection among specific high-risk individuals. However, this evidence is mainly based on evaluations of European populations. Our large-scale analyses of more than 100,000 individuals, including 14 disease cases and non-cancer controls in the Japanese population, suggest some discrepancies in the associations between cancer-predisposing genes and diseases, expansion of the targeted diseases of BRCA1 and BRCA2, and a potential novel risk-reduction measure for gastric cancer. They are likely to be explained by population and region variations; therefore, more population-wide and region-wide research could provide improved personalized medicine as well as a better understanding of disease mechanisms. This review summarizes current personalized medicine and discusses the potential use of germline pathogenic variants.

The Role of Germline Mutations in Thoracic Malignancies: Between Myth and Reality

Considering the established contribution of environmental factors to the development of thoracic malignancies, the inherited susceptibility of these tumors has rarely been explored. However, the recent introduction of next-generation sequencing-based tumor molecular profiling in the real-word setting enabled us to deeply characterize the genomic background of patients with lung cancer with or without smoking-related history, increasing the likelihood of detecting germline mutations with potential prevention and treatment implications. Pathogenic germline variants have been detected in 2% to 3% of patients with NSCLC undergoing next-generation sequencing analysis, whereas the proportion of germline mutations associated with the development of pleural mesothelioma widely varies across different studies, ranging between 5% and 10%. This review provides an updated summary of emerging evidence about germline mutations in thoracic malignancies, focusing on pathogenetic mechanisms, clinical features, therapeutic implications, and screening recommendations for high-risk individuals.

Recurrent Tumor Suppressor Alterations in Primary Pericardial Mesothelioma

Primary pericardial mesotheliomas are extremely rare, accounting for <1% of all mesotheliomas, and their molecular genetic features and predisposing factors remain to be determined. Here, we report the clinicopathologic, immunohistochemical, and molecular genetic findings of 3 pericardial mesotheliomas without pleural involvement. Three cases diagnosed between 2004 and 2022 were included in the study and analyzed by immunohistochemistry and targeted next-generation sequencing (NGS); corresponding nonneoplastic tissue was sequenced in all cases. Two patients were female and 1 was male, aged between 66 and 75 years. Two patients each had prior asbestos exposure and were smokers. Histologic subtypes were epithelioid in 2 cases and biphasic in 1 case. Immunohistochemical staining identified expression of cytokeratin AE1/AE3 and calretinin in all cases, D2-40 in 2 cases, and WT1 in 1 case. Staining for tumor suppressors revealed loss of p16, MTAP, and Merlin (NF2) expression in 2 cases and loss of BAP1 and p53 in 1 case. Abnormal cytoplasmic BAP1 expression was observed in an additional case. Protein expression abnormalities correlated with NGS results, which showed concurrent complete genomic inactivation of CDKN2A/p16, CDKN2B, MTAP, and NF2 in 2 mesotheliomas and of BAP1 and TP53 in 1 mesothelioma each, respectively. In addition, 1 patient harbored a pathogenic BRCA1 germline mutation, which resulted in biallelic inactivation in the mesothelioma. All mesotheliomas were mismatch repair proficient and showed several chromosomal gains and losses. All patients died from disease. Our study demonstrates that pericardial mesotheliomas share common morphologic, immunohistochemical, and molecular genetic features with pleural mesothelioma, including recurrent genomic inactivation of canonical tumor suppressors. Our study adds new insights into the genetic landscape of primary pericardial mesothelioma and highlights BRCA1 loss as a potential contributing factor in a subset of cases, thereby contributing to refined precision diagnostics for this rare cancer.

