Germline mutations of homologous recombination genes and clinical outcomes in pancreatic cancer: a multicenter study in Taiwan.

BACKGROUND: Cancer susceptibility germline mutations are associated with pancreatic ductal adenocarcinoma (PDAC). However, the hereditary status of PDAC and its impact on survival is largely unknown in the Asian population. METHODS: Exome sequencing was performed on 527 blood samples from PDAC individuals and analyzed for mutations in 80 oncogenic genes. Pathogenic and likely pathogenic (P/LP) germline variants were diagnosed according to the ACMG variant classification categories. The association between germline homologous recombination gene mutations (gHRmut, including BAP1, BRCA1, BRCA2, PALB2, ATM, BLM, BRIP1, CHEK2, NBN, MUTYH, FANCA and FANCC) and the treatment outcomes was explored in patients with stage III/IV diseases treated with first-line (1L) platinum-based versus platinum-free chemotherapy. RESULTS: Overall, 104 of 527 (19.7%) patients carried germline P/LP variants. The most common mutated genes were BRCA2 (3.60%), followed by ATR (2.66%) and ATM (1.9%). After a median follow-up duration of 38.3-months (95% confidence interval, 95% CI 35.0-43.7), the median overall survival (OS) was not significantly different among patients with gHRmut, non-HR germline mutations, or no mutation (P = 0.43). Among the 320 patients with stage III/IV disease who received 1L combination chemotherapy, 32 (10%) had gHRmut. Of them, patients receiving 1L platinum-based chemotherapy exhibited a significantly longer median OS compared to those with platinum-free chemotherapy, 26.1 months (95% CI 12.7-33.7) versus 9.6 months (95% CI 5.9-17.6), P = 0.001. However, the median OS of patients without gHRmut was 14.5 months (95% CI 13.2-16.9) and 12.6 months (95% CI 10.8-14.7) for patients receiving 1L platinum-based and platinum-free chemotherapy, respectively (P = 0.22). These results were consistent after adjusting for potential confounding factors including age, tumor stage, performance status, and baseline CA 19.9 in the multivariate Cox regression analysis. CONCLUSIONS: Our study showed that nearly 20% of Taiwanese PDAC patients carried germline P/LP variants. The longer survival observed in gHRmut patients treated with 1L platinum-based chemotherapy highlights the importance of germline testing for all patients with advanced PDAC at diagnosis.

Human NOP2/NSUN1 regulates ribosome biogenesis through non-catalytic complex formation with box C/D snoRNPs.

5-Methylcytosine (m5C) is a base modification broadly found on various RNAs in the human transcriptome. In eukaryotes, m5C is catalyzed by enzymes of the NSUN family composed of seven human members (NSUN1-7). NOP2/NSUN1 has been primarily characterized in budding yeast as an essential ribosome biogenesis factor required for the deposition of m5C on the 25S ribosomal RNA (rRNA). Although human NOP2/NSUN1 has been known to be an oncogene overexpressed in several types of cancer, its functions and substrates remain poorly characterized. Here, we used a miCLIP-seq approach to identify human NOP2/NSUN1 RNA substrates. Our analysis revealed that NOP2/NSUN1 catalyzes the deposition of m5C at position 4447 on the 28S rRNA. We also find that NOP2/NSUN1 binds to the 5'ETS region of the pre-rRNA transcript and regulates pre-rRNA processing through non-catalytic complex formation with box C/D snoRNAs. We provide evidence that NOP2/NSUN1 facilitates the recruitment of U3 and U8 snoRNAs to pre-90S ribosomal particles and their stable assembly into snoRNP complexes. Remarkably, expression of both WT and catalytically inactive NOP2/NSUN1 in knockdown background rescues the rRNA processing defects and the stable assembly of box C/D snoRNP complexes, suggesting that NOP2/NSUN1-mediated deposition of m5C on rRNA is not required for ribosome synthesis.

Resolving Molecular Heterogeneity with Single-Molecule Centrifugation.

