LINE-1 hypomethylation, increased retrotransposition and tumor-specific insertion in upper gastrointestinal cancer.

The long interspersed nuclear element-1 (LINE-1) retrotransposons are a major family of mobile genetic elements, comprising approximately 17% of the human genome. The methylation state of LINE-1 is often used as an indicator of global DNA methylation levels and it regulates the retrotransposition and somatic insertion of the genetic element. We have previously reported the significant relationship between LINE-1 hypomethylation and poor prognosis in upper gastrointestinal (GI) cancers. However, the causal relationships between LINE-1 hypomethylation, retrotransposition, and tumor-specific insertion in upper GI cancers remain unknown. We used bisulfite-pyrosequencing and quantitative real-time PCR to verify LINE-1 methylation and copy number in tissue samples of 101 patients with esophageal and 103 patients with gastric cancer. Furthermore, we analyzed the LINE-1 retrotransposition profile with an originally developed L1Hs-seq. In tumor samples, LINE-1 methylation levels were significantly lower than non-tumor controls, while LINE-1 copy numbers were markedly increased. As such, there was a significant inverse correlation between the LINE-1 methylation level and copy number in tumor tissues, with lower LINE-1 methylation levels corresponding to higher LINE-1 copy numbers. Of particular importance is that somatic LINE-1 insertions were more numerous in tumor than normal tissues. Furthermore, we observed that LINE-1 was inserted evenly across all chromosomes, and most often within genomic regions associated with tumor-suppressive genes. LINE-1 hypomethylation in upper GI cancers is related to increased LINE-1 retrotransposition and tumor-specific insertion events, which may collectively contribute to the acquisition of aggressive tumor features through the inactivation of tumor-suppressive genes.

Presence of Fusobacterium nucleatum in relation to patient survival and an acidic environment in oesophagogastric junction and gastric cancers.

BACKGROUND: Fusobacterium nucleatum inhabits the oral cavity and affects the progression of gastrointestinal cancer. Our prior findings link F. nucleatum to poor prognosis in oesophageal squamous cell carcinoma via NF-κB pathway. However, its role in oesophagogastric junction and gastric adenocarcinoma remains unexplored. We investigated whether F. nucleatum influences these cancers, highlighting its potential impact. METHODS: Two cohorts of EGJ and gastric adenocarcinoma patients (438 from Japan, 380 from the USA) were studied. F. nucleatum presence was confirmed by qPCR, FISH, and staining. Patient overall survival (OS) was assessed based on F. nucleatum positivity. EGJ and gastric adenocarcinoma cell lines were exposed to F. nucleatum to study molecular and phenotypic effects, validated in xenograft mouse model. RESULTS: In both cohorts, F. nucleatum-positive EGJ or gastric adenocarcinoma patients had notably shorter OS. F. nucleatum positivity decreased in more acidic tumour environments. Cancer cell lines with F. nucleatum showed enhanced proliferation and NF-κB activation. The xenograft model indicated increased tumour growth and NF-κB activation in F. nucleatum-treated cells. Interestingly, co-occurrence of F. nucleatum and Helicobacter pylori, a known risk factor, was rare. CONCLUSIONS: F. nucleatum can induce the NF-κB pathway in EGJ and gastric adenocarcinomas, leading to tumour progression and poor prognosis.

Cancer-Associated Fibroblast-Derived IL-8 Upregulates PD-L1 Expression in Gastric Cancer Through the NF-κB Pathway.

