Preoperative Chemotherapy for Gastric Cancer: Personal Interventions and Precision Medicine

Intratumoral and peritumoral radiomics predict pathological response after neoadjuvant chemotherapy against advanced gastric cancer

BACKGROUND

To investigate whether intratumoral and peritumoral radiomics may predict pathological responses after neoadjuvant chemotherapy against advanced gastric cancer.

METHODS

Clinical, pathological, and CT data from 231 patients with advanced gastric cancer who underwent neoadjuvant chemotherapy at our hospital between July 2014 and February 2022 were retrospectively collected. Patients were randomly divided into a training group (n = 161) and a validation group (n = 70). The support vector machine classifier was used to establish radiomics models. A clinical model was established based on the selected clinical indicators. Finally, the radiomics and clinical models were combined to generate a radiomics-clinical model. ROC analyses were used to evaluate the prediction efficiency for each model. Calibration curves and decision curves were used to evaluate the optimal model.

RESULTS

A total of 91 cases were recorded with good response and 140 with poor response. The radiomics model demonstrated that the AUC was higher in the combined model than in the intratumoral and peritumoral models (training group: 0.949, 0.943, and 0.846, respectively; validation group: 0.815, 0.778, and 0.701, respectively). Age, Borrmann classification, and Lauren classification were used to construct the clinical model. Among the radiomics-clinical models, the combined-clinical model showed the highest AUC (training group: 0.960; validation group: 0.843), which significantly improved prediction efficiency.

CONCLUSION

The peritumoral model provided additional value in the evaluation of pathological response after neoadjuvant chemotherapy against advanced gastric cancer, and the combined-clinical model showed the highest predictive efficiency.

CRITICAL RELEVANCE STATEMENT

Intratumoral and peritumoral radiomics can noninvasively predict the pathological response against advanced gastric cancer after neoadjuvant chemotherapy to guide early treatment decision and provide individual treatment for patients.

KEY POINTS

1. Radiomics can predict pathological responses after neoadjuvant chemotherapy against advanced gastric cancer. 2. Peritumoral radiomics has additional predictive value. 3. Radiomics-clinical models can guide early treatment decisions and improve patient prognosis.

Evaluation of Event-Free Survival Surrogating Overall Survival as the Endpoint in Neoadjuvant Clinical Trials of Gastroesophageal Adenocarcinoma

Background

Gastric cancer (GC) is one of the most common malignant cancers worldwide. The development of potential antitumor agents is being investigated and stimulates more clinical trials. Overall survival (OS) is consistently considered the primary endpoint for clinical trials on treatment effect assessment. However, finding an appropriate endpoint more sensitive and easy for trials is vital. For adjuvant chemotherapy, current evidence has shown that disease-free survival (DFS) could be a surrogate endpoint for randomized controlled trials (RCTs) with GC, but evidence for neoadjuvant chemotherapy (NCT) or chemoradiotherapy (NCRT) is inadequate. This study was designed to evaluate the possibility that event-free survival (EFS) surrogates OS in RCTs of NCT/NCRT of gastric orss gastroesophageal (GC or GEJ) adenocarcinoma patients (ADK).

Methods

A literature search was conducted through databases including PubMed, the Cochrane Library, and Embase. References and articles from other sources were also included. A total of 8 RCTs with 2,837 patients were eventually analyzed. Hazard ratios (HRs) of OS and EFS were directly approached. The surrogacy of EFS was assessed through the correlation of determination R². We used Review Manage pooling HRs of OS and EFS at the trial level. I² was used to demonstrate the heterogeneity of inclusions. Publication bias was summarized and illustrated through funnel plots. All analyses were on two sides with a setting statistical significance as p < 0.05.

Results

Eight RCTs of 2,837 patients were analyzed at the trial level. The I² for OS was 21% and 51% for EFS, and a fixed-effect model was used. The pooled HR of OS was 0.83 (95% CI: 0.75–0.92, p < 0.001), and that of EFS was 0.78 (95% CI: 0.71–0.86, p < 0.001). The regression correlation coefficient between EFS and OS was 0.76 (95% CI: 0.41–1.11, p = 0.002), and the coefficient of determination R² = 0.826.