For many classes of biomolecules, population-level heterogeneity is an essential aspect of biological function─from antibodies produced by the immune system to post-translationally modified proteins that regulate cellular processes. However, heterogeneity is difficult to fully characterize for multiple reasons: (i) single-molecule approaches are needed to avoid information lost by ensemble-level averaging, (ii) sufficient statistics must be gathered on both a per-molecule and per-population level, and (iii) a suitable analysis framework is required to make sense of a potentially limited number of intrinsically noisy measurements. Here, we introduce an approach that overcomes these difficulties by combining three techniques: a DNA nanoswitch construct to repeatedly interrogate the same molecule, a benchtop centrifuge force microscope (CFM) to obtain thousands of statistics in a highly parallel manner, and a Bayesian nonparametric (BNP) inference method to resolve separate subpopulations with distinct kinetics. We apply this approach to characterize commercially available antibodies and find that polyclonal antibody from rabbit serum is well-modeled by a mixture of three subpopulations. Our results show how combining a spatially and temporally multiplexed nanoswitch-CFM assay with BNP analysis can help resolve complex biomolecular interactions in heterogeneous samples.

Serial Femtosecond Crystallography Reveals that Photoactivation in a Fluorescent Protein Proceeds via the Hula Twist Mechanism.

Chromophore cis/trans photoisomerization is a fundamental process in chemistry and in the activation of many photosensitive proteins. A major task is understanding the effect of the protein environment on the efficiency and direction of this reaction compared to what is observed in the gas and solution phases. In this study, we set out to visualize the hula twist (HT) mechanism in a fluorescent protein, which is hypothesized to be the preferred mechanism in a spatially constrained binding pocket. We use a chlorine substituent to break the twofold symmetry of the embedded phenolic group of the chromophore and unambiguously identify the HT primary photoproduct. Through serial femtosecond crystallography, we then track the photoreaction from femtoseconds to the microsecond regime. We observe signals for the photoisomerization of the chromophore as early as 300 fs, obtaining the first experimental structural evidence of the HT mechanism in a protein on its femtosecond-to-picosecond timescale. We are then able to follow how chromophore isomerization and twisting lead to secondary structure rearrangements of the protein ß-barrel across the time window of our measurements.

Knowledge-based classification of fine-grained immune cell types in single-cell RNA-Seq data.

Single-cell RNA sequencing (scRNA-Seq) is an emerging strategy for characterizing immune cell populations. Compared to flow or mass cytometry, scRNA-Seq could potentially identify cell types and activation states that lack precise cell surface markers. However, scRNA-Seq is currently limited due to the need to manually classify each immune cell from its transcriptional profile. While recently developed algorithms accurately annotate coarse cell types (e.g. T cells versus macrophages), making fine distinctions (e.g. CD8+ effector memory T cells) remains a difficult challenge. To address this, we developed a machine learning classifier called ImmClassifier that leverages a hierarchical ontology of cell type. We demonstrate that its predictions are highly concordant with flow-based markers from CITE-seq and outperforms other tools (+15% recall, +14% precision) in distinguishing fine-grained cell types with comparable performance on coarse ones. Thus, ImmClassifier can be used to explore more deeply the heterogeneity of the immune system in scRNA-Seq experiments.

Distinct Failure Patterns in Hypopharyngeal Cancer Patients Receiving Surgery-Based Versus Radiation-Based Treatment.

BACKGROUND: To cure advanced hypopharyngeal squamous cell carcinoma (HPSCC), primary operation followed by adjuvant (chemo-)radiotherapy (OP-CRT) or definitive chemoradiation (CCRT) are the two primary options. This study aimed to compare the failure patterns and long-term survival outcomes of HPSCC patients treated with these two strategies. PATIENTS AND METHODS: From 2007 to 2015, 198 pathologically confirmed HPSCC patients receiving either OP-CRT or CCRT were retrospectively reviewed. Failure patterns and survival outcomes stratified by the 7th American Joint Committee on Cancer staging system and treatment modalities were compared. RESULTS: One hundred and eighty-nine patients (95.4%) were stage III/IV and 62 patients (31.3%) received OP-CRT. Median follow-up duration was 4.9 years. Compared with CCRT, OP-CRT provided better 3-year local relapse-free survival for T3 (93 vs 48%, p < 0.0001), T4a (88 vs 37%, p = 0.0005) and better 3-year regional relapse-free survival for N2b+2c (93 vs 60%, p < 0.0001). Of note, for stage IVA subjects, OP-CRT provided better 3-year loco-regional relapse-free survival (85 vs 37%, p < 0.0001), marginal poor 3-year distant metastasis-free survival (62 vs 79%, p = 0.06), but comparable 3-year OS (52 vs 44%, p = 0.37) and 5-year OS (44 vs 31%, p = 0.15) compared with CCRT. CONCLUSIONS: For patients with advanced HPSCC, although OP-CRT and CCRT provided similar overall survival, failure patterns were distinct. OP-CRT provided better loco-regional control but was more likely to encounter distant metastases than CCRT. The detailed analysis of failure patterns will pave the way to improve this devastating disease.