BACKGROUND: The expression of programmed death-ligand 1 (PD-L1) in tumor cells is a leading cause of tumor immune escape; however, the precise mechanism underlying the regulation of PD-L1 expression in gastric cancer (GC) cells remains unknown. In this study, we aimed to investigate the potential mechanism of cancer-associated fibroblasts (CAFs) regulating PD-L1 expression in GC cells. METHODS: We evaluated the immunomodulatory effects of CAFs in GC cells in vitro via the transwell co-culture system, cytometric bead array, and Western blotting. We detected the role of interleukin (IL)-8 in affecting underlying pathways in GC cells via transfecting IL-8 small-interfering RNA (siRNA), and the protection effects of CAFs on GC cells exposed to CD8+ T cells via cytotoxicity assays. RESULTS: The results revealed that CAFs upregulated PD-L1 expression of GC cells. IL-8 expression was increased after KATO III or MKN45 cells co-cultured with CAF. Additionally, CAF-derived IL-8 promoted PD-L1 expression in GC cells through the P38, JNK, and NF-κB pathways. Besides, repertaxin, an IL-8 receptors (CXCR1/2) inhibitor, reduced PD-L1 expression in GC cells by blocking the P38, JNK, and NF-κB pathways. Furthermore, the expressions of p-P38, p-JNK, and p-NF-κB decreased after GC cells co-cultured with siIL-8-treated CAF. Moreover, repertaxin attenuated the protection of CAFs to cancer cells that were resistant to CD8+ T-cell cytotoxicity, and improved the antibody effects of anti-PD-L1 facilitating CD8+ T-cell cytotoxicity by targeting IL-8. CONCLUSION: Targeting CAF-derived IL-8 may defeat PD-L1 upregulation-mediated immune resistance in GC cells, which provides a novel approach to improve the immunotherapeutic efficacies of patients with GC.

Body Composition and Clinical Outcomes in Esophageal Cancer Patients Treated with Immune Checkpoint Inhibitors.

BACKGROUND: Obesity is associated with increased mortality in various cancers, but the relationship between obesity and clinical outcomes in unresectable or recurrent esophageal cancer who receive immune checkpoint inhibitors (ICIs) remains unknown. This study investigated the association between body composition and clinical outcomes in patients with unresectable or recurrent esophageal cancer who received ICIs. METHODS: Utilizing an unbiased database of 111 unresectable or recurrent esophageal cancers, we evaluated the relationships between body composition (body mass index, waist circumference, psoas major muscle volume, and subcutaneous and visceral fat areas) at the initiation of ICI treatment and clinical outcomes including the disease control rate and progression-free survival (PFS). RESULTS: Waist circumference was significantly associated with the disease control rate at the first assessment (P = 0.0008). A high waist circumference was significantly associated with favorable PFS in patients treated with nivolumab. In an univariable model, for 5-cm increase of waist circumference in the outcome category of PFS, univariable hazard ratio (HR) was 0.73 (95% confidence interval [CI], 0.61-0.87; P = 0.0002). A multivariable model controlling for potential confounders yielded a similar finding (multivariable HR, 0.56; 95% CI, 0.33-0.94; P = 0.027). We observed the similar finding in esophageal cancer patients treated with pembrolizumab+CDDP+5-FU (P = 0.048). In addition, waist circumference was significantly associated with the prognostic nutritional index (P = 0.0073). CONCLUSIONS: A high waist circumference was associated with favorable clinical outcomes in ICI-treated patients with unresectable or recurrent esophageal cancer, providing a platform for further investigations on the relationships among body composition, nutrition, and the immune status.

FBXW7 regulates the sensitivity of imatinib in gastrointestinal stromal tumors by targeting MCL1.

BACKGROUND: Imatinib contributes to improving prognosis of high-risk or unresectable gastrointestinal stromal tumors (GISTs). As therapeutic efficacy is limited by imatinib resistance and toxicity, the exploration of predictive markers of imatinib therapeutic efficacy that enables patients to utilize more effective therapeutic strategies remains urgent. METHODS: The correlation between FBXW7 and imatinib resistance via FBXW7-MCL1 axis was evaluated in vitro and in vivo experiments. The significance of FBXW7 as a predictor of imatinib treatment efficacy was examined in 140 high-risk patients with GISTs. RESULTS: The ability of FBXW7 to predict therapeutic efficacy of adjuvant imatinib in high-risk GIST patients was determined through 5-year recurrence-free survival (RFS) rates analysis and multivariate analysis. FBXW7 affects imatinib sensitivity by regulating apoptosis in GIST-T1 cells. FBXW7 targets MCL1 to regulate apoptosis. MCL1 involves in the regulation of imatinib sensitivity through inhibiting apoptosis in GIST-T1 cells. FBXW7 regulates imatinib sensitivity by down-regulating MCL1 to enhance imatinib-induced apoptosis in vitro. FBXW7 regulates imatinib sensitivity of GIST cells by targeting MCL1 to predict efficacy of imatinib treatment in vivo. CONCLUSIONS: FBXW7 regulates imatinib sensitivity by inhibiting MCL1 to enhance imatinib-induced apoptosis in GIST, and predicts efficacy of imatinib treatment in high-risk GIST patients treated with imatinib.

