An individualized stemness-related signature to predict prognosis and immunotherapy responses for gastric cancer using single-cell and bulk tissue transcriptomes

BACKGROUND

Currently, many stemness-related signatures have been developed for gastric cancer (GC) to predict prognosis and immunotherapy outcomes. However, due to batch effects, these signatures cannot accurately analyze patients one by one, rendering them impractical in real clinical scenarios. Therefore, we aimed to develop an individualized and clinically applicable signature based on GC stemness.

METHODS

Malignant epithelial cells from single-cell RNA-Seq data of GC were used to identify stemness-related signature genes based on the CytoTRACE score. Using two bulk tissue datasets as training data, the enrichment scores of the signature genes were applied to classify samples into two subtypes. Then, using the identified subtypes as criteria, we developed an individualized stemness-related signature based on the within-sample relative expression orderings of genes.

RESULTS

We identified 175 stemness-related signature genes, which exhibited significantly higher AUCell scores in poorly differentiated GCs compared to differentiated GCs. In training datasets, GC samples were classified into two subtypes with significantly different survival times and genomic characteristics. Utilizing the two subtypes, an individualized signature was constructed containing 47 gene pairs. In four independent testing datasets, GC samples classified as high risk exhibited significantly shorter survival times, higher infiltration of M2 macrophages, and lower immune responses compared to low-risk samples. Moreover, the potential therapeutic targets and corresponding drugs were identified for the high-risk group, such as CD248 targeted by ontuxizumab.

CONCLUSIONS

We developed an individualized stemness-related signature, which can accurately predict the prognosis and efficacy of immunotherapy for each GC sample.

The Associations between Perioperative Blood Transfusion and Long-Term Outcomes after Stomach Cancer Surgery

Simple Summary

Stomach cancer is a common malignancy and one of the leading causes of cancer death in Taiwan. Although tumor characteristics are the main determinants of oncological outcomes, modulation of the immune system may also play some role in cancer progression. Despite the hypothesis that perioperative blood transfusion may suppress the immune reactivity and promote tumor recurrence, the role of perioperative transfusion in the prognosis of stomach cancer remains controversial. To fill this gap, we designed this retrospective study using sound analytical approaches to investigate the impact of perioperative transfusion on oncologic outcomes after curative resection for stomach cancer. We demonstrated that perioperative transfusion was associated with inferior disease-free and overall survival after stomach cancer surgery and a dose-response relationship was also noted between the amount of transfusion and risk of cancer recurrence or mortality.

Abstract

Background: Whether perioperative packed red blood cell (pRBC) transfusion is associated with inferior long-term outcomes after stomach cancer surgery remains controversial. Methods: This research used a retrospective cohort study. Patients with stage I~III stomach cancer undergoing tumor resection were collected at a tertiary medical center. Patient characteristics, surgical features and pathologic findings were gathered from an electronic medical chart review. The associations of perioperative pRBC transfusion with postoperative disease-free and overall survivals were evaluated using Cox regression analysis with an inverse probability of treatment weighting (IPTW). Restricted cubic spline functions were employed to characterize dose-response relationships between the amount of transfusion and cancer outcomes after surgery. Results: Among the 569 patients, 160 (28.1%) received perioperative pRBC transfusion. Perioperative transfusion was associated with worse disease-free survival (IPTW adjusted HR: 1.42, 95% CI: 1.18–1.71, p < 0.001) and overall survival (IPTW adjusted HR: 1.27, 95% CI: 1.05–1.55, p = 0.014). A non-linear dose-response relationship was noted between the amount of transfusions and worse disease-free or overall survival. Conclusions: Perioperative pRBC transfusion was associated with worse disease-free and overall survival after stomach cancer surgery, and strategies aiming to minimize perioperative transfusion exposure should be further considered to reduce the potential risk.

Computed Tomography-Based Radiomics Nomogram: Potential to Predict Local Recurrence of Gastric Cancer After Radical Resection

Objective

Accurate prediction of postoperative recurrence risk of gastric cancer (GC) is critical for individualized precision therapy. We aimed to investigate whether a computed tomography (CT)-based radiomics nomogram can be used as a tool for predicting the local recurrence (LR) of GC after radical resection.

Materials and Methods

342 patients (194 in the training cohort, 78 in the internal validation cohort, and 70 in the external validation cohort) with pathologically proven GC from two centers were included. Radiomics features were extracted from the preoperative CT imaging. The clinical model, radiomics signature, and radiomics nomogram, which incorporated the radiomics signature and independent clinical risk factors, were developed and verified. Furthermore, the performance of these three models was assessed by using the area under the curve (AUC) of receiver operating characteristic (ROC) curve analysis and decision curve analysis (DCA).

Results

The radiomics signature, which was comprised of two selected radiomics features, namely, contrast_GLCM and dissimilarity_GLCM, showed better performance than the clinical model in predicting the LR of GC, with AUC values of 0.83 in the training cohort, 0.84 in the internal validation cohort, and 0.73 in the external cohort, respectively. By integrating the independent clinical risk factors (N stage, bile acid duodenogastric reflux and nodular or irregular outer layer of the gastric wall) into the radiomics signature, the radiomics nomogram achieved the highest accuracy in predicting LR, with AUC values of 0.89, 0.89 and 0.80 in the three cohorts, respectively. DCA in the validation cohort showed that radiomics nomogram added more net benefit than the clinical model within the range of 0.01-0.98.

Conclusion

The CT-based radiomics nomogram has the potential to predict the LR of GC after radical resection.