Risk factors for massive transfusion in obstetrical hemorrhage and consideration of a whole blood program.

BACKGROUND: Postpartum hemorrhage (PPH) is one of the leading causes of obstetric complications. The goal of this study was to identify risk factors for obstetric (OB) massive transfusion (MT) and determine the feasibility of developing a low-titer group O RhD-positive whole blood (LTO + WB) protocol for OB hemorrhage. STUDY DESIGN AND METHODS: A retrospective study of OB patients who received transfusion within 24 h. MT patients were those who received >3 U of pRBC within 1 h or > 10 U in 24 h. Patient demographics, OB history, comorbidities, blood type, antibody status, and known risk factors for PPH and maternal-fetal outcomes were compared. Logistic regression was used for univariate and multivariate analyses. RESULTS: Of the 610 transfused OB patients, 12.0% (n = 73) required MT. Groups were well matched for body mass index (BMI), maternal comorbidities, and history of spontaneous vaginal deliveries. The incidence of the previous cesarean section was higher in the MT group. Exactly 93.9% of patients were RhD-positive and 3.77% of all patients possessed an antibody on pretransfusion testing. Patients with MT had a longer length of stay (LOS), higher rate of intensive care unit (ICU) admission, fetal death, and hysterectomy. Multivariate analysis found age >35, PPH, placenta percreta, accreta, and increta to be significant (p < .05) risk factors for MT. DISCUSSION: Patients over 35 years and those with abnormal placentation are at increased risk of requiring MT. With a time to delivery of 2 days, potential MT patients can be identified early, and with a 94% rate of RhD-positive+, they are eligible to receive low-titer O whole blood (LTOWB) providing hemostatic resuscitation with reduced donor exposure.

Circulating immune cell phenotype dynamics reflect the strength of tumor-immune cell interactions in patients during immunotherapy.

The extent to which immune cell phenotypes in the peripheral blood reflect within-tumor immune activity prior to and early in cancer therapy is unclear. To address this question, we studied the population dynamics of tumor and immune cells, and immune phenotypic changes, using clinical tumor and immune cell measurements and single-cell genomic analyses. These samples were serially obtained from a cohort of advanced gastrointestinal cancer patients enrolled in a trial with chemotherapy and immunotherapy. Using an ecological population model, fitted to clinical tumor burden and immune cell abundance data from each patient, we find evidence of a strong tumor-circulating immune cell interaction in responder patients but not in those patients that progress on treatment. Upon initiation of therapy, immune cell abundance increased rapidly in responsive patients, and once the peak level is reached tumor burden decreases, similar to models of predator-prey interactions; these dynamic patterns were absent in nonresponder patients. To interrogate phenotype dynamics of circulating immune cells, we performed single-cell RNA sequencing at serial time points during treatment. These data show that peripheral immune cell phenotypes were linked to the increased strength of patients' tumor-immune cell interaction, including increased cytotoxic differentiation and strong activation of interferon signaling in peripheral T cells in responder patients. Joint modeling of clinical and genomic data highlights the interactions between tumor and immune cell populations and reveals how variation in patient responsiveness can be explained by differences in peripheral immune cell signaling and differentiation soon after the initiation of immunotherapy.

Measuring distance from the incisors to the esophageal cancer by FDG PET/CT: endoscopy as the reference.

