Construction of a gene model related to the prognosis of patients with gastric cancer receiving immunotherapy and exploration of COX7A1 gene function

BACKGROUND

GC is a highly heterogeneous tumor with different responses to immunotherapy, and the positive response depends on the unique interaction between the tumor and the tumor microenvironment (TME). However, the currently available methods for prognostic prediction are not satisfactory. Therefore, this study aims to construct a novel model that integrates relevant gene sets to predict the clinical efficacy of immunotherapy and the prognosis of GC patients based on machine learning.

METHODS

Seven GC datasets were collected from the Gene Expression Omnibus (GEO) database, The Cancer Genome Atlas (TCGA) database and literature sources. Based on the immunotherapy cohort, we first obtained a list of immunotherapy related genes through differential expression analysis. Then, Cox regression analysis was applied to divide these genes with prognostic significancy into protective and risky types. Then, the Single Sample Gene Set Enrichment Analysis (ssGSEA) algorithm was used to score the two categories of gene sets separately, and the scores differences between the two gene sets were used as the basis for constructing the prognostic model. Subsequently, Weighted Correlation Network Analysis (WGCNA) and Cytoscape were applied to further screen the gene sets of the constructed model, and finally COX7A1 was selected for the exploration and prediction of the relationship between the clinical efficacy of immunotherapy for GC. The correlation between COX7A1 and immune cell infiltration, drug sensitivity scoring, and immunohistochemical staining were performed to initially understand the potential role of COX7A1 in the development and progression of GC. Finally, the differential expression of COX7A1 was verified in those GC patients receiving immunotherapy.

RESULTS

First, 47 protective genes and 408 risky genes were obtained, and the ssGSEA algorithm was applied for model construction, showing good prognostic discrimination ability. In addition, the patients with high model scores showed higher TMB and MSI levels, and lower tumor heterogeneity scores. Then, it is found that the COX7A1 expressions in GC tissues were significantly lower than those in their corresponding paracancerous tissues. Meanwhile, the patients with high COX7A1 expression showed higher probability of cancer invasion, worse clinical efficacy of immunotherapy, worse overall survival (OS) and worse disease-free survival (DFS).

CONCLUSIONS

The ssGSEA score we constructed can serve as a biomarker for GC patients and provide important guidance for individualized treatment. In addition, the COX7A1 gene can accurately distinguish the prognosis of GC patients and predict the clinical efficacy of immunotherapy for GC patients.

Perioperative toripalimab and chemotherapy in locally advanced gastric or gastro-esophageal junction cancer: a randomized phase 2 trial

Perioperative chemotherapy is the standard treatment for locally advanced gastric or gastro-esophageal junction cancer, and the addition of programmed cell death 1 (PD-1) inhibitor is under investigation. In this randomized, open-label, phase 2 study (NEOSUMMIT-01), patients with resectable gastric or gastro-esophageal junction cancer clinically staged as cT3-4aN + M0 were randomized (1:1) to receive either three preoperative and five postoperative 3-week cycles of SOX/XELOX (chemotherapy group, n = 54) or PD-1 inhibitor toripalimab plus SOX/XELOX, followed by toripalimab monotherapy for up to 6 months (toripalimab plus chemotherapy group, n = 54). The primary endpoint was pathological complete response or near-complete response rate (tumor regression grade (TRG) 0/1). The results showed that patients in the toripalimab plus chemotherapy group achieved a higher proportion of TRG 0/1 than those in the chemotherapy group (44.4% (24 of 54, 95% confidence interval (CI): 30.9%-58.6%) versus 20.4% (11 of 54, 95% CI: 10.6%-33.5%)), and the risk difference of TRG 0/1 between toripalimab plus chemotherapy group and chemotherapy group was 22.7% (95% CI: 5.8%-39.6%; P = 0.009), meeting a prespecified endpoint. In addition, a higher pathological complete response rate (ypT0N0) was observed in the toripalimab plus chemotherapy group (22.2% (12 of 54, 95% CI: 12.0%-35.6%) versus 7.4% (4 of 54, 95% CI: 2.1%-17.9%); P = 0.030), and surgical morbidity (11.8% in the toripalimab plus chemotherapy group versus 13.5% in the chemotherapy group) and mortality (1.9% versus 0%), and treatment-related grade 3-4 adverse events (35.2% versus 29.6%) were comparable between the treatment groups. In conclusion, the addition of toripalimab to chemotherapy significantly increased the proportion of patients achieving TRG 0/1 compared to chemotherapy alone and showed a manageable safety profile. ClinicalTrials.gov registration: NCT04250948 .

Comprehensive genomic characterization of sporadic synchronous colorectal cancer: Implications for treatment optimization and clinical outcome

Sporadic synchronous colorectal cancer (SCRC) refers to multiple primary CRC tumors detected simultaneously in an individual without predisposing hereditary conditions, which accounts for the majority of multiple CRCs while lacking a profound understanding of the genomic landscape and evolutionary dynamics to optimize its treatment. In this study, 103 primary tumor samples from 51 patients with SCRC undergo whole-exome sequencing. The germline and somatic mutations and evolutionary and clinical features are comprehensively investigated. Somatic genetic events are largely inconsistent between paired tumors. Compared with solitary CRC, SCRCs have higher prevalence of tumor mutation burden high (TMB-H; 33.3%) and microsatellite-instability high (MSI-H; 29.4%) and different mutation frequencies in oncogenic signaling pathways. Moreover, neutrally evolving SCRC tumors are associated with higher intratumoral heterogeneity and better prognosis. These findings unveil special molecular features, carcinogenesis, and prognosis of sporadic SCRC. Strategies for targeted therapy and immunotherapy should be optimized accordingly.

IL-1β-associated NNT acetylation orchestrates iron-sulfur cluster maintenance and cancer immunotherapy resistance

Interleukin-1β (IL-1β) is a key protein in inflammation and contributes to tumor progression. However, the role of IL-1β in cancer is ambiguous or even contradictory. Here, we found that upon IL-1β stimulation, nicotinamide nucleotide transhydrogenase (NNT) in cancer cells is acetylated at lysine (K) 1042 (NNT K1042ac) and thereby induces the mitochondrial translocation of p300/CBP-associated factor (PCAF). This acetylation enhances NNT activity by increasing the binding affinity of NNT for NADP⁺ and therefore boosts NADPH production, which subsequently sustains sufficient iron-sulfur cluster maintenance and protects tumor cells from ferroptosis. Abrogating NNT K1042ac dramatically attenuates IL-1β-promoted tumor immune evasion and synergizes with PD-1 blockade. In addition, NNT K1042ac is associated with IL-1β expression and the prognosis of human gastric cancer. Our findings demonstrate a mechanism of IL-1β-promoted tumor immune evasion, implicating the therapeutic potential of disrupting the link between IL-1β and tumor cells by inhibiting NNT acetylation.

[A case of Stevens-Johnson syndrome with binocular corneal perforation and multiple corneal transplantation which was difficult to control]

The 31-year-old female patient was admitted to the General Hospital of the Chinese People's Liberation Army for 3 days after the corneal transplantation of her right eye for 5 months.Four years ago, the patient developed red eyes, pain, dryness and photophobia after intravenous drip of cefuroxime sodium and metronidazole due to pelvic inflammation, accompanied by high fever, systemic rash and epidermal exfoliation, fingernail peeling, and mucosal ulceration in the eyes and mouth.Later, the patient received systemic hormone shock and point eye treatment in a local hospital, and the dry eyes gradually worsened. Despite continuous artificial tears and bandage mirror treatment, the corneal ulcer perforation in both eyes still occurred successively. After several penetrating keratografts and drug therapy, the ulcer and dissolution could not be prevented. He was admitted to our hospital due to corneal perforation in both eyes.Ophthalmic examination: visual acuity manual/15 cm in the right eye, intraocular pressure T-2, conjunctival sac stenosis, extensive corneal opacity and edema, ulcer about 8 mm, corneal perforation near the corneal limbus about 2 mm×5 mm below.The left eye had no light perception, a central corneal ulcer of about 8 mm, bulge of the posterior elastic layer, no anterior chamber, and atrophy of the eyeball.B-ultrasound showed choroidal detachment of the right eye.On the second day, the patient received right eye intraocular exploration, vitrectomy, ecotopic keratoscleral carrier Boston Ⅱ artificial keratoplasty, glaucoma valve implantation, autogenous ear cartilage implantation, conjunctival occlusion, and left eye lamellar keratoplasty, conjunctival occlusion.Postoperative visual acuity of right eye was -6.50 DS=0.12, intraocular pressure TN, ocular surface was stable.The left eye has no light perception and the ocular surface is stable.