New insights into the biology and development of lung cancer in never smokers-implications for early detection and treatment

Lung cancer is the leading cause of cancer deaths worldwide. Despite never smokers comprising between 10 and 25% of all cases, lung cancer in never smokers (LCNS) is relatively under characterized from an etiological and biological perspective. The application of multi-omics techniques on large patient cohorts has significantly advanced the current understanding of LCNS tumor biology. By synthesizing the findings of multi-omics studies on LCNS from a clinical perspective, we can directly translate knowledge regarding tumor biology into implications for patient care. Primarily focused on never smokers with lung adenocarcinoma, this review details the predominance of driver mutations, particularly in East Asian patients, as well as the frequency and importance of germline variants in LCNS. The mutational patterns present in LCNS tumors are thoroughly explored, highlighting the high abundance of the APOBEC signature. Moreover, this review recognizes the spectrum of immune profiles present in LCNS tumors and posits how it can be translated to treatment selection. The recurring and novel insights from multi-omics studies on LCNS tumor biology have a wide range of clinical implications. Risk factors such as exposure to outdoor air pollution, second hand smoke, and potentially diet have a genomic imprint in LCNS at varying degrees, and although they do not encompass all LCNS cases, they can be leveraged to stratify risk. Germline variants similarly contribute to a notable proportion of LCNS, which warrants detailed documentation of family history of lung cancer among never smokers and demonstrates value in developing testing for pathogenic variants in never smokers for early detection in the future. Molecular driver subtypes and specific co-mutations and mutational signatures have prognostic value in LCNS and can guide treatment selection. LCNS tumors with no known driver alterations tend to be stem-like and genes contributing to this state may serve as potential therapeutic targets. Overall, the comprehensive findings of multi-omics studies exert a wide influence on clinical management and future research directions in the realm of LCNS.

Clinical risk management of breast, ovarian, pancreatic, and prostatic cancers for BRCA1/2 variant carriers in Japan

Opportunities for genetic counseling and germline BRCA1/2 (BRCA) testing are increasing in Japan owing to cancer genomic profiling testing and companion diagnostics being covered by national health insurance for patients with BRCA-related cancers. These tests are useful not only to judge whether platinum agents and PARP inhibitors are indicated but also to reveal an autosomal-dominant inherited cancer syndrome: hereditary breast and ovarian cancer. In individuals with germline BRCA variants, risk of cancers of the breast, ovary, pancreas, and prostate is significantly increased at various ages of onset, but the stomach, uterus, biliary tract, and skin might also be at risk. For women with pathogenic BRCA variants, breast awareness and image analyses should be initiated in their 20s, and risk-reducing procedures such as mastectomy are recommended starting in their 30s, with salpingo-oophorectomy in their late 30s. For male BRCA pathogenic variant carriers, prostatic surveillance should be applied using serum prostate-specific antigen starting in their 40s. For both sexes, image examinations ideally using endoscopic ultrasound and magnetic resonance cholangiopancreatography and blood testing should begin in their 50s for pancreatic surveillance. Homologous recombination pathway-associated genes are also causative candidates. Variant pathogenicity needs to be evaluated every 6-12 months when results are uncertain for clinical significance. Genetic counseling needs to be offered to the blood relatives of the pathogenic variant carriers with suitable timing. We review the recommended cross-organ BRCA risk management in Japan.

It Is All in the Genes: A Story of Unexpected Survival in a 67-Year-Old Male with Metastatic Pancreatic Cancer

Background

We describe a case report of a 67-year-old male with PDAC who experienced an exceptional survival outcome during systemic therapy and its implications in precision medicine. We hypothesize that his outcomes are attributable, in part, to a germline BRCA2 deletion and somatic GNAS substitution.

Methods

Retrospective single-patient chart review was performed at the London Regional Cancer Program, as well as a structured literature search spanning all years in PubMed of BRCA and GNAS mutations in pancreatic cancer.

Results

The case described herein represents a 67-year-old male who survived over 27 months after third-line treatment with gemcitabine, docetaxel, and capecitabine (GTX) chemotherapy for metastatic PDAC after progression on gemcitabine and Abraxane and then on FOLFIRINOX. His survival far exceeded the median overall survival metrics. Genetic testing revealed a pathogenic heterozygous germline BRCA2 6643delT p.(Tyr2215Thrfs∗14) frameshift mutation and somatic GNAS 2531G > A p.(Arg844His) mutation.

Conclusions

This case highlights the urgent need to expand our knowledge of cancer biology to advance personalized cancer treatment and therapy development.