BACKGROUND: Using endoscopy as the reference, this study evaluated the accuracy of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) in measuring distance from the incisors to the PET detectable esophageal cancer. If there is high concordance between endoscopic and PET measurements, our results may provide a basis to use FDG PET/CT in cooperation with endoscopic measurement to localize those PET/CT and CT undetectable esophageal tumors for radiotherapy planning. MATERIALS: Esophageal cancer patients with pretreatment endoscopy and FDG PET/CT detectable esophageal tumors were recruited retrospectively. The distances from the incisors to the proximal esophageal tumor margins were determined by endoscopy and by the sagittal images of FDG PET/CT. The endoscopic measurement was used as the comparative reference. A nuclear medicine doctor and a radiation oncologist each performed the FDG PET/CT measurement twice for every patient. We analyzed the differences in these measurements, and assessed agreement and reproducibility of the results by the intraclass correlation coefficient (ICC). RESULTS: Thirty-four patients, with 35 esophageal tumors, were included. By endoscopy and FDG PET/CT, the mean distances from the incisors to the proximal esophageal tumor margin were 27.3 ± 6.4 cm (range 17.1-40.0 cm) and 26.8 ± 6.3 cm (range 15.7-41.3 cm), respectively. The mean absolute differences between the endoscopic and four FDG PET/CT measurements ranged from 1.129 to 1.289 cm (SD: 0.98-1.19). The measurement agreement between FDG PET/CT and endoscopy by ICC was between 0.962 and 0.971. The intra- and interobserver reproducibilities of the two readers were excellent (intraobserver ICC: 0.985, 0.996; interobserver ICC: 0.976-0.984). CONCLUSIONS: FDG PET/CT was in high agreement with endoscopy in measuring the distance from the incisors to the proximal esophageal tumor margin. For FDG PET/CT and CT undetectable esophageal cancer, incorporation of the endoscopic measurement with PET/CT might be a way for making radiotherapy plan.

The impact of differential lignin S/G ratios on mutagenicity and chicken embryonic toxicity.

Lignin and lignin-based materials have received considerable attention in various fields due to their promise as sustainable feedstocks. Guaiacol (G) and syringol (S) are two primary monolignols that occur in different ratios for different plant species. As methoxyphenols, G and S have been targeted as atmospheric pollutants and their acute toxicity examined. However, there is a rare understanding of the toxicological properties on other endpoints and mixture effects of these monolignols. To fill this knowledge gap, our study investigated the impact of different S/G ratios (0.5, 1, and 2) and three lignin depolymerization samples from poplar, pine, and miscanthus species on mutagenicity and developmental toxicity. A multitiered method consisted of in silico simulation, in vitro Ames test, and in vivo chicken embryonic assay was employed. In the Ames test, syringol showed a sign of mutagenicity, whereas guaiacol did not, which agreed with the T.E.S.T. simulation. For three S and G mixture and lignin monomers, mutagenic activity was related to the proportion of syringol. In addition, both S and G showed developmental toxicity in the chicken embryonic assay and T.E.S.T. simulation, and guaiacol had a severe effect on lipid peroxidation. A similar trend and comparable developmental toxicity levels were detected for S and G mixtures and the three lignin depolymerized monomers. This study provides data and insights on the differential toxicity of varying S/G ratios for some important building blocks for bio-based materials.

Kras mutation rate precisely orchestrates ductal derived pancreatic intraepithelial neoplasia and pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDAC) is the third leading cause of cancer-related death in the United States. Despite the high prevalence of Kras mutations in pancreatic cancer patients, murine models expressing the oncogenic mutant Kras (Krasmut) in mature pancreatic cells develop PDAC at a low frequency. Independent of cell of origin, a second genetic hit (loss of tumor suppressor TP53 or PTEN) is important for development of PDAC in mice. We hypothesized ectopic expression and elevated levels of oncogenic mutant Kras would promote PanIN arising in pancreatic ducts. To test our hypothesis, the significance of elevating levels of K-Ras and Ras activity has been explored by expression of a CAG driven LGSL-KrasG12V allele (cKras) in pancreatic ducts, which promotes ectopic Kras expression. We predicted expression of cKras in pancreatic ducts would generate neoplasia and PDAC. To test our hypothesis, we employed tamoxifen dependent CreERT2 mediated recombination. Hnf1b:CreERT2;KrasG12V (cKrasHnf1b/+) mice received 1 (Low), 5 (Mod) or 10 (High) mg per 20 g body weight to recombine cKras in low (cKrasLow), moderate (cKrasMod), and high (cKrasHigh) percentages of pancreatic ducts. Our histologic analysis revealed poorly differentiated aggressive tumors in cKrasHigh mice. cKrasMod mice had grades of Pancreatic Intraepithelial Neoplasia (PanIN), recapitulating early and advanced PanIN observed in human PDAC. Proteomics analysis revealed significant differences in PTEN/AKT and MAPK pathways between wild type, cKrasLow, cKrasMod, and cKrasHigh mice. In conclusion, in this study, we provide evidence that ectopic expression of oncogenic mutant K-Ras in pancreatic ducts generates early and late PanIN as well as PDAC. This Ras rheostat model provides evidence that AKT signaling is an important early driver of invasive ductal derived PDAC.

c-Myc promotes lymphatic metastasis of pancreatic neuroendocrine tumor through VEGFC upregulation.

