pubmed > TP53 > rb1

Balanced and unbalanced translocations in a multicentric series of 2,843 patients with chronic lymphocytic leukemia.
Chromosomal translocations in chronic lymphocytic leukemia (CLL) are very rare, and therefore systematic analysis of large series of cases are needed to allow the identification of recurrent rearrangements, breakpoints involved, and target genes. The aims of the present study were to identify new translocations and their clinical impact and to establish their frequency in a large cohort of 2,843 CLL patients. By conventional cytogenetics 250 translocations were identified in 215 (7.5%) patients, 186 (74%) were apparently balanced and 64 (26%) were unbalanced. All chromosomes were involved in translocations, except Y chromosome. The chromosomes more frequently translocated were in decreasing frequency chromosomes 14, 18, 13, 17, 1, 6, 2, 3, 8, and 11. Translocations were found in the karyotypes either as the unique chromosomal abnormality (27%), associated with another alteration (24%), or as a part of a complex karyotype (48%). A large proportion of rearranged breakpoints involved genes related to CLL such as IGH (14q32), RB1, MIR15A, MIR16-1 (13q14), BCL2 (18q21), IGL (22q11.2), TP53 (17p13), IRF4 (6p25-p23), ATM (11q22) and CDK6 (7q21). Overall, 76 novel CLL translocations were identified, including a recurrent t(8;11)(p21;q21-23). Whole-genome sequencing and/or copy-number microarray data of 24 cases with translocations confirmed all rearrangements, enabled refinement of 3 karyotypes and all breakpoints at gene level. The projected survival and time to first treatment significantly decreased linearly with the number of translocations. In summary, this study allowed to establish the frequency of translocations (7.5%) and to identify new translocations in a cohort of 2,843 CLL patients.
Publication Date: 2021-08-21
Journal: Genes, chromosomes & cancer

Two progressed malignant phyllodes tumors of the breast harbor alterations in genes frequently involved in other advanced cancers.
The genomic landscape of phyllodes tumors (PTs) of the breast is not well defined, especially in patients with advanced disease. To shed light on this topic, paired primary and progressed tumor samples from two patients with malignant PTs were subjected to next-generation sequencing (NGS) followed by functional analysis of genetic alterations using two prediction tools. The DNA of both the primary tumor and distant metastases of Patient 1 and the primary and recurrent tumor of Patient 2 were subjected to molecular profiling. NGS with the FoundationOne® assay was performed in a commercial molecular pathology laboratory. Two in silico prediction tools were used to estimate the pathogenicity of indicated genetic alterations. In total, 38 genomic alterations were detected, of which 11 were predicted to be probably benign. In Patient 1, 14 aberrations were identified in the primary tumor and 17 in pulmonary metastases, 12 of which were identical. In the primary and recurrent tumor of Patient 2, 17 and 15 sequence variants, respectively, were found, with 13 overlapping findings. Affected genes included seven (TP53, TERT, APC, ARID1A, EGFR, KMT2D, and RB1) of the top 10 most frequently altered genes in other advanced cancer entities, as well as four actionable therapeutic targets (EGFR, KIT, PDGFRA, and BRIP1). Of note, seven genes coding for receptor tyrosine kinases were affected: three in Patient 1 and four in Patient 2. Several genes (e.g. EPHA3, EPHA7, and EPHB1) were shown to be altered for the first time in PTs. The two progressed malignant PTs investigated here share some of the major genetic events occurring in other advanced cancers.
Publication Date: 2021-08-18
Journal: Orphanet journal of rare diseases

