Cancer Genetics and Epigenetics 2024, Vol.12, No.5, 279-293 http://medscipublisher.com/index.php/cge 281 2022). 3 Current Status of Genetic Diagnostic Technologies 3.1 Advances in Gene Sequencing Technologies Whole-genome sequencing (WGS) has revolutionized the field of genetic diagnostics by providing comprehensive insights into the cancer genome. For instance, WGS has been applied to triple-negative breast cancers (TNBCs) to classify tumors based on mutational signatures, revealing that 59% of TNBCs exhibit homologous-recombination-repair deficiency. This classification has significant prognostic value, as patients with high HRDetect scores showed better outcomes on adjuvant chemotherapy (Staaf et al., 2019). Additionally, WGS has been used in cancer genetics clinics to identify pathogenic variants in patients with and without BRCA1/2 mutations, demonstrating its potential to improve cancer risk diagnoses and patient care (Foley et al., 2014). Moreover, WGS and whole-transcriptome sequencing (WTS) have been benchmarked as diagnostic tools for acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL). These technologies allow for the simultaneous analysis of all genetic alterations, providing a comprehensive genome-wide characterization that surpasses traditional cytogenetics and targeted sequencing methods. This approach has proven effective in identifying chromosomal and molecular abnormalities relevant for disease stratification and prognostication (Haferlach et al., 2021; Cai, 2024). 3.2 Applications of gene chips and PCR in early detection of breast cancer Gene chips and polymerase chain reaction (PCR) technologies have been instrumental in the early detection of breast cancer. Gene chips, also known as DNA microarrays, enable the simultaneous analysis of thousands of genes, allowing for the identification of gene expression patterns associated with breast cancer. This technology has been used to develop gene expression profiles that can predict the likelihood of breast cancer recurrence and response to therapy, thereby aiding in personalized treatment planning. PCR, on the other hand, is a highly sensitive technique used to amplify specific DNA sequences. It has been widely used in the detection of BRCA1 and BRCA2 mutations, which are known to significantly increase the risk of breast cancer. The development of real-time PCR has further enhanced the sensitivity and specificity of this method, making it a valuable tool for early diagnosis. For example, PCR-based assays have been used to detect circulating tumor DNA (ctDNA) in the blood of breast cancer patients, providing a non-invasive method for monitoring disease progression and response to treatment. 3.3 Development and prospects of liquid biopsy techniques Liquid biopsy techniques, such as circulating tumor DNA (ctDNA) testing, represent a promising advancement in the early detection and monitoring of breast cancer. These techniques involve the analysis of ctDNA, which is shed by tumors into the bloodstream, providing a non-invasive method for detecting genetic alterations associated with cancer. For instance, WGS has been used to analyze ctDNA, revealing clinically relevant insights into the aetiology of familial breast cancers and identifying somatic mutational signatures that can guide treatment decisions (Nones et al., 2019). The clinical validation of WGS for cancer diagnostics has shown that this technology can provide comprehensive genomic profiling for the vast majority of patients, identifying actionable biomarkers and therapy options that may not be detected by standard molecular diagnostics (Samsom et al., 2022). Additionally, periodic reanalysis of WGS data has been shown to enhance the diagnostic yield, highlighting the potential of liquid biopsy techniques to improve the accuracy and timeliness of cancer diagnosis (Costain et al., 2018). As these technologies continue to evolve, they hold great promise for improving the early detection and personalized treatment of breast cancer. 4 BRCA Gene Mutation Detection and Early Diagnosis 4.1 Standardized procedures for BRCA1 and BRCA2 mutation detection Standardized procedures for detecting BRCA1 and BRCA2 mutations have evolved significantly with advancements in genetic testing technologies. Traditionally, Sanger sequencing was the primary method used for
RkJQdWJsaXNoZXIy MjQ4ODYzNQ==