Detection of Germline Mutations in Breast Cancer Patients with Clinical Features of Hereditary Cancer Syndrome Using a Multi-Gene Panel Test / Journal of the Korean Cancer Association, 대한암학회지

Purpose@#Hereditary cancer syndrome means that inherited genetic mutations can increase a person's risk of developing cancer. We assessed the frequency of germline mutations using an nextgeneration sequencing (NGS)–based multiple-gene panel containing 64 cancer-predisposing genes in Korean breast cancer patients with clinical features of hereditary breast and ovarian cancer syndrome (HBOC). @*Materials and Methods@#A total of 64 genes associated with hereditary cancer syndrome were selected for development of an NGS-based multi-gene panel. Targeted sequencing using the multi-gene panel was performed to identify germline mutations in 496 breast cancer patients with clinical features of HBOC who underwent breast cancer surgery between January 2002 and December 2017. @*Results@#Of 496 patients, 95 patients (19.2%) were found to have 48 deleterious germline mutations in 16 cancer susceptibility genes. The deleterious mutations were found in 39 of 250 patients (15.6%) who had breast cancer and another primary cancer, 38 of 169 patients (22.5%) who had a family history of breast cancer (≥ 2 relatives), 16 of 57 patients (28.1%) who had bilateral breast cancer, and 29 of 84 patients (34.5%) who were diagnosed with breast cancer at younger than 40 years of age. Of the 95 patients with deleterious mutations, 60 patients (63.2%) had BRCA1/2 mutations and 38 patients (40.0%) had non-BRCA1/2 mutations. We detected two novel deleterious mutations in BRCA2 and MLH1. @*Conclusion@#NGS-based multiple-gene panel testing improved the detection rates of deleterious mutations and provided a cost-effective cancer risk assessment.

Comprehensive Cancer Panel Sequencing Defines Genetic Diversity and Changes in the Mutational Characteristics of Pancreatic Cancer Patients Receiving Neoadjuvant Treatment

BACKGROUND/AIMS: Pancreatic ductal adenocarcinoma (PDA) is associated with an extremely poor prognosis. This study assessed the genetic diversity among patients with PDA and compared their mutational profiles before and after treatment. METHODS: Tumors and matched blood samples were obtained from 22 PDA patients treated with neoadjuvant chemoradiation therapy. The somatic mutations were analyzed with comprehensive cancer gene panel (CCP). In addition, the biopsy samples obtained at diagnosis and the surgically resected samples after treatment were compared for seven patients. The CCP provided formalin-fixed paraffin-embedded sample-compatible multiplexed target selection for 409 genes implicated in cancer. RESULTS: Assessments of the MLH1, MLH3, MSH2, and PMS2 genes showed that the four patients with the highest relative burdens of mutations harbored somatic mutations in at least three of these genes. Genes in the histone-lysine N-methyltransferase 2 (KMT2) family, such as KMT2D, KMT2A, and KMT2C, were frequently mutated in tumor samples. Survival was worse in patients with ARID1A gene mutations than those without ARID1A gene mutations. Mutation patterns were compared between tissue samples before and after neoadjuvant treatment in seven patients who underwent surgical resection. The allelic fraction of mutations in KRAS codon 12 was lower in the surgically resected samples than in the endoscopic ultrasonography-guided fine needle aspiration biopsy samples of six patients. The number of mutant alleles of the histone lysine methyltransferase gene WHSC1 also decreased after treatment. CONCLUSIONS: These results indicate that tumor tissue from PDA patients is genetically diverse and suggest that ARID1A mutations may be a potential prognostic marker for PDA.