LAG3-PD1 or CTLA4-PD1 inhibition in advanced melanoma: Indirect cross comparisons of the CheckMate-067 and relativity-047 trials

e21511

Background: There remain unmet needs to identify novel immune checkpoint inhibitors to improve the benefit-risk profile of immunotherapy for advanced melanoma. The comparison between LAG3-PD1 inhibition and CTLA4-PD1 inhibition was lacked. To compare the inhibition of lymphocyte-activation gene 3 (LAG3) plus programmed cell death 1 (PD-1) versus the inhibition of cytotoxic T-lymphocyte antigen 4 (CTLA-4) plus PD-1 in patients with previously untreated advanced melanoma. Methods: The individual participant data (IPD) data were extracted from the KM plots using a graphical reconstructive algorithm through eligible. Log-rank, Cox proportional hazard model, Bayesian hierarchical model with time-varying hazard ratio (HR) effect, and restricted mean survival time (RMST) were performed to estimate survival benefits. The primary endpoint was progression-free survival. Results: The CheckMate-067 (N = 630) and RELATIVITY-047 (N = 714) trials were included for analysis. The graphical reconstructive algorithm showed that IPD had similar HRs and log-rank values as the original plots. The HR of nivolumab-relatlimab (LAG3 inhibitor) versus nivolumab-ipilimumab (CTLA4 inhibitor) was 1.19 (95% confidence interval [CI] 0.96 to1.48). The 24-months RMST of nivolumab-relatlimab versus nivolumab alone was 2.35 (95% CI 0.77 to 3.94) months, compared with 1.87 (95% CI 0.25-3.49) months for nivolumab-ipilimumab versus nivolumab. The Bayesian hierarchical model showed that patients treated with nivolumab-relatlimab had earlier PFS benefits than those with nivolumab-ipilimumab. Grade 3 or 4 treatment-related adverse events occurred in 18.9% of patients using nivolumab-relatlimab and 55.0% of patients using nivolumab-ipilimumab. Conclusions: These findings suggest that the PFS of LAG3-PD1 and CTLA4-PD1 inhibition were similar and that LAG3-PD1 inhibition tended to exhibit earlier survival benefit and lesser TRAEs.

Circulating tumor DNA and recurrence risk in stage II-III gastric cancer

4054

Background: Circulating tumor DNA (ctDNA) is a promising biomarker for detecting molecular residual disease (MRD) and relapse after definitive treatment in multiple solid cancers. However, the significance of ctDNA is rarely clarified in locoregional gastric cancer (GC). Here, we conducted a prospective and observational study to evaluate the utility of ctDNA in predicting the recurrence risk of GC. Methods: From October 2016 to June 2019, 100 patients with stage II/III resectable GC were recruited in this study (NCT02887612). Primary tumors and plasma samples were collected perioperatively and after adjuvant chemotherapy (ACT). Somatic variants were captured via a targeted sequencing panel of 425 cancer-related genes. The plasma of patients was defined as ctDNA positive only if one or more variants detected in the plasma presented in at least 2% of the primary tumors. All the patients received curative-intent standard-of-care therapy. Results: Preoperative ctDNA was detectable in 38 (38.0%) patients but showed limited value for predicting recurrence. After surgery (median days, 4), the plasma of 25 (25.0%) patients were still ctDNA positive and they had higher recurrence risk than the non-positive patients (hazard ratio [HR], 2.74 (95% CI: 1.37–5.48); P = 0.003). Forty-one patients had evaluable plasma after ACT and 10 (24.4%) of them who were ctDNA positive had remarkably higher recurrence and death risk compared with ctDNA-negative patients (recurrence-free survival [RFS] HR = 14.99 (95% CI: 3.08–72.96); P < 0.001; overall survival HR, 11.88 (95% CI: 2.38–59.24); P < 0.001). In particular, post-ACT ctDNA achieved better predictive performance (sensitivity, 77.8%; specificity, 90.6%) than both postoperative ctDNA and post-treatment tumor biomarkers (i.e., CEA, CA199, and CA72-4). In all multivariate analyses, ctDNA positivity was an independent factor of RFS. Patients with ERBB4 mutation in their primary tumors had poorer RFS compared to those were ERBB4 wildtype (HR = 3.46 (95% CI: 1.32–9.03); P = 0.007). A comprehensive model incorporating ctDNA status for recurrence risk prediction showed a higher concordance index (0.78; 95%CI, 0.71–0.84) than the model without ctDNA status (0.71; 95%CI, 0.64–0.79; P = 0.009). Conclusions: Postoperative and post-ACT ctDNA was associated with MRD and high risk of relapse in patients with stage II/III GC and can be utilized to guide GC management in post-surgical settings.

Elevated peripheral blood neutrophil-to-lymphocyte ratio is associated with an immunosuppressive tumour microenvironment and decreased benefit of PD-1 antibody in advanced gastric cancer

Background

Due to its limited efficacy and potential toxicity, anti-PD-1 monoclonal antibody is not suitable for all advanced gastric cancer (AGC) patients and predictive biomarkers identifying patients who can benefit from it are urgently needed. This study aimed to evaluate the predictive and prognostic value of inflammatory markers in the context of the systemic inflammatory status and tumour microenvironment.

Methods

The study included 58 patients from a prospective study investigating the safety and efficacy of toripalimab in chemorefractory AGC patients. Patient characteristics, treatment outcomes, and haematological parameters were analysed. Immune-cell infiltration and gene expression in tumour tissue were examined using transcriptome sequencing.

Results

In this cohort, the median follow-up time was 4.5 months, the median progression-free survival was 1.9 months, and the median overall survival (OS) was 4.8 months. The objective response rate was 12.1% and th disease control rate (DCR) was 39.7%. Both the baseline blood neutrophil-to-lymphocyte ratio (bNLR) with a cut-point of 2.7 and the early elevated dynamic change of the bNLR (dNLR) with a cut-point of 1.5 were prognostic factors of survival. Patients in the high bNLR or dNLR group had remarkably poor DCR (25.8% vs 59.1%, P = 0.023; 15.8% vs 54.6%, P = 0.008). In multivariate analysis, bNLR and tumour mutational burden were independent prognostic factors of OS. Tumour RNA-seq analysis revealed enriched neutrophil infiltration and a higher tumour NLR in the bNLR-high group. Corresponding tumour gene-expression profiles were associated with neutrophil recruitment and inflammatory cytokine aggregation.

Conclusions

Our study demonstrated the potential clinical utility of NLR as a biomarker for patient selection and clinical management in predicting the prognosis of AGC patients as well as response to anti-PD-1 therapy. In addition, high bNLR reflected the imbalance of tumour-tissue-infiltrating neutrophils and lymphocytes, and was associated with an immunosuppressive and pro-tumour microenvironment.

Association Between Body Mass Index and Survival Outcomes In Patients Treated With Immune Checkpoint Inhibitors: Meta-analyses of Individual Patient Data

Despite that immune checkpoint inhibitors (ICIs) had tremendous improved the survival of multiple solid tumors, only a limited proportion of patients are responsive to ICIs. Therefore, effective variables are urgently needed to predict the probability of response to ICIs. Systematic searches were conducted from inception up to May, 2020. Prospective or retrospective studies of ICIs that investigated the association between body mass index (BMI) and survival outcomes, including overall survival (OS) and/or progression-free survival (PFS), were selected. The association between each BMI category and survival outcomes was calculated using Cox proportional hazard regression models and quantified as hazard ratio (HR) with corresponding 95% confidence interval. Seven clinical studies involving data from 3768 individual patients were included. The median OS was 15.5 months (95% confidence interval: 14.7-16.2 mo) and the median PFS was 5.7 months (5.2-6.3 mo). The median OS was significantly longer in overweight/obese patients than in nonoverweight patients (20.7 vs. 11.3 mo; P<0.001). The difference in OS between overweight and obese patients was not statistically significant (HR: 1.14, P=0.098). Similar results were observed for PFS outcomes. Subgroup analysis demonstrated improved OS in overweight/obese patients with nonsmall-cell lung cancer (HR: 0.81, P=0.002), melanoma (HR: 0.66, P<0.001), renal cell carcinoma (HR: 0.53, P<0.001), and multiple cancer type (HR: 0.34, P<0.001), with parallel results noted regarding PFS outcomes. Results of the present study suggested that BMI may be a satisfactory prognostic factor for patients treated with ICIs.

The genomic architecture of EBV and infected gastric tissue from precursor lesions to carcinoma

BACKGROUND

Epstein-Barr virus (EBV)-associated gastric carcinomas (EBVaGCs) present unique molecular signatures, but the tumorigenesis of EBVaGCs and the role EBV plays during this process remain poorly understood.

METHODS

We applied whole-exome sequencing, EBV genome sequencing, and whole-genome bisulfite sequencing to multiple samples (n = 123) derived from the same patients (n = 25), which covered saliva samples and different histological stages from morphologically normal epithelial tissues to dysplasia and EBVaGCs. We compared the genomic landscape between EBVaGCs and their precursor lesions and traced the clonal evolution for each patient. We also analyzed genome sequences of EBV from samples of different histological types. Finally, the key molecular events promoting the tumor evolution were demonstrated by MTT, IC50, and colony formation assay in vitro experiments and in vivo xenograft experiments.

