Distinct clinical and somatic mutational features of breast tumors with high-, low-, or non-expressing human epidermal growth factor receptor 2 status.

BACKGROUND: HER2-low breast cancers were reported to have distinct clinicopathological characteristics from HER2-zero; however, the difference in their genetic features remains unclear. This study investigated the clinical and molecular features of breast tumors according to HER2 status. METHODS: We analyzed the clinicopathological and genomic data of 523 Chinese women with breast cancer. Genomic data was generated by targeted next-generation sequencing (NGS) of breast tumor samples using a commercial 520 gene panel. The cohort was stratified according to HER2 status as HER2-zero (n = 90), HER2-low (n = 231), and HER2-positive (n = 202) according to their immunohistochemistry and fluorescence in situ hybridization results. RESULTS: HER2-low breast tumors were enriched with hormone receptor-positive tumors, and who had lower Ki67 expression levels. Genes were differentially mutated across HER2 subgroups. HER2-low tumors had significantly more mutations involved in PI3K-Akt signaling than HER2-positive (p < 0.001) and HER2-zero breast tumors (p < 0.01). HER2-zero tumors had more mutations in checkpoint factors (p < 0.01), Fanconi anemia (p < 0.05), and p53 signaling and cell cycle pathway (p < 0.05) compared to HER2-low breast tumors. Compared with HER2-zero tumors, HER2-low tumors had significantly lower pathological complete response rates after neoadjuvant therapy (15.9% vs. 37.5%, p = 0.042) and proportion of relapsed/progressed patients across follow-up time points (p = 0.031), but had comparable disease-free survival (p = 0.271). CONCLUSION: Our results demonstrate the distinct clinical and molecular features and clinical outcomes of HER2-low breast tumors.

Genetic mutation profile of Chinese HER2-positive breast cancers and genetic predictors of responses to Neoadjuvant anti-HER2 therapy.

PURPOSE: Despite the therapeutic success of existing HER2-targeted therapies, tumors respond quite differently to them. This study aimed at figuring out genetic mutation profile of Chinese HER2-positive patients and investigating predictive factors of neoadjuvant anti-HER2 responses. METHODS: We employed two cohorts. The first cohort was comprised of 181 HER2-positive patients treated at Guangdong Provincial People's Hospital from 2012 to 2018. The second cohort included 40 patients from the first cohort who underwent HER2-targeted neoadjuvant chemotherapy. Genetic mutations were characterized using next-generation sequencing. We employed the most commonly used definition of pathological complete response (pCR)-eradication of tumor from both breast and lymph nodes (ypT0/is ypN0). RESULTS: In Chinese HER2-positive breast cancer patients, TP53 (74.6%), CDK12 (64.6%) and PIK3CA (46.4%) have the highest mutation frequencies. In cohort 2, significant differences were found between pCR and non-pCR groups in terms of the initial Ki67 status, TP53 missense mutations, TP53 LOF mutations, PIK3CA mutations and ROS1 mutations (p = 0.028, 0.019, 0.005, 0.013, 0.049, respectively). Furthermore, TP53 LOF mutations and initial Ki67 status (OR 7.086, 95% CI 1.366-36.749, p = 0.020 and OR 6.007, 95% CI 1.120-32.210, p = 0.036, respectively) were found to be predictive of pCR status. CONCLUSION: TP53 LOF mutations and initial Ki67 status in HER2-positive breast cancer are predictive of pCR status after HER2-targeted NACT.

miR-96 and autophagy are involved in the beneficial effect of grape seed proanthocyanidins against high-fat-diet-induced dyslipidemia in mice.

We aimed to investigate the possible signaling pathways underlying the regulation of grape seed proanthocyanidins extracts (GSPE) on lipid metabolism. One hundred male C57BL/6 mice were divided into four groups: control group (normal diet), GSPE group (normal diet + GSPE), high-fat diet group (HFD), and high-fat diet plus GSPE (200 mg/kg/day) group (HFD + GSPE). Mice received the diets for 180 days. Body weight and serum lipid levels were measured. Autophagic flux characteristics, such as accumulation of lipids, mitochondria, and autophagosomes in the liver, were detected using transmission electron microscopy. Expression profile of microRNAs (miRNAs) in the liver was determined using RNA microarray and quantitative real time polymerase chain reaction (qRt-PCR). GSPE significantly decreased the weight gain, serum levels of triglycerides, total cholesterol, and low-density lipoprotein cholesterol but increased high-density lipoprotein cholesterol in the HFD mice. Autophagic flux was significantly increased by HFD but decreased by GSPE treatment. GSPE significantly attenuated HFD-induced miR-96 upregulation, which in turn reduced the expressions of miR-96 downstream molecules, FOXO1, mTOR, p-mTOR, and LC3A/B. These results suggested that the miR-96 is involved in the protective effect of GSPE against HFD-induced dyslipidemia. Possible mechanisms might be through mTOR and FOXO1, which facilitate autophagic flux for clearance of lipid accumulation.

