Publications by authors named "Xiaohong R Yang"

Background Increased mammographic density (MD) is a known breast cancer (BC) risk factor, but its influencing factors are unclear in Asian populations. This study examined the links between known BC risk factors and quantitatively measured MD in 7,351 Chinese women with non-malignant mammographic findings. Methods VolparaDensity software quantified volumetric MD measures: total breast (TBV), absolute dense (ADV), percent dense (PDV= ADV/TBV), and non-dense volumes (NDV= TBV-ADV).

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  • Normal tissues adjacent to breast tumors (NATs) may contain early signs of breast cancer development due to a phenomenon called field cancerization.
  • A study using advanced genomic techniques on samples from 43 breast cancer patients in Hong Kong revealed that NATs often had single-nucleotide variants (SNVs) in driver genes also found in tumor samples, but rarely had large-scale genomic changes.
  • The researchers identified different evolutionary patterns among NAT and tumor pairs, indicating distinct genomic characteristics and the influence of the tumor microenvironment on cancer development.
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  • Chordoma is a rare bone cancer affecting mainly adults, with an average diagnosis age of 45.5 years; it is most commonly found in the clivus, spinal column, and sacrum.
  • A large majority of patients (97.5%) underwent surgery, and many also received supplementary treatments; however, no significant cancer types appeared frequently among patients' families aside from the most common cancers.
  • Genomic analysis of tumor samples revealed recurrent mutations, notably in PIK3CA, and differences in genetic alterations based on the tumor location, indicating a complex relationship between tumor genetics and clinical outcomes.
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Background: Breast cancer is comprised of distinct molecular subtypes. Studies have reported differences in risk factor associations with breast cancer subtypes, especially by tumor estrogen receptor (ER) status, but their consistency across racial and ethnic populations has not been comprehensively evaluated.

Methods: We conducted a qualitative, scoping literature review using the Preferred Reporting Items for Systematic Reviews and Meta-analysis, extension for Scoping Reviews to investigate consistencies in associations between 18 breast cancer risk factors (reproductive, anthropometric, lifestyle, and medical history) and risk of ER-defined subtypes in women who self-identify as Asian, Black or African American, Hispanic or Latina, or White.

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Background: Breast cancer consists of distinct molecular subtypes. Studies have reported differences in risk factor associations with breast cancer subtypes, especially by tumor estrogen receptor (ER) status, but their consistency across racial and ethnic populations has not been comprehensively evaluated.

Methods: We conducted a qualitative, scoping literature review using the Preferred Reporting Items for Systematic Reviews and Meta-analysis, extension for Scoping Reviews to investigate consistencies in associations between 18 breast cancer risk factors (reproductive, anthropometric, lifestyle, and medical history) and risk of ER-defined subtypes in women who self-identify as Asian, Black or African American, Hispanic or Latina, or White.

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Background: Higher mammographic density (MD), a radiological measure of the proportion of fibroglandular tissue in the breast, and lower terminal duct lobular unit (TDLU) involution, a histological measure of the amount of epithelial tissue in the breast, are independent breast cancer risk factors. Previous studies among predominantly white women have associated reduced TDLU involution with higher MD.

Methods: In this cohort of 611 invasive breast cancer patients (ages 23-91 years [58.

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Unlabelled: Women of African descent have the highest breast cancer mortality in the United States and are more likely than women from other population groups to develop an aggressive disease. It remains uncertain to what extent breast cancer in Africa is reminiscent of breast cancer in African American or European American patients. Here, we performed whole-exome sequencing of genomic DNA from 191 breast tumor and non-cancerous adjacent tissue pairs obtained from 97 African American, 69 European American, 2 Asian American, and 23 Kenyan patients.

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Importance: Knowledge about the prevalence and tumor types of CDKN2A-related melanoma-astrocytoma syndrome (MAS) is limited and could improve disease recognition.

Objective: To estimate the prevalence and describe the tumor types of MAS.

Design, Setting, And Participants: This retrospective cohort study analyzed all available MAS cases from medical centers in the US (2 sites) and Europe (2 sites) and from biomedical population genomic databases (UK Biobank [United Kingdom], Geisinger MyCode [US]) between January 1, 1976, and December 31, 2020.

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  • A genome-wide study explored gene-environment interactions (G×E) to identify variants that could impact breast cancer risk, analyzing data from around 72,285 breast cancer cases and 80,354 controls.
  • Researchers found two specific SNP-risk factor pairs that showed a significant association with breast cancer risk, including variations related to adult height and age at menarche.
  • Overall, the study concluded that G×E interactions contribute minimally to the heritability of breast cancer and don't significantly enhance risk prediction for the disease.
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  • Polygenic risk scores (PRSs), derived from genome-wide association studies (GWASs), can enhance breast cancer risk evaluation but are primarily based on European populations.
  • This study analyzed the effectiveness of European-based PRS models in identifying breast cancer risk among Ashkenazi Jewish women in Israel using data from two cohorts.
  • Results indicated that these PRS models successfully identified Ashkenazi Jewish women at high risk for breast cancer, suggesting they could improve risk assessment in this group.
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  • * The study revealed significant variation in the prevalence of four common PTVs across different regions in Europe, with p.Gln1701* being most common in Northern Europe and p.Gly1906Alafs*12 most common in Southern Europe.
  • * Findings suggest that the distribution of rare PTVs is more heterogeneous in Southwestern and Central Europe compared to Northeastern Europe, which will aid in crafting targeted genetic testing for breast cancer in specific European populations.
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Tumor mutational signatures are informative for cancer diagnosis and treatment. However, targeted sequencing, commonly used in clinical settings, lacks specialized analytical tools and a dedicated catalogue of mutational signatures. Here, we introduce SATS, a scalable mutational signature analyzer for targeted sequencing data.