Prognostic impact of lymph node micrometastasis in patients with gastric cancer

PURPOSE

The clinical significance of lymph node micrometastasis (LNMM) remains controversial in gastric cancer (GC). In this study, we investigated the prognostic impact of LNMM in patients with GC.

METHODS

A total of 624 patients with pathologically lymph node metastasis-negative (pN0) and N1 status (pN1) who underwent gastrectomy between 2004 and 2018 were enrolled in this retrospective study. The diameter of tumor cell clusters in metastatic lymph nodes was measured in 120 patients with pN1 GC.

RESULTS

Patients with lymph node tumors < 1500 μm in diameter (LNMM) had a significantly better prognosis than those with tumors ≥ 1500 μm in diameter (p = 0.012; log-rank test). Cox's proportional hazards model revealed that LNMM (p = 0.016), several dissected lymph nodes (p = 0.049), and the provision of adjuvant chemotherapy (p = 0.002) were independent prognostic factors for the overall survival of patients with pN1 GC. There was no significant difference in the overall survival between patients with LNMM who received chemotherapy and those who did not (p = 0.332).

CONCLUSIONS

LNMM is associated with a favorable prognosis and maybe an independent prognostic marker in patients with pN1 GC. LNMM in GC may be considered a factor preventing adjuvant chemotherapy.

Diagnostic and prognostic values of anti-helicobacter pylori antibody combined with serum CA724, CA19-9, and CEA for young patients with early gastric cancer

Background

To investigate the value of anti‐helicobacter pylori (Hp) antibody, serum carbohydrate antigen (CA)‐724, CA19‐9, and carcinoembryonic antigen (CEA) in the diagnosis and prognosis evaluation of young patients with early gastric cancer.

Methods

A total of 200 young patients with gastric cancer from April 2014 to December 2015 were enrolled. A total of 206 patients with gastritis and 204 healthy subjects were also selected. Gastric cancer patients were followed up for 3 years, and the number of recurrences, metastasis, and death was recorded.

Results

The positive rate of anti‐Hp antibody, CA724, CA19‐9, and CEA in young patients with early gastric cancer were significantly higher than those in gastritis and healthy subjects (P < .05), and was positively correlated with tumor stage, tumor size, and lymph node metastasis (P < .05). The predicting model was as follows: Logit (P) = 26.433‐3.014(CA724)‐3.908(CA19‐9)‐0.303(CEA)‐2.208(anti‐Hp antibody, Positive = 1; Negative = 0). This model had a high value in identifying young patients with early gastric cancer with AUC of 0.918, and the estimated probability was .806. Compared to patients with negative anti‐Hp antibody and low serum levels of CA724, CA19‐9, and CEA, the recurrence rate, metastasis rate, and mortality of patients with positive anti‐Hp antibody, high serum levels of CA724, CA19‐9, and CEA increased significantly (P < .05).

Conclusion

This study indicated that anti‐Hp antibody combined with CA724, CA19‐9, and CEA had important value in the identification of young patients with early gastric cancer and were of great value in evaluating the risk of postoperative recurrence, metastasis, and death.

Prognostic significance of the neutrophil-to-lymphocyte and platelet-to-lymphocyte ratio in patients with metastatic gastric cancer

Advanced gastric cancer has a poor prognosis because of advanced gastric cancer is prone to metastasis. It is urgent for us to find an indicator to predict the prognosis of gastric cancer in a timely fashion. Research has revealed that inflammation has an important role in predicting survival in some cancers. The purpose of this study was to evaluate the significance of neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) on the prognosis of metastatic gastric cancer (GC).This was a retrospective review of 110 patients were at presentation diagnosed with stage IV metastatic GC and all patients received palliative chemotherapy between January 2012 and January 2016 at the Affiliated Hospital of Qingdao University. Pretreatment NLR and PLR, as well as clinicopathological characteristics were collected. Patients were divided into high and low groups according to the cutoff values for NLR and PLR. The Kaplan-Meier method was applied to estimate the overall survival (OS) and the Cox proportional hazards model to evaluate the related risk factors for OS. All tests were 2-tailed and a P < .05 was considered to indicate a statistically significant difference.One hundred ten patients were enrolled. Eighty-four patients were men, 24 patients were women, 61 patients were ≥65 years of age, and 49 patients were <65 years of age. The Eastern Cooperative Oncology Group (ECOG) score of most patients (n = 107) ranged from 0 to 1. Ten patients were human epidermal growth factor receptor 2 (HER2)-positive. Seventy-one patients presented with an elevated carcinoembryonic antigen (CEA) level and 49 patients had an elevated Carcinoembryonic 199 (CA-199) level. Fifty-two patients received first-line chemotherapy only. Nineteen patients received third-line or greater chemotherapy. One hundred patients chose dual drug chemotherapy. The median duration of follow-up was 11.6 months. Based on the receiver operating characteristic (ROC) curve, the optimal cut-off value for NLR and PLR was 2.48 and 143.39. Patients with high NLR and high PLR had poor overall survival compared with those who had low NLR and low PLR (P < .001 and P = .013, respectively). In univariate analysis, old age (P = .013), liver metastasis (P = .001), >1 metastatic sites (P = .028), higher NLR (P = .000), and higher PLR (P = .014) were identified as poor prognostic factors associated with OS. Our multivariate analysis had indicated that high NLR (hazard ratio [HR]: 1.617, 95% CI: 1.032-2.525, P = .036) and peritoneal metastasis (HR: 1.547, 95% CI:1.009-2.454, P = .045) was independent prognostic factors for overall survival; however, the PLR was not shown to be an independent prognostic factor.Our study suggested that the pretreatment NLR can be used as significant prognosis biomarker in metastatic gastric cancer patients receiving palliative chemotherapy.