Clinical genomic profiling to identify actionable alterations for very early relapsed triple-negative breast cancer patients in the Chinese population.
Triple-negative breast cancer (TNBC) represents about 19% of all breast cancer cases in the Chinese population. Lack of targeted therapy contributes to the poorer outcomes compared with other breast cancer subtypes. Comprehensive genomic profiling helps to explore the clinically relevant genomic alterations (CRGAs) and potential therapeutic targets in very-early-relapsed TNBC patients. Formalin-fixed paraffin-embedded (FFPE) tumour tissue specimens from 23 patients with very-early-relapsed TNBC and 13 patients with disease-free survival (DFS) more than 36 months were tested by FoundationOne CDx (F1CDx) in 324 genes and select gene rearrangements, along with genomic signatures including microsatellite instability (MSI) and tumour mutational burden (TMB). In total, 137 CRGAs were detected in the 23 very-early-relapsed TNBC patients, averaging six alterations per sample. The mean TMB was 4 Muts/Mb, which was higher than that in non-recurrence patients, and is statistically significant. The top-ranked altered genes were TP53 (83%), PTEN (35%), RB1 (30%), PIK3CA (26%) and BRCA1 (22%). RB1 mutation carriers had shorter DFS. Notably, 100% of these patients had at least one CRGA, and 87% of patients had at least one actionable alteration. In pathway analysis, patients who carried a mutation in the cell cycle pathway were more likely to experience very early recurrence. Strikingly, we detected one patient with ERBB2 amplification and one patient with ERBB2 exon20 insertion, both of which were missed by immunohistochemistry (IHC). We also detected novel alterations of ROS1-EPHA7 fusion for the first time, which has not been reported in breast cancer before. The comprehensive genomic profiling can identify novel treatment targets and address the limited options in TNBC patients. Therefore, incorporating F1CDx into TNBC may shed light on novel therapeutic opportunities for these very-early-relapsed TNBC patients.
Publication Date: 2021-08-17
Journal: Annals of medicine

Circulating tumor cell heterogeneity in neuroendocrine prostate cancer by single cell copy number analysis.
Neuroendocrine prostate cancer is an aggressive variant of prostate cancer that may arise de novo or develop from pre-existing prostate adenocarcinoma as a mechanism of treatment resistance. The combined loss of tumor suppressors RB1, TP53, and PTEN are frequent in NEPC but also present in a subset of prostate adenocarcinomas. Most clinical and preclinical studies support a trans-differentiation process, whereby NEPC arises clonally from a prostate adenocarcinoma precursor during the course of treatment resistance. Here we highlight a case of NEPC with significant intra-patient heterogeneity observed across metastases. We further demonstrate how single-cell genomic analysis of circulating tumor cells combined with a phenotypic evaluation of cellular diversity can be considered as a window into tumor heterogeneity in patients with advanced prostate cancer.
Publication Date: 2021-08-14
Journal: NPJ precision oncology

Mixed Neuroendocrine/Non-neuroendocrine Neoplasm (MiNEN) of the Ovary Arising from Endometriosis: Molecular Pathology Analysis in Support of a Pathogenetic Paradigm.
Primary ovarian neuroendocrine neoplasms (Ov-NENs) are infrequent and mainly represented by well-differentiated forms (neuroendocrine tumors - NETs - or carcinoids). Poorly differentiated neuroendocrine carcinomas (Ov-NECs) are exceedingly rare and only few cases have been reported in the literature. A subset of Ov-NECs are admixed with non-neuroendocrine carcinomas, as it occurs in other female genital organs, as well (mostly endometrium and uterine cervix), and may be assimilated to mixed neuroendocrine/non-neuroendocrine neoplasms (MiNENs) described in digestive and extra-digestive sites. Here, we present a case of large cell Ov-NEC admixed with an endometrioid carcinoma of the ovary, arising in the context of ovarian endometriosis, associated with a uterine endometrial atypical hyperplasia (EAH). We performed targeted next-generation sequencing analysis, along with a comprehensive immunohistochemical study and FISH analysis for TP53 locus, separately on the four morphologically distinct lesions (Ov-NEC, endometrioid carcinoma, endometriosis, and EAH). The results of our study identified molecular alterations of cancer-related genes (PIK3CA, CTNNB1, TP53, RB1, ARID1A, and p16), which were present with an increasing gradient from preneoplastic lesions to malignant proliferations, both neuroendocrine and non-neuroendocrine components. In conclusion, our findings underscored that the two neoplastic components of this Ov-MiNEN share a substantially identical molecular profile and they progress from a preexisting ovarian endometriotic lesion, in a patient with a coexisting preneoplastic proliferation of the endometrium, genotypically and phenotypically related to the ovarian neoplasm. Moreover, this study supports the inclusion of MiNEN in the spectrum ovarian and, possibly, of all gynecological NENs, among which they are currently not classified.
Publication Date: 2021-08-04
Journal: Endocrine pathology