Status of BRCA1/2 Genetic Testing Practices in Korea (2014)

BACKGROUND: The aim of this study was to investigate the status of BRCA1/2 genetic testing practices in Korea in 2014. METHODS: A structured questionnaire was provided to the specialist in charge of BRCA1/2 genetic testing via e-mail between 28 July and 10 August 2015. A total of 11 genetic testing professionals from 14 organizations responded to the survey that asked about the status of BRCA1/2 genetic testing in the year 2014. RESULTS: The average number of BRCA1/2 genetic tests executed was 192; 6 organizations had executed less than 100 tests, and 5 organizations had conducted more than 100 tests. The primary testing method used was Sanger sequencing (100%), and 2 institutes performed multiplex ligation-dependent probe amplification (MLPA). The analysis software differed across the various organizations, with Sequencher (81.81%), Seqscape (27.27%), and Codoncode Aligner (9.09%) reported as utilized. We found that the guidelines for the interpretation of the genetic tests were different at each institution. CONCLUSIONS: Although this study only examined the status of the 2014 BRCA1/2 genetic testing practices of 11 institutions, it illustrates the necessity for standardized genetic testing or interpretation guidelines in Korea.

Somatic Mutations from Whole Exome Sequencing Analysis of the Patients with Biliary Tract Cancer

Biliary tract cancer (BTC) is a rare cancer and is associated with a poor prognosis. To understand the genetic characteristics of BTC, we analyzed whole-exome sequencing data and identified somatic mutations in patients with BTC. Tumors and matched blood or normal samples were obtained from seven patients with cholangiocarcinoma who underwent surgical resection. We discovered inactivating mutations of tumor suppressor genes, including APC, TP53, and ARID1A, in three patients. Activating mutations of KRAS and NRAS were also identified. Our analyses identified somatic mutations in Korean patients with BTC

Induction Chemotherapy with Gemcitabine and Cisplatin Followed by Simultaneous Integrated Boost–Intensity Modulated Radiotherapy with Concurrent Gemcitabine for Locally Advanced Unresectable Pancreatic Cancer: Results from a Feasibility Study / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: This study assessed the feasibility and compliance of induction chemotherapy with gemcitabine and cisplatin followed by simultaneous integrated boost–intensity modulated radiotherapy (SIB-IMRT) with concurrent gemcitabine in patients with locally advanced unresectable pancreatic cancer. MATERIALS AND METHODS: In this trial, patients received induction chemotherapy consisting of gemcitabine (1,000 mg/m²) and cisplatin (25 mg/m²) on days 1, 8, and 15 of each treatment cycle. Patients were subsequently treated with gemcitabine (300 mg/m²/wk) during SIB-IMRT. The patients received total doses of 55 and 44 Gy in 22 fractions to planning target volume 1 and 2, respectively. As an ancillary study, digital polymerase chain reaction was performed to screen for the seven most common mutations in codons 12 and 13 of the KRAS oncogene of circulating cell free DNA (cfDNA). RESULTS: Forty-four patients were enrolled between 2012 and 2015. Of these, 33 (75%) completed the treatment. The most common toxicities during induction chemotherapy were grades 3 and 4 neutropenia (18.2%), grade 3 nausea (6.8%) and vomiting (6.8%). The most common toxicities during SIB-IMRT were grade 3 neutropenia (24.2%) and grade 3 anemia (12.1%). Ten patients (23%) underwent a curative resection after therapy. Median overall survival was significantly longer in patients who underwent curative resection (16.8 months vs. 11 months, p < 0.01). The median cfDNA concentration was significantly lower after treatment (108.5 ng/mL vs. 18.4 ng/mL, p < 0.001). CONCLUSION: Induction chemotherapy with gemcitabine and cisplatin followed by concurrent SIB-IMRT was well tolerated and active.