Conclusions

A strong correlation was observed between OS and EFS at the trial level. EFS could be a surrogate endpoint for neoadjuvant RCTs of GC and GEJ adenocarcinoma. Further studies and evidence from individual data are expected.

MTA2 sensitizes gastric cancer cells to PARP inhibition by induction of DNA replication stress

Poly (ADP-ribose) polymerase (PARP) inhibitor olaparib selectively kills cancer cells with BRCA-deficiency and is approved for BRCA-mutated breast, ovarian and pancreatic cancers by FDA. However, phase III study of olaparib failed to show a significant improvement in overall survival in patients with gastric cancer (GC). To discover an effective biomarker for GC patient-selection in olaparib treatment, we analyzed proteomic profiling of 12 GC cell lines. MTA2 was identified to confer sensitivity to olaparib by aggravating olaparib-induced replication stress in cancer cells. Mechanistically, we applied Cleavage Under Targets and Tagmentation assay to find that MTA2 proteins preferentially bind regions of replication origin-associated DNA sequences, which could be enhanced by olaparib treatment. Furthermore, MTA2 was validated here to render cancer cells susceptible to combination of olaparib with ATR inhibitor AZD6738. In general, our study identified MTA2 as a potential biomarker for olaparib sensitivity by aggravating olaparib-induced replication stress.

Delta-radiomics and response to neoadjuvant treatment in locally advanced gastric cancer-a multicenter study of GIRCG (Italian Research Group for Gastric Cancer)

BACKGROUND

To predict response to neoadjuvant chemotherapy (NAC) of gastric cancer (GC), prior to surgery, would be pivotal to customize patient treatment. The aim of this study is to investigate the reliability of computed tomography (CT) texture analysis (TA) in predicting the histo-pathological response to NAC in patients with resectable locally advanced gastric cancer (AGC).

METHODS

Seventy (40 male, mean age 63.3 years) patients with resectable locally AGC, treated with NAC and radical surgery, were included in this retrospective study from 5 centers of the Italian Research Group for Gastric Cancer (GIRCG). Population was divided into two groups: 29 patients from one center (internal cohort for model development and internal validation) and 41 from other four centers (external cohort for independent external validation). Gross tumor volume (GTV) was segmented on each pre- and post-NAC multidetector CT (MDCT) image by using a dedicated software (RayStation), and 14 TA parameters were then extrapolated. Correlation between TA parameters and complete pathological response (tumor regression grade, TRG1), was initially investigated for the internal cohort. The univariate significant variables were tested on the external cohort and multivariate logistic analysis was performed.

RESULTS

In multivariate logistic regression the only significant TA variable was delta gray-level co-occurrence matrix (GLCM) contrast (P=0.001, Nagelkerke R2: 0.546 for the internal cohort and P=0.014, Nagelkerke R2: 0.435 for the external cohort). Receiver operating characteristic (ROC) curves, generated from the logistic regression of all the patients, showed an area under the curve (AUC) of 0.763.

CONCLUSIONS

Post-NAC GLCM contrast and dissimilarity and delta GLCM contrast TA parameters seem to be reliable for identifying patients with locally AGC responder to NAC.

Histologic Lymph Nodes Regression after Preoperative Chemotherapy as Prognostic Factor in Non-metastatic Advanced Gastric Adenocarcinoma

Background: The study aims to evaluate the lymph node (LN) response to preoperative chemotherapy and its impact on long-term outcomes in advanced gastric cancer (AGC). Methods: Histological specimens retrieved at gastrectomy from patients who received preoperative chemotherapy were evaluated. LN regression was graded by the adapted tumor regression grading system proposed by Becker. Patients were classified as node-negative (lnNEG) in the case of all negative LN without evidence of previous tumor involvement. Patients with LN metastasis were classified as nodal responders (lnR) in case of a regression score 1a-2 was detected in the LN. Nodal non-responders (lnNR) had a regression score of 3 in all of the metastatic nodes. Survival was compared using Kaplan-Meier and Cox regression analysis. Results: Among 87 patients included in the final analysis 29.9 % were lnNEG, 21.8 % were lnR and 48.3 % were lnNR. Kaplan-Meier curves showed a survival benefit for lnR over lnNR (p=0.03), while the survival of lnR and lnNEG patients was similar. Cox regression confirmed nodal response to be associated with decreased odds for death in univariate (HR: 0.33; 95 % CI 0.11-0.96, p=0.04) and multivariable (HR 0.37; 95 CI% 0.14-0.99, p=0.04) analysis. Conclusions: Histologic regression of LN metastasis after preoperative chemotherapy predicts the increased survival of patients with non-metastatic resectable AGC.