Analysis of Threshold Change of Tumor Mutation Burden in Gastric Cancer.
The purpose of this study was to investigate the change of tumor mutation burden (TMB) in gastric cancer (GC) and its relationship with prognosis. A total of 262 patients with GC from January 2018 to December 2019 were included in this study. All patients were in the advanced stage and were treated with surgical removal of D2 lymph nodes and dissection. Clinical data and gene expression profile data of the GC dataset in The Cancer Genome Atlas were collected. Patients were randomly divided into a high-level group and a low-level group according to the TMB of 8 mutations/Mb. TMB of GC was calculated based on cell mutation data. Cox regression model was used to evaluate the relationship between TMB and prognosis of GC patients. The total mutation rate of 262GC patients was 92.85%. The top 5 mutant genes were TP53, RB1, ARID1A, KMT2B, and RET. The expression level of TMB in GC patients was statistically significant with age, drinking history, and differentiation type. 94 of the 262 patients died, and 168 survived during the follow-up period. Patients with a high level of TMB had a worse prognosis than those with low level of TMB. The results of univariate and multivariate logistic analysis showed that the overall survival rate of GC patients was statistically significant with age, drinking history, clinical stage, differentiation type, and TMB. GC patients are often accompanied by changes in TMB, and its expression level is closely related to the degree of pathological differentiation, which is an independent factor affecting the prognosis of GC patients. High TMB value can evaluate the prognosis and provide a reference for the formulation of clinical treatment plans for GC patients.
Publication Date: 2021-08-03
Journal: Journal of oncology

The genomic landscape of 85 advanced neuroendocrine neoplasms reveals subtype-heterogeneity and potential therapeutic targets.
Metastatic and locally-advanced neuroendocrine neoplasms (aNEN) form clinically and genetically heterogeneous malignancies, characterized by distinct prognoses based upon primary tumor localization, functionality, grade, proliferation index and diverse outcomes to treatment. Here, we report the mutational landscape of 85 whole-genome sequenced aNEN. This landscape reveals distinct genomic subpopulations of aNEN based on primary localization and differentiation grade; we observe relatively high tumor mutational burdens (TMB) in neuroendocrine carcinoma (average 5.45 somatic mutations per megabase) with TP53, KRAS, RB1, CSMD3, APC, CSMD1, LRATD2, TRRAP and MYC as major drivers versus an overall low TMB in neuroendocrine tumors (1.09). Furthermore, we observe distinct drivers which are enriched in somatic aberrations in pancreatic (MEN1, ATRX, DAXX, DMD and CREBBP) and midgut-derived neuroendocrine tumors (CDKN1B). Finally, 49% of aNEN patients reveal potential therapeutic targets based upon actionable (and responsive) somatic aberrations within their genome; potentially directing improvements in aNEN treatment strategies.
Publication Date: 2021-07-31
Journal: Nature communications

Diagnosis and Molecular Profiles of Large Cell Neuroendocrine Carcinoma With Potential Targets for Therapy.
Large cell neuroendocrine carcinoma (LCNEC) together with small cell carcinoma (SCLC) and typical and atypical carcinoids form the group of pulmonary neuroendocrine tumors. LCNEC and SCLC are high-grade carcinomas. Although both can be found outside the thoracic cavity, they are most common in the lung. LCNEC differs from SCLC by morphologic pattern, and by cytological features such as nuclear size, nucleoli, chromatin pattern, but also by genetic differences. Originally thought to represent a single entity, it became evident, that three subgroups of LCNEC can be identified at the molecular level: a SCLC-like type with loss of retinoblastoma 1 gene (RB1) and TP53 mutations; a non-small cell lung carcinoma (NSCLC)-like type with wildtype RB1, TP53 mutation, and activating mutations of the phosphoinositol-3 kinase (PI3K-CA), or loss of PTEN; and a carcinoid-like type with MEN1 gene mutation. These subtypes can be identified by immunohistochemical staining for RB1, p53, and molecular analysis for PI3K and MEN1 mutations. These subtypes might also respond differently to chemotherapy. Immuno-oncologic treatment has also been applied to LCNEC, however, in addition to the evaluation of tumor cells the stroma evaluation seems to be important. Based on personal experiences with these tumors and available references this review will try to encompass our present knowledge in this rare entity and provoke new studies for better treatment of this carcinoma.
Publication Date: 2021-07-27
Journal: Frontiers in oncology