Clinically Significant Unclassified Variants in BRCA1 and BRCA2 genes among Korean Breast Cancer Patients / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: Unclassified variants (UVs) of BRCA1 and BRCA2 genes are not defined as pathogenic for breast cancer, and their clinical significance currently remains undefined. Therefore, this study was conducted to identify potentially pathogenic UVs by comparing their prevalence between breast cancer patients and controls. MATERIALS AND METHODS: A total of 328 breast cancer patients underwent BRCA1/2 genetic screening at the National Cancer Center of Korea. Genetic variants of BRCA genes that were categorized as unclassified according to the Breast Cancer Information Core database were selected based on allelic frequency, after which candidate variants were genotyped in 421 healthy controls. We also examined family members of the study participants. Finally, the effects of amino acid substitutions on protein structure and function were predicted in silico. RESULTS: Genetic tests revealed 33 UVs in BRCA1 and 47 in BRCA2. Among 15 candidates genotyped in healthy controls, c.5339T>C in BRCA1 and c.6029T>G, c.7522G>A in BRCA2 were not detected. Moreover, the c.5339T>C variant in the BRCA1 gene was detected in four patients with a family history of breast cancer. This nonsynonymous variant (Leu1780Pro) in the BRCA1 C-terminal domain was predicted to have an effect on BRCA1 protein structure/function. CONCLUSION: This study showed that comparison of genotype frequency between cases and controls could help identify UVs of BRCA genes that are potentially pathogenic. Moreover, ourfindings suggest that c.5339T>C in BRCA1 might be a pathogenic variant for patients and their families.

A Novel Germline Mutation in BRCA1 Causes Exon 20 Skipping in a Korean Family with a History of Breast Cancer / 한국유방암학회지

Germline mutations in the BRCA1 and BRCA2 genes are strong genetic factors for predispositions to breast, ovarian, and other related cancers. This report describes a family with a history of breast and ovarian cancers that harbored a novel BRCA1 germline mutation. A single nucleotide deletion in intron 20, namely c.5332+4delA, was detected in a 43-year-old patient with breast cancer. This mutation led to the skipping of exon 20, which in turn resulted in the production of a truncated BRCA1 protein that was 1773 amino acids in length. The mother of the proband had died due to ovarian cancer and had harbored the same germline mutation. Ectopically expressed mutant BRCA1 protein interacted with the BARD1 protein, but showed a reduced transcriptional function, as demonstrated by the expression of cyclin B1. This novel germline mutation in the BRCA1 gene caused familial breast and ovarian cancers.

Chromothripsis in Treatment Resistance in Multiple Myeloma

Multiple myeloma (MM) is a malignant disease caused by an abnormal proliferation of plasma cells, of which the prognostic factors include chromosomal abnormality, β-2 microglobulin, and albumin. Recently, the term chromothripsis has emerged, which is the massive but highly localized chromosomal rearrangement in response to a one-step catastrophic event. Many studies have shown an association of chromothripsis with the prognosis in several cancers; however, few studies have investigated it in MM. Here, we studied the association between chromothripsis-like patterns and treatment resistance or prognosis. First, we analyzed nine MM cell lines (U266, MM.1S, RPMI8226, KMS-11, KMS-12-BM, KMS-12-PE, KMS-28-BM, KMS-28-PE, and NCI-H929) and bone marrow samples of four patients who were diagnosed with MM by next-generation sequencing-based copy number variation analysis. The frequency of the chromothripsis-like pattern was observed in seven cell lines. We analyzed the treatment-induced chromothripsis-like patterns in KMS-12-BM and KMS-12-PE cells. As a result, breakpoints and chromothripsis-like patterns were increased after drug treatment in the relatively resistant KMS-12-BM. We further analyzed the patients’ results according to the therapeutic response, which was divided into sensitive and resistant, as suggested by the International Myeloma Working Group. The chromothripsis-like pattern was more frequently observed in the resistant group. In the sensitive group, the frequency of the chromothripsis-like pattern decreased after treatment, whereas the resistant group showed increased chromothripsis-like patterns after the treatment. These results suggest that the chromothripsis-like pattern is associated with treatment response in MM.