Global trends in BRCA-related breast cancer research from 2013 to 2022: A scientometric analysis

Introduction

Since the mid-2000s, breast cancer incidence among women has slowly increased at about 0.5% per year. In the last three decades, Breast Cancer Susceptibility Gene (BRCA) has been proven to be the crucial gene in encouraging the incidence and development of breast cancer. However, scientometric analysis on BRCA-related breast cancer is in shortage. Thus, to have a clear understanding of the current status and catch up with the hotspots, a scientometric analysis was conducted on specific academic publications collected from the Web of Science (WoS).

Methods

We searched the Web of Science Core Collection (WoSCC) to procure associated articles as our dataset. Bibliometric, CiteSpace, VOSviewer, and HistCite software were then applied to conduct visual analyses of countries, institutions, journals, authors, landmark articles, and keywords in this research field.

Results

A total of 7,266 articles and 1,310 review articles published between 2013 to 2022 were retrieved eventually. The annual output steadily rose year by year and peaked in 2021. The USA led the way in the number of published works, total citations, and collaboration. Breast Cancer Research and Treatment was the most favoured journal in this research field. Narod SA from the University of Toronto produced the most publications. At last, the most prominent keywords were "breast cancer" (n=1,778), "women" (n=1,369), "brca1" (n=1,276), "ovarian cancer" (n=1,259), "risk" (n=1,181), and "mutations" (n=929), which exposed the hotspots within the BRCA domain of breast cancer study.

Conclusion

The tendency in the BRCA research field over the past decade was presented by the scientometric analysis. The current research focus is the clinical trials of poly-adenosine diphosphate ribose polymerase inhibitors (PARPi) drugs and their resistance mechanisms.

Usefulness of BRCA and ctDNA as Prostate Cancer Biomarkers: A Meta-Analysis

Prostate cancer represents the most common male urologic neoplasia. Tissue biopsies are the gold standard in oncology for diagnosing prostate cancer. We conducted a study to find the most reliable and noninvasive diagnostic tool. We performed a systematic review and meta-analysis of two biomarkers which we believe are the most interesting: BRCA (BRCA1 and 2) and ctDNA. Our systematic research yielded 248 articles. Forty-five duplicates were first excluded and, upon further examination, a further 203 articles were excluded on the basis of the inclusion and exclusion criteria, leaving 25 articles. A statistical analysis of the obtained data has been performed. With a collective calculation, BRCA1 was expressed in 2.74% of all cases from 24,212 patients examined and BRCA2 in 1.96% of cases from 20,480 patients. In a total calculation using ctDNA, it was observed that 89% of cases from 1198 patients exhibited high expression of circulating tumor DNA. To date, no ideal PCa biomarker has been found. Although BRCA1 and BRCA2 work well for breast and ovarian cancers, they do not seem to be reliable for prostate cancer. ctDNA seems to be a much better biomarker; however, there are few studies in this area. Further studies need to be performed.

Roles of the PARP Inhibitor in BRCA1 and BRCA2 Pathogenic Mutated Metastatic Prostate Cancer: Direct Functions and Modification of the Tumor Microenvironment

Cancer cells frequently exhibit defects in DNA damage repair (DDR), leading to genomic instability. Mutations in DDR genes or epigenetic alterations leading to the downregulation of DDR genes can result in increased dependency on other DDR pathways. Therefore, DDR pathways could be a treatment target for various cancers. In fact, polyadenosine diphosphatase ribose polymerase (PARP) inhibitors, such as olaparib (Lynparza^®), have shown remarkable therapeutic efficacy against BRCA1/2-mutant cancers through synthetic lethality. Recent genomic analytical advancements have revealed that BRCA1/BRCA2 pathogenic variants are the most frequent mutations among DDR genes in prostate cancer. Currently, the PROfound randomized controlled trial is investigating the efficacy of a PARP inhibitor, olaparib (Lynparza^®), in patients with metastatic castration-resistant prostate cancer (mCRPC). The efficacy of the drug is promising, especially in patients with BRCA1/BRCA2 pathogenic variants, even if they are in the advanced stage of the disease. However, olaparib (Lynparza^®) is not effective in all BRCA1/2 mutant prostate cancer patients and inactivation of DDR genes elicits genomic instability, leading to alterations in multiple genes, which eventually leads to drug resistance. In this review, we summarize PARP inhibitors' basic and clinical mechanisms of action against prostate cancer cells and discuss their effects on the tumor microenvironment.