Pigment epithelium-derived factor (PEDF) inhibits breast cancer metastasis by down-regulating fibronectin.

Pigment epithelium-derived factor (PEDF) plays an important role in the tumor growth and metastasis inhibition. It has been reported that PEDF expression is significantly reduced in breast cancer, and associated with disease progression and poor patient outcome. However, the exact mechanism of PEDF on breast cancer metastasis including liver and lung metastasis remains unclear. The present study aims to reveal the impact of PEDF on breast cancer. The orthotopic tumor mice model inoculated by MDA-MB-231 cells stably expressing PEDF or control cells was used to assess liver and lung metastasis of breast cancer. In vitro, migration and invasion experiments were used to detect the metastatic abilities of MDA-MB-231 and SKBR3 breast cancer cells with or without overexpression of PEDF. The metastatic-related molecules including EMT makers, fibronectin, and p-AKT and p-ERK were detected by qRT-PCR, Western blot, and Fluorescent immunocytochemistry. PEDF significantly inhibited breast cancer growth and metastasis in vivo and in vitro. Mechanically, PEDF inhibited breast cancer cell migration and invasion by down-regulating fibronectin and subsequent MMP2/MMP9 reduction via p-ERK and p-AKT signaling pathways. However, PEDF had no effect on EMT conversion in the breast cancer cells which was usually involved in cancer metastasis. Furthermore, the study showed that laminin receptor mediated the down-regulation of fibronectin by PEDF. These results reported for the first time that PEDF inhibited breast cancer metastasis by down-regulating fibronectin via laminin receptor/AKT/ERK pathway. Our findings demonstrated PEDF as a dual effector in limiting breast cancer growth and metastasis and highlighted a new avenue to block breast cancer progression.

A NEW DOSE DETERMINATION METHOD FOR HP(3) AND DP LENS FOR BETA REFERENCE RADIATION QUALITIES.

For the purpose of obtaining the smaller uncertainties for Hp(3) and Dp lens in 90Sr/90Y beta reference fields, a new dose determination method based on the Monte-Carlo simulation was proposed. The conversion coefficients from the absorbed dose in air, at the reference point of the extrapolation ionisation chamber, Dair, det to Hp(3; α) and the conversion factors from Dair, det to Dp lens(α) were calculated with EGSnrc, respectively, for the irradiation angles from 0° to 60°. Compared with the dose determination method in International Organization for Standardization (ISO) 6980 standard, the uncertainty reductions of 7.7-52.8% for Hp(3; α) and 7.9-55.0% for Dp lens(α) were achieved, respectively. In addition, for the conversion coefficients from the reference absorbed dose DR to Hp(3; α), the calculations were performed for more irradiation conditions, which are not included in the current ISO 6980 standard. For the calculations of the conversion factors from DR to Dp lens(α), the eye and head phantoms with Chinese characteristics were utilised, which makes the conversion factors more suitable for use in China.

Genomic alteration profile and PD-L1 expression among different breast cancer subtypes in Chinese population and their correlations.