Nucleotide Excision Repair Gene ERCC2 and ERCC5 Variants Increase Risk of Uterine Cervical Cancer / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: Defects in the DNA damage repair process can cause genomic instability and play an important role in cervical carcinogenesis. The purpose of this study was to analyze the association of 29 candidate single nucleotide polymorphisms (SNPs) in genes in the DNA repair pathway, TP53, and TP53BP1 with the risk of cervical cancer. MATERIALS AND METHODS: Twenty-nine SNPs in four genes in the DNA repair pathway (ERCC2, ERCC5, NBS1, and XRCC1), TP53, and TP53BP1 were genotyped for 478 cervical cancer patients and 922 healthy control subjects, and their effects on cervical carcinogenesis were analyzed. RESULTS: The most significant association was found for rs17655 in ERCC5, with an age-adjusted p-value < 0.0001, for which a strong additive effect of the risk allele C was observed (odds ratio, 2.01 for CC to GG). On the other hand, another significant polymorphism rs454421 in ERCC2 showed a dominant effect (odds ratio, 1.68 for GA+AA to GG) with an age-adjusted p-value of 0.0009. The association of these polymorphisms remained significant regardless of the age of onset. The significant result for rs17655 was also consistent for subgroups of patients defined by histology and human papillomavirus (HPV) types. However, for rs454421, the association was observed only in patients with squamous cell carcinoma and non-HPV 18 type. CONCLUSION: The results of this study show a novel association of cervical cancer and the genes involved in the nucleotide excision pathway in the Korean population.

Interleukin-10 Polymorphisms in Association with Prognosis in Patients with B-Cell Lymphoma Treated by R-CHOP

Interleukin-10 (IL10) plays an important role in initiating and maintaining an appropriate immune response to non-Hodgkin lymphoma (NHL). Previous studies have revealed that the transcription of IL10 mRNA and its protein expression may be infl uenced by several single-nucleotide polymorphisms in the promoter and intron regions, including rs1800896, rs1800871, and rs1800872. However, the impact of polymorphisms of the IL10 gene on NHL prognosis has not been fully elucidated. Here, we investigated the association between IL10 polymorphisms and NHL prognosis. This study involved 112 NHL patients treated at the National Cancer Center, Korea. The median age was 57 years, and 70 patients (62.5%) were men. Clinical characteristics, including age, performance status, stage, and extra-nodal involvement, as well as cell lineage and International Prognostic Index (IPI), were evaluated. A total of four polymorphisms in IL10 with heterozygous alleles were analyzed for hazard ratios of overall survival (OS) and progression-free survival (PFS) using Cox proportional hazards regression analysis. Diffuse large B-cell lymphoma was the most common histologic type (n = 83), followed by T-cell lymphoma (n = 18), mantle cell lymphoma (n = 6), and others (n = 5). Cell lineage, IPI, and extra-nodal involvement were predictors of prognosis. In the additive genetic model results for each IL10 polymorphism, the rs1800871 and rs1800872 polymorphisms represented a marginal association with OS (p = 0.09 and p = 0.06) and PFS (p = 0.05 and p = 0.08) in B-cell lymphoma patients treated with rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP). These findings suggest that IL10 polymorphisms might be prognostic indicators for patients with B-cell NHL treated with R-CHOP.

Infrared spectroscopy characterization of normal and lung cancer cells originated from epithelium

The vibrational spectral differences of normal and lung cancer cells were studied for the development of effective cancer cell screening by means of attenuated total reflection infrared spectroscopy. The phosphate monoester symmetric stretching nus(PO3(2-)) band intensity at ~970 cm-1 and the phosphodiester symmetric stretching nus(PO2-) band intensity at ~1,085 cm-1 in nucleic acids and phospholipids appeared to be significantly strengthened in lung cancer cells with respect to the other vibrational bands compared to normal cells. This finding suggests that more extensive phosphorylation occur in cancer cells. These results demonstrate that lung cancer cells may be prescreened using infrared spectroscopy tools.