Comparison of short-term outcomes from the International Oesophago-Gastric Anastomosis Audit (OGAA), the Esophagectomy Complications Consensus Group (ECCG), and the Dutch Upper Gastrointestinal Cancer Audit (DUCA)

BACKGROUND

The Esophagectomy Complications Consensus Group (ECCG) and the Dutch Upper Gastrointestinal Cancer Audit (DUCA) have set standards in reporting outcomes after oesophagectomy. Reporting outcomes from selected high-volume centres or centralized national cancer programmes may not, however, be reflective of the true global prevalence of complications. This study aimed to compare complication rates after oesophagectomy from these existing sources with those of an unselected international cohort from the Oesophago-Gastric Anastomosis Audit (OGAA).

METHODS

The OGAA was a prospective multicentre cohort study coordinated by the West Midlands Research Collaborative, and included patients undergoing oesophagectomy for oesophageal cancer between April and December 2018, with 90 days of follow-up.

RESULTS

The OGAA study included 2247 oesophagectomies across 137 hospitals in 41 countries. Comparisons with the ECCG and DUCA found differences in baseline demographics between the three cohorts, including age, ASA grade, and rates of chronic pulmonary disease. The OGAA had the lowest rates of neoadjuvant treatment (OGAA 75.1 per cent, ECCG 78.9 per cent, DUCA 93.5 per cent; P < 0.001). DUCA exhibited the highest rates of minimally invasive surgery (OGAA 57.2 per cent, ECCG 47.9 per cent, DUCA 85.8 per cent; P < 0.001). Overall complication rates were similar in the three cohorts (OGAA 63.6 per cent, ECCG 59.0 per cent, DUCA 62.2 per cent), with no statistically significant difference in Clavien-Dindo grades (P = 0.752). However, a significant difference in 30-day mortality was observed, with DUCA reporting the lowest rate (OGAA 3.2 per cent, ECCG 2.4 per cent, DUCA 1.7 per cent; P = 0.013).

CONCLUSION

Despite differences in rates of co-morbidities, oncological treatment strategies, and access to minimal-access surgery, overall complication rates were similar in the three cohorts.

[Clinical characteristics and microbiome analysis in patients with anti-programmed cell death protein 1 related colitis]

Objective: To analyze clinical characteristics and monitor microbiome changes in patients with anti-PD-1 associated colitis. Methods: Two patients with non-small cell lung cancer who developed colitis after treated with anti-PD-1 antibodies were retrospectively analyzed in Peking Union Medical College Hospital from January 2019 to January 2020. The clinical symptoms, endoscopic and pathological manifestations, as well microbiome changes were analyzed and compared during pre-treatment, post-treatment and relapse. Results: The main clinical manifestations included diarrhea, elevated inflammatory indicators, colonic mucosal diffuse hyperemic edema with erosion by endoscopy. Changes in the structure of crypts were common pathological characteristics. Glucocorticoids were effective agents, which achieved clinical remission and mucosal healing. The microbiome composition of OTUs was different. After glucocorticoid treatment, the alpha diversity Observed species, Shannon, Simpson, Chao1, ACE indexes all decreased. The Firmicutes decreased with Bacteroidetes increasing in phylum level; while the Bacteroides increased with Ruminococcaceae decreasing in genus level. Lactobacillus was the potentially beneficial genus. Conclusion: Patients developing anti-PD-1 associated colitis have characteristic clinical and pathological manifestations. Glucocorticoids are effective treatment. The fecal microbiome diversity, relative abundance of major phylum and genus have changed after treatment.

[Protective effect and mechanism of Lactobacillus rhamnosus on immune checkpoint inhibitors related colitis in mice]