Differential impact of tumor suppressor gene (TP53, PTEN, RB1) alterations and treatment outcomes in metastatic, hormone-sensitive prostate cancer.
Altered tumor suppressor genes (TSG-alt) in prostate cancer are associated with worse outcomes. The prognostic value of TSG-alt in metastatic, hormone-sensitive prostate cancer (M1-HSPC) is unknown. We evaluated the effects of TSG-alt on outcomes in M1-HSPC and their prognostic impact by first-line treatment. We retrospectively identified patients with M1-HSPC at our institution treated with first-line androgen deprivation therapy plus docetaxel (ADT + D) or abiraterone acetate (ADT + A). TSG-alt was defined as any alteration in one or more TSG. The main outcomes were Kaplan-Meier-estimated progression-free survival (PFS) and overall survival, analyzed with the log-rank test. Clinical characteristics were compared with the χ We identified 97 patients with M1-HSPC: 48 (49%) with ADT + A and 49 (51%) with ADT + D. Of 96 patients with data available, 33 (34%) had 1 TSG-alt, 16 (17%) had 2 TSG-alt, and 2 (2%) had 3 TSG-alt. The most common alterations were in TP53 (36%) and PTEN (31%); 6% had RB1 alterations. Median PFS was 13.1 (95% CI, 10.3-26.0) months for patients with normal TSGs (TSG-normal) vs. 7.8 (95% CI, 5.8-10.5) months for TSG-alt (P = 0.005). Median PFS was lower for patients with TSG-alt vs TSG-normal for those with ADT + A (TSG-alt: 8.0 [95% CI, 5.8-13.8] months vs. TSG-normal: 23.2 [95% CI, 13.1-not estimated] months), but not with ADT + D (TSG-alt: 7.8 [95% CI, 5.7-12.9] months vs. TSG-normal: 9.5 [95% CI, 4.8-24.7] months). On multivariable analysis, only TSG-alt predicted worse PFS (hazard ratio, 2.37; 95% CI, 1.42-3.96; P < 0.001). The presence of TSG-alt outperforms clinical criteria for predicting early progression during first-line treatment of M1-HSPC. ADT + A was less effective in patients with than without TSG-alt. Confirmation of these findings may establish the need for inclusion of molecular stratification in treatment algorithms.
Publication Date: 2021-07-24
Journal: Prostate cancer and prostatic diseases

A hypoxia related long non-coding RNA signature could accurately predict survival outcomes in patients with bladder cancer.
Hypoxia plays a significant role in tumor progression. This study aimed to develop a hypoxia-related long noncoding RNA (lncRNA) signature for predicting survival outcomes of patients with bladder cancer (BC). The transcriptome and clinicopathologic data were downloaded from The Cancer Genome Atlas (TCGA) database. Univariate Cox regression analysis and Lasso regression analysis were used to screened lncRNAs. Ten lncRNAs were screened out and included into the hypoxia lncRNA signature. The risk score based on hypoxia lncRNA signature could accurately predict the survival outcomes of BC patients. Immune infiltration analysis showed that six types of immune cells had significant different infiltration. Tumor mutation burden (TMB) analysis showed that the risk scores between the wild types and the mutation types of TP53, FGFR3, and RB1 were significantly different. Gene Set Enrichment Analysis (GSEA) showed that cancer-associated pathways belonged to the high risk groups and immune-related signal pathways were enriched into the low risk group. Then, we constructed a predictive model with the risk score, age, and clinical stage, which showed a robust prognostic performance. An lncRNA-mRNA coexpression network was constructed, which contained 62 lncRNA-mRNA links among 10 lncRNAs and 40 related mRNAs. In summary, the hypoxia lncRNA signature could accurately predict prognosis, chemotherapy and immunotherapy response in patients with BC and was relevant to clinicopathologic parameters and immune cell infiltration.
Publication Date: 2021-07-21
Journal: Bioengineered