Evaluation of the associations of interlukin-7 genetic variants with toxicity and efficacy of immune checkpoint inhibitors: A replication study of a Japanese population, based on the findings of a European genome-wide association study.

AIM: Recent genome-wide association studies of European populations have identified rs16906115, a single-nucleotide polymorphism in the interleukin-7 gene, as a predictor of immune-related adverse events (irAEs) and the therapeutic efficacy of immune checkpoint inhibitors. We evaluated this single-nucleotide polymorphism in a Japanese population. METHODS: From January 2021, we stored host DNA from individuals who received various types of immune checkpoint inhibitors. From this population, we categorized 510 participants into cases (grade ≥2 irAEs) and controls (received ≥3 immune checkpoint inhibitor doses, follow-up ≥12 weeks, no irAEs), and divided 339 hepatocellular carcinoma patients treated with atezolizumab/bevacizumab into responders and non-responders, evaluated using the modified response evaluation criteria in solid tumors. We compared the minor allele frequencies of rs16906115 between cases and controls, and responders and non-responders. RESULTS: In the irAE prediction analysis of 234 cases and 276 controls, the minor allele frequency was 0.244 in the case group and 0.265 in the control group. This difference is not significant. In the analysis predicting the therapeutic efficacy for hepatocellular carcinoma patients, the responders had a significantly lower minor allele frequency of 0.220, compared with 0.300 for the non-responders (p = 0.022). Univariate and multivariate analyses identified the minor allele homozygosity as a significant predictor of treatment response, with odds ratios of 0.292 (p = 0.015) in the univariate analysis and 0.315 (p = 0.023) in the multivariate analysis. CONCLUSIONS: In our Japanese cohort, no association was found between the rs16906115 minor allele and irAEs or treatment efficacy. The minor allele homozygosity may be associated with a negative therapeutic outcome. CLINICAL TRIAL REGISTRATION: UMIN Clinical Trials Registry with the number UMIN000043798.

Laparoscopic versus open abdominal lymph node dissection for esophageal squamous cell carcinoma: a propensity score matching analysis.

PURPOSE: To compare the short- and long-term outcomes of laparoscopic and open abdominal lymph node dissection using propensity score matching (PSM) analysis. METHODS: The subjects of this retrospective analysis were 459 patients who underwent curative resection for esophageal squamous cell carcinoma (ESCC) between May, 2005 and December, 2019, at our hospital. Patients were divided into two groups: the Laparoscopic (Lap group) and the Open (Open group). Post-PSM, 139 patients from each group were selected for the analysis to compare the short- and long-term outcomes between the groups. RESULTS: The Lap group experienced fewer Clavien-Dindo (CD) Grade ≥ 2 complications (28.1% vs. 40.3%, P = 0.04) and lower rates of abdominal surgical site infections (SSI) (2.9% vs. 7.9%, P = 0.02) than the Open group. The number of lymph nodes harvested was similar in the Lap and Open groups (14.8 ± 7.5 vs. 15.7 ± 8.6, P = 0.34). There was no significant difference in 3-year overall survival rates (81.2% vs. 69.5%, P = 0.12) or relapse-free survival rates (61.1% vs. 58.2%, P = 0.54) between the groups. CONCLUSIONS: Laparoscopic abdominal lymph node dissection for ESCC can be performed safely and appears to be beneficial.

The relationship between the treatment course and prognosis of oligometastasis after esophageal squamous cell carcinoma resection.

