Identification of the factor affecting learning curves of laparoscopic gastrectomy through the experience at a Japanese high-volume center over the last decade.

Background: Though laparoscopic gastrectomy (LG) has become the gold standard for gastric cancer treatment according to the Japanese treatment guidelines, its learning curve remains steep. Decreasing numbers of surgeons and transitions in the work environment have changed LG training recently. We analyzed LG training over the last decade to identify factors affecting the learning curve. Study Design: Laparoscopic distal and pylorus-preserving gastrectomies conducted between 2010 and 2020 were included. We assessed learning curves based on the standard operation time (SOT) defined by analysis of covariance. Then we divided the trainees into two groups based on the length of the learning curve and examined the factors affecting the learning curve with linear regression analysis. Results: Among 2335 LGs, 960 cases treated by 27 trainees and 1301 cases treated by six attending surgeons were analyzed. The operation time was prolonged (p = 0.009) and postoperative morbidity rates were lower (p = 0.0003) for cases treated by trainees. Trainees experienced 38 (range, 9-81) cases as scopists and nine (range, 0-41) cases as first assistants to the first operator. The learning curve was approximately 30 cases. The SOT was calculated based on gender, body mass index, tumor location, reconstruction, and lymph node dissection. Trainees who had shorter learning curves had more experience (51-100 cases) with any laparoscopic surgery before LG training than the others (11-50 cases, p = 0.017). Conclusion: Sufficient experience with laparoscopic surgery before starting LG training might contribute to the efficiency of LG training and shorten the learning curve.

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.

Prognostic Impact of PD-1 on Tumor-Infiltrating Lymphocytes in 433 Resected Esophageal Cancers.

BACKGROUND: Immune checkpoint inhibitors targeting the programmed death 1 (PD-1)/programmed death-ligand 1 (PD-L1) pathway have demonstrated antitumor effects in patients with various malignancies, including esophageal cancer. Thus, a better understanding of local immunity in esophageal cancer is crucial for improving treatment and clinical outcomes. METHODS: We evaluated PD-1 expression on tumor-infiltrating lymphocytes (TILs), as well as PD-L1 expression on cancer cells, by immunohistochemistry and immunofluorescence using a nonbiased database of 433 curatively resected esophageal cancers. With the idea of application as liquid biopsy, PD-1 expression status on peripheral lymphocytes was evaluated by flow cytometry. RESULTS: The cutoff value of PD-1 expression was the median PD-1 count. Compared with cases of low PD-1 expression (n = 219), cases with high levels of PD-1 expression (n = 213) showed significantly worse overall survival (log-rank P = .0017). The prognostic effect of PD-1 differed according to the preoperative treatment status (P for interaction = .040); PD-1 expression was associated with high overall mortality among patients without preoperative therapy, while no such association was present among those with preoperative treatment. A stratification based on PD-1 and PD-L1 status was also significantly associated with overall survival (log-rank P = .0005). PD-1 expression on TILs was significantly associated with that on peripheral lymphocytes (P < .0001). CONCLUSIONS: PD-1 expression on TILs was associated with an unfavorable clinical outcome in esophageal cancer, supporting its role as a prognostic biomarker. The combination of PD-1 and PD-L1 expression enabled further classification of patients according to clinical outcome.

Molecular classification of gastric cancer predicts survival in patients undergoing radical gastrectomy based on project HOPE.