Objective: Modeling the immune-related adverse events (irAE) colitis in mice, and explore the protective effect and related mechanism of Lactobacillus rhamnosus GG (LGG) on irAE colitis. Methods: C57BL/6 mice were divided into dextran sodium sulfate (DSS) group (n=3), DSS+anti-programmed death receptor 1 (PD-1) group (n=4), DSS+anti-PD-1+anti-cytotoxic T lymphocyte associated protein 4 (CTLA-4) Group (n=4), DSS+anti-PD-1+anti-CTLA-4+LGG group (n=4), all were given corresponding drugs and probiotics intervention. The severity of colitis were assessed by weight loss, disease activity index (DAI), colon length, colon histopathological score. The inflammatory cytokines and T cell immunity of CD4⁺, CD8⁺, FoxP3⁺regulatory T cells (Treg), were detected by real-time quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and immunohistochemical staining respectively. Results: Compared to DSS group, the Day 9 weight [(87.40±1.79)% vs (94.57±0.53)%, P<0.05], colon length [(5.33±0.27)cm vs (6.63±0.12)cm, P<0.05] were lower, and DAI score(2.66±0.24 vs 0.89±0.48), colon histopathological score (12.50±1.04 vs 5.67±0.33), tumor necrosis factor-α (TNF-α) (6.73±1.68 vs 0.91±0.40) (P<0.05), as well CD8⁺T cells (156.80±8.84 vs 89.00±6.66) and FoxP3⁺Treg cells (103.80±2.66 vs 48.33±3.18) (P<0.05) were higher in DSS+anti-PD-1+anti-CTLA-4 group. Compared to DSS+anti-PD-1+anti-CTLA-4 group, the DAI score(1.83±0.17 vs 2.66±0.24), colonic histopathology score (8.75±0.63 vs 12.50±1.04), TNF-α level (1.32±0.18 vs 6.73±1.68) (P<0.05) were lower; and CD8⁺T cells(97.75±3.75 vs 156.80±8.84, P<0.01) level was lower with higher FoxP3⁺Treg cells (126.00±8.33 vs 103.80±2.66, P=0.046) in DSS+anti-PD-1+anti-CTLA-4+LGG group. Conclusion: DSS combined with anti-PD-1 and anti-CTLA-4 can successfully modeling the irAE colitis in mice, LGG can reduce irAE colitis severity by regulating Treg cells.

Diagnostic value of the combined detection of CEA, NSE and IL-18 for lung cancer and their relationship with apoptosis gene Bcl-2

This study aims to investigate the value of the combined detection of carcinoembryonic antigen (CEA), Neuron-specific enolase (NSE) and the level of Interleukin-18 (IL-18) in the serum in the diagnosis of lung cancer. The correlation between these parameters and the expression levels of B-cell lymphoma-2 (Bcl-2) protein were also studied. Eighty patients with lung cancer were included in the lung cancer group. These patients underwent surgery in the Department of Oncology of Huai'an Second People's Hospital between February 2016 and February 2018. During the same period, another 80 patients with benign lung lesions were registered in the benign lesion group and 80 healthy people were enrolled in the control group. Enzyme-linked immunosorbent assay (ELISA) was used to detect the expression levels of CEA, NSE and IL-18. The diagnostic critical value of these factors was used as positive indicator. When CEA, NSE and IL-18 levels were positive at the same time, the combined detection was considered to be positive. WB was used to detect Bcl-2 expression level. We also analyzed the possible correlation between CEA, NSE, IL-18 levels and the Bcl-2 expression levels. The CEA, NSE and IL-18 expression levels in the serum of the lung cancer group were significantly higher than those in the benign lesion and the control groups (p<0.05). The area under ROC curve for CEA, NSE and IL-18 respectively was 0.770 (0.697-0.843), 0.829 (0.767-0.890), 0.721 (0.642-0.800) (p<0.001). IL-18 level was negatively correlated with the level of Bcl-2 mRNA in the tissue (r=-0.380, p<0.001). In conclusion, CEA, NSE and IL-18 have a good auxiliary diagnostic value in patients with lung cancer. The combined detection could improve the sensitivity and specificity of lung can¬cer diagnosis. There was a negative correlation between IL-18 and Bcl-2 levels which suggested a potential inhibitory role of IL-18 on the lung cancer cells apoptosis pathway.

Progress and current status of molecule-targeted therapy and drug resistance in gastric cancer

Gastric cancer is one of the most common malignant tumors in the world. In China, its morbidity and mortality are second only to lung cancer. Chemotherapy combined with targeted therapy brings survival benefits to patients with advanced gastric cancer. Targets for targeted therapy of gastric cancer include human epidermal growth factor receptor (EGFR), human epidermal growth factor receptor 2 (HER2), vascular endothelial growth factor (VEGF), mammalian target of rapamycin (mTOR) and Claudin 18.2 (CLDN 18.2). The main challenge of tumor molecule-targeted drugs is resistance. The main mechanisms of drug resistance include tumor establishment of compensatory signaling pathways, target protein changes, tumor microenvironment changes, tumor heterogeneity and tumor adaptation to targeted drugs. The combined action of multiple drug resistance mechanisms promotes the development of targeted drug resistance. In order to attract the attention of researchers, this paper reviews the mechanisms of drug resistance in gastric cancer-targeted therapy. In addition, the research status of drug resistance in molecule-targeted therapy of gastric cancer is summarized. It is of great clinical significance to explore the drug resistance mechanisms of targeted drugs and reverse drug resistance in gastric cancer. Last, the future development of molecule-targeted therapy is prospected.