BACKGROUD: There were limitations existing in programmed cell-death ligand 1 (PD-L1) as predictive biomarkers for breast cancer (BC), hence exploring the correlation between PD-L1 levels and other biomarkers in BC may become a very useful therapeutic clinical tool. METHODS: A total of 301 Chinese patients with different BC subtypes including 47 HR+/HER2+, 185 HR+/HER2-, 38 HR-/HER2+, and 31 triple-negative breast cancer (TNBC) were enrolled in our study. Next-generation sequencing based Yuansu450 gene panel was used for genomic alteration identification and PD-L1 expression was tested using immunohistochemistry. RESULTS: The most prevalent BC-related mutations were TP53 mutations, followed by mutations in PIK3CA, ERBB2, CDK12, and GATA3 in our Chinese cohort. We found that mutations DDR2 and MYCL were only mutated in HR-/HER2+ subtype, whereas H3-3A and NRAS mutations were only occurred in HR-/HER2- subtype. The percentage of patients with PD-L1-positive expression was higher in patients with HR-/HER2- mainly due to the percentage of PD-L1-high level. Mutational frequencies of TP53, MYC, FAT4, PBRM1, PREX2 were observed to have significant differences among patients with different BC subtypes based on PD-L1 levels. Moreover, a positive correlation was observed between TMB and PD-L1 level in HR+/HER2- subtype, and showed that the proportion of patients with high PD-L1 expression was higher than that of patients with low PD-L1 expression in the HR+/HER2- and HR+/HER2+ cohorts with high Ki67 expression. CONCLUSIONS: The genomic alterations based on PD-L1 and other biomarkers of different cohorts may provide more possibilities for the treatment of BC with different subtypes.

Clinical significance and outcomes of bilateral and unilateral recurrent laryngeal nerve lymph node dissection in esophageal squamous cell carcinoma: A large-scale retrospective cohort study.

BACKGROUND: The survival benefits of recurrent laryngeal nerve lymph node dissection (RLNLD) in esophageal squamous cell carcinoma (ESCC) are still under debate, and the prognostic value of unilateral RLNLD has been rarely studied. Therefore, the aim of the present study was to investigate the clinical significance and outcomes of RLNLD in ESCC in a large-scale cohort study, to shed light on the outcomes of unilateral RLNLD, and to identify the factors that affect the prognostic outcome of RLNLD. METHODS: We retrospectively reviewed 1153 patients with thoracic ESCC who underwent right thoracotomy with lymphadenectomy. The impact of RLNLD on disease-free survival (DFS) and overall survival (OS) was estimated using the Kaplan-Meier method and Cox proportional hazard models. Inverse probability of treatment weighting (IPTW) was performed to adjust for differences in baseline variables in pairwise comparisons. Subgroup analysis of survival and postoperative complications was conducted for selective RLNLD. RESULTS: RLN lymph node (LN) metastasis was independently associated with tumor location and most other LN station metastases. RLNLD was an independent prognostic factor for DFS and OS. Both patients who underwent unilateral and bilateral RLNLD had significantly better DFS and OS than the non-RLNLD patients. Furthermore, pairwise comparisons with IPTW confirmed these results, and we found that patients who underwent bilateral RLNLD had better survival than those who underwent unilateral RLNLD. However, subgroup analysis showed that there was no survival benefit and higher morbidity after bilateral RLNLD for patients with cancer in the lower thoracic esophagus, and elderly and female patients. CONCLUSION: RLN LN metastasis is very frequent in ESCC, and both unilateral and bilateral RLNLD have considerable survival benefits. Selective RLNLD with better survival and lower morbidity was recommend for some defined subgroups.

Characteristics of MYC Amplification and Their Association with Clinicopathological and Molecular Factors in Patients with Breast Cancer.

MYC amplification is detected in ∼15% of breast tumors and is associated with poor prognosis by mediating acquired resistance to anticancer therapies. This study aimed to determine the prevalence of MYC amplifications in Chinese women with breast cancer (BRCA) and investigate the correlation between MYC amplification and clinicopathological and molecular characteristics and its clinical implications. We analyzed MYC alterations in tissue specimens from 410 women diagnosed with BRCA in our hospital from June 1, 2017 to September 27, 2018. We compared our results with publicly available data from The Cancer Genome Atlas (TCGA) BRCA cohort (n = 1079). MYC amplification was identified in 12.4% (51/410) of our cohort, with mean copy number (CN) of 4.42 (range: 2.84-11.27). In TCGA cohort, MYC amplification was identified in 21.2% (229/1079) and was associated with age, estrogen receptor status, progesterone receptor status, human epidermal growth factor receptor 2 (HER2) status, and molecular subtype, whereas in our cohort, MYC amplification was associated with smaller tumor size (T1-2, p = 0.023) and higher Ki-67 levels (≥20%; p = 0.031). Analysis of molecular profiles revealed that MYC-amplified breast tumors had significantly more concurrent CN variations compared with MYC nonamplified BRCA in both Guangdong Provincial People's Hospital (GDPH) and TCGA cohorts (p < 0.001). Pathway mapping analysis demonstrated that MYC-amplified tumors had more mutations involved in 15 different but interrelated pathways critical in DNA repair, cell cycle, and cell proliferation. Patients in TCGA cohort with MYC-amplified hormone receptor (HR)-positive/HER2-positive BRCA (p = 0.038) and MYC nonamplified triple-negative BRCA (p = 0.027) had significantly shorter overall survival. In conclusion, this study contributes to a better understanding that MYC-amplified breast tumors had distinct clinicopathological and molecular features compared with MYC nonamplified breast tumors. Further research with a larger sample size is necessary to further elucidate the clinical and survival implications of MYC amplifications.