BACKGROUND: Gastric cancer (GC) has been classified based on molecular profiling like The Cancer Genome Atlas (TCGA) and Asian Cancer Research Group (ACRG), and attempts have been made to establish therapeutic strategies based on these classifications. However, it is difficult to predict the survival according to these classifications especially in radically resected patients. We aimed to establish a new molecular classification of GC which predicts the survival in patients undergoing radical gastrectomy. METHODS: The present study included 499 Japanese patients with advanced GC undergoing radical (R0/R1) gastrectomy. Whole-exome sequencing, panel sequencing, and gene expression profiling were conducted (High-tech Omics-based Patient Evaluation [Project HOPE]). We classified patients according to TCGA and ACRG subtypes, and evaluated the clinicopathologic features and survival. Then, we attempted to classify patients according to their molecular profiles associated with biological features and survival (HOPE classification). RESULTS: TCGA and ACRG classifications failed to predict the survival. In HOPE classification, hypermutated (HMT) tumors were selected first as a distinctive feature, and T-cell-inflamed expression signature-high (TCI) tumors were then extracted. Finally, the remaining tumors were divided by the epithelial-mesenchymal transition (EMT) expression signature. HOPE classification significantly predicted the disease-specific and overall survival (p < 0.001 and 0.020, respectively). HMT + TCI showed the best survival, while EMT-high showed the worst survival. The HOPE classification was successfully validated in the TCGA cohort. CONCLUSIONS: We established a new molecular classification of gastric cancer that predicts the survival in patients undergoing radical surgery.

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.

Prognostic and clinical impact of PD-L2 and PD-L1 expression in a cohort of 437 oesophageal cancers.

BACKGROUND: The PD-1/PD-L1 pathway plays critical roles in tumour immunology, and serves as an immune-based therapeutic target. Less is known regarding PD-L2, another ligand of PD-1, and its relation to clinical outcome in human cancers. METHODS: We used a database of 437 surgically and 100 endoscopically resected oesophageal cancers (squamous cell carcinoma, n = 483; adenocarcinoma, n = 36; others, n = 18) to evaluate PD-L2 and PD-L1 expression by immunohistochemistry. RESULTS: Compared with PD-L2-negative cases (n = 366, 83.8%), PD-L2-positive cases (n = 71, 16.2%) had worse overall survival (P = 0.011, log-rank test). There was not a significant correlation between PD-L2 and PD-L1 expression. Multiplex immunofluorescence revealed that there was variability in the expression pattern of PD-L2 and PD-L1. In early-stage tumours, PD-L2 expression was more frequently observed compared with PD-L1. CONCLUSIONS: PD-L2 as well as PD-L1 were associated with an unfavourable prognosis in oesophageal cancer, supporting the role of PD-L2 as a prognostic biomarker. Considering that PD-L2 and PD-L1 had different features in terms of expression timing and responses to chemotherapeutic drugs, evaluation of both PD-L2 and PD-L1 expression may be clinically important.

Prognostic Nutritional Index, Tumor-infiltrating Lymphocytes, and Prognosis in Patients with Esophageal Cancer.

OBJECTIVE: To determine whether prognostic nutritional index (PNI) affects clinical outcome through local immunity in esophageal cancers. BACKGROUND: PNI is an indicator of nutritional status and systemic immune competence, and has attracted attention as a prognostic biomarker. Tumor-infiltrating lymphocytes (TILs) are a specific histological feature of human cancers, reflecting an individual's immunological tumor response. METHODS: Using a nonbiased database of 337 curatively resected esophageal cancers, we evaluated the relationship between PNI, TILs status, CD8 expression by immunohistochemical staining, and clinical outcome. RESULTS: Compared with PNI-high cases (n = 220), PNI-low cases (n = 117) showed significantly worse overall survival (log-rank P < 0.001; hazard ratio: 2.23; 95% confidence interval: 1.56-3.18; P < 0.001; multivariate hazard ratio: 1.67; 95% confidence interval: 1.14-2.44; P = 0.008). The TILs status was also significantly correlated with overall survival (P < 0.001). In addition, PNI was significantly associated with TILs status (P < 0.001) and the CD8-positive cell count (P = 0.041). A significant relationship between the peripheral blood lymphocyte count and TILs status was also observed (P < 0.001). CONCLUSIONS: PNI and TILs score expression were associated with clinical outcome in esophageal cancer, supporting their roles as prognostic biomarkers. Considering the relationship between PNI and TILs, nutritional status and systemic immune competence may influence patient prognosis through local immune response.

Tumor Long-interspersed Nucleotide Element-1 Methylation Level and Immune Response to Esophageal Cancer.