Relationship between homologous recombination deficiency and clinical features of breast cancer based on genomic scar score

BACKGROUND

Homologous recombination deficiency (HRD) phenotype will sensitize tumors to poly (ADP-ribose) polymerases inhibitors and platinum. However, previous studies did not focus on the prevalence of HRD among Chinese breast cancer (BC) patients.

METHODS

One hundred and forty-seven BC patients were included in this study. Their HRD status was assessed by Genomic Scar Score (GSS), which was determined according to the length, site, and type of copy number. HRD was defined as positive when a harmful BRCA1/2 mutation was detected or GSS ≥50.

RESULTS

Our data revealed that 9.5% of the 147 patients tested positive for BRCA1/2 mutation, while approximately 34.7% were HRD-positive. For triple negative BC (TNBC), HRD positivity rate (60.5%) was higher than Luminal A (5.3%), Luminal B (HER2-) (28.8%), and Luminal B (HER2+) (31.6%) subgroups. HRD-positive tumors were more likely to be ER/PR-negative and exhibited higher Ki-67 expression. 50.0% of the HRD-positive patients achieved pathologic complete remission (pCR) after neoadjuvant therapy. HRD-positive patients tended to have a higher risk for cancer recurrence or metastasis compared to HRD-negative patients (29.4% vs. 13.5%).

CONCLUSION

We investigated the HRD status among Chinese BC patients using an HRD detection tool developed based on the Chinese population. The clinical characteristics, pathological profile, family history pattern, neoadjuvant efficacy, and disease progression events of HRD-positive and negative patients were described and compared. Thus, our data provided an evidence-based basis for applying the original HRD assay in Chinese BC.

Association between homologous recombination gene variants and efficacy of oxaliplatin-based chemotherapy in advanced pancreatic cancer: prospective multicenter observational study

Next-generation sequencing (NGS)-based gene profiling can identify patients with pancreatic cancer with homologous recombinant repair gene pathogenic variants (HRRv). Several retrospective studies have reported a positive association between HRRv and the efficacy of platinum-based chemotherapy. However, this association remains to be validated in a prospective study. This multicenter, prospective, observational study included patients with histologically confirmed unresectable or recurrent pancreatic cancer who required systemic chemotherapy. Patients who were oxaliplatin-naïve patients were eligible. The HRRv status was measured using a College of American Pathologists-accredited NGS panel. One-year overall survival rate (1yr-OS%) was calculated after initiation of oxaliplatin-based chemotherapy and was set as the primary endpoint. Forty patients were enrolled between August 2018 and March 2020. The NGS success rate was 95% (38/40). HRRv was detected in 11 patients (27.5%). Oxaliplatin-based chemotherapy was administered to 9 of 11 patients with HRRv (81.8%) and 15 of 29 patients with non-HRRv (51.7%). The 1yr-OS% after initiation of oxaliplatin-based chemotherapy was 44.4% [95% confidence interval (CI) 13.7-71.9] and 57.1% (95% CI 28.4-78.0) in HRRv-positive and -negative cohorts, respectively. These data suggested that HRRv status alone could not be a potential predictive marker of oxaliplatin-based chemotherapy in patients with advanced pancreatic cancer. These results were in line with the results of a recent phase II study reporting the limited efficacy of poly(adenosine diphosphate-ribose) polymerase inhibitor in patients with pancreatic cancer who harbored HRRv other than BRCA. Future studies investigating patients with biallelic HRRv in the first-line setting are warranted.Trial registration UMIN000033655.

Helicobacter pylori, Homologous-Recombination Genes, and Gastric Cancer

BACKGROUND

Helicobacter pylori infection is a well-known risk factor for gastric cancer. However, the contribution of germline pathogenic variants in cancer-predisposing genes and their effect, when combined with H. pylori infection, on the risk of gastric cancer has not been widely evaluated.