RESULTS

Our analysis revealed increasing mutational burden and EBV load from normal tissues and low-grade dysplasia (LD) to high-grade dysplasia (HD) and EBVaGCs, and oncogenic amplifications occurred late in EBVaGCs. Interestingly, within each patient, EBVaGCs and HDs were monoclonal and harbored single-strain-originated EBV, but saliva or normal tissues/LDs had different EBV strains from that in EBVaGCs. Compared with precursor lesions, tumor cells showed incremental methylation in promotor regions, whereas EBV presented consistent hypermethylation. Dominant alterations targeting the PI3K-Akt and Wnt pathways were found in EBV-infected cells. The combinational inhibition of these two pathways in EBV-positive tumor cells confirmed their synergistic function.

CONCLUSIONS

We portrayed the (epi) genomic evolution process of EBVaGCs, revealed the extensive genomic diversity of EBV between tumors and normal tissue sites, and demonstrated the synergistic activation of the PI3K and Wnt pathways in EBVaGCs, offering a new potential treatment strategy for this disease.

Adjuvant chemotherapy for gastric cancer patients with mismatch repair deficiency or microsatellite instability

e16004

Background: Mismatch repair deficient (dMMR) or microsatellite instability-high (MSI-H) serves as a predictor poor response to adjuvant chemotherapy in stage II colon cancer patients. Our objective was to investigate the efficacy of adjuvant chemotherapy in dMMR/MSI-H gastric cancer (GC). Methods: We searched literatures through December, 2020 to identify clinical studies that reported survival comparing adjuvant chemotherapy with surgery alone in dMMR/MSI-H GCs. Two approaches were used to pool the hazard ratio (HR) of survival: (1) If Kaplan-Meier curves and number at risk were provided, individual patient data were extracted. Cox models were used to calculate the HR with 95% confidence interval (CI); (2) for study-level data, pooled HR was estimated using fixed/random-effects models. Results: Six clinical studies were identified. For dMMR/MSI-H versus mismatch repair proficient (pMMR)/microsatellite stable (MSS)/microsatellite instability-low (MSI-L), the estimated 5-years DFS were 74.2% versus 51.5% (HR, 0.44; 95% CI, 0.32-0.62; P < 0.001); the estimated 5-years OS were 60.8% versus 50.1% (HR, 0.72; 95% CI, 0.60-0.88; P = 0.001). At study-level data, the pooled HRs were 0.42 for DFS (95% CI, 0.31-0.57; P < 0.001) and 0.66 for OS (95% CI, 0.32-1.38; P = 0.268). For adjuvant chemotherapy versus observation in dMMR/MSI-H, the estimated 5-years DFS were 76.1% versus 73.3% (HR, 0.72; 95% CI, 0.45-1.15; P = 0.171); the estimated 5-years OS were 74.9% versus 60.2% (HR, 0.60; 95% CI, 0.44-0.83; P = 0.001). Significant survival differences were also observed at study-level. Conclusions: This study further suggested adjuvant chemotherapy could be beneficial even in dMMR/MSI-H GC patients.

Efficacy of Anti-PD-1/PD-L1 Monotherapy or Combinational Therapy in Patients Aged 75 Years or Older: A Study-Level Meta-Analysis

Recent trials have shown a promising anti-tumor activity for advanced cancer patients treated with PD-1/PD-L1 inhibitors; however, little is known on the use of PD-1/PD-L1 inhibitors in adults over 75 years of age. Here, we performed a study-level meta-analysis to compare the efficacy of anti-PD-1/PD-L1 agents between elderly (≥ 75 years) and non-elderly (< 75 years) patients. In the present study, we systematically reviewed phase 2/3 trials of PD-1/PD-L1 inhibitors of advanced solid tumors that reported treatment effect (hazard ratio [HR]) in patients based on age (≥ 75 years vs. < 75 years) and set anti-PD-1/PD-L1 monotherapy or combinational therapy as experimental arm. The HRs of OS and progression-free survival (PFS) are based on random-effect models. Overall, a total of eight qualifying trials comprising 5,393 subjects were included for meta-analysis, and 472 patients (8.8%) were aged 75 years or older. The overall estimated HR for OS was 0.70 (0.62-0.79) in patients < 75 years vs. 0.94 (0.67-1.30) in patients ≥ 75 years. Anti-PD-1/PD-L1 agents improved OS of melanoma patients in both elderly (HR 0.25 [0.10-0.60]) and non-elderly (HR 0.49 [0.33-0.71]) group. The OS difference in the efficacy of PD-1/PD-L1 inhibitors between elderly and non-elderly patients was significant (P = 0.043 for interaction). The overall estimated HR for PFS was 0.77 (0.60-1.00) in patients < 75 years vs. 0.97 (0.60-1.58) in patients ≥ 75 years. Therefore, with the exception of melanoma, elderly patients (≥ 75 years) could not benefit from the anti-PD-1/PD-L1 agents in survival, and toxicity profile of anti-PD-1/PD-L1 drugs should be explored in this population.

Surrogate endpoints for overall survival in anti-programmed death-1 and anti-programmed death ligand 1 trials of advanced melanoma

Background

We assessed the surrogacy of objective response rate (ORR), disease control rate (DCR) and progression-free survival (PFS) for overall survival (OS) in anti-PD-1/PD-L1 trials of metastatic melanoma through a meta-analysis of randomized controlled trials (RCTs).

Methods

PubMed and EMBASE were searched for phase II/III RCTs till June 2019 investigating anti-PD-1/PD-L1 agents. Treatment effect (hazard ratio or odds ratio) on potential surrogates (ORR/DCR/PFS) and OS were collected. At trial level, we assessed the correlation between treatment effect on potential surrogates and OS, weighted by sample size, fixed and random effect models, and calculated the surrogate threshold effect (STE). Sensitivity analyses and leave-one-out cross-validation approach were performed to evaluate the robustness of our findings.

Results

We included 8 RCTs (4110 patients; 11 comparisons). We did not identify strong correlations between ORR [coefficient of determination (R ²): 0.09-0.25], DCR (0.41-0.57) and OS. However, we noted a strong correlation between PFS and OS, with R ² of 0.82 in sample size, 0.75 in fixed effect and 0.72 in random effect model weighting, the robustness of which was further verified by leave-one-out cross-validation approach. Sensitivity analyses with restriction to trials with less than 50% crossover, phase III trials, large trials and first-line trials strengthened the correlation (0.78-0.94). The STE for PFS was 0.78.

Conclusions

PFS may be the appropriate surrogate for OS in anti-PD-1/PD-L1 trials of metastatic melanoma. A future anti-PD-1/PD-L1 trial would need less than 0.78 for PFS of the upper limit of confidence interval to predict an OS benefit.

Surgical Outcome and Long-Term Survival of Conversion Surgery for Advanced Gastric Cancer

BACKGROUND

The present study aims to report the surgical outcome and long-term survival of conversion surgery and clarify its role in advanced gastric cancer.

PATIENTS AND METHODS

A total of 95 primary advanced gastric adenocarcinoma patients who underwent systemic chemotherapy and conversion surgery were reviewed retrospectively. The survival of conversion surgery was analyzed by Cox regression and the Kaplan-Meier method. Surgical outcomes were analyzed according to the Clavien-Dindo classification.

RESULTS

The median survival time (MST) of the 95 patients was 26.8 months, and the postoperative MST was 19.3 months. The MSTs of the patients in categories 1, 2, 3, and 4 were 28.8, 25.5, 43.6, and 11.3 months, respectively. The MSTs of the patients who underwent R0 resection (47 cases) and R1/2 resection (48 cases) were 49.3 months and 21.9 months, respectively. The MST of patients treated with total gastrectomy was shorter (21.9 months) than that of patients who underwent proximal (55.0 months) or distal (46.3 months) gastrectomy. Patients who received more than 6 cycles of induction chemotherapy had a longer MST than patients who received 3-5 cycles or 1-2 cycles (MST: 55.0 months versus 21.1 months versus 21.7 months). The incident postoperative complications and postoperative mortality rates were 10.5% and 1.1%, respectively.

CONCLUSIONS

Advanced gastric cancer patients may obtain a survival benefit from conversion surgery, except category 4. Performing a sufficient number of cycles of induction chemotherapy (usually ≥ 6 cycles) is recommended. Surgical oncologists should perform R0 resection and avoid total gastrectomy.