Analysis of candidate genes expected to be essential for melanoma surviving

Introduction

Cancers may be treated by selective targeting of the genes vital for their survival. A number of attempts have led to discovery of several genes essential for surviving of tumor cells of different types. In this work, we tried to analyze genes that were previously predicted to be essential for melanoma surviving. Here we present the results of transient siRNA-mediated knockdown of the four of such genes, namely, UNC45A, STK11IP, RHPN2 and ZNFX1, in melanoma cell line A375, then assayed the cells for their viability, proliferation and ability to migrate in vitro. In our study, the knockdown of the genes predicted as essential for melanoma survival does not lead to statistically significant changes in cell viability. On the other hand, for each of the studied genes, mobility assays showed that the knockdown of each of the target genes accelerates the speed of cells migrating. Possible explanation for such counterintuitive results may include insufficiency of the predicting computational models or the necessity of a multiplex knockdown of the genes.

Aims

To examine the hypothesis of essentiality of hypomutated genes for melanoma surviving we have performed knockdown of several genes in melanoma cell line and analyzed cell viability and their ability to migrate.

Methods

Knockdown was performed by siRNAs transfected by Metafectene PRO. The levels of mRNAs before and after knockdown were evaluated by RT-qPCR analysis. Cell viability and proliferation were assessed by MTT assay. Cell migration was assessed by wound healing assay.

Results

The knockdown of the genes predicted as essential for melanoma survival does not lead to statistically significant changes in cell viability. On the other hand, for each of the studied genes, mobility assays showed that the knockdown of each of the target genes accelerates the speed of cells migrating.

Conclusion

Our results do not confirm initial hypothesis that the genes predicted essential for melanoma survival as a matter of fact support the survival of melanoma cells.

The efficacy and safety of neoadjuvant chemotherapy on patients with advanced gastric cancer: A multicenter randomized clinical trial

OBJECTIVES

Exploring the efficacy and safety of perioperative chemotherapy on patients with AGC at different clinical and pathological stages.

METHODS

A phase III randomized, multicenter, trial comparing adjuvant (arm A) or perioperative S-1 plus oxaliplatin (SOX, arm B), and perioperative capecitabine plus oxaliplatin (XELOX, arm C) was initiated in T3/4, node + gastric cancer patients (unclear). Each patient received an 8-cycle chemotherapy (3 weeks for one cycle). Group arms B and C received two cycles preoperatively, and six cycles postoperatively. Primary endpoints were R0 resection rate and DFS, and secondary endpoints included OS, ORR, DCR, and safety. This study was registered on Clinicaltrials.gov. NCT01516944.

RESULTS

A total of 749 patients were randomly assigned into groups A, B, and C. Group A received 1460 circles chemotherapy and group B received 1177 circles while group C received 1200 circles. R0 resection rates in the three groups were 81.7%, 88.7%, and 83.1%, respectively. The difference between groups A and B was considered to be statistically significant (P = .018), and no significant difference between groups B and C (P = .051). Hazard ratio were compared between groups B and C and DFS showed 0.72 (0.67-0.77 with 95% CI), Pnon-inferiority  < .0001, Plog-rank  = .064). The CI top limit actually lower than the estimated value of 1.38, which indicated noninferiority of SOX to XELOX.