Pancreatic neuroendocrine tumor (pNET) is a pancreatic neoplasm with neuroendocrine differentiation. pNET in early stage can be treated with surgical resection with long-term survival, whereas the prognosis of pNET with locoregional or distant metastasis is relatively poor. Lymphangiogenesis is essential for tumor metastasis via the lymphatic system and may overhead distant metastasis. c-Myc overexpression is involved in tumorigenesis. The role of c-Myc in lymphangiogenesis is unclear. In this study, we evaluated the mechanism and effect of c-Myc on lymphangiogenesis of pNET via interaction of lymphatic endothelial cells (LECs) and pNET cells. Lymph node metastasis was evaluated in pNET xenograft mice. Potential target agents to inhibit lymph node metastasis were evaluated in an animal model. We found that vascular endothelial growth factor C (VEGFC) expression and secretion was increased in pNET cell lines with c-Myc overexpression. c-Myc transcriptionally upregulates VEGFC expression and the secretion of pNET cells by directly binding to the E-box of the VEGFC promoter and enhances VEGF receptor 3 phosphorylation and the tube formation of LECs. c-Myc overexpression is associated with lymph node metastasis in pNET xenograft mice. Combinational treatment with an mTOR inhibitor and c-Myc inhibitor or VEGFC-neutralizing chimera protein reduced lymph node metastasis in the mice with c-Myc overexpression. The mTOR inhibitor acts on lymphangiogenesis by reducing VEGFC expression in pNET cells and inhibiting the tube formation of LECs. In conclusion, mTOR and c-Myc are important for lymphangiogenesis of pNET and are potential therapeutic targets for prevention and treatment of lymph node metastasis in pNET.

EMTome: a resource for pan-cancer analysis of epithelial-mesenchymal transition genes and signatures.

BACKGROUND: The epithelial-mesenchymal transition (EMT) enables dissociation of tumour cells from the primary tumour mass, invasion through the extracellular matrix, intravasation into blood vessels and colonisation of distant organs. Cells that revert to the epithelial state via the mesenchymal-epithelial transition cause metastases, the primary cause of death in cancer patients. EMT also empowers cancer cells with stem-cell properties and induces resistance to chemotherapeutic drugs. Understanding the driving factors of EMT is critical for the development of effective therapeutic interventions. METHODS: This manuscript describes the generation of a database containing EMT gene signatures derived from cell lines, patient-derived xenografts and patient studies across cancer types and multiomics data and the creation of a web-based portal to provide a comprehensive analysis resource. RESULTS: EMTome incorporates (i) EMT gene signatures; (ii) EMT-related genes with multiomics features across different cancer types; (iii) interactomes of EMT-related genes (miRNAs, transcription factors, and proteins); (iv) immune profiles identified from The Cancer Genome Atlas (TCGA) cohorts by exploring transcriptomics, epigenomics, and proteomics, and drug sensitivity and (iv) clinical outcomes of cancer cohorts linked to EMT gene signatures. CONCLUSION: The web-based EMTome portal is a resource for primary and metastatic tumour research publicly available at www.emtome.org .

CD8+ T cells inhibit metastasis and CXCL4 regulates its function.

BACKGROUND: The mechanism by which immune cells regulate metastasis is unclear. Understanding the role of immune cells in metastasis will guide the development of treatments improving patient survival. METHODS: We used syngeneic orthotopic mouse tumour models (wild-type, NOD/scid and Nude), employed knockout (CD8 and CD4) models and administered CXCL4. Tumours and lungs were analysed for cancer cells by bioluminescence, and circulating tumour cells were isolated from blood. Immunohistochemistry on the mouse tumours was performed to confirm cell type, and on a tissue microarray with 180 TNBCs for human relevance. TCGA data from over 10,000 patients were analysed as well. RESULTS: We reveal that intratumoral immune infiltration differs between metastatic and non-metastatic tumours. The non-metastatic tumours harbour high levels of CD8+ T cells and low levels of platelets, which is reverse in metastatic tumours. During tumour progression, platelets and CXCL4 induce differentiation of monocytes into myeloid-derived suppressor cells (MDSCs), which inhibit CD8+ T-cell function. TCGA pan-cancer data confirmed that CD8lowPlatelethigh patients have a significantly lower survival probability compared to CD8highPlateletlow. CONCLUSIONS: CD8+ T cells inhibit metastasis. When the balance between CD8+ T cells and platelets is disrupted, platelets produce CXCL4, which induces MDSCs thereby inhibiting the CD8+ T-cell function.