Surrogate endpoints for overall survival in anti-programmed death-1 and anti-programmed death ligand 1 trials of advanced melanoma

10030

Background: The mechanisms of action of anti-PD-1/PD-L1 agents are markedly distinct from those of cytotoxic agents, thus a critical issue that is under investigation is what is the optimal endpoint and how should tumor response be evaluated in anti-PD-1/PD-L1 trials for metastatic melanoma. Here, we assessed surrogacy of objective response rate (ORR), disease control rate (DCR) and progression-free survival (PFS) for overall survival (OS) in anti-PD-1/PD-L1 trials of metastatic melanoma through a meta-analysis of randomized controlled trials (RCTs). Methods: PubMed and EMBASE were searched for phase 2/3 RCTs till June 2019 investigating anti-PD-1/PD-L1 agents. Treatment effect (hazard ratio or odds ratio) on potential surrogates (ORR/DCR/PFS) and OS were collected. At trial level, we assessed the correlation between treatment effect on potential surrogates and OS, weighted by sample size, fixed and random effect models, and calculated the surrogate threshold effect (STE). Sensitivity analyses and leave-one-out cross-validation approach were performed to evaluate the robustness of our findings. Results: We included 8 RCTs (4,110 patients; 11 comparisons). We did not identify strong correlations between ORR (coefficient of determination [ R2]: 0.09 to 0.25), DCR (0.41 to 0.57) and OS. However, we noted a strong correlation between PFS and OS, with R2 of 0.82 in sample size, 0.75 in fixed effect, and 0.72 in random effect model weighting, the robustness of which was further verified by leave-one-out cross-validation approach. Sensitivity analyses with restriction to trials with less than 50% crossover ( R2: 0.94-0.94), phase 3 trials ( R2: 0.94-0.95), large trials ( R2: 0.78-0.86) and first-line trials ( R2: 0.83-0.91) strengthened the correlation. The STE for PFS was 0.78. Conclusions: PFS may be the appropriate surrogate for OS in anti-PD-1/PD-L1 trials of metastatic melanoma. A future anti-PD-1/PD-L1 trial would need less than 0.78 for PFS of the upper limit of confidence interval to predict an OS benefit.

Disease-free survival as a surrogate endpoint for overall survival in adjuvant trials of pancreatic cancer: a meta-analysis of 20 randomized controlled trials

Background

We aimed to assess whether disease-free survival (DFS) could serve as a reliable surrogate endpoint for overall survival (OS) in adjuvant trials of pancreatic cancer.

Methods

We systematically reviewed adjuvant randomized trials for non-metastatic pancreatic cancer after curative resection that reported a hazard ratio (HR) for DFS and OS. We assessed the correlation between treatment effect (HR) on DFS and OS, weighted by sample size or precision of hazard ratio estimate, assuming fixed and random effects, and calculated the surrogate threshold effect (STE). We also performed sensitivity analyses and a leave-one-out cross validation approach to evaluate the robustness of our findings.

Results

After screening 450 relevant articles, we identified a total of 20 qualifying trails comprising 5170 patients for quantitative analysis. We noted a strong correlation between the treatment effects for DFS and OS, with coefficient of determination of 0.82 in the random effect model, 0.82 in the fixed effect model, and 0.80 in the sample size weighting; the robustness of this finding was further verified by the leave-one-out cross-validation approach. Sensitivity analyses with restriction to phase 3 trials, large trials, trials with mature follow-up periods, and trials with adjuvant therapy versus adjuvant therapy strengthened the correlation (0.75 to 0.88) between DFS and OS. The STE was 0.96 for DFS.

Conclusions

Therefore, DFS could be regarded as a surrogate endpoint for OS in adjuvant trials of pancreatic cancer. In future similar adjuvant trials, a hazard ratio for DFS of 0.96 or less would predict a treatment impact on OS.

Downregulation of PSCA promotes gastric cancer proliferation and is related to poor prognosis

Background: Dysregulation of prostate stem cell antigen (PSCA) has been implicated in human cancers. Studies have reported that PSCA expression is generally high in prostate cancer, which correlates with a worse survival. PSCA is also highly expressed in bladder, ovarian, and pancreatic cancers. However, PSCA is expressed at low levels in gastric, gallbladder and oesophageal cancers. At present, the clinical significance, expression pattern and biological function of PSCA in gastric cancer (GC) are still unclear.

Methods: Previously, we used cDNA microarray as a screening tool to compare GC tissues with its matched normal gastric mucosa tissues (MNGT), and obtained the differentially expressed genes of the two tissue types. PSCA is one of the genes significantly down-regulated in GC tissues. In this study, we detected the expression of PSCA in GC tissues and MNGT by western-blot experiment and immunohistochemical staining (IHC). Then the relationship between the expression pattern of PSCA and the clinicopathological characteristics and survival in GC was analyzed. In order to further study the function of PSCA in GC, lentivirus was used to construct stable cell lines with knockdown and overexpression of PSCA gene. We used AGS and MKN45 cell lines for plasmid transfection. Colony formation assay, MTS and nude mice xenograft model were performed to investigate the effect of PSCA in GC.

Results: Western-blot and IHC assays demonstrated that the expression of PSCA in GC tissues was significantly lower than that in the MNGT. PSCA expression in GC tissues was high in 252 (57.5%) and low in 186 (42.5%) of 438 patients. PSCA expression for MNGT was high in 273 (62.3%) and low in 165 (37.7%) of 438 patients. PSCA expression was significantly associated with T classification (P=0.024), N classification (P=0.018) and TNM stage (P=0.019) using χ² test. The relationship between PSCA expression level and patient survival was analysed using Kaplan-Meier analysis and the log-rank test. Low levels of PSCA expression were significantly associated with a poorer OS than high expression levels of PSCA (P=0.011). In the COX regression analysis of OS, all 9 variables in the univariate analysis were significantly correlated with OS (P<0.05), while the variables found to be independently correlated with OS in the multivariate analysis were PSCA expression (P=0.036), age (P<0.001), gender (P=0.007), and TNM stage (P<0.001), respectively. Univariate and multivariate analyses showed that PSCA was an independent prognostic factor for OS in GC. In vitro MTS cell proliferation experiment and clonal formation experiment and in vivo nude mouse subcutaneous tumorigenesis experiment all proved that knockdown of PSCA gene can improve the proliferation ability of GC cells, while in vitro experiment proved that overexpression of PSCA can reduce the proliferation ability of GC cells.It was found that knockdown of PSCA gene can improve the proliferation ability of GC cells both in vitro and in vivo, while overexpression of PSCA can reduce the proliferation ability of GC cells in vitro.

Conclusion: Our study showed that the expression of PSCA gene was decreased in GC, which was related to more advanced pathological stages. And the expression level of PSCA in GC was an independent good prognostic factor. PSCA gene had the function of inhibiting GC proliferation.

[Progress in the diagnosis and treatment of oropharyngeal cancer]

SummaryIn recent years，human papillomavirus has been proved to be closely related to the occurrence and prognosis of oropharyngeal cancer.The treatment of oropharyngeal cancer has evolved from the primary radiotherapy to the corresponding treatment according to different tumor stages.For patients with advanced oropharyngeal cancer，the treatment strategy is mostly surgery + postoperative concurrent chemoradiotherapy.Patients are often accompanied by large defects in the surgical area after surgery.With the improvement of head and neck surgical repair technology and the progress of free flap technology，various repair methods can be adopted to repair and reconstruct.

Robust immunoscore model to predict the response to anti-PD1 therapy in melanoma

This study aimed to construct immune-related predictors to identify responders to anti-PD1 therapy of melanoma through CIBERSORT algorithm. Using the least absolute shrinkage and selection operator (LASSO) logistic regression, we constructed an immunoscore consisting of 8 immune subsets to predict the anti-PD1 response. This score achieved an overall accuracy of AUC = 0.77, 0.80 and 0.73 in the training cohort, validation cohort and on-anti-PD1 cohort, respectively. Patients with high immunoscores had significantly higher objective response rates (ORRs) than did those with low immunoscores (ORR: 53.8% vs 17.7%, P < 0.001 for entire pre-anti-PD1 cohort; 42.1% vs 15.1%, P = 0.022 for on-anti-PD1 cohort; 66.7% vs 16.7%, P = 0.038 for neoadjuvant anti-PD1 cohort). Prolonged survival trends were observed in high-immunoscore group (1-year PFS: 42.4% vs 14.3%, P = 0.059; 3-year OS: 41.5% vs 31.6%, P = 0.057). Furthermore, we found that high-immunoscore group exhibited higher fractions of tumor-infiltrating lymphocytes and an increased IFN-γ response. Analysis of the results of the GSEA indicated a significant enrichment of antitumor immunity pathways in the high-immunoscore group. Therefore, this study indicated that we constructed a robust immunoscore model to predict the anti-PD1 response of metastatic melanoma and the neoadjuvant anti-PD1 response of resectable melanoma.

A real-world evidence of efficacy of palliative gastrectomy plus chemotherapy in metastatic gastric cancer patients

Background: The benefit of palliative gastrectomy for patients with metastatic gastric cancer (mGC) is controversial, and suitable candidates for surgery and treatment strategies remain unclear. The present study aimed to investigate the efficacy of palliative gastrectomy plus chemotherapy among patients with mGC and to identify the potential patients for such treatment using real-world data.

Methods: A dataset of 236 patients with mGC diagnosed at the Sun Yat-Sen University Cancer Center from January 1, 2006 to December 31, 2012 were analyzed retrospectively. The cohort comprised 80 patients who had palliative gastrectomy plus chemotherapy (SC) and 156 patients who had chemotherapy only (CO). Propensity score matching (PSM) was employed to minimize the influence of confounders.