METHODS

We evaluated the association between germline pathogenic variants in 27 cancer-predisposing genes and the risk of gastric cancer in a sample of 10,426 patients with gastric cancer and 38,153 controls from BioBank Japan. We also assessed the combined effect of pathogenic variants and H. pylori infection status on the risk of gastric cancer and calculated the cumulative risk in 1433 patients with gastric cancer and 5997 controls from the Hospital-based Epidemiologic Research Program at Aichi Cancer Center (HERPACC).

RESULTS

Germline pathogenic variants in nine genes (APC, ATM, BRCA1, BRCA2, CDH1, MLH1, MSH2, MSH6, and PALB2) were associated with the risk of gastric cancer. We found an interaction between H. pylori infection and pathogenic variants in homologous-recombination genes with respect to the risk of gastric cancer in the sample from HERPACC (relative excess risk due to the interaction, 16.01; 95% confidence interval [CI], 2.22 to 29.81; P = 0.02). At 85 years of age, persons with H. pylori infection and a pathogenic variant had a higher cumulative risk of gastric cancer than noncarriers infected with H. pylori (45.5% [95% CI, 20.7 to 62.6] vs. 14.4% [95% CI, 12.2 to 16.6]).

CONCLUSIONS

H. pylori infection modified the risk of gastric cancer associated with germline pathogenic variants in homologous-recombination genes. (Funded by the Japan Agency for Medical Research and Development and others.).

Ethnic-specificity, evolution origin and deleteriousness of Asian BRCA variation revealed by over 7500 BRCA variants derived from Asian population

Pathogenic variation in BRCA1 and BRCA2 (BRCA) causes high risk of breast and ovarian cancer, and BRCA variation data are important markers for BRCA-related clinical cancer applications. However, comprehensive BRCA variation data are lacking from the Asian population despite its large population size, heterogenous genetic background and diversified living environment across the Asia continent. We performed a systematic study on BRCA variation in Asian population including extensive data mining, standardization, annotation and characterization. We identified 7587 BRCA variants from 685 592 Asian individuals in 40 Asia countries and regions, including 1762 clinically actionable pathogenic variants and 4915 functionally unknown variants (https://genemutation.fhs.um.edu.mo/Asian-BRCA/). We observed the highly ethnic-specific nature of Asian BRCA variants between Asian and non-Asian populations and within Asian populations, highlighting that the current European descendant population-based BRCA data is inadequate to reflect BRCA variation in the Asian population. We also provided archeological evidence for the evolutionary origin and arising time of Asian BRCA variation. We further provided structural-based evidence for the deleterious variants enriched within the functionally unknown Asian BRCA variants. The data from our study provide a current view of BRCA variation in the Asian population and a rich resource to guide clinical applications of BRCA-related cancer for the Asian population.

Preoperative screening endometrial cytology discovered incidental gynaecological malignancy in two patients undergoing risk-reducing salpingo-oophorectomy

Pelvic ultrasonography and measurement of serum cancer antigen 125 (CA-125) are recommended for preoperative evaluation before performing risk-reducing salpingo-oophorectomy (RRSO). We report our experience with two patients in whom an incidental gynaecological malignancy was found using endometrial cytology as a preoperative screening test for RRSO. Patient 1 was an early 50s woman with a pathologic variant of BRCA1 Transvaginal ultrasonography showed no endometrial abnormalities, but preoperative endometrial cytology revealed high-grade serous carcinoma. The patient underwent total hysterectomy, bilateral adnexectomy, pelvic and para-aortic lymph node dissection, and omentectomy. Patient 2 was a late 40s woman with a pathological variant of BRCA1 Transvaginal ultrasonography showed mild enlargement of the left ovary, and her CA-125 level was elevated. Preoperative endometrial cytology revealed high-grade serous cancer. She underwent total hysterectomy, bilateral adnexectomy and omentectomy. These case reports illustrate the importance of preoperative screening-including endometrial cytology-before performing RRSO.

Cancer risk in relatives of BRCA1/2 pathogenic variant carriers in a large series of unselected patients with breast cancer

OBJECTIVE

The spectrum and risk of cancer in relatives of BRCA1/2 pathogenic variant carriers in the Chinese population have not been established.