PURPOSE: The concept of oligometastasis, which represents limited metastatic disease, has recently gained interest, accompanied by a more detailed classification. This study aims to investigate the relationship between the treatment course and prognosis in patients with a recurrence of esophageal squamous cell carcinoma (ESCC) after curative esophagectomy. METHODS: 126 patients with ESCC recurrence after curative resection were enrolled in this study. Oligometastasis was defined as fewer than five recurrences in a single organ. Patients were classified as having oligometastatic recurrence (OLR) or polymetastatic recurrence (PLR). Patients were further classified into four subgroups according to lesion progression: persistent oligorecurrence (PER-OLR), converted polyrecurrence (CON-PLR), induced oligorecurrence (IND-OLR), and persistent polyrecurrence (PER-PLR). We analyzed the relationship between the recurrence patterns and prognosis according to the progression of oligometastatic lesions. RESULTS: OLR was identified in 58 (46%) of 126 patients with recurrence. Patients with OLR had a significantly better prognosis than those with PLR (P < 0.0001). A further subgroup analysis revealed that patients who underwent IND-OLR had a similar prognosis to those who underwent PER-OLR. CONCLUSIONS: This study suggests that OLR is a prognostic factor after recurrence following resection of ESCC and that PLR can be converted to OLR by therapeutic intervention to achieve a long-term survival.

Intratumour Fusobacterium nucleatum and immune response to oesophageal cancer.

BACKGROUND: Experimental evidence suggests a role of intratumour Fusobacterium nucleatum in the aggressive behaviour of gastrointestinal cancer through downregulating anti-tumour immunity. We investigated the relationship between intratumour F. nucleatum and immune response to oesophageal cancer. METHODS: Utilising an unbiased database of 300 resected oesophageal cancers, we measured F. nucleatum DNA in tumour tissue using a quantitative polymerase chain reaction assay, and evaluated the relationship between the abundance of F. nucleatum and the densities of T cells (CD8 + , FOXP3 + and PDCD1 + ), as well as lymphocytic reaction patterns (follicle lymphocytic reaction, peritumoural lymphocytic reaction, stromal lymphocytic reaction and tumour-infiltrating lymphocytes) in oesophageal carcinoma tissue. RESULTS: F. nucleatum was significantly and inversely associated only with the peritumoural lymphocytic reaction (P = 0.0002). Compared with the F. nucleatum-absent group, the F. nucleatum-high group showed a much lower level of the peritumoural lymphocytic reaction (univariable odds ratio, 0.33; 95% confidence interval, 0.16-0.65; P = 0.0004). A multivariable model yielded a similar finding (multivariable odds ratio, 0.34; 95% confidence interval 0.16-0.69; P = 0.002). CONCLUSIONS: Intratumour F. nucleatum is associated with a diminished peritumoural lymphocytic reaction, providing a platform for further investigations on the potential interactive roles between intratumour F. nucleatum and host immunity.

Frailty Assessed by the Clinical Frailty Scale is Associated with Prognosis After Esophagectomy.

BACKGROUND: The Clinical Frailty Scale (CFS) is a simple and validated tool for assessing frailty, and higher CFS scores are correlated with worse perioperative outcomes after cardiovascular surgery. However, the relationship between the CFS scores and postoperative outcomes after esophagectomy remain unclear. METHODS: We retrospectively analyzed data from 561 patients with esophageal cancer (EC) who underwent resection from August 2010 to August 2020. We defined a CFS score of ≥4 as indicative of frailty; thus, patients were classified into frail patients (CFS scores of ≥4) and non-frail patients (CFS scores of ≤3). The Kaplan-Meier method was used to describe the overall survival (OS) distributions with the log-rank test. RESULTS: Of the 561 patients, 90 (16%) had frailty and 471 (84%) did not. Frail patients had a significantly older age, lower body mass index, higher American Society of Anesthesiologists physical status classification, and greater cancer progression than non-frail patients. The 5-year survival rate was 68% in non-frail patients and 52% in frail patients. OS was significantly shorter in frail than non-frail patients (p = 0.017 by log-rank test). In particular, OS was significantly shorter in frail patients with clinical stage I-II EC (p = 0.0024 by log-rank test) but was not correlated with frailty in patients with clinical stage III-IV EC (p = 0.87 by log-rank test). CONCLUSIONS: Preoperative frailty was associated with shorter OS after resection of EC. The CFS score may be a prognostic biomarker for patients with EC, especially early-stage EC.