Results: The median overall survival of the SC group was significantly better than that of the CO group (Before PSM: 17.0 months vs 12.0 months, P=0.038; after PSM: 17.0 months vs 13.0 months, P=0.017). In the multivariate analysis, SC (Before PSM: hazard ratio (HR) =0.68, P=0.023; after PSM: HR =0.64, P=0.021) was favored for better survival after adjustment for sex, age, year of diagnosis, primary tumor location, and tumor grade. Total gastrectomy (P=0.026) was associated with worse survival for the SC group. The significant survival advantage of SC over CO was retained in patients with single organ metastasis (P=0.016), peritoneal seedings (P=0.039), and those receiving taxane-based chemotherapy (P=0.011).

Conclusion: SC could improve the overall survival of patients with mGC as compared with CO. The chemotherapy regimen and type of resection were proven to influence efficacy. Patients who received taxane-based regimens might be suitable for palliative gastrectomy.

Additional gastrectomy in early-stage gastric cancer after non-curative endoscopic resection: a meta-analysis

Background and objective

The role of additional gastrectomy after non-curative endoscopic resection remains uncertain. The present meta-analysis aimed to explore the risk factors for early-stage gastric-cancer patients after non-curative endoscopic resection and evaluate the efficacy of additional gastrectomy.

Methods

Relevant studies that reported additional gastrectomy after non-curative endoscopic resection were comprehensively searched in MedLine, Web of Science and EMBASE. We first investigated the risk factors for residual tumor and lymph-node metastasis after non-curative endoscopic resection and then analysed the survival outcome, including 5-year overall survival (OS) and 5-year disease-free survival, of additional gastrectomy.

Results

Twenty-one studies comprising 4870 cases were included in the present study. We found that residual tumor was associated with larger tumor size (>3 cm) (odds ratio [OR] = 2.81, P < 0.001), undifferentiated tumor type (OR = 1.78, P = 0.011) and positive horizontal margin (OR = 9.78, P < 0.001). Lymph-node metastasis was associated with larger tumor size (>3 cm) (OR = 1.73, P < 0.001), elevated tumor type (OR = 1.60, P = 0.035), deeper tumor invasion (>SM1) (OR = 2.68, P < 0.001), lymphatic invasion (OR = 4.65, P < 0.001) and positive vertical margin (OR = 2.30, P < 0.001). Patients who underwent additional gastrectomy had longer 5-year OS (hazard ratio [HR] = 0.34, P < 0.001), 5-year disease-free survival (HR = 0.52, P = 0.001) and 5-year disease-specific survival (HR = 0.50, P < 0.001) than those who did not. Moreover, elderly patients also benefited from additional gastrectomy regarding 5-year OS (HR = 0.41, P = 0.001).

Conclusions

Additional gastrectomy with lymph-node dissection might improve the survival of early-stage gastric-cancer patients after non-curative endoscopic resection. However, risk stratification should be performed to avoid excessive treatment.

Prognostic Factors and Recurrence Patterns in T4 Gastric Cancer Patients after Curative Resection

Background: To investigate prognostic factors and recurrence patterns in T4 gastric cancer (GC) patients after curative resection.

Methods: Between January 2004 and December 2014, 249 patients with T4 gastric cancer undergoing curative resection were recruited. Patient characteristics, survival, prognostic factors and recurrence patterns were analyzed.

Results: Our results showed that the median survival time (MST) for T4 gastric cancer after curative resection was 55.47 months, with 59.47 months for T4a (tumor perforating serosa) and 25.90 months for T4b (tumor invasion of the adjacent structure). Multivariate analysis indicated that age (hazard ratio [HR], 1.86; P = 0.006), location of tumor (HR, 1.25, 0.90 - 5.64; P < 0.001) and intraoperative blood loss (HR, 1.85; P = 0.010) were independent prognostic factors for overall survival (OS). After a median follow-up of 25.87 months, a total of 109 (43.8%) patients suffered from recurrence, and 90 patients had been observed specific recurrence sites, among which peritoneal metastasis was the most common recurrence pattern, 59.0% for T4a and 88.3% for T4b, respectively.

Conclusions: For T4 gastric cancer patients after curative resection, older age, gastric cancer of the entire stomach and more intraoperative blood loss were associated with poor OS. The recurrence rate after curative resection for T4 was high, and the most common recurrence pattern was peritoneal metastasis.

Prognostic Value of the Nutritional Risk Screening 2002 Scale in Metastatic Gastric Cancer: A Large-Scale Cohort Study

Background: The prognostic value of the nutritional risk screening 2002 (NRS 2002) scale in metastatic gastric cancer remains unclear. We aimed to explore the role of NRS 2002 in metastatic gastric cancer.

Methods: In this study, 1664 metastatic gastric cancer patients at our institution between 2000 and 2015 were retrospectively analyzed. The characteristics and clinical outcomes of the included patients were analyzed.

Results: Receiver operating characteristic (ROC) curves showed that the regrouping NRS 2002 scale (≤ 3 vs. > 3) provided a similar risk stratification predicting 2-year overall survival (OS) (area under the curves [AUCs]: 0.563 vs. 0.564, P > 0.05) but a better stratification predicting the risk of complications of palliative surgery (AUCs: 0.563 vs. 0.522, P = 0.050) than the original NRS 2002 scale (< 3 vs. ≥ 3). Patients with NRS 2002 > 3 tended to have higher postoperative morbidity (13.3% vs. 8.5%, P = 0.027) and mortality (5.3% vs. 2.0%, P = 0.013) and shorter progression-free survival (PFS) (median PFS: 6.70 vs. 7.70 months, P = 0.002) and overall survival (OS) (median OS: 9.03 vs. 12.63 months, P < 0.001) than those with NRS 2002 ≤ 3. Multivariable analysis demonstrated that the regrouping NRS 2002 scale was the independent prognostic factor for PFS (hazard ratio [HR]: 1.16, P = 0.028) and OS (HR: 1.29, P < 0.001).

Conclusions: The present study indicated that the NRS 2002 scale (regrouping scale) was an independent prognostic factor to predict the morbidity, mortality and survival outcomes for metastatic gastric cancer.

Evaluation of objective response, disease control and progression-free survival as surrogate end-points for overall survival in anti-programmed death-1 and anti-programmed death ligand 1 trials

BACKGROUND

We aimed to assess whether the Response Evaluation Criteria in Solid Tumors (RECIST) criteria-based objective response rate (ORR), disease control rate (DCR) and progression-free survival (PFS) could be valid surrogate end-points for overall survival (OS) in anti-programmed death-1 (PD-1)/programmed death ligand 1 (PD-L1) trials.

METHODS

We systematically reviewed phase 2 and phase 3 trials of anti-PD-1/PD-L1 drug trials of advanced or recurrent solid tumours that reported OS and at least one of the RECIST criteria-based end-points. We used Spearman rank correlation to evaluate the strength of the association between these end-points and OS and a linear regression model, weighted by the sample size, to assess the association between the treatment effect on these end-points and OS. We also performed sensitivity analyses and a leave-one-out cross-validation approach to evaluate the robustness of our findings.

RESULTS

Forty-three qualifying trails comprising 15,088 patients were eligible. PFS showed good correlation with OS (squared Spearman rank correlation coefficient [r_s²] = 0.54; P < 0.001), while ORR and DCR illustrated moderate association with OS (r_s² = 0.29 and 0.28, respectively; both P < 0.001). The correlation was moderate between the treatment effects on PFS and OS (coefficient of determination [R²] = 0.37, P < 0.001) and poor among ORR, DCR and OS (R² = 0.10 and 0.08, respectively); these were confirmed by sensitivity analyses (all R² < 0.75) and the leave-one-out cross-validation approach.

CONCLUSIONS

No RECIST criteria-based end-points could be a valid surrogate for OS. At present, we proposed to set OS as the primary end-point in anti-PD-1/PD-L1 drug trials of advanced or recurrent solid tumours.

Phase II clinical trial of S-1 plus nanoparticle albumin-bound paclitaxel in untreated patients with metastatic gastric cancer

The present study is the first phase II clinical trial aimed to evaluate the efficacy and safety of S‐1 plus nanoparticle albumin‐bound paclitaxel (Nab‐PTX) as first‐line chemotherapy for advanced gastric cancer (AGC). Previously untreated patients with metastatic gastric adenocarcinoma received S‐1 in oral doses of 40 mg (BSA <1.25 m²), 50 mg (1.25 ≤ BSA < 1.50 m²) and 60 mg (BSA ≥1.50 m²) b.i.d. on days 1‐14 in combination with Nab‐PTX (120 mg/m², on days 1 and 8) for each 21‐day cycle. Primary endpoint was progression‐free survival (PFS), and secondary endpoints were overall response rate (ORR), overall survival (OS), disease control rate (DCR), and toxicity. A total of 73 gastric cancer patients with metastatic and measurable lesions were enrolled in the first‐line setting. Median PFS and OS were 9.63 months and 14.60 months, respectively. Four (5.5%) patients had complete responses, 39 (53.4%) had partial responses (PRs), 21 (28.8%) had stable disease, four (5.5%) progressed and five (6.8%) were not evaluable. ORR and DCR were 58.9% and 87.7%, respectively. Most toxicities were mild, and no treatment‐related deaths occurred. Grade 3 to 4 toxicities occurred in 22 patients (30.1%) as follows: leukopenia (13.7%), neutropenia (12.3%), anemia (5.5%), thrombocytopenia (1.4%), diarrhea (6.8%), vomiting (2.7%), stomatitis (1.4%), peripheral neuropathy (1.4%), and hand‐foot syndrome (1.4%). Seven patients achieved good responses and underwent gastrectomy plus metastasectomy. Thirty (41.1%) patients had S‐1 maintenance with a median of four cycles. S‐1 plus Nab‐PTX is an efficient and safe regimen as first‐line treatment for patients with AGC.