Silencing of TPD52 inhibits proliferation, migration, invasion but induces apoptosis of pancreatic cancer cells by deactivating Akt pathway

Pancreatic cancer (PC) is a complex and multifactorial human malignancy with a low survival rate. Tumor protein D52 (TPD52) was abnormally expressed in several cancers and participated in tumorigenesis. However, the oncogenic effect of TPD52 on PC remains unknown. In the present study, after transfecting AsPC-1 and PANC-1 cells with NC or sh-TPD52, the CCK-8 assay, Hoechst staining, western blot, transwell assay, flow cytometry were used to examine the cell proliferation, migration, invasion and apoptosis. qRT-PCR results confirmed that the expression of TPD52 was significantly increased in PC cells, especially AsPC-1 and PANC-1 cells. The present study revealed that silencing of TPD52 significantly suppressed the proliferation, migration and invasion, but induced apoptosis of AsPC-1 and PANC-1 cells in vitro by dephosphorylating Akt at Ser473. Conversely, SC79, an Akt activator, could partially reverse the anti-metastatic effects of sh-TPD52, accompanied by the reactivating of Akt pathway. Additional in vivo studies are warranted to elucidate that knockdown of TPD52 could inhibit tumor growth in PC mice models. These findings suggested that TPD52 might be a novel therapeutic target for PC treatment.

Effects of Bacillus thuringiensis Genetic Engineering on Induced Volatile Organic Compounds Emission in Maize and the Attractiveness to a Parasitic Wasp

In order to control lepidopteran and coleopteran insects, the genes expressing Bacillus thuringiensis (Bt) insecticidal proteins have been transferred into crops. Ecological risk assessments of the transgenic plants have included impacts on non-target entomophagous insects, such as parasitoid wasps. Herbivore-induced plant volatiles are considered to be important defensive traits of plants because these compounds play as an important role in recruitment of natural enemies. Here, we evaluated induced volatile emissions of maize seedlings of two Bt cultivars (5422Bt1, event Bt11 and 5422CBCL, event Mon810), and their nearly isogenic non-Bt line 5422. We damaged plants mechanically and then applied with the regurgitant of Spodoptera litura (F.) caterpillars (Lepidoptera: Noctuidae), or treated the plants with the plant hormone jasmonic acid (JA), to trigger similar defensive responses of plants. Compared to the non-Bt isoline 5422 and the Bt maize 5422CBCL, the other Bt maize 5422Bt1 released more (3E)-4,8-dimethyl-1,3,7-nonatriene (DMNT) when they were all treated by artificial wounds and caterpillar regurgitant; and released more linalool, DMNT and (E)-β-farnesene when applied with JA solution. As a result, the total volatile emission of the 5422Bt1 was highest. However, the difference in volatile emission did not affect the attractiveness of the Bt maize plants to the egg parasitoid Trichogramma ostriniae Pang et Chen (Hymenoptera: Trichogrammatidae) compared to the nearly isogenic non-Bt plants. The variability of induced volatiles of maize cultivars derived from conventional breeding programs and transgenic methods are discussed.

Relationship between extralaryngeal endoscopic findings, proton pump inhibitor (PPI) response, and pH measures in suspected laryngopharyngeal reflux

Laryngopharyngeal reflux (LPR) is a clinical entity diagnosed by history laryngoscopic findings that has a variable response to empiric proton-pump inhibitor (PPI) therapy. While the reflux finding score (RFS), an endoscopic scoring scheme, has been advanced as a measure of LPR, it has not been externally validated against symptom severity in practice. Extralaryngeal pharyngeal endoscopic findings may have diagnostic utility but remain underexplored. This study assesses the correlation between extralaryngeal findings and (1) 24-hour oropharyngeal pH & (2) PPI response in patients with suspected LPR. Subjects presented to a tertiary care center with laryngeal symptoms ≥1 month and reflux symptom index (RSI) ≥13. Following baseline questionnaires, laryngoscopy, and a 24-hour oropharyngeal pH probe study, subjects were prescribed 8-12 week omeprazole trials. Baseline endoscopic findings were scored in a blinded fashion using the RFS and extralaryngeal score criteria, summatively the 'ELS.' PPI response was defined as ≥50% improvement in RSI. Thirty-three subjects with flexible endoscopic recordings completed baseline and follow-up questionnaires. The cohort's baseline mean RSI was 23.0 ± 7.2 with a ΔRSI = 9.8 after PPI therapy. The baseline RFS score averaged 5.3 ± 2.7. 45% of our subjects was found to be PPI responsive. The Cohen's kappa for the ELS but not the RFS was significant. There were no significant differences between the RFS (P = 0.10) or ELS (P = 0.07) for PPI responders & nonresponders. Oropharyngeal pH measures did not correlate with the RFS or ELS. In conclusion, endoscopic scores of laryngeal and extralaryngeal findings did not predict PPI response or oropharyngeal acid exposure in suspected LPR.