C-Reactive Protein Levels After Esophagectomy are Associated with Increased Surgical Complications and Poor Prognosis in Esophageal Squamous Cell Carcinoma Patients.

BACKGROUND: C-reactive protein (CRP) levels are reported to predict complications and survival after surgery in various cancers. However, the relationship between postoperative CRP levels and short- and long-term outcomes of esophageal squamous cell carcinoma (ESCC) patients after esophagectomy is unclear. METHOD: We reviewed the records of 543 ESCC patients who underwent subtotal esophagectomy with gastric conduit reconstruction at Kumamoto University Hospital between August 2010 and July 2021. Blood tests for CRP were done on postoperative days (PODs) 1, 3, 5 or 6, and 7 or 8. RESULTS: The mean CRP levels on day 1, day 3, day 5/6, and day 7/8 were 6.68 ± 0.13 mg/dL, 11.49 ± 0.27 mg/dL, 7.48 ± 0.26 mg/dL, and 5.38 ± 0.22 mg/dL, respectively. Mean CRP levels were highest on day 3, and CRP levels after day 3 correlated with grade >2 complications based on the Clavien-Dindo classification. Receiver operating characteristic curve analysis established the optimal cut-off value for CRP day 3 levels to be 12.19 mg/dL. Multivariate logistic regression analyses found that high CRP day 3 levels significantly correlated with grade >2 complications (odds ratio [OR] 3.77, 95% confidence interval [CI] 2.56-5.35; p < 0.001). Moreover, high day 7/8 CRP levels (>3.52) correlated with postoperative survival, and based on multivariate logistic regression analyses, were significantly associated with poor prognosis (hazard ratio 1.67, 95% CI 1.14-2.43; p = 0.008). CONCLUSION: Our findings suggest CRP day 3 levels as a potential biomarker for predicting postoperative complications and that CRP day 7/8 levels have potential prognostic value for ESCC patients after esophagectomy.

Dynamic Alteration in HLA-E Expression and Soluble HLA-E via Interaction with Natural Killer Cells in Gastric Cancer.

BACKGROUND: Some reports showed the immune tolerance of soluble human leukocyte antigen E (HLA-E), but the role that soluble HLA-E plays in gastric cancer (GC) is unknown. We aimed to clarify the molecular mechanism and clinical significance of soluble HLA-E in GC. METHODS: We examined the expression of HLA-E on GC cells and soluble HLA-E under co-culture with natural killer (NK) cells in a time-dependent manner. Changes in NK cell activity were investigated using anti-NK group 2 member A (NKG2A) antibodies in the presence of soluble HLA-E. Expression of soluble HLA-E in the serum of GC patients was determined. RESULTS: Whereas HLA-E expression on GC cells peaked with interferon (IFN)-γ secretion by NK cells in a time-dependent manner, soluble HLA-E was upregulated in conditioned medium. Pre-incubation with anti-NKG2A antibodies increased the activation of NKG2A+ NK cells in the presence of soluble HLA-E. Expression of soluble HLA-E in the serum of GC patients correlated with disease progression. CONCLUSIONS: HLA-E expression dynamically changes on GC cells and in conditioned medium. Furthermore, soluble HLA-E can contribute to immune escape in GC cell lines, which may have significance in clinical practice. Moreover, soluble HLA-E may be a potential prognostic biomarker.

Localized Gastroesophageal Adenocarcinoma in the Elderly: Is Age a Factor Associated with Suboptimal Treatment?