OBJECTIVE: To examine the relationship between tumor long-interspersed nucleotide element-1 (LINE-1) methylation level and immune response to esophageal cancer. BACKGROUND: Evidence points to a correlation between the abundance of immune cells and a favorable prognosis in esophageal cancer patients. Accumulating evidence indicates a critical role of tumor LINE-1 hypomethylation in the aggressive behavior of esophageal cancer, which in turn leads to an unfavorable prognosis. METHODS: Utilizing a nonbiased database of 292 resected esophageal cancers, we measured tumor LINE-1 methylation level by pyrosequencing assay, and examined the relationship between LINE-1 methylation and the density of T cells (CD8 and FOXP3) and the lymphocytic reaction patterns (follicle lymphocytic reaction, peritumoral lymphocytic reaction, stromal lymphocytic reaction, and tumor-infiltrating lymphocytes) in esophageal carcinoma tissue. RESULTS: LINE-1 hypomethylation was associated with male gender and advanced stage cancer (P = 0.03 and P = 0.048, respectively). Tumor LINE-1 methylation level was significantly positively associated with peritumoral lymphocytic reaction (P = 0.004), but not with others. Compared with LINE-1 hypermethylation group, LINE-1 hypomethylation group showed much lower level of peritumoral lymphocytic reaction (univariable odds ratio 0.32, 95% confidence interval 0.16-0.64, P = 0.002). In multivariable model to control for potential confounders including disease stage, the similar finding was observed (multivariable odds ratio 0.31, 95% confidence interval 0.14-0.66, P = 0.004). CONCLUSIONS: Tumor LINE-1 hypomethylation level is associated with a diminished peritumoral lymphocytic reaction, providing impetus for further investigations on potential interactive roles of tumor LINE-1 hypomethylation and host immunity in esophageal cancer development.

Maf expression in human macrophages and lymph node sinus macrophages in patients with esophageal cancer.

The large Maf transcription factors are expressed in immune cells including macrophages and lymphocytes. To investigate the distribution of Maf expression in human organs, immunostaining for Maf was performed using sections of several human organs. High Maf expression was seen in the nucleus of macrophages in the gastrointestinal tract and lymph node sinus macrophages (LySMs). Then, we assessed whether Maf expression in LySMs was correlated with CD169 expression and the clinical prognosis in patients with esophageal cancer. Maf expression was associated with CD169 expression, but Maf expression in LySMs was not associated with the clinical course in patients with esophageal cancer. We determined which cytokines stimulate Maf expression using cultured macrophages. Immunocytochemistry showed that Maf expression was significantly elevated by interferon-γ. These results are the first report of Maf expression in human samples. Maf expression may be a marker for the macrophage population in humans.

Clinical Importance of Sputum in the Respiratory Tract as a Predictive Marker of Postoperative Morbidity After Esophagectomy for Esophageal Cancer.

BACKGROUND: Respiratory morbidity is common after esophagectomy and can be a major cause of surgery-related mortality. Thus, it is important to identify novel predictors that can preoperatively estimate the incidence of postoperative respiratory morbidity. Asymptomatic sputum in the respiratory tract is sometimes observed on preoperative computed tomography (CT). This study aimed to determine the clinical importance of sputum in the respiratory tract as a predictor of postoperative morbidity after esophagectomy for esophageal cancer. PATIENTS AND METHODS: The study included 609 consecutive patients who underwent three-incisional esophagectomy for esophageal cancer between April 2005 and November 2018. RESULTS: Among the patients, 76 (12.5%) had sputum in the respiratory tract on preoperative CT. This finding was significantly associated with older age, more extreme smoking habit, worse performance status, lower forced expiratory volume 1%, and more frequent pulmonary comorbidities. Additionally, the incidence of postoperative pneumonia was higher in these patients than in those without sputum (16 vs 8%, p = 0.028). Sputum in the main bronchus was associated with higher frequencies of morbidity of Clavien-Dindo classification (CDc) ≥ II (p = 0.019), severe morbidity of CDc ≥ IIIb (p = 0.058), pneumonia (p = 0.10), and pulmonary morbidity (p = 0.19) compared with the finding of sputum in the trachea alone. On multivariate analysis, sputum in the respiratory tract was an independent risk factor (hazard ratio, 2.07; 95% confidence interval, 1.019-4.207; p = 0.044) for postoperative pneumonia. CONCLUSIONS: Sputum in the respiratory tract is a novel predictor of postesophagectomy pneumonia. Patients with sputum in the more distal respiratory tract might have high risk of postoperative morbidities.