Proposal of a modified American Joint Committee on Cancer staging scheme for resectable pancreatic ductal adenocarcinoma with a lymph node ratio-based N classification: A retrospective cohort study

The recently launched 8th edition of the American Joint Committee on Cancer (AJCC) staging scheme for pancreatic ductal adenocarcinoma (PDAC) did not account for the impact of the total examined lymph node count on prognostic accuracy. In this population-based cohort study, we proposed a modified AJCC staging scheme by incorporating a lymph node ratio (LNR)-based N classification for patients with resectable PDAC.We analyzed 8615 patients with resectable PDAC from the Surveillance, Epidemiology, and End Results database between 2004 and 2013. The optimal cut-off points for LNR were identified by recursive partitioning, and an LNR-based N classification was designed accordingly.The LNR-based N classification could further stratify patients with the 8th AJCC N1 and N2 disease into subgroups with significantly different overall survival (P < .001 for both). By replacing the 8th AJCC N classification with the corresponding LNR-based N classification, we further proposed a modified AJCC staging scheme. The modified AJCC staging outperformed the 8th AJCC staging in terms of the discriminatory capacity measured by the concordance index and Akaike information criterion, and the prognostic homogeneity assessed by using the likelihood ratio chi-squared test and stratified survival analysis.Replacing the 8th AJCC N classification with the LNR-based N classification can improve the prognostic performance of the 8th AJCC staging scheme for PDAC.

Preoperative apolipoprotein B/apolipoprotein A1 ratio: a novel prognostic factor for gastric cancer

Background

The correlations between lipid profile (lipid molecules and their derivative indexes) and clinical outcome have been widely testified in many carcinomas, but its prognostic value remains unknown in gastric cancer (GC). Our purpose in the study was to comprehensively evaluate the clinical significance of lipid profile in GC.

Methods

We retrospectively collected clinical information of 1,201 GC patients who received surgery at Sun Yat-sen University Cancer Center from 2005 to 2010. Kaplan–Meier analysis and Cox proportional hazards regression model were performed to determine its prognostic significance.

Results

Lipid profile including cholesterol, triglyceride, high-density lipoprotein-cholesterol (HDL-C), low-density lipoprotein-cholesterol (LDL-C), apolipoprotein A1 (ApoA1), apolipoprotein B (ApoB), LDL-C/HDL-C ratio, and ApoB/ApoA1 ratio were analyzed. For the first time, we found ApoB/ApoA1 ratio showed the biggest prognostic potency among all lipid-related variables and could act as an independent prognostic factor in GC. Patients with a high ApoB/ApoA1 ratio (≥1) had a shorter overall survival (hazard ratio: 1.373, 95% confidence interval: 1.123–1.68; P=0.002).

Conclusion

Preoperative serum ApoB/ApoA1 ratio might be used as a novel prognostic indicator of GC.

Bursectomy for advanced gastric cancer: an update meta-analysis

Background

The present meta-analysis was to explore the surgical and oncological outcomes of bursectomy for advanced gastric cancer (AGC).

Methods

Relevant studies that evaluated the role of bursectomy for AGC were comprehensively examined to perform a meta-analysis. The primary outcomes were overall survival (OS) and disease-free survival (DFS). The secondary outcomes were the number of harvested lymph nodes (LNs), operation time, operative bleeding, hospital stay, postoperative complication and mortality.

Results

A total of seven studies comprising 2633 cases (1176 cases in the bursectomy group and 1457 cases in the non-bursectomy group) were finally included. There was no significant difference in OS (HR 0.95, P = 0.647) and DFS (HR 0.99, P = 0.936) between the two groups. Even for patients with serosa-penetrating tumours, OS was comparable between the two groups (HR 0.87, P = 0.356). The operation time of the bursectomy group was longer (weighted mean difference, WMD 32.76 min, P = 0.002). No significant difference was found between the two groups in terms of the number of dissected LNs (WMD 5.86, P = 0.157), operative bleeding (WMD 66.99 ml, P = 0.192) and hospital stay (WMD − 0.15 days, P = 0.766). The overall postoperative complication (relative risk, RR 1.08, P = 0.421) and mortality (RR 0.44, P = 0.195) were similar between two groups.

Conclusions

This meta-analysis indicated that bursectomy is time-consuming without increasing the number of harvested LNs. Although bursectomy can be safely performed without increasing complications and mortality, it does not prolong the OS and DFS of AGC patients, including patients with serosa-penetrating tumours. Therefore, bursectomy should not be recommended as a standard procedure for AGC.

Electronic supplementary material

The online version of this article (10.1186/s12957-018-1354-1) contains supplementary material, which is available to authorized users.

Glasgow Prognostic Score is superior to ECOG PS as a prognostic factor in patients with gastric cancer with peritoneal seeding

The Glasgow Prognostic Score (GPS) has been shown to be associated with survival rates in patients with advanced cancer. The present study aimed to compare the GPS with the Eastern Cooperative Oncology Group Performance Status (ECOG PS) in patients with gastric cancer with peritoneal seeding. For the investigation, a total of 384 gastric patients with peritoneal metastasis were retrospectively analyzed. Patients with elevated C-reactive protein (CRP; >10 mg/l) and hypoalbuminemia (<35 mg/l) were assigned a score of 2. Patients were assigned a score of 1 if presenting with only one of these abnormalities, and a score of 0 if neither of these abnormalities were present. The clinicopathologic characteristics and clinical outcomes of patients with peritoneal seeding were analyzed. The results showed that the median overall survival (OS) of patients in the GPS 0 group was longer, compared with that in the GPS 1 and GPS 2 groups (15.50, vs. 10.07 and 7.97 months, respectively; P<0.001). No significant difference was found between the median OS of patients with a good performance status (ECOG <2) and those with a poor (ECOG ≥2) performance status (13.67, vs. 11.80 months; P=0.076). In the subgroup analysis, the median OS in the GPS 0 group was significantly longer, compared with that in the GPS 1 and GPS 2 groups, for the patients receiving palliative chemotherapy and patients without palliative chemotherapy. Multivariate survival analysis demonstrated that CA19-9, palliative gastrectomy, first-line chemotherapy and GPS were the prognostic factors predicting OS. In conclusion, the GPS was superior to the subjective assessment of ECOG PS as a prognostic factor in predicting the outcome of gastric cancer with peritoneal seeding.

Development and Validation of a Nomogram to Predict the Benefit of Adjuvant Radiotherapy for Patients with Resected Gastric Cancer

Background: The US guidelines for gastric cancer (GC) recommend adjuvant radiotherapy (ART) combined with 5-fluorouracil as a standard treatment for patients with resected locally advanced GC. However, patient selection criteria for optimizing the use of adjuvant therapies are lacking. In this study, we developed and validated a nomogram to predict the individualized overall survival (OS) benefit of ART among patients with resected ≥stage IB GC. Patients and Methods: The 2002-2006 Surveillance, Epidemiology, and End Results (SEER) data of 5,206 patients with resected GC were used as a training set for the development of a nomogram. The 2007-2008 SEER data of 1,986 patients with resected GC were used as validation data. Results: In the multivariate analysis weighted by inverse propensity score, the efficacy of ART varied by the ratio of positive to examined nodes (Pinteraction <0.01). The magnitude of this difference was included in the nomogram with associated prognosticators to predict the 3- and 5-year OS with and without ART. The nomogram showed significant prognostic superiority to the 8th TNM staging in the training set (Concordance index, 0.68 versus 0.65; P<0.01) and the validation set (Concordance index, 0.68 versus 0.64; P<0.01). Moreover, the calibration was accurate, and the actual efficacy of ART was positively correlated with the nomogram-estimated survival benefit from ART (Pinteraction <0.01 and Pinteraction =0.02 in the training set and the validation set, respectively). Conclusion: The nomogram can aid individualized clinical decision making by estimating the 3- and 5-year OS and potential benefits of ART among patients with resected GC.