INTRODUCTION: Gastroesophageal adenocarcinoma is relatively common in elderly patients as the incidence increases with age. However, the optimal treatment approach is not well established in this group of patients. The aim of this study is to review our experience for localized gastroesophageal adenocarcinoma in patients aged ≥80 years and to assess association between patient characteristics, clinical factors, and overall survival (OS) in order to optimize the therapeutic approaches for this population. METHODS: Patients ≥80 years old treated for localized gastroesophageal adenocarcinoma were retrospectively analyzed. Survival curves were estimated using the Kaplan-Meier method. Univariate and multivariate Cox proportional hazards regression models were applied to assess the association between patient characteristics and OS. Factors that were significant in the multivariate model were included in the final reduced model. RESULTS: 127 patients ≥80 years old, were included in this study with median age of 83 years. The median follow-up time was 3.2 years, and median OS was 2.5 years (95% CI: 2.0-3.1 years). Independent prognostic factors for OS were Eastern Cooperative Oncology Group (ECOG) performance status (PS) (p = 0.003), baseline clinical stage (p = 0.01), and surgery (p = 0.001). ECOG PS, tumor location, baseline stage, tumor grade, and surgery were included in the final reduced model. CONCLUSION: Surgical treatment can improve survival in elderly patients. Therapeutic decisions should be based on the patients' general condition rather that age alone.

Postoperative respiratory morbidity can adversely affect prognosis in thoracoscopic esophagectomy for esophageal cancer: a retrospective study.

BACKGROUND: Esophagectomy for esophageal cancer is associated with frequent respiratory morbidities, which may deteriorate postoperative survival outcomes. Thoracoscopic esophagectomy (TE) is less invasive and is associated with fewer respiratory morbidities than open esophagectomy. However, the relationship between post-TE respiratory morbidity and prognosis has not been well established. METHODS: This study included 378 patients who underwent TE for esophageal cancer between May 2011 and November 2020. Patients were divided into two groups based on the presence of respiratory morbidity. Short-term and long-term outcomes of the groups were retrospectively compared. RESULTS: Respiratory morbidity was significantly associated with heavy past smoking habits (Brinkman index, p = 0.0039), short duration of smoking cessation (p = 0.0012), worse American Society of Anesthesiologists physical status (p = 0.016), frequent cardiovascular comorbidities (p = 0.0085), and long hospital stay (p < 0.001). Respiratory morbidity significantly deteriorated overall survival (OS) (p = 0.011) and relapse-free survival (p = 0.062) and could be an independent prognostic factor for OS (hazard ratio = 1.90, 95% confidence interval = 1.093-3.311, p = 0.023) along with clinical stage. CONCLUSION: Respiratory morbidity can adversely affect prognosis after TE. Various prophylaxes for respiratory morbidity are required to improve the short-term and long-term outcomes of TE for esophageal cancer.

Textbook outcome contributes to long-term prognosis in older adults with gastric cancer.

PURPOSE: Textbook outcome (TO) is a composite quality measurement of short-term outcomes for evaluating surgical procedures. We investigated whether TO can be used to predict outcomes after curative gastric cancer (GC) surgery in older adults. METHODS: We retrospectively analyzed 492 consecutive patients who underwent curative gastrectomy for GC from 2005 to 2017. Among these, 141 advanced-age patients were eligible. The patients were divided into two groups: those who achieved TO (a-TO group) and those who failed to achieve TO (f-TO group). In accordance with previous reports, TO consisted of eight metrics. We evaluated the association between TO and long-term survival. RESULTS: TO was achieved 73 (52%) patients. The patients in the f-TO group had a significantly higher body mass index (P = 0.01), longer surgery time (P = 0.03), and more blood loss (P = 0.001). The metric with the lowest achievement rate was "no postoperative severe complication." The patients in the f-TO group had significantly shorter overall survival than those in the a-TO group (P = 0.03). Multivariable Cox regression analyses of overall survival revealed that an American Society of Anesthesiologists physical status classification of 3 (hazard ratio [HR], 3.28; 95% confidence interval [CI], 1.79-5.98; P < 0.0001) and f-TO (HR, 1.92; 95% CI, 1.09-3.39; P = 0.02) were significantly associated with poor overall survival. CONCLUSION: TO can be used to predict outcomes after curative GC surgery in patients of advanced age.

Textbook outcome contributes to long-term prognosis in elderly colorectal cancer patients.