IDO1 Expression Is Associated With Immune Tolerance and Poor Prognosis in Patients With Surgically Resected Esophageal Cancer.

OBJECTIVES: To evaluate the relationship between indoleamine 2, 3-dioxygenase (IDO1) expression and tumoral immune status and clinical outcome in esophageal cancer. SUMMARY BACKGROUND DATA: IDO1 is a primary enzyme that generates immunosuppressive metabolites such as tryptophan and kynurenine. Like the PD-1/PD-L1 pathway, IDO1 plays a major role in tumor immunology and is a potential immune-based therapeutic target. METHODS: The expressions of IDO1, CD8 (a marker of cytotoxic T cells), FOXP3 [a marker of regulatory T cells (Treg)], and PD-L1 in 305 curatively resected esophageal cancers were evaluated by immunostaining. RESULTS: Overall survival was significantly better in the IDO1 negative cases (n = 234) than in the IDO1 positive cases (n = 71) [log-rank P = 0.0041; hazard ratio (HR): 1.75; 95% confidence interval (CI): 1.12-2.67; P = 0.015]. CD8 high expression was significantly positively correlated with overall survival (log-rank P = 0.025) and low IDO1 expression (P = 0.044). The inverse correlation between CD8 and IDO1 expressions was confirmed by double immunostaining for IDO1 and CD8. Stratification based on IDO1 and CD8 expressions was also significantly associated with overall survival (log-rank P = 0.0024). In addition, the IDO1-positive group was correlated with high counts of FOXP3-positive cells (P = 0.020), but not with PD-L1 expression status (P = 0.19). CONCLUSIONS: IDO1 expression was associated with an unfavorable clinical outcome in esophageal cancer, supporting its role as a prognostic biomarker. Combining the IDO1 and CD8 statuses enabled further classification of the clinical outcomes of patients.

Indoleamine 2, 3-dioxygenase 1 promoter hypomethylation is associated with poor prognosis in patients with esophageal cancer.

Indoleamine 2, 3-dioxygenase 1 (IDO1) is a primary enzyme that generates immunosuppressive metabolites. It plays a major role in tumor immunology and is a potential immune-based therapeutic target. We have reported that IDO1 protein expression was associated with an unfavorable clinical outcome in esophageal cancer. Recently, it has been reported that IDO1 expression is regulated by methylation of the IDO1 promoter. Thus, the aim of this study was to examine the relationship between IDO1 expression, IDO1 promoter methylation, and clinicopathological features in esophageal cancer. We first confirmed changes in IDO1 expression levels in vitro by treating cells with 5-azacytidine. We then evaluated the relationship between IDO1 expression levels, IDO1 promoter methylation (bisulfite pyrosequencing), and clinicopathological features using 40 frozen samples and 242 formalin-fixed, paraffin-embedded samples resected from esophageal cancer patients. We treated cell lines with 5-azacytidine, and the resulting hypomethylation induced significantly higher IDO1 expression (P < .001). In frozen samples, IDO1 expression levels correlated inversely with IDO1 promoter methylation levels (R = -0.47, P = .0019). Furthermore, patients in the IDO1 promoter hypomethylation group (n = 67) had a poor prognosis compared with those in the IDO1 promoter hypermethylation group (n = 175) (overall survival, P = .011). Our results showed that IDO1 promoter hypomethylation regulated IDO1 expression and was associated with a poor prognosis in esophageal cancer patients.

Tumour-associated macrophages are associated with poor prognosis and programmed death ligand 1 expression in oesophageal cancer.