CONCLUSIONS

Compared with PAC, perioperative chemotherapy showed a significant improvement in R0 resection rates and prognosis in AGC patients with higher safety rates. This study was powered to show superiority of perioperative over adjuvant SOX, and noninferiority of SOX to XELOX. Volume measurement, repeated laparoscopic exploration combined with exfoliative cytology can be used as a supplementary method in the clinical staging and efficacy evaluation of AGC.

Study protocol of a multicenter phase III randomized controlled trial investigating the efficiency of the combination of neoadjuvant chemotherapy (NAC) and neoadjuvant laparoscopic intraperitoneal hyperthermic chemotherapy (NLHIPEC) followed by R0 gastrectomy with intraoperative HIPEC for advanced gastric cancer (AGC): dragon II trial

Background

Even though treatment modalities such as adjuvant systemic radio-chemotherapy and neoadjuvant chemotherapy (NAC) have individually have improved overall survival (OS) and progression-free survival (PFS) rates in advanced Gastric Cancer (AGC), the peritoneum still presides as a common site of treatment failure and disease recurrence. The role of hyperthermic intraperitoneal chemotherapy (HIPEC) has been acknowledged as prophylaxis for peritoneal carcinomatosis (PC) in AGC patients and in this study, we aim at investigating the safety and efficacy of the combination of neoadjuvant laparoscopic HIPEC (NLHIPEC) with NAC in the neoadjuvant phase followed by surgery of curative intent with intraoperative HIPEC followed by adjuvant chemotherapy (AC).

Methods

In this multicenter Phase III randomized controlled trial, 326 patients will be randomly separated into 2 groups into a 1:1 ratio after laparoscopic exploration. The experiment arm will receive the proposed comprehensive Dragon II regimen while the control group will undergo standard R0 D2 followed by 8 cycles of AC with oxaliplatin with S-1 (SOX) regimen. The Dragon II regimen comprises of 1 cycle of NLHIPEC for 60mins at 43 ± 0.5 °C with 80 mg/m² of Paclitaxel followed by 3 cycles of NAC with SOX regimen and after assessment, standard R0 D2 gastrectomy with intraoperative HIPEC followed by 5 cycles of SOX regimen chemotherapy. The end-points for the study are 5 year PFS, 5 year OS, peritoneal metastasis rate (PMR) and morbidity rate.

Discussion

This study is one of the first to combine NLHIPEC with NAC in the preoperative phase which is speculated to provide local management of occult peritoneal carcinomatosis or peritoneal free cancer cells while NAC will promote tumor downsizing and down-staging. The addition of the intraoperative HIPEC is speculated to manage dissemination due to surgical trauma. Where the roles of intraoperative HIPEC and NAC have individually been investigated, this study provides innovative insight on a more comprehensive approach to management of AGC at high risk of peritoneal recurrence. It is expected that the combination of NLHIPEC with NAC and HIPEC will increase PFS by 15% and decrease PMR after gastrectomy of curative intent.

Trial registration

World Health Organization Clinical Trials - International Registry Platform (WHO-ICTRP) with Registration ID ChiCTR1900024552, Registered Prospectively on the 16th July, 2019.

Optimization of perioperative approaches for advanced and late stages of gastric cancer: clinical proposal based on literature evidence, personal experience, and ongoing trials and research

BACKGROUND

The high incidence of gastric cancer (GC) and paradoxical high prevalence of advanced stage GC, amounting to around 2/3 at time of diagnosis, have urged doctors and researchers around the world not only to ameliorate the detection rate of GC at early stages but also to optimize the clinical management of GC at advanced stages.