AR gene rearrangement analysis in liquid biopsies reveals heterogeneity in lethal prostate cancer.
Castration-resistant prostate cancer (CRPC) is driven by AR gene aberrations that arise during androgen receptor (AR)-targeted therapy. AR amplification and mutations have been profiled in circulating tumor cells (CTCs), but whether AR gene rearrangements can be assessed in CTCs is unknown. In this study, we leveraged CRPC cell lines with defined AR gene rearrangements to develop and validate a CTC DNA analysis approach that utilized whole genome amplification and targeted DNA-sequencing of AR and other genes important in CRPC. We tested the utility of this approach by analyzing matched CTC DNA and plasma cell-free DNA (cfDNA) from a case series of ten CRPC patients. One of ten CTC samples and two of ten cfDNA samples were positive for AR gene rearrangements. All AR gene rearrangements were discordant between matched liquid biopsy samples. One patient harbored separate AR gene rearrangements in CTC DNA and cfDNA, but concordant AR amplification and AR T878A mutation. This patient also displayed concordant loss of TP53 and PTEN, but the loss of RB1 in cfDNA only. The overall frequency of discordant alterations in these genes between matched CTC DNA and cfDNA was high. This study establishes the technical feasibility of analyzing structural rearrangements, mutations, and copy number variants in AR and other CRPC genes using two different sources of DNA from a single blood sample. Paired CTC DNA and cfDNA analysis may have utility for capturing the heterogeneity of genetic alterations in CRPC patients.
Publication Date: 2021-07-20
Journal: Endocrine-related cancer

Clinicopathological and genomic features in patients with head and neck neuroendocrine carcinoma.
Neuroendocrine carcinoma (NEC) of the head and neck is a rare type of malignancy, accounting for only 0.3% of all head and neck cancers, and its clinicopathological and genomic features have not been fully characterized. We conducted a retrospective analysis of 27 patients with poorly differentiated NEC of the head and neck seen at our institution over a period of 15 years. Patient characteristics, adopted therapies, and clinical outcomes were reviewed based on the medical records. Pathological analysis and targeted sequencing of 523 cancer-related genes were performed using evaluable biopsied/resected specimens based on the clinical data. The most common tumor locations were the paranasal sinus (33%) and the oropharynx (19%). Eighty-one percent of the patients had locally advanced disease. The 3-year overall survival rates in all patients and in the 17 patients with locally advanced disease who received multimodal curative treatments were 39% and 53%, respectively. Histologically, large cell neuroendocrine carcinoma was the predominant subtype (58% of evaluable cases), and the Ki-67 labeling index ranged from 59 to 99% (median: 85%). Next-generation sequencing in 14 patients identified pathogenic/likely pathogenic variants in TP53, RB1, PIK3CA-related genes (PREX2, PIK3CA, and PTEN), NOTCH1, and SMARCA4 in six (43%), three (21%), two (14%), two (14%), and one (7%) patients, respectively. Sequencing also detected the FGFR3-TACC3 fusion gene in one patient. The median value of the total mutational burden (TMB) was 7.1/Mb, and three patients had TMB ≥ 10. Regardless of the aggressive pathological features, our data revealed favorable clinical characteristics in the patients with locally advanced disease who received curative treatment. The lower TP53 and RB1 mutation prevalence rates compared to those described for small cell lung cancer suggests the biological heterogeneity of NEC in different parts of the body. Furthermore, the FGFR3-TACC3 fusion gene and mutations in genes encoding the components of the NOTCH and PI3K/AKT/mTOR pathways found in our study may be promising targets for NEC of the head and neck.
Publication Date: 2021-07-12
Journal: Modern pathology : an official journal of the United States and Canadian Academy of Pathology, Inc

Genomic Analysis Revealed Mutational Traits Associated with Clinical Outcomes in Osteosarcoma.
The limited understanding of correlation between genomic features and biological behaviors has impeded the therapeutic breakthrough in osteosarcoma (OS). This study aimed to reveal the correlation of mutational and evolutionary traits with clinical outcomes. We applied a case-based targeted and whole exome sequencing of eleven matched primary, recurrent and metastatic samples from three OS patients characterized by different clinical behaviors in local recurrence or systematic progression pattern. Extensive OS-associated driver genes were detected including TP53, RB1, NF1, PTEN, SPEN, CDKN2A. Oncogenic signaling pathways including cell cycle, TP53, MYC, Notch, WNT, RTK-RAS and PI3K were determined. MYC amplification was observed in the patient with shortest disease-free interval. Linear, branched or mixed evolutionary models were constructed in the three OS cases. A branched evolution with limited root mutation was detected in patient with shorter survival interval. ADAM17 mutation and HEY1 amplification were identified in OS happening dedifferentiation. Signatures 21 associated with microsatellite instability (MSI) was identified in OS patient with extra-pulmonary metastases. OS was characterized by complex genomic alterations. MYC aberration, limited root mutations, and a branched evolutionary model were observed in OS patient with relatively aggressive course. Extra-pulmonary metastases of OS might attribute to distinct mutational process pertaining to MSI. Further research in a larger number of people is needed to confirm these findings.
Publication Date: 2021-07-09
Journal: Cancer management and research