INTRODUCTION: Tumour-associated macrophages (TAMs) in tumour microenvironments promote cancer cell proliferation, immunosuppression and angiogenesis, leading to tumour growth and metastasis. TAMs have become increasingly recognised as a cancer therapy target, such as in combination therapy with an immunity checkpoint inhibitor. However, the clinical and prognostic features of TAMs, and the relationship between TAMs and programmed death ligand 1 (PD-L1), remain unexplored in oesophageal cancer. METHODS: Using a non-biased database of 305 resected oesophageal cancer preparations, we evaluated the expression of two M2-like macrophage markers (CD163 and CD204) and PD-L1 on tumour cells by immunostaining. Through in vitro assays, we examined how TAMs influence phenotypic malignancy and PD-L1 expression. RESULTS: High density of CD163 (n = 160) or CD204 (n = 146) was associated with significantly worse overall survival than low expression (log rank P = 0.0025 and 0.018 for CD163 and CD204, respectively). The prognostic effect of TAMs was not significantly modified by any clinical factors (P > 0.05 for all interactions). High TAM density was significantly associated with increased PD-L1 expression. In in vitro assays, cell invasion and migration ability were significantly more upregulated in oesophageal cancer cell lines cocultured with activated macrophages than in control cell lines. Coculture with activated macrophages elevated the PD-L1 expression in cancer cells. CONCLUSIONS: High TAM density in oesophageal cancer tissues was associated with shorter survival, suggesting a prognostic biomarker role for TAMs. TAMs also increase PD-L1 expression in tumour cells. Given the significant interest in cancer immunotherapies targeting TAMs and PD-L1, the current findings should have considerable clinical implications.

PD-L1 Expression, Tumor-infiltrating Lymphocytes, and Clinical Outcome in Patients With Surgically Resected Esophageal Cancer.

OBJECTIVES: To examine the prognostic impact of the programmed death ligand 1 (PD-L1) expression, tumor-infiltrating lymphocyte (TIL) status, and their combination in esophageal cancer. SUMMARY BACKGROUND DATA: PD-L1 has garnered much attention for its roles in tumor immunology and as an immune-based therapeutic target. To ensure a response to PD-L1 checkpoint inhibitor, a new framework based on PD-L1 expression and the presence or absence of TILs is required. METHODS: Using a nonbiased database of 305 curatively resected esophageal cancers, we evaluated PD-L1 expression and TIL status (cluster of differentiation 8 (CD8) expression) by immunohistochemical analysis. The Cox proportional hazard model was used to compute the hazard ratio (HR) for mortality. RESULTS: Compared with PD-L1 negative cases (n=252), PD-L1 positive cases (n = 53) showed significantly worse overall survival [log-rank P = 0.016; HR: 1.71; 95% confidence interval: 1.08-2.61; P = 0.024; multivariate HR: 1.69; 95% confidence interval: 1.05-2.67; P = 0.033]. TIL positivity was significantly correlated with longer overall survival (log-rank P < 0.0001) and high CD8 expression (P < 0.0001). A stratification based on PD-L1 expression and TIL status was also significantly associated with overall survival (log rank P < 0.0001). CONCLUSIONS: PD-L1 expression was associated with an unfavorable clinical outcome in esophageal cancer, supporting its role as a prognostic biomarker. In addition, the combination with TIL status enabled further classification patients according to clinical outcome. PD-L1 expression and TIL status may serve as predictive tissue biomarkers and can be used for patient selection in clinical trials of drugs targeting the PD-1/PD-L1 pathways.

High CD169 expression in lymph node macrophages predicts a favorable clinical course in patients with esophageal cancer.