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Background: The immune landscape of breast cancer (BC) in patients from Sub Saharan Africa is understudied. Our aims were to describe the distribution of Tumour Infiltrating Lymphocytes (TILs) within the intratumoural stroma (sTILs) and the leading/invasive edge stroma (LE-TILs), and to evaluate TILs across BC subtypes with established risk factors and clinical characteristics in Kenyan women.

Methods: Visual quantification of sTILs and LE-TILs were performed on Haematoxylin and eosin -stained pathologically confirmed BC cases based on the International TIL working group guidelines.

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Background: Few studies have examined epigenetic age acceleration (AA), the difference between DNA methylation (DNAm) predicted age and chronological age, in relation to somatic genomic features in paired cancer and normal tissue, with less work done in non-European populations. In this study, we aimed to examine DNAm age and its associations with breast cancer risk factors, subtypes, somatic genomic profiles including mutation and copy number alterations and other aging markers in breast tissue of Chinese breast cancer (BC) patients from Hong Kong.

Methods: We performed genome-wide DNA methylation profiling of 196 tumor and 188 paired adjacent normal tissue collected from Chinese BC patients in Hong Kong (HKBC) using Illumina MethylationEPIC array.

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Background: Spitzoid morphology in familial melanoma has been associated with germline variants in , a telomere maintenance gene (TMG), suggesting a link between telomere biology and spitzoid differentiation.

Objective: To assess if familial melanoma cases associated with germline variants in TMG (, , , and ) commonly exhibit spitzoid morphology.

Methods: In this case series, melanomas were classified as having spitzoid morphology if at least 3 of 4 dermatopathologists reported this finding in ≥25% of tumor cells.

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  • - The study investigated the links between genetic variants in breast cancer susceptibility genes (besides BRCA1, BRCA2, and CHEK2) and risks of developing contralateral breast cancer (CBC) and breast cancer-specific survival (BCSS) in 34,401 women of European ancestry who had been diagnosed with breast cancer.
  • - Significant findings revealed that protein-truncating variants (PTVs) and certain missense variants (MSVs) in genes like BRCA1, BRCA2, TP53, CHEK2, and PALB2 were associated with higher CBC risk and negative impacts on BCSS, indicating that these genetic factors play a crucial role in cancer outcomes.
  • - The results showed minimal
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Evidence from literature, including the BRIDGES study, indicates that germline protein truncating variants (PTVs) in FANCM confer moderately increased risk of ER-negative and triple-negative breast cancer (TNBC), especially for women with a family history of the disease. Association between FANCM missense variants (MVs) and breast cancer risk has been postulated. In this study, we further used the BRIDGES study to test 689 FANCM MVs for association with breast cancer risk, overall and in ER-negative and TNBC subtypes, in 39,885 cases (7566 selected for family history) and 35,271 controls of European ancestry.

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Background: Low-frequency variants play an important role in breast cancer (BC) susceptibility. Gene-based methods can increase power by combining multiple variants in the same gene and help identify target genes.

Methods: We evaluated the potential of gene-based aggregation in the Breast Cancer Association Consortium cohorts including 83,471 cases and 59,199 controls.

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  • The study investigates the role of specific genes in pancreatic ductal adenocarcinoma (PDAC), particularly focusing on patients with germline pathogenic variants (GPVs) and those without.
  • Researchers analyzed data from 189 cancer predisposition genes through various statistical tests to find potential associations with PDAC in different patient groups.
  • Results indicate that certain genes show strong links to PDAC in GPV patients, while others emerge as new candidates for non-GPV patients, suggesting distinct genetic factors underlying PDAC in these populations.
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Background: Few studies have evaluated the relationship between CDKN2A germline pathogenic variants (GPV), transcript (p16/p14ARF) alteration, and cancer risk.

Methods: Standardized incidence ratios (SIRs) comparing cancer risk with the general population were calculated for 385 CDKN2A GPV carriers from 2 large cohorts (259 United States and 126 Swedish individuals) using Poisson regression; statistical significance was defined as P less than .002 (Bonferroni correction).

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Purpose: Chordoma is a rare bone tumor with a high recurrence rate and limited treatment options. The aim of this study was to identify molecular subtypes of chordoma that may improve clinical management.

Experimental Design: We conducted RNA sequencing in 48 tumors from patients with Chinese skull-base chordoma and identified two major molecular subtypes.

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Chordoma is a rare bone tumor with genetic risk factors largely unknown. We conducted a whole-exome sequencing (WES) analysis of germline DNA from 19 familial chordoma cases in five pedigrees and 137 sporadic chordoma patients and identified 17 rare germline variants in PALB2 and BRCA2, whose products play essential roles in homologous recombination (HR) and tumor suppression. One PALB2 variant showed disease cosegregation in a family with four affected people or obligate gene carrier.

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  • Reproductive factors, such as parity and breastfeeding, show varying associations with different subtypes of breast cancer, particularly distinguishing between estrogen receptor-positive and -negative types.
  • In a vast study involving over 23,000 cases and 71,000 controls, researchers used statistical methods to examine how these factors relate to intrinsic breast cancer subtypes like luminal A-like and triple-negative.
  • The findings revealed that parous women face a decreased risk of certain ER-positive breast cancers after a significant time post-birth, while they show an increased risk of triple-negative breast cancer, particularly soon after childbirth, indicating the complexity of reproductive biology's role in breast cancer risk.
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