CONTENT

We hereby recommend a more goal-oriented multimodality approach with objectives to increase survival rate and improve survival status. Based on precision and accurate clinical staging at diagnosis, we suggest that advanced stage GC (AGC) patients should be channeled into different treatment plans according to their disease status where they can be subjected to comprehensive measures involving chemo, radio, immunological, or target therapies depending on the pathophysiological behavior of their tumor. Patients assessed as potentially resectable cT4N + M0 can undergo neoadjuvant chemotherapy with intent of tumor downsizing and downgrading followed by surgery with intraoperative hyperthermic intraperitoneal chemotherapy (HIPEC) to decrease the incidence of peritoneal dissemination due to surgical trauma and adjuvant chemotherapy and radiation in cases of bulky nodal metastasis. In cases with distal metastasis, conversion therapy is recommended with the possibility of surgery of curative intent in case of favorable response. The options of alternate treatment options such as trans-catheter arterial chemoembolization (TACE) for limited liver lesions or neoadjuvant intraperitoneal plus systemic chemotherapy (NIPS) for peritoneal carcinomatosis have to be negotiated. With surgery as the cornerstone for cancer treatment, there is acknowledgment of the significance of perioperative comprehensive approaches but there has not been some consensus guiding clinical application. Henceforth, in this review, based on past literature, current guidelines and ongoing clinical trials, we have shared a proposal of the current treatment modalities in practice for the advanced stages of gastric cancer.

CONCLUSION

Even though surgery is the golden standard of radical cancer treatment, clinical reality shows that without proper perioperative management, patients undergoing radical resections manifest high rates of recurrence and metastasis. Hence, in this review, we have outlined a clinical agenda to optimize the management of advanced stage GC with objective to improve survival outcome and quality of life of patients.

CTHRC1 promotes gastric cancer metastasis via HIF-1α/CXCR4 signaling pathway

Metastasis is the main cause of gastric cancer (GC) related death and the underlying mechanisms still remain unclear. Collagen triple helix repeat containing 1 (CTHRC1) protein is known to be involved in tissue remodeling processes and closely associated with carcinogenesis and metastasis in solid tumors, but the functional role of CTHRC1 and its underlying mechanism with tumor metastasis in GC have not been fully illuminated. In the present study, CTHRC1 was highly expressed in tumor tissues and associated with poor prognosis of GC according to TCGA and GEO database. Functional studies revealed that CTHRC1 overexpression in GC significantly increased cell migration and invasion capacity. However, the promoting effects were abolished subsequent to silencing of CXCR4. In addition, CTHRC1 increased CXCR4 expression through upregulating HIF-1α expression, which eventually contributed to the promotion of cell migration and invasion. Inhibiting HIF-1α expression decreased CXCR4 expression and suppressed cell migration and invasion in GC. These results substantiated our hypothesis that HIF-1α/CXCR4 signaling pathway mediated the promoting effect of CTHRC1 on cell migration and invasion in GC.

Glutathione S-transferases genes variants and chemotherapy efficacy in gastrointestinal cancer patients: a meta-analysis based on 50 pharmacogenetic studies

Background: The role of glutathione s-transferase genes (GSTP1, GSTM1 and GSTT1) variants and the GSTP1 expression level on chemotherapy efficacy of gastrointestinal cancer (GIC) patients were inconsistent. Methods: A meta-analysis about GSTP1, GSTM1 and GSTT1 variants and the GSTP1 expression level on chemotherapy efficacy of GIC patients was performed using data from PubMed, PMC, EMBASE, Web of Science, and Wanfang database. Results: Our meta-analysis enrolled 50 publications including 6518 patients. We found that patients with GIC harboring GSTP1 (IIe105Val) Val locus had higher objective response rates (ORR) than the IIe/IIe genotypic patients (odds ratio (OR) = 1.580, 95% confidence interval (CI) = 1.159-2.154, P = 0.004). Significant associations were found between the Ile105Val variant and overall survival of Caucasian GIC patients (IIe/Val vs. IIe/IIe: OR = 0.797 (0.674-0.944), P = 0.009). Caucasian GIC patients and gastric cancer patients with GSTT1 null genotype had worse response rates compared to GSTT1 present patients (OR = 0.530 (0.356-0.789), P = 0.002; OR = 0.643 (0.463-0.895), P = 0.009, respectively). Conclusion: This meta-analysis illustrates that GSTP1 IIe105Val and GSTT1 null/present variants could be useful predictors of chemotherapy efficacy in patients with gastrointestinal cancer.

Prognostic significance of galectin-1 and vasculogenic mimicry in patients with gastric cancer

INTRODUCTION

We evaluated the expression of galectin-1 (Gal-1) and vasculogenic mimicry (VM) in gastric cancer (GC) and investigated their relationships with the clinicopathological factors and prognostic significance in GC.