Recent findings indicate CD169-positive lymph node sinus macrophages (LySMs) in the regional lymph nodes (RLNs) play an important role in anti-cancer immunity. In the present study, we investigated the correlation between CD169 expression in RLNs and clinicopathologic factors. Higher CD169 expression in LySMs was significantly associated with longer cancer-specific survival (CSS). The density of tumor-infiltrating lymphocytes (TILs) in the cancer nest and CD169 expression on LySMs were positively associated in patients who underwent pretreatment. As CD169 expression is thought to reflect a high interferon signature in RLNs, we tried to identify immunity-related genes that are up-regulated by interferon in macrophages as well as CD169. Indoleamine 2,3-dioxygenase (IDO1) was found to be elevated by interferon, and expression of IDO1 was tested using immunohistochemistry. IDO1 expression on LySMs was positively correlated with CD169 expression; however, there was no significant correlation between IDO1 and clinicopathologic factors. These results suggest that high expression of CD169 in LySMs reflects a high potential for anti-cancer immune responses in esophageal cancer patients and that monitoring CD169 expression would be useful for evaluating the potential of anti-cancer immune reactions.

The association of the lymph node ratio and serum carbohydrate antigen 19-9 with early recurrence after curative gastrectomy for gastric cancer.

PURPOSE: This study investigated the predictors associated with early recurrence (i.e. within 12 months) after curative gastrectomy for gastric cancer (GC). METHODS: We evaluated the clinicopathological factors in 429 patients who underwent curative gastrectomy for GC without preoperative chemotherapy and analyzed these factors' associations with early recurrence. RESULTS: Of 429 patients, 57 experienced recurrences, which were associated with gender, diameter, depth of invasion, lymph node (LN) metastasis, the LN ratio (LNr; LNs with metastasis/dissected LNs), lymphatic invasion, vascular invasion, carbohydrate antigen 19-9 (CA19-9) levels, C-reactive protein levels and the neutrophil/lymphocyte ratio. Twenty-one patients (36.8%) recurred within 12 months. Early recurrence was associated with a high LNr (P = 0.0020) and high CA19-9 levels (P = 0.0415). The other factors were not significantly associated with early recurrence. The 12-month recurrence rate was 33.9% in patients with a high LNr and 1.9% in those with a low LNr and 20.3% in patients with high CA19-9 levels and 3.5% in those with low CA19-9 levels. The 12-month recurrence rate was 62.5% in patients with a high LNr and high CA19-9 levels, 18.4% in those with a high LNr or high-CA19-9 levels, and 1.4% in those with a low LNr and low CA19-9 levels. CONCLUSION: LNr ≥ 0.15 and CA19-9 ≥ 37 U/ml were effective surrogate markers for predicting early recurrence.

Total iron-binding capacity is a novel prognostic marker after curative gastrectomy for gastric cancer.

BACKGROUND: Patients with gastric cancer (GC) are affected by changes in iron status. Before surgery, GC patients are likely to have iron-deficiency anemia; and after gastrectomy, patients suffer from low nutritional status and low iron. This study investigated preoperative iron status associated with prognosis after curative gastrectomy for gastric cancer. METHODS: We evaluated preoperative serum hemoglobin (Hgb), Fe and total iron-binding capacity (TIBC) in 298 patients who underwent curative gastrectomy for GC without preoperative chemotherapy, and analyzed these factors' associations with prognosis after surgery. RESULTS: Of the 298 patients, 129 (43.2%) had low Hgb levels, and 33 (11.1%) had low TIBC (< 260 µg/dl) that was not associated with Hgb or Fe level. Patients with low TIBC were significantly associated with older age (≥ 65 years old; P = 0.0085), low albumin (< 3.9 g/dl; P = 0.0388) and high CRP (≥ 0.15 mg/dl; P = 0.0018) in multivariate analysis. Low Fe (< 60 µg/dl) was not associated with disease-free survival (DFS) or overall survival (OS); however, low Fe was associated with longer cancer-specific survival in Stage III GC patients (P = 0.0333). Both low Hgb and low TIBC were significantly associated with shorter DFS (Hgb: P = 0.0433; TIBC: P < 0.0001) and shorter OS (Hgb: P = 0.0352; TIBC: P < 0.0001). Low TIBC were significantly associated with shorter DFS (HR 2.167, 95% CI 1.231-3.639, P = 0.0086) and shorter OS (HR 2.065, 95% CI 1.144-3.570, P = 0.0173) in multivariate Cox hazard regression analysis. CONCLUSIONS: Preoperative serum TIBC level of GC patients who undergo curative gastrectomy is a novel prognostic marker in univariate and multivariate analyses.