Clinicopathological Characteristics and Prognostic Value of Signet Ring Cells in Gastric Carcinoma: A Meta-Analysis

Background and Objectives: Previous studies of the prognostic value of the signet ring cell (SRC) type have yielded inconsistent results. Therefore, the aim of the present meta-analysis is to explore the clinicopathological characteristics and prognostic value of SRCs.

Methods: Relevant articles that compared SRC and non-SRC type in PubMed and Web of Science were comprehensively searched. Then, a meta-analysis was performed.

Results: A total of 19 studies including 35947 cases were analyzed. Compared with non-SRC patients, SRC patients tended to be younger (WMD: -3.88, P=0.001) and predominantly female (OR: 1.60, P<0.001). Additionally, SRC patients exhibited less upper third tumor location (OR: 0.62, P<0.001) and less frequent hematogenous metastasis (OR: 0.41, P<0.001). There was no difference in overall survival (OS) between SRC and non-SRC patients in the total population (HR: 1.02, P=0.830). Early gastric cancer with SRCs was associated with better OS (HR: 0.57, P=0.002), while advanced gastric cancer with non-SRCs was associated with a worse prognosis (HR: 1.17, P<0.001).

Conclusions: This meta-analysis revealed that SRC tends to affect young females and tends to be located in the middle and lower third of the stomach. Early SRCs are associated with better prognoses, while advanced SRCs are associated with worse prognoses.

Selective Gastric Cancer Patients with Peritoneal Seeding Benefit from Gastrectomy after Palliative Chemotherapy: A Propensity Score Matching Analysis

Background: The present study aimed to explore whether gastric cancer patients with peritoneal seeding after receiving palliative chemotherapy could benefit from gastrectomy and to identify patients with peritoneal seeding who should be selected to receive gastrectomy.

Methods: A total of 201 gastric cancer patients were diagnosed with peritoneal seeding and received palliative chemotherapy. Propensity score matching (PSM) was performed to balance the selection bias.

Results: After PSM, compared with non-gastrectomy group, gastrectomy group had a longer median overall survival (OS) (23.60 vs. 13.80 moths; P=0.034). Patients with R0 resection had a median OS of 43.60 months compared with 11.27 months in patients who underwent R1/2 resection (P<0.001). The median OS times between the R1/2 resection and non-gastrectomy groups were not different (P=0.139). Subgroup analysis revealed that only patients receiving more than 4 periods of first-line chemotherapy benefited from gastrectomy (P=0.018), whereas patients receiving 1-4 periods of first-line chemotherapy did not (P=0.275). Multivariate analysis showed that gastrectomy (P=0.012) and the period of first-line chemotherapy (P<0.001) were independent prognostic factors. The overall postoperative morbidity was 3.03% (1/33) in the gastrectomy group, and no treatment-related death was observed.

Conclusions: The present study indicated that gastrectomy after palliative chemotherapy is a safe procedure and showed a survival benefit for gastric cancer patients with peritoneal seeding. Moreover, clinically curative R0 gastrectomy and more than 4 periods of palliative chemotherapy resulted in better clinical outcomes.

Endoscopic ultrasonography compared with multidetector computed tomography for the preoperative staging of gastric cancer: a meta-analysis

Background

The current study sought to perform a meta-analysis to compare the preoperative staging of endoscopic ultrasonography (EUS) and multidetector computed tomography (MDCT) in gastric carcinoma.

Methods

Articles published between January 1, 2000, and April 1, 2016, that compared EUS with MDCT were included, and data were presented as 2 × 2 tables. The sensitivities, specificities and summary receiver operating characteristic (ROC) curves for T and N staging were calculated using a bivariate mixed effects model. Data were weighted by generic variance and then pooled by random-effects modeling.

Results

Eight studies comprising 1736 patients were included in this meta-analysis. For T1 staging, the sensitivity value for EUS (82%) was significantly higher than that for MDCT (41%) (relative risk (RR): 2.06, 95% confidence interval (CI) 1.07–3.94; P = 0.030). For lymph node involvement, the sensitivity value for EUS (91%) was also significantly higher than that for MDCT (77%) (RR 1.14, 95% CI 1.05–1.23; P = 0.001). However, the specificity values of both EUS and MDCT were quite low, at 49 and 63%, respectively. No significant differences in T2–4 staging between EUS and MDCT were noted.

Conclusion

This meta-analysis indicates that EUS may be superior to MDCT in preoperative T1 and N staging. Additionally, the low specificity values of EUS and MDCT for N staging merits attention.

Phase II trial of S-1 plus leucovorin in patients with advanced gastric cancer and clinical prediction by S-1 pharmacogenetic pathway

Background

The first one-arm phase II trial aimed to evaluate and predict efficacy and safety of S-1 plus oral leucovorin (S-1/LV) as first-line chemotherapy for patients with advanced gastric cancer (AGC), using S-1 pharmacogenetic pathway approach.

Patients and methods

A total of 39 patients orally took S-1 at conventional dose and LV simultaneously at a dose of 25 mg twice daily for a week, within a 2-week cycle. The primary endpoint was overall response rate (ORR), while the secondary endpoints were progression-free survival (PFS), time to failure (TTF), overall survival (OS), disease control rate (DCR), and adverse events (AEs). Peripheral blood was sampled prospectively for baseline expression of dihydropyrimidine dehydrogenase (DPD), orotate phosphoribosyltransferase (OPRT), thymidine phosphorylase (TP), and thymidylate synthase (TS), CYP2A6 gene polymorphisms, and 5-FU pharmacokinetics.

Results

The ORR and DCR were 41.0 and 76.9%. The median PFS, TTF, and OS were 4.13, 3.70, and 11.40 months. Grade 3–4 AEs occurred in only 13 patients, and grade 4 AEs occurred in only 1 of them. High OPRT/TS and peritoneal metastasis (vs. liver metastasis) independently predicted responding. High OPRT/DPD independently predicted grade 3–4 AEs. High AUC_0–24h of 5-FU and metastatic/recurrent sites ≤2 (vs. >3) independently predicted prolonged PFS. Low baseline plasmic DPD independently predicted prolonged OS.

Conclusions

Two-week, oral S-1/LV regimen demonstrated promising efficacy and safety as first-line chemotherapy for AGC.

ClinicalTrials.gov identifier

NCT02090153

Electronic supplementary material

The online version of this article (doi:10.1007/s00280-016-3209-1) contains supplementary material, which is available to authorized users.

Experimental investigation on dynamic characteristics and strengthening mechanism of laser-induced cavitation bubbles

The dynamic features of nanosecond laser-induced cavitation bubbles near the light alloy boundary were investigated with the high-speed photography. The shock-waves and the dynamic characteristics of the cavitation bubbles generated by the laser were detected using the hydrophone. The dynamic features and strengthening mechanism of cavitation bubbles were studied. The strengthening mechanisms of cavitation bubble were discussed when the relative distance parameter γ was within the range of 0.5-2.5. It showed that the strengthening mechanisms caused by liquid jet or shock-waves depended on γ much. The research results provided a new strengthening method based on laser-induced cavitation shotless peening (CSP).

Significant Role of Palliative Gastrectomy in Selective Gastric Cancer Patients with Peritoneal Dissemination: A Propensity Score Matching Analysis

OBJECTIVE

The aim of this study was to explore whether palliative gastrectomy is suitable for gastric cancer patients with peritoneal metastasis, and for patients in whom the type of peritoneal metastasis should be selected to receive palliative gastrectomy.

METHODS

A total of 747 patients diagnosed with gastric adenocarcinoma with peritoneal metastasis at our centers between January 2000 and April 2014 were retrospectively analyzed. After propensity score matching, the clinicopathologic characteristics and clinical outcomes of patients with peritoneal dissemination were analyzed.

RESULTS

After propensity score matching, the median overall survival (OS) of patients in the gastrectomy group was longer than that for patients in the non-gastrectomy group (11.87 vs. 9.27 months; p = 0.020). Patients who received first-line chemotherapy had a significantly longer median OS than those who did not (11.97 vs. 7.03 months; p < 0.001); among these patients, those undergoing more than eight periods of first-line chemotherapy benefited the most (p < 0.001). Subgroup analyses revealed that patients classified as P1 who were undergoing chemotherapy benefited from gastrectomy (p = 0.024), and patients without multisite metastasis also benefited from gastrectomy with regard to OS (p = 0.007). In the multivariate survival analysis, multisite distant metastasis was the independent poor prognostic factor (p < 0.001), while palliative gastrectomy (p = 0.006) and a period of first-line chemotherapy (p < 0.001) were good prognostic factors. Morbidity rates in the gastrectomy and non-gastrectomy groups were 10.4 and 1.0 %, respectively (p = 0.003); however, no difference in mortality was noted between the two groups (p = 0.590).

CONCLUSIONS

Palliative gastrectomy can prolong the survival of P1 patients without multisite distant metastasis when combined with more than five periods, and particularly more than eight periods, of first-line chemotherapy.