Coexistence of a secondary STRN-ALK, EML4-ALK double-fusion variant in a lung adenocarcinoma patient with EGFR mutation: a case report.
ALK-positive disease is characterized by the presence of ALK gene rearrangements that encode driver fusion oncoproteins. EML4-ALK fusion is regarded as the most common type in advanced nonsmall cell lung cancers. STRN-ALK is a novel ALK fusion partner in NSCLC and is considered sensitive to targeted therapy. However, there was no study regarding effective therapy for EML4-ALK and STRN-ALK double fusion variants in EGFR-resistant mutant lung cancer. TP53, RB1, and EGFR exon 21 L858R were found in tumor tissues and plasma from patients with capture-based NGS. After 3 months of gefitinib treatment, an NGS of plasma circulating tumor DNA showed that all variants disappeared significantly, and the tumor mass regressed on CT. However, after 10 months, the patient developed drug resistance and the disease progressed with the appearance of new metastatic lesions in the liver and bones. A repeated NGS test revealed EGFR exon20 T790M and the appearance of a novel double-fusion EML4-ALK and STRN-ALK. A combined therapeutic regimen of crizotinib plus osimertinib showed a promising prognosis confirmed with lung CT scans showing stable lesions without any new metastasis. Moreover, a subsequent genotype by NGS also showed the disappearance of STRN-ALK and EGFR exon20 T790M. The therapeutic efficacy of crizotinib plus osimertinib on EML4-ALK and STRN-ALK double-fusion variant in patients with EGFR-resistant mutant lung cancer may provide a supportive reference for the patients with such genetic alteration.
Publication Date: 2021-07-08
Journal: Anti-cancer drugs

Transdifferentiation of mantle cell lymphoma into sarcoma with limited neuromuscular differentiation after conventional chemotherapy.
We report an exceptionally rare case of mantle cell lymphoma (MCL) that transdifferentiated into sarcoma with limited neuromuscular differentiation. An 81-year-old man with t(11;14)-positive MCL was treated with rituximab and bendamustine and achieved complete remission; however, just 2 months later, the patient developed multiple systemic tumors. Pathologic studies revealed round cell sarcoma expressing synaptophysin, CD56, and myogenin without any B-cell markers. The CCND1 translocation and an identical IGL gene rearrangement were shared by both the MCL and sarcoma. Whole-exome sequencing detected 189 single nucleotide variants (SNVs) in the MCL and 205 SNVs in the sarcoma; 160 SNVs including NSD2, ATM, RB1, and TP53 mutations were shared between MCL and sarcoma cells. An additional PTPN11 mutation was specifically found in the sarcoma. These findings confirmed the shared clonal origin of MCL and sarcoma in this patient and indicated that MCL can transdifferentiate into sarcoma in rare cases.
Publication Date: 2021-07-07
Journal: Virchows Archiv : an international journal of pathology

Genetic profile of primary mucinous cystadenocarcinoma of the breast-A case report.
Primary mucinous cystadenocarcinoma of the breast is a rare neoplasm with few reports in the literature. Here, we report for the first time a comprehensive genetic profile of a primary mucinous cystadenocarcinoma of the breast, using next-generation sequencing 580 cancer-associated gene panel. Mutations in TP53, RB1, and BAP1 were identified. The findings suggest that this tumor is driven mostly by abnormalities in tumor suppressor genes, primarily involved in cell cycle control and chromatin remodeling. Molecular characterization of additional primary mucinous cystadenocarcinomas of the breast is warranted and might provide information related to its biology and behavior.
Publication Date: 2021-06-29
Journal: The breast journal