Lipidomic atlas of mammalian cell membranes reveals hierarchical variation induced by culture conditions, subcellular membranes, and cell lineages.

Lipid membranes are ubiquitous biological organizers, required for structural and functional compartmentalization of the cell and sub-cellular organelles. Membranes in living cells are compositionally complex, comprising hundreds of dynamically regulated, distinct lipid species. Cellular physiology requires tight regulation of these lipidomic profiles to achieve proper membrane functionality. While some general features of tissue- and organelle-specific lipid complements have been identified, less is known about detailed lipidomic variations caused by cell-intrinsic or extrinsic factors. Here, we use shotgun lipidomics to report detailed, comprehensive lipidomes of a variety of cultured and primary mammalian membrane preparations to identify trends and sources of variation. Unbiased principle component analysis (PCA) shows clear separation between cultured and primary cells, with primary erythrocytes, synaptic membranes, and other mammalian tissue lipidomes sharply diverging from all cultured cell lines and also from one other. Most broadly, cultured cell membrane preparations were distinguished by their paucity of polyunsaturated lipids. Cultured mammalian cell lines were comparatively similar to one another, although we detected clear, highly reproducible lipidomic signatures of individual cell lines and plasma membrane (PM) isolations thereof. These measurements begin to establish a comprehensive lipidomic atlas of mammalian cells and tissues, identifying some major sources of variation. These observations will allow investigation of the regulation and functional significance of mammalian lipidomes in various contexts.

Ex vivo shaping ability of reciprocating instruments operated by new users: Reciproc versus WaveOne.

OBJECTIVES: To compare two reciprocating NiTi systems operated by novices for use in curved root canals. METHODS: Fifty mesial roots of extracted mandibular first molars, with 2-2 canal configuration, were scanned with micro-CT and divided into 2 groups according to canal length and curvature: Reciproc and WaveOne. Each system was used to prepare one of the two canals by fourth-year dental students, who were new to reciprocating files and were blinded to the system being used. After another scanning, the pre- and post-instrumentation images were compared 3-dimensionally in software. RESULTS: Some 43 to 46% of the canal wall area remained un-instrumented. Significantly higher proportions of canals were transported towards the isthmus or furcation aspect than the mesial or external aspect. Mean transported distance was the greatest in the coronal one-third. Remaining dentine wall was the thinnest at the furcal aspect near the middle root region. No significant difference was noted between the two brands in the parameters examined. CONCLUSIONS: Both brands of reciprocating file left similar amounts of un-instrumented canal wall, and resulted in similar extent of canal transportation. CLINICAL RELEVANCE: NiTi reciprocating files can safely be used by new users to prepare curved root canals into a predictable shape.

Experience of sorafenib treatment in differentiated thyroid cancer from Taiwan.

BACKGROUND: Sorafenib has been shown to prolong the progression free survival (PFS) of advanced radioiodine (RAI) refractory differentiated thyroid cancer (DTC) and has been approved by the FDA as the result of the phase III DECISION trial. Sorafenib has been reimbursed for the treatment of RAI refractory DTC in Taiwan since Jan 2017. High percentage of adverse events (AE) was noted in DECISION trial. We conducted a study to show the real-world experience of sorafenib in Taiwan. METHODS: We retrospectively collected the clinical data, including dose, AE, and PFS of sorafenib, of the DTC patients who received sorafenib treatment in National Cheng Kung University Hospital and China Medical University Hospital by chart review from 2012 to 2018. RESULTS: Thirty-six advanced DTC patients with progression were included in this study. The starting dose of sorafenib in most patients was 200 mg twice daily and the mean daily maintenance dose was 433 mg. Five patients had partial response (13.9%) and 28 patients had stable disease (77.8%). The median PFS was 17.3 months (95% confidence interval: 11.9-33.6 months). Daily maintenance dose ≥ 600 mg was associated with better PFS (median PFS, not reached). The most common toxicity of sorafenib was hand foot skin reaction (69%), followed by diarrhea (42%), and skin rash (33%). Most of the toxicities were grade I/II. CONCLUSION: Higher maintenance dose of sorafenib is associated with longer PFS while starting from half dose is feasible to minimize the incidence of high grade toxicities in the real-world use of sorafenib.