PURPOSE: Textbook outcome (TO) has been used to define achievement of multiple "ideal" or "optimal" surgical and postoperative quality measures from the patient's perspective. However, TO has not been reported for their impact on survival in elderly, including CRC surgery. This study determined whether TO is associated with long-term outcomes after curative colorectomy in patients with colorectal cancer (CRC). METHODS: Patient who underwent curative surgery over 75 years old for CRC between March 2005 and December 2016. TO included five separate parameters: surgery within 6 weeks, radical resection, Lymph node (LN) yield ≥ 12, no stoma, and no adverse outcome. When all 5 short-term quality of care parameters were realized, TO was achieved (TO). If any one of the 5 parameters was not met, the treatment was not considered TO (nTO). RESULTS: TO was realized in 80 patients (43.0%). Differences in surgical-related characteristics and pathological characteristics according to TO had no statistically significant differences in baseline characteristics, except for Lymph node dissection. The Kaplan-Meier curves for OS and RFS association between TO and nTO had significantly poor 5-year OS and 5-year RFS compared with the TO groups (OS, 77.8% vs. 60.8%, P < 0.01; RFS, 69.6% vs. 50.8%, P = 0.01). In the multivariate analysis, nTO was an independent predictive factor for worse OS (HR, 2.04; 95% confidence interval (CI), 1.175-3.557; P = 0.01) and RFS (HR, 1.72; 95% CI, 1.043-2.842; P = 0.03). CONCLUSIONS: TO can be a useful predictor for postoperative morbidity and prognosis after curative colorectomy for CRC.

Relationship between gut microbiome Fusobacterium nucleatum and LINE-1 methylation level in esophageal cancer.

BACKGROUND: We previously demonstrated the relationship of human microbiome Fusobacterium nucleatum with unfavorable clinical outcomes and inferior chemotherapeutic responses in esophageal cancer. Global DNA methylation is associated with the occurrence and development of various cancers. In our previous study, LINE-1 hypomethylation (i.e., global DNA hypomethylation) was associated with a poor prognosis in esophageal cancer. As the gut microbiota may play crucial roles in the DNA methylation of host cells, we hypothesized that F. nucleatum might influence LINE-1 methylation levels in esophageal cancer. METHODS: We qualified the F. nucleatum DNA using a quantitative PCR assay and LINE-1 methylation via a pyrosequencing assay using formalin-fixed paraffin-embedded specimens from 306 esophageal cancer patients. RESULTS: Intratumoral F. nucleatum DNA was detected in 65 cases (21.2%). The LINE-1 methylation scores ranged from 26.9 to 91.8 (median = 64.8) in tumors. F. nucleatum DNA was related to the LINE-1 hypomethylation of tumor lesions in esophageal cancer (P < 0.0001). The receiver operating characteristic curve analysis showed that the area under the curve was 0.71 for F. nucleatum positivity. Finally, we found that the impact of F. nucleatum on clinical outcomes was not modified by LINE-1 hypomethylation (P for interaction = 0.34). CONCLUSIONS: F. nucleatum alters genome-wide methylation levels in cancer cells, which may be one of the mechanisms by which F. nucleatum affects the malignant behavior of esophageal cancer.

PD-L1 and PD-L2 expression status in relation to chemotherapy in primary and metastatic esophageal squamous cell carcinoma.

Immune checkpoint inhibitors have shown efficacy in various cancers. Although programmed death ligand 1/2 (PD-L1/L2) expressions have been demonstrated as predictive biomarkers of response to immune checkpoint inhibitors and prognostic markers, whether PD-L1/L2 expression is altered in esophageal squamous cell carcinoma during the therapeutic course is unclear. Whether PD-L1/L2 expression in metastatic or recurrent lesions is consistent with that in primary tumors is also unknown. This study included 561 surgically resected esophageal squamous cell carcinomas and PD-L1/L2 expression was evaluated by immunohistochemistry. We investigated the influence of chemotherapeutic drugs (cisplatin and fluorouracil) on PD-L1/L2 expression and PD-L1/L2-related pathways in vitro. We also examined PD-L1/L2 expression in 18 surgically resected lymph node metastases and 10 recurrent lesions compared with primary lesions. The positive rate of PD-L1 was significantly higher in patients with preoperative chemotherapy than in those without preoperative therapy. The positive rate of PD-L2 expression showed no significant difference between patient groups. Cisplatin increased PD-L1 expression in cancer cell lines in vitro, but decreased PD-L2 in some cell lines. The effects of cisplatin on phosphorylated signal transducer and activator of transcription 1/3 (pSTAT1/3) also differed depending on cell lines. Fluorouracil increased PD-L1 and PD-L2 expression. PD-L1/L2 expression in lymph node metastases and recurrent lesions did not always match expression in primary lesions. PD-L1/L2 expression may be altered by preoperative chemotherapy, and PD-L1 /L2 expression in primary lesions does not always match that of metastatic/recurrent lesions. Thus, one-time evaluation is not sufficient to evaluate PD-L1/L2 expression as a biomarker in esophageal cancer.