Long Interspersed Element-1 Methylation Level as a Prognostic Biomarker in Gastrointestinal Cancers.

Epigenetic changes play a crucial role in human cancer development. DNA methylation is a central epigenetic process that regulates levels of gene expression. Changes in DNA methylation that occur in human tumors include global DNA hypomethylation and site-specific CpG island promoter hypermethylation. Long interspersed element-1 (LINE-1) is a repetitive DNA retrotransposon that duplicates via a copy-and-paste genetic mechanism. As LINE-1 constitutes approximately 17% of the human genome, the extent of LINE-1 methylation is regarded as a surrogate marker of global DNA methylation. In a variety of gastrointestinal (GI) cancers, LINE-1 hypomethylation is strongly associated with a poor prognosis, supporting its potential role as a prognostic biomarker. In this article, we summarize current knowledge regarding LINE-1 methylation and its prognostic impact in GI cancers.

Prognostic Factors of Salvage Esophagectomy for Residual or Recurrent Esophageal Squamous Cell Carcinoma After Definitive Chemoradiotherapy.

BACKGROUND: The aim of this study was to confirm prognostic factors for salvage esophagectomy for remnant or recurrent esophageal squamous cell carcinoma after definitive chemoradiotherapy. STUDY DESIGN: We retrospectively analyzed clinicopathological backgrounds of 50 patients who underwent salvage esophagectomy between April 2005 and January 2016. Salvage esophagectomy comprised 40 three-incision esophagectomies, two transhiatal esophagectomies and eight pharyngolaryngoesophagectomies. Independent prognostic factors for overall survival were assessed using Cox regression analysis of the factors. RESULTS: Salvage esophagectomy remains a highly invasive surgery and correlated with a higher incidence of all morbidities of Clavien-Dindo classification (CDc) ≥II, severe morbidities of CDc ≥ IIIb, any pulmonary morbidities and chylorrhea, compared with those in patients without preoperative definitive chemoradiotherapy. Cox regression analysis suggested that R0 resection (hazard ratio [HR] 6.39; 95% confidence interval [CI] 2.03-9.68, P = 0.002), absence of severe complications (HR 4.97; 95% CI 1.70-14.81, P = 0.004) and early pStage (0-II) (HR 3.42; 95% CI 1.24-10.12, P = 0.018) were independent prognostic factors for salvage esophagectomy. CONCLUSIONS: Salvage esophagectomy remains correlated with a high incidence of postoperative complications. Avoiding non-curative surgery and reducing the incidence of severe postoperative complications are important if patients are to receive prognostic benefit of this highly invasive surgery.

Risk factors for pulmonary morbidities after minimally invasive esophagectomy for esophageal cancer.

BACKGROUND: Pulmonary morbidities after esophagectomy are still common and are a major cause of surgery-related mortality. The relationship between minimally invasive esophagectomy (MIE) and pulmonary morbidities is not clear. The current study aimed to examine the incidence of pulmonary morbidities after MIE and to clarify the associated risk factors. METHODS: Between May 2011 and December 2016, 184 patients underwent MIE for esophageal cancer. Clinical data were prospectively collected and analyzed. Patient- and surgery-related factors, relating to pulmonary complications, were compared between the complicated and uncomplicated cases. RESULTS: The incidence of any pulmonary morbidity following MIE was 17.9%. Univariate analysis showed that past heavy smoking [Brinkman index (BI) ≥ 1000], presence of neoadjuvant therapy, advanced clinical stage (stage III, IV), and intraoperative bleeding ≥ 600 g were candidates for being postoperative pulmonary morbidity risk factors. Multivariate analysis suggested that BI ≥ 1000 and advanced clinical stage were independent risk factors for causing pulmonary morbidities. CONCLUSIONS: Past heavy smoking and advanced stage are independent risk factors for pulmonary morbidities after MIE. When performing MIE for such cases, various preoperative precautions and careful postoperative monitoring are necessary.