Three-dimensional morphologic classifications and analysis of canal isthmuses in permanent molars.

PURPOSE: To investigate the three-dimensional morphology of isthmuses in molars according to their boundary characteristics using micro-computed tomography (micro-CT). METHODS: Micro-CT reconstructed images of 248 molars were evaluated. Isthmuses were classified into four types based on the boundary characteristics: isthmus with roof, isthmus with floor, band-shaped isthmus, and isthmus without boundary. The tooth and root with isthmuses, the number and location of the isthmuses in the root, and the canal configurations were recorded. The maximum of the major diameter of all canal cross-sections in one isthmus (dmax), the minor diameter of the canal in same cross-section (dmin), the distance between the dmax cross-section and apex (Dm-a), isthmus length (Li), and distance from the isthmus ending cross-section to apex (De-a) were measured and analysed with a significance threshold set to 5%. RESULTS: Isthmuses were present in 75.4% specimens. The four types of isthmuses were found in various molars and roots. Their distribution in different root locations and canal configurations was significantly different. The dmax, dmin, Li, and De-a were analysed according to different molars and different isthmus types; their respective median values were 2.508 mm, 0.07 mm, 3.09 mm, and 3.96 mm. CONCLUSION: The three-dimensional classification of isthmuses according to the boundary characteristics provides a comprehensive picture of the isthmus in molars. Their corresponding distributions in different molars, location in roots, and canal configurations will be helpful in predicting the type of isthmus based on the tooth position and canal configurations.

Methodological Advancements for Investigating Intra-tumoral Heterogeneity in Breast Cancer at the Bench and Bedside.

There is a major need to overcome therapeutic resistance and metastasis that eventually arises in many breast cancer patients. Therapy resistant and metastatic tumors are increasingly recognized to possess intra-tumoral heterogeneity (ITH), a diversity of cells within an individual tumor. First hypothesized in the 1970s, the possibility that this complex ITH may endow tumors with adaptability and evolvability to metastasize and evade therapies is now supported by multiple lines of evidence. Our understanding of ITH has been driven by recent methodological advances including next-generation sequencing, computational modeling, lineage tracing, single-cell technologies, and multiplexed in situ approaches. These have been applied across a range of specimens, including patient tumor biopsies, liquid biopsies, cultured cell lines, and mouse models. In this review, we discuss these approaches and how they have deepened our understanding of the mechanistic origins of ITH amongst tumor cells, including stem cell-like differentiation hierarchies and Darwinian evolution, and the functional role for ITH in breast cancer progression. While ITH presents a challenge for combating tumor evolution, in-depth analyses of ITH in clinical biopsies and laboratory models hold promise to elucidate therapeutic strategies that should ultimately improve outcomes for breast cancer patients.

Investigating the health disparities in the association between lifestyle behaviors and the risk of head and neck cancer.

Many studies have reported a positive association between lower socioeconomic status (SES) and higher head and neck cancer (HNC) risk. Fewer studies have examined the impact of SES on the association between alcohol or cigarette use and HNC risk. The current case-control study (1104 HNC cases and 1363 controls) investigated the influence of education, a SES indicator, on the association between HNC and the use of alcohol, cigarettes, or betel quids in Taiwan, a country with universal health care. Our results showed a larger increase in HNC risk associated with alcohol among those with lower educational level (odds ratio [OR] = 2.07; 95% confidence interval [CI], 1.53-2.80) than those with higher educational level (OR = 1.38; 95% CI, 1.04-1.85) (heterogeneity-P = .03). Educational level had an influence on the association between alcohol use and HNC risk among those with genetic susceptibility (ALDH2-deficient) to the carcinogenic effect of alcohol. The association between cigarette or betel quid use and HNC risk was similar between the high and low educational groups. National policies and social interventions have led to the decline in the prevalence of cigarette and betel quid users in Taiwan. In contrast, due to the lack of adequate alcohol control policies, alcohol consumption in Taiwan has continued to rise. A higher impact of alcohol on HNC risk among lower SES individuals even with universal health care could be the result of insufficient alcohol control policies in Taiwan.