High expression level of T-box transcription factor 5 predicts unfavorable survival in stage I and II gastric adenocarcinoma

The expression of T-box transcription factor 5 (TBX5) has previously been observed in human cancer. The aim of the present study was to investigate TBX5 expression and its potential clinical significance in gastric cancer (GC). Using reverse transcription-quantitative polymerase chain reaction, the TBX5 mRNA expression levels in 30 pairs of surgically resected healthy gastric tissues and early stage (stages I and II) GC tissues were evaluated. The TBX5 mRNA expression levels were increased in GC stage I and II tumor tissues (P=0.01, n=30) compared with the matched adjacent non-tumor tissue. However, no significant difference was observed in TBX5 mRNA expression levels in matched adjacent non-tumor tissue compared with the tumor tissue from stage III and IV GC samples (P=0.318, n=30). Immunohistochemical analysis for TBX5 expression was performed on 161 paraffin-embedded stage I and II GC tissue blocks. Statistical analysis was performed to evaluate the associations between TBX5 expression, clinicopathological factors and prognosis. Patients with stage I and II GC and tumors with high TBX5 expression levels presented poor overall survival (OS) rate (P=0.024). The Cox proportional hazards model analysis demonstrated that TBX5 expression was an independent risk factor (P=0.017). The present study indicates that high expression of TBX5 is associated with unfavorable OS rates in patients with stage I and II GC. In conclusion, the expression of TBX5 may be a valuable biomarker for the selection of cases of high-risk stage I and II GC.

[Correlation of chemosensitivity tested using histoculture drug response assay to expression of multidrug resistance genes and proteins in colorectal cancer tissues]

BACKGROUND AND OBJECTIVE

The therapeutic effects of chemotherapy for malignant neoplasms are still unsatisfactory. This study was to evaluate the chemosensitivity of colorectal cancer tissues to therapeutic agents using histoculture drug response assay (HDRA), and explore the correlation of chemosensitivity to the expression levels of multidrug resistance (MDR) genes and proteins.

METHODS

Twenty-two specimens of colorectal cancer were collected. The inhibition rates of single agents, including epirubicin, cisplatin (DDP), oxaliplatin, 5-FU, taxetere, irinotecan, and combinations of these agents, including 5-FU+epirubicin+DDP, 5-FU+irinotecan, 5-FU+oxaliplatin, 5-FU+taxetere+ DDP on colorectal cancer tissues were evaluated by HDRA. The agent whose inhibition rate was greater than 30% was considered sensitive, and the sensitivity was calculated. mRNA and protein levels of MDR genes and proteins in colorectal cancer tissues were measured by RT-PCR and immunohistochemistry.

RESULTS

Among the single agents, the inhibition rate of oxaliplatin (17.5%) and sensitivity of cancer tissues to 5-FU (36.4%) were the highest. In the combination groups of agents, the inhibition rate of 5-FU+ oxaliplatin (54.1%), and sensitivity of cancer tissues to 5-FU+epirubicin+DDP (71.4%) and to 5-FU+taxetere+DDP (71.4%) were the highest. The inhibition rates of and sensitivity of cancer tissues to combined agents were higher than those of single agents (P<0.05). Expressions of MDR1, multidrug resistance protein-1 (MRP1), ABC-binding cassette transporter superfamily-G-2 (ABCG2) mRNA were detected in 88.9%, 55.6% and 55.6% of specimens respectively; while those of MDR1, MRP1 and ABCG2 proteins were detected in 55.6%, 33.3%, and 50.0% of specimens respectively. Expressions of mRNA and proteins had no correlation in MDR1, MRP1 and ABCG2 (P>0.05). High expression of ABCG2 protein was correlated to the resistance of colorectal cancer cells to epirubicin (P<0.05).

CONCLUSIONS

Expressions of MDR proteins are correlated to chemosensitivity of colorectal cancer to some extents. By combining HDRA with measurement of MDR genes and proteins, chemosensitivity of individual tumors may be predicted to guide selection of effective chemotherapeutic agents.

[Correlation of chemosensitivity measured by histoculture drug response assay to expression of multidrug resistance genes and proteins in gastric cancer]

BACKGROUND AND OBJECTIVE

The therapeutic effects of chemotherapy on gastric cancer are still unsatisfactory. Predicting chemosensitivity of tumors as therapeutic guidance could help to improve the efficacy of chemotherapy. This study was to evaluate the chemosensitivity of gastric cancer to single or combined therapeutic agents by histoculture drug response assay, to evaluate the expression levels of multidrug resistance (MDR) genes and proteins and analyze their correlations to the chemosensitivity of gastric cancer.

METHODS

The inhibitory effects of single agents, including epirubicin, cisplatin (DDP), oxaliplatin, 5-fluorouracil (5-FU), taxetere, irinotecan, and combined regimens, including 5-FU, epirubicin plus DDP, 5-FU plus irinotecan, 5-FU plus oxaliplatin, and 5-FU, taxetere plus DDP, on 22 specimens of gastric cancer were evaluated by histoculture drug response assay. The mRNA and protein expression of MDR1, MRP1 and ABCG2 in gastric cancer were detected by reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemistry.

RESULTS

The inhibition rate of gastric cancer by 5-FU (29.8%) and sensitivity of gastric cancer to 5-FU (50.0%) were the highest among single agents; the inhibition rate of gastric cancer by 5-FU, taxetere plus DDP (59.8%) and sensitivity to 5-FU, epirubicin plus DDP (77.3%) were the highest among combined regimens; combined regimens achieved higher inhibition rate and sensitivity as compared with single agents (P<0.05). The positive rates of MDR1, MRP1, and ABCG2 mRNA were 90.9%, 54.5%, and 77.3%; the positive rates of MDR1, MRP1, and ABCG2 proteins were 36.4%, 54.5%, and 36.4%. High expression of MDR proteins in gastric cancer was related with the resistance to epirubicin (P<0.05).

CONCLUSION

High expression of MDR1, MRP1, ABCG2 proteins in gastric cancer is related with the resistance to epirubicin, which indicates that these MDR genes may play a role in conferring the drug resistance to epirubicin.

The role of half-life of carcinoembryonic antigen (CEA) in prognosis prediction of colorectal cancer patients with preoperatively elevated CEA

BACKGROUND & OBJECTIVE

Carcinoembryonic antigen (CEA) monitoring plays an important role in the management of malignancies, especially in colorectal cancer (CRC). The half-life (T1/2) of CEA has also been applied as a new predictor in the surveillance of some malignancies. This study was to examine the preoperative and early postoperative levels of CEA in CRC patients and calculate postoperative T1/2 of CEA to evaluate its potential role in prognosis prediction.

METHODS

In this retrospective study, 98 CRC patients who had preoperatively elevated levels of CEA (>or=5 microg/L) and serum CEA surveillance after radical operation were included. Postoperative T1/2 of CEA was calculated. Its correlation to prognosis was analyzed.

RESULTS

Of the 98 patients, 21 had local recurrence or distant metastasis (recurrence group), 77 had no recurrence (non-recurrence group). The median value of preoperative CEA level was significantly higher in recurrence group than in non-recurrence group (23.9 microg/L vs. 12.3 microg/L, P=0.010); the median value of postoperative T1/2 of CEA was significantly longer in recurrence group than in non-recurrence group (6.2 days vs. 4.7 days, P=0.042); the later the TNM stage was, the poorer the prognosis was (P<0.001). The 3-year disease-free survival (DFS) rate and overall survival (OS) rate were significantly higher in the patients with postoperative T1/2 of CEA of <4.8 days than in those with T1/2 of >or=4.8 days (87% vs. 66%, P=0.017; 90% vs. 80%, P=0.032). The patients at earlier TNM stage had survival benefits both in DFS and OS: the 3-year DFS rates in stage I, II, and III patients were 100%, 93%, and 55%, respectively (P<0.001); the 3-year OS rates were 100%, 98%, and 77%, respectively (P=0.192). In Cox regression analysis, both TNM stage and postoperative T1/2 of CEA were confirmed to be independent prognostic factors of CRC patients with preoperatively elevated CEA level.

CONCLUSIONS

In addition to TNM stage, the T1/2 of CEA may be an independent prognostic factor in CRC patients with preoperatively elevated CEA level. The patients with longer T1/2 of CEA after radical operation have poorer prognosis.

[Effects of dingduwan on electric activities of gastrointestinal smooth muscle and effect of gastrointestinal motility]

Dingduwan (DDW) is a Chinese herbal medicine. Method of modified synchronous recording was used to study the electric activities of gastrointestinal (GI) smooth muscle and the effect of GI motility treated by DDW. A dosage of 3.5 g/kg for ingestion in rats markedly increased the average amplitude of GI slow wave, the total amplitude of GI motion, the rate of GI slow wave and intestinal motion (P < 0.05), but it had no significant effects on the frequency of gastroelectric slow wave and gastric motility (P < 0.05). DDW in the dosage of 5.2 g/kg for ingestion markedly promoted the recovery of intestinal intussusception in mice (P > 0.05). The results showed that DDW markedly increased the intestinal electricity and motility more than that of stomach.