Comprehensive Analysis of Multiple Primary Cancers in Patients With Esophageal Squamous Cell Carcinoma Undergoing Esophagectomy.

OBJECTIVE: The aim of this study was to elucidate the latest epidemiology and risk factors for multiple primary cancers (MPCs), and the association between neoadjuvant chemotherapy (NAC) and postoperative metachronous cancer (PMC) in patients with esophageal squamous cell carcinoma (ESCC) who underwent esophagectomy. SUMMARY OF BACKGROUND DATA: Background data to derive appropriate screening strategies are insufficient. METHODS: This study consisted of 3 retrospective investigations. A total of 766 consecutive patients with ESCC who underwent esophagectomy between April 2005 and December 2019 were eligible for epidemiological analysis. Of these, 688 patients without missing data were analyzed for the risk of MPCs. In total, 364 patients who underwent NAC (115) and no preoperative treatments (249) were investigated for the association between NAC and PMC. RESULTS: Of 766 patients, 288 (38%) patients experienced 357 MPCs in their life. PMCs identified after the completion of 5-year postoperative follow-up were significantly more advanced (P = 0.019). Male sex [hazard ratio (HR) = 3.04, P = 0.038], older age (HR = 2.39, P < 0.001), and diabetes mellitus (HR = 1.76, P = 0.034) were risk factors for preoperative metachronous cancers. Heavy smoking (HR = 1.70, P = 0.014) and drinking (HR = 1.61, P = 0.029) were risk factors for synchronous cancers. NAC significantly reduced PMC incidence ( P = 0.043). NAC showed a trend to contribute to improved survival via reduced deaths from PMCs, although this did not reach significance ( P = 0.082). CONCLUSIONS: ESCC is associated with a high risk of MPCs. Continuing follow-up for PMCs after the completion of 5-year postoperative follow-up is important. NAC may reduce PMCs, representing a novel mechanism for improving survival in patients with locally advanced ESCC.

Evaluation of HLA-E Expression Combined with Natural Killer Cell Status as a Prognostic Factor for Advanced Gastric Cancer.

BACKGROUND: The NKG2A/HLA-E pathway functions as an immune checkpoint with potential for inhibition using therapeutic antibodies. Through this pathway, immune cells lose activity, which allows cancers to progress. We aimed to determine whether HLA-E expression combined with NK cell status serves as a prognostic biomarker for gastric cancer (GC). METHODS: We enrolled patients (n = 232) with advanced GC who underwent curative gastrectomy. Immunohistochemical analyses of global HLA-E expression, and the expression of CD56 and CD3 to identify NK cells were performed. Survival analysis was performed to evaluate the significance of HLA-E expression and NK status. RESULTS: Patients with HLA-E-positive was 104 (41.3%) and had significantly worse prognosis of relapse-free survival (RFS) compared with those with HLA-E-negative. Moreover, patients with NK Low status had worse prognoses for RFS compared with those with NK High status. Statistical analysis of RFS demonstrated that HLA-E expression was a significant independent factor for poor prognosis (HR 1.57, 95% CI 1.04-2.36, P = 0.031). Furthermore, HLA-E-positive patients with low NK low status experienced the shortest RFS, particularly those in the upper GC group. CONCLUSIONS: HLA-E served as a prognostic factor after curative resection of GC, and HLA-E expression combined with NK status served as a sensitive prognostic biomarker for advanced GC.