Heterogenous and Low Expression of HER2 in Breast Cancer Overcome by DS-8201a in a Heavily Treated Patient: Case Report and Review of the Literature.

Breast cancer is highly heterogenous with temporal and spatial heterogeneity making it necessary for rebiopsy. DS-8201a, a new potential therapy for human epidermal growth factor receptor 2 (HER2) low expression breast cancer, had been proved that it could overcome heterogenous HER2 expression in a preclinical setting. In January 2014, a 23-year-old woman was presented with a lump in the right breast with bone metastasis, diagnosed as infiltrating ductal carcinoma, estrogen receptor (ER)+, progesterone receptor (PR)+, HER2 immunohistochemistry (IHC) 2+, and fluorescence in situ hybridization negative. The patient received a series of therapies including surgery, radiotherapy, endocrine therapy, target therapy, and chemotherapy. The longest progression-free survival was 17 months after surgery. Biopsy of liver metastasis in February 2020 showed triple negative (HER2-, ER-, PR-), which was quite different from the initial diagnosis in 2014, so retesting was performed and the results showed ER-, PR+ by 10%, HER2 IHC score of 1+, indicating heterogeneity of HER2 expression. In May 2020, DS-8201a treatment was initiated and continued for 10 cycles until November 2020. Remarkable relief in symptoms was observed after the first dose. A reduction in the metastatic lesion size (liver and brain) and improved liver function was observed during the therapy. This case indicated the heterogeneity of breast cancer, and impressive efficacy of DS-8201a in a heavily treated patient with HER2-low and HER2 heterogeneity.

Spectrum of MAP3K1 mutations in breast cancer is luminal subtype-predominant and related to prognosis.

MAP3K1 is a MAPK family serine-threonine kinase that is frequently mutated in human cancer. The association between mutations in the MAP3K1 gene and the clinicopathological characteristics and prognosis of patients with breast cancer remain unclear in the Chinese population. Thus, the aim of the present retrospective study was to investigate the possible role and function of MAP3K1 in breast cancer. Data obtained from 412 consecutive patients with breast cancer were selected from Guangdong Provincial People's Hospital (GDPH) for analysis in the present study. Mutations were assessed using next-generation sequencing. The association between MAP3K1 mutations and clinicopathological features were analyzed and further compared with the Molecular Taxonomy of Breast Cancer International Consortium (METABRIC) cohort and data from The Cancer Genome Atlas (TCGA). In the GDPH cohort, a total of 45 mutations MAP3K1 were identified in 8.5% (n=35) of the 412 patients, compared with 9.7% (n=244) in METABRIC and 7.9% (n=88) in TCGA. The majority of the mutations identified in the in three cohorts were truncating mutations, followed by mis-sense mutations. Mutations in MAP3K1 were predominant in patients with the luminal A and B breast cancer subtypes in METABRIC datasets (P<0.001), although no significant differences were observed in the GDPH cohort (P=0.227). In the METABRIC cohort, patients with MAP3K1 mutations experienced a improved overall survival (OS) rate than patients without MAP3K1 mutations (P=0.006). In patient with hormone receptor (HR)+ breast cancer, a more significantly higher OS rate was observed in patients with MAP3K1 mutations (P<0.001). MAP3K1 expression was associated with OS in the HR+ subgroup. Moreover, the MAP3K1 methylation levels were reduced in primary breast cancer tissue, compared with normal tissue. Thus, the present findings identified MAP3K1 mutations in Chinese patients with breast cancer, and compared MAP3K1 mutations between the cohorts from Western and Eastern countries.