MATERIALS AND METHODS

Immunohistochemical (IHC) staining and CD34-periodic acid-Schiff double stain were used to investigate Gal-1 expression and VM in paraffin-embedded sections from 127 patients with GC of all tumor stages. The relationships between Gal-1 expression and VM, clinicopathological variables, and survival were analyzed. P < 0.05 was considered statistically significant.

RESULTS

Among the 127 cases, 86 (67.7%) were positive for Gal-1; VM was detected in 29 cases (22.8%). There was a significant association between VM and the Gal-1 IHC staining; all cases with VM were positive for Gal-1 staining. Gal-1 expression and VM in primary GC tissue were associated with tumor size, differentiation, depth of tumor invasion, stage, lymph node metastases, and tumor emboli in microvessels (all, P < 0.05). Kaplan-Meier analysis revealed that the overall survival time was 52.56 ± 2.44 months (95% confidence interval [CI]: 47.77-57.35) for patients with Gal-1-negative and VM-negative primary GC tissue, 43.83 ± 2.17 months (95% CI: 39.58-48.08) for patients with Gal-1-positive but VM-negative primary GC tissue, and 23.97 ± 2.44 months (95% CI: 19.18-28.76) for patients with Gal-1-positive and VM-positive primary GC tissue (χ2 = 60.21, P < 0.01). Gal-1 expression was positively associated with VM in primary GC tissue.

CONCLUSION

Both Gal-1 expression and VM in primary GC tissue are indicators of poor prognosis for GC after gastrectomy, and Gal-1 may be a novel target for treating VM in GC.

Neoadjuvant chemotherapy for gastric cancer. Is it a must or a fake?

AIM

To investigate the neoadjuvant chemotherapy (NAC) effect on the survival of patients with proper stomach cancer submitted to D2 gastrectomy.

METHODS

We proceeded to a review of the literature with PubMed, Embase, ASCO and ESMO meeting abstracts as well as computerized use of the Cochrane Library for randomized controlled trials (RCTs) comparing NAC followed by surgery (NAC + S) with surgery alone (SA) for gastric cancer (GC). The primary outcome was the overall survival rate. Secondary outcomes were the site of the primary tumor, extension of node dissection according to Japanese Gastric Cancer Association (JGCA) performed in both arms, disease-specific (DSS) and disease-free survival (DFS) rates, clinical and pathological response rates and resectability rates after perioperative treatment.

RESULTS

We identified a total of 16 randomized controlled trials comparing NAC + S (n = 1089) with SA (n = 973) published in the period from January 1993 - March 2017. Only 6 of these studies were well-designed, structured trials in which the type of lymph node (LN) dissection performed or at least suggested in the trial protocol was reported. Two out of three of the RCTs with D2 lymphadenectomy performed in almost all cases failed to show survival benefit in the NAC arm. In the third RCT, the survival rate was not even reported, and the primary end points were the clinical outcomes of surgery with and without NAC. In the remaining three RCTs, D2 lymph node dissection was performed in less than 50% of cases or only recommended in the “Study Treatment” protocol without any description in the results of the procedure really perfomed. In one of the two studies, the benefit of NAC was evident only for esophagogastric junction (EGJ) cancers. In the second study, there was no overall survival benefit of NAC. In the last trial, which documented a survival benefit for the NAC arm, the chemotherapy effect was mostly evident for EGJ cancer, and more than one-fourth of patients did not have a proper stomach cancer. Additionally, several patients did not receive resectional surgery. Furthermore, the survival rates of international reference centers that provide adequate surgery for homogeneous stomach cancer patients’ populations are even higher than the survival rates reported after NAC followed by incomplete surgery.

CONCLUSION

NAC for GC has been rapidly introduced in international western guidelines without an evidence-based medicine-related demonstration of its efficacy for a homogeneous population of patients with only stomach tumors submitted to adequate surgery following JGCA guidelines with extended (D2) LN dissection. Additional larger sample-size multicentre RCTs comparing the newer NAC regimens including molecular therapies followed by adequate extended surgery with surgery alone are needed.