Dynamics of circulating tumor DNA during postoperative radiotherapy in patients with residual triple-negative breast cancer following neoadjuvant chemotherapy: a prospective observational study.
This study was performed to evaluate circulating tumor DNA (ctDNA) kinetics during postoperative radiotherapy (PORT) in patients with residual triple-negative breast cancer (TNBC) at surgery following neoadjuvant chemotherapy (NAC). Stage II/III patients with post-NAC residual TNBC who required PORT were prospectively included in this study between March 2019 and July 2020. For 11 TNBC patients, next-generation sequencing targeting 38 genes was conducted in 55 samples, including tumor tissue, three plasma samples, and leukocytes from each patient. The plasma samples were collected at three-time points; pre-PORT (T0), after 3 weeks of PORT (T1), and 1 month after PORT (T2). Serial changes in ctDNA variant allele frequency (VAF) were analyzed. Somatic variants were found in the tumor specimens in 9 out of 11 (81.8%) patients. Mutated genes included TP53 (n = 7); PIK3CA (n = 2); and AKT1, APC, CSMD3, MYC, PTEN, and RB1 (n = 1). These tumor mutations were not found in plasma samples. Plasma ctDNA variants were detected in three (27.3%) patients at T0. Mutations in EGFR (n = 1), CTNNB1 (n = 1), and MAP2K (n = 1) was identified with ctDNA analysis. In two (18.2%) patients, the ctDNA VAF decreased through T1 and T2 while increasing at T2 in one (9.1%) patient. After a median follow-up of 22 months, no patient showed cancer recurrence. Among patients with post-NAC residual TNBC, more than a quarter exhibited a detectable amount of ctDNA after curative surgery. The ctDNA VAF changed variably during the course of PORT. Therefore, ctDNA kinetics can serve as a biomarker for optimizing adjuvant treatment.
Publication Date: 2021-06-22
Journal: Breast cancer research and treatment

Prevalence of TP-53/Rb-1 Co-Mutation in Large Cell Neuroendocrine Carcinoma.
Large cell neuroendocrine carcinoma (LCNEC) is a rare and highly aggressive high-grade neuroendocrine neoplasm, which can arise from anywhere in the body. Due to its rarity there is a lacuna in our understanding of LCNEC's molecular biology. In 2016, Rekhtman and colleagues presented one of the largest molecular sequencing series of pulmonary LCNEC. They differentiated genomic profiles of LCNEC into two major subsets: small cell lung cancer (SCLC)-like, characterized by TP53 + RB1 co-mutation/loss, and non-small cell lung cancer (NSCLC)-like, characterized by the lack of co-altered TP53 + RB1. This finding is of significance because at present LCNEC patients are often treated like SCLC. However, the universal genomic SCLC biomarker of TP53 and RB1 co-mutation was only found in 40% of their cohort. Since then various other scientists have looked into molecular profiling of LCNEC with markedly discordant results. The objective of this study was to conduct a systematic review of publicly available next generation sequencing (NGS) data to evaluate the prevalence of TP53 + RB1 co-mutation in LCNEC. We conducted a literature search using PubMed. Seven studies including 302 patients with pulmonary LCNEC and four studies including 20 patients with extra-pulmonary LCNEC underwent final analysis. The prevalence of TP53 + RB1 co-mutation was 36% (109/302) among pulmonary LCNEC patients and 35% (7/20) among the extra-thoracic LCNEC cohort. This finding is in stark contrast to >90% TP53 + RB1 co-mutation in SCLC. It is now well established that LCNEC is molecularly distinct from SCLC. LCNEC seems to have two molecularly defined sub-cohort based on TP53 + RB1 co-mutation status. Future studies should look into prognostic and predictive implication of TP53 + RB1 co-mutation status in LCNEC. Prospective studies should be designed to characterize molecular subtypes and direct treatment accordingly. We are currently conducting a prospective pilot clinical trial wherein LCNEC patients are treated based on TP53 + RB1 co-mutation status. The study is currently enrolling. "Next Generation Sequencing-Based Stratification of Front Line Treatment of Neuroendocrine Carcinoma (PRECISION-NEC). ClinicalTrials.gov, identifier NCT04452292.
Publication Date: 2021-06-19
Journal: Frontiers in oncology