Abstract P6-17-39: BAT8001, a potent anti-HER2 antibody-drug conjugate with a novel stable linker for the treatment of HER2-positive breast cancer

Overexpression of HER2 occurs in approximately 20% of breast cancers and is associated with shortened survival. Trastuzumab emtansine (T-DM1), an anti-HER2 ADC, has shown efficacy in HER2-positive breast cancer patients and was approved by the FDA and EMA for advanced HER2-positive breast cancer. However T-DM1 causes grade 3 and 4 thrombocytopenia in up to 14.5% of patients as its major toxicity. The thrombocytopenia is likely caused by one of T-DM1's catabolites and payload, DM1, indicating T-DM1's linker can be cleaved. Here we adopted a novel noncleavable linker and created an anti-HER2 ADC, BAT8001, which is expected be efficacious in HER2-positive breast cancer and have a better side effect profile relative to T-DM1 due to the stability of BAT8001's noncleavable linker. BAT8001 is internalized in HER2-positive cancer cells. It inhibits proliferation of HER2-positive tumor cells with IC50s of ˜0.1 nM, similar to the potency of T-DM1. BAT8001 also induces apoptosis in HER2-positive cancer cells. In both cell-line and patient-derived mouse xenograft (PDX) models, BAT8001 demonstrates strong inhibition activity on tumor growth. For example, in a cell-line model of breast cancer (BT474), BAT8001 demonstrates potent activity with complete responses in all animals tested at the 15mg/kg dose level. Pharmacokinetics studies in monkey reveals BAT8001 has similar Cmax, AUC, and t1/2 as T-DM1. The major catabolite of BAT8001 is the Cys-linker-payload containing product. No free payload is observed. This compares favorably with T-DM1 where free DM1, T-DM1's payload, is one of the major catabolites. In a multiple dose toxicity study, BAT8001 had a NOAEL of 15 mg/kg versus 10 mg/kg for T-DM1. BAT8001 exhibits similar potency to T-DM1 on inhibiting HER2-positive cell proliferation and tumor growth, yet demonstrates better multiple dose toxicity than T-DM1. The improved toxicity profile of BAT8001 suggests that the novel noncleavable linker utilized in BAT8001 is more stable than the linker utilized in T-DM1. BAT8001 is very efficacious in cell-line xenograft models of breast cancer. The preclinical profile of BAT8001 warrants further development for the treatment of breast cancer and other HER2-positive cancers.

Citation Format: Tang W, Deng X, Ou Z, Gan J, Dong Q, Tan B, Lu L, Chen B, Bao C, Li S, Thomas B, Yu J-C. BAT8001, a potent anti-HER2 antibody-drug conjugate with a novel stable linker for the treatment of HER2-positive breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-17-39.

Contemporary global perspectives of medical students on research during undergraduate medical education: a systematic literature review

BACKGROUND

The need for increased expertise in evidence-based medicine and concerns about the decreasing numbers of physician-scientists have underscored the need for promoting and encouraging research in medical education. The critical shortage of physician-scientists has assumed a dimension demanding a coordinated global response. This systematic review examined the perceptions of medical students regarding research during undergraduate medical school from a global perspective.

METHODS

Articles for this review were searched using PubMed, SCOPUS and Cochrane. Studies published within the last 10 years of the start date of the study that met specified criteria were included. Identified articles were initially screened by title as well as keywords and their abstracts were further screened to determine relevance. Full-text of screened articles were read for validation prior to inclusion.

RESULTS

A total of 26 articles from the literature met the set criteria for final inclusion. Contents of the abstracts and corresponding full-text articles were analyzed for themes on the research perspectives of medical students. The themes derived comprised: research interest, physician-scientist decline and shortage, responses to physician-scientist shortage, curriculum issues, skills (motivation and self-efficacy), research needs, socioeconomic and cultural issues, and barriers.

CONCLUSION

Despite the wide variations in medical education systems worldwide, the perspectives of medical students on research in undergraduate medical education shared many common themes. Globally, medical students underscored the necessity and importance of research in medical education as reflected by many students reporting positive attitudes and interest in research endeavors. Moreover, a worldwide consensus emerged regarding the decline in the numbers of physician-scientists and the necessity for a reversal of that trend. Various barriers to research engagement and participation were highlighted.