METHODS

A family history of cancer in 9903 unselected breast cancer patients was retrospectively analyzed. BRCA1/2 status was determined for all patients and relative risks (RRs) were calculated to evaluate cancer risk in relatives of the patients.

RESULTS

The incidences of breast cancer in female relatives of BRCA1 carriers, BRCA2 carriers, and non-carriers were 33.0%, 32.2%, and 7.7%, respectively. The corresponding incidences of ovarian cancer were 11.5%, 2.4%, and 0.5%, respectively. The incidences of pancreatic cancer in male relatives of BRCA1 carriers, BRCA2 carriers, and non-carriers were 1.4%, 2.7%, and 0.6%, respectively. The corresponding incidences of prostate cancer were 1.0%, 2.1%, and 0.4%, respectively. The risks of breast and ovarian cancers in female relatives of BRCA1 and BRCA2 carriers were significantly higher than female relatives of non-carriers (BRCA1: RR = 4.29, P < 0.001 and RR = 21.95, P < 0.001; BRCA2: RR = 4.19, P < 0.001 and RR = 4.65, P < 0.001, respectively). Additionally, higher risks of pancreatic and prostate cancers were noted in male relatives of BRCA2 carriers than non-carriers (RR = 4.34, P = 0.001 and RR = 4.86, P = 0.001, respectively).

CONCLUSIONS

Female relatives of BRCA1 and BRCA2 carriers are at increased risk for breast and ovarian cancers, and male relatives of BRCA2 carriers are at increased risk for pancreatic and prostate cancers.

Risks of second non-breast primaries following breast cancer in women: a systematic review and meta-analysis

BACKGROUND

Second primary cancer incidence is rising among breast cancer survivors. We examined the risks of non-breast second primaries, in combination and at specific cancer sites, through a systematic review and meta-analysis.

METHODS

We conducted a systematic search of PubMed, Embase, and Web of Science, seeking studies published by March 2022. We included studies that reported standardized incidence ratios (SIRs), with associated standard errors, assessing the combined risk of second non-breast primaries following breast cancer. We performed meta-analyses of combined second primary risks, stratifying by age, follow-up duration, and geographic region. We also assessed second primary risks at several specific sites, stratifying by age. The inverse variance method with DerSimonian-Laird estimators was used in all meta-analyses, assuming a random-effects model. Associated biases and study quality were evaluated using the Newcastle-Ottawa scale.

RESULTS

One prospective and twenty-seven retrospective cohort studies were identified. SIRs for second non-breast primaries combined ranged from 0.84 to 1.84. The summary SIR estimate was 1.24 (95% CI 1.14-1.36, I2: 99%). This varied by age: the estimate was 1.59 (95% CI 1.36-1.85) when breast cancer was diagnosed before age 50, which was significantly higher than in women first diagnosed at 50 or over (SIR: 1.13, 95% CI 1.01-1.36, p for difference: < 0.001). SPC risks were also significantly higher when based on Asian, rather than European, registries (Asia-SIR: 1.47, 95% CI 1.29-1.67. Europe-SIR: 1.16, 95% CI 1.04-1.28). There were significantly increased risks of second thyroid (SIR: 1.89, 95% CI 1.49-2.38), corpus uteri (SIR: 1.84, 95% CI 1.53-2.23), ovary (SIR: 1.53, 95% CI 1.35-1.73), kidney (SIR: 1.43, 95% CI 1.17-1.73), oesophagus (SIR: 1.39, 95% CI 1.26-1.55), skin (melanoma) (SIR: 1.34, 95% CI 1.18-1.52), blood (leukaemia) (SIR: 1.30, 95% CI 1.17-1.45), lung (SIR: 1.25, 95% CI 1.03-1.51), stomach (SIR: 1.23, 95% CI 1.12-1.36) and bladder (SIR: 1.15, 95% CI 1.05-1.26) primaries.

CONCLUSIONS

Breast cancer survivors are at significantly increased risk of second primaries at many sites. Risks are higher for those diagnosed with breast cancer before age 50 and in Asian breast cancer survivors compared to European breast cancer survivors. This study is limited by a lack of data on potentially confounding variables. The conclusions may inform clinical management decisions following breast cancer, although specific clinical recommendations lie outside the scope of this review.