Uterine PEComas: correlation between melanocytic marker expression and TSC alterations/TFE3 fusions.
Uterine PEComas often present a diagnostic challenge as they share morphological and immunohistochemical features with smooth muscle tumors. Herein we evaluated a series of 19 uterine PEComas to compare the degree of melanocytic marker expression with their molecular profile. Patients ranged from 32-77 (median 48) years, with six tumors classified as malignant based on the modified gynecologic-specific prognostic algorithm. All patients with malignant PEComas were alive with disease or dead  of disease at last follow-up, while all those of uncertain malignant potential were alive and well (median follow-up, 47 months).Seventeen of 19 (89%) PEComas harbored either a TSC1 or TSC2 alteration. One of the two remaining tumors showed a TFE3 rearrangement, but the other lacked alterations in all genes evaluated. All showed at least focal (usually strong) positivity for HMB-45, with 15/19 (79%) having >50% expression, while the tumor lacking TSC or TFE3 alterations was strongly positive in 10% of cells. Melan-A and MiTF were each positive in 15/19 (79%) tumors, but staining extent and intensity were much more variable than HMB-45. Five of six (83%) malignant PEComas also harbored alterations in TP53, ATRX, or RB1, findings not identified in any tumors of uncertain malignant potential. One malignant PEComa was microsatellite-unstable/mismatch repair protein-deficient.In summary, TSC alterations/TFE3 fusions and diffuse (>50%) HMB-45 expression are characteristic of uterine PEComas. In morphologically ambiguous mesenchymal neoplasms with myomelanocytic differentiation, especially those with metastatic or recurrent disease, next-generation sequencing is recommended to evaluate for TSC alterations; as such, patients can be eligible for targeted therapy.
Publication Date: 2021-06-17
Journal: Modern pathology : an official journal of the United States and Canadian Academy of Pathology, Inc

Development and Validation of a Hypoxia-Related Signature for Predicting Survival Outcomes in Patients With Bladder Cancer.
This study aimed to develop and validate a hypoxia signature for predicting survival outcomes in patients with bladder cancer. We downloaded the RNA sequence and the clinicopathologic data of the patients with bladder cancer from The Cancer Genome Atlas (TCGA) (https://portal.gdc.cancer.gov/repository?facetTab=files) and the Gene Expression Omnibus (GEO) (https://www.ncbi.nlm.nih.gov/geo/) databases. Hypoxia genes were retrieved from the Molecular Signatures Database (https://www.gsea-msigdb.org/gsea/msigdb/index.jsp). Differentially expressed hypoxia-related genes were screened by univariate Cox regression analysis and Lasso regression analysis. Then, the selected genes constituted the hypoxia signature and were included in multivariate Cox regression to generate the risk scores. After that, we evaluate the predictive performance of this signature by multiple receiver operating characteristic (ROC) curves. The CIBERSORT tool was applied to investigate the relationship between the hypoxia signature and the immune cell infiltration, and the maftool was used to summarize and analyze the mutational data. Gene-set enrichment analysis (GSEA) was used to investigate the related signaling pathways of differentially expressed genes in both risk groups. Furthermore, we developed a model and presented it with a nomogram to predict survival outcomes in patients with bladder cancer. Eight genes (AKAP12, ALDOB, CASP6, DTNA, HS3ST1, JUN, KDELR3, and STC1) were included in the hypoxia signature. The patients with higher risk scores showed worse overall survival time than the ones with lower risk scores in the training set (TCGA) and two external validation sets (GSE13507 and GSE32548). Immune infiltration analysis showed that two types of immune cells (M0 and M1 macrophages) had a significant infiltration in the high-risk group. Tumor mutation burden (TMB) analysis showed that the risk scores between the wild types and the mutation types of TP53, MUC16, RB1, and FGFR3 were significantly different. Gene-Set Enrichment Analysis (GSEA) showed that immune or cancer-associated pathways belonged to the high-risk groups and metabolism-related signal pathways were enriched into the low-risk group. Finally, we constructed a predictive model with risk score, age, and stage and validated its performance in GEO datasets. We successfully constructed and validated a novel hypoxia signature in bladder cancer, which could accurately predict patients' prognosis.
Publication Date: 2021-06-15
Journal: Frontiers in genetics

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n 2(2)

stk11 smarcb1(2)

rb1 nf1(2)

pik3ca fbxw7(2)

tp53 tert(2)

cdh1 foxa1(2)

pik3ca ctnnb1(2)

2 6 33 3(1)

8 7(1)

tp53 gof mutations(1)

3 31(1)

p 0 007(1)

0 001 chisquare(1)

95 ci(1)

25 49 51 0(1)

3 25 12 0(1)

tp53 e204∗ pi3kca e545k(1)

ras braf(1)

rb1 n 2(1)

tp53 rb1 co-mutation(1)

braf 20 2(1)

cdk12 15 4(1)

c 376-161a g(1)

19 7(1)

pten 35(1)

apc csmd3(1)