Gastrectomy with or without neoadjuvant S-1 plus cisplatin for type 4 or large type 3 gastric cancer (JCOG0501): an open-label, phase 3, randomized controlled trial

Upregulation of CRABP2 by TET1-mediated DNA hydroxymethylation attenuates mitochondrial apoptosis and promotes oxaliplatin resistance in gastric cancer

Oxaliplatin is the main chemotherapy drug for gastric cancer (GC), but quite a few patients are resistant to oxaliplatin, which contributes to the poor prognosis of GC patients. There is therefore an urgent need to identify potential targets for reversing chemotherapy resistance in GC patients. In this study, we analyzed the tumor samples of GC patients who received neoadjuvant chemotherapy based on oxaliplatin through quantitative proteomics and identified the potential chemoresistance-related protein cellular retinoic acid binding protein 2 (CRABP2). CRABP2 was significantly upregulated in the tumor tissues of chemoresistant GC patients and was closely related to prognosis. The results of cell function experiments showed that CRABP2 can promote the oxaliplatin resistance of GC cells in vitro. Coimmunoprecipitation and GST pulldown assays showed that CRAPB2 expedited the binding of BAX and PARKIN in GC cells and facilitated the ubiquitination-mediated degradation of BAX. Furthermore, both the in vitro assay and cell-derived xenograft (CDX) in vivo model verified that CRABP2 promoted oxaliplatin resistance by inhibiting BAX-dependent cell apoptosis. Further experiments proved that the abnormally high expression of CRABP2 in oxaliplatin-resistant GC cells was affected by TET1-mediated DNA hydroxymethylation. The patient-derived xenograft (PDX) model suggested that interference with CRABP2 reversed oxaliplatin resistance in GC in vivo. In conclusion, the results of our study show that CRABP2 was a key molecule in oxaliplatin resistance regulation and could be a new target for reversing the chemoresistance of GC.

Accuracy of preoperative clinical staging for locally advanced gastric cancer in KLASS-02 randomized clinical trial

Purpose

The discrepancy between preoperative and final pathological staging has been a long-standing challenge for the application of clinical trials or appropriate treatment options. This study aimed to demonstrate the accuracy of preoperative staging of locally advanced gastric cancer using data from a large-scale randomized clinical trial.

Materials and methods

Of the 1050 patients enrolled in the clinical trial, 26 were excluded due to withdrawal of consent (n = 20) or non-surgery (n = 6). The clinical and pathological staging was compared. Risk factor analysis for underestimation was performed using univariate and multivariate analyses.

Results

Regarding T staging by computed tomography, accuracy rates were 74.48, 61.62, 58.56, and 85.16% for T1, T2, T3 and T4a, respectively. Multivariate analysis for underestimation of T staging revealed that younger age, ulcerative gross type, circular location, larger tumor size, and undifferentiated histology were independent risk factors. Regarding nodal status estimation, 54.9% of patients with clinical N0 disease were pathologic N0, and 36.4% of patients were revealed to have pathologic N0 among clinical node-positive patients. The percentage of metastasis involvement at the D1, D1+, and D2 lymph node stations significantly increased with the advanced clinical N stage. Among all patients, 29 (2.8%), including 26 with peritoneal seeding, exhibited distant metastases.

Conclusions

Estimating the exact pathologic staging remains challenging. A thorough evaluation is mandatory before treatment selection or trial enrollment. Moreover, we need to set a sufficient case number when we design the clinical trial considering the stage migration.

Poorly cohesive cells gastric carcinoma including signet-ring cell cancer: Updated review of definition, classification and therapeutic management

While the incidence of gastric cancer (GC) in general has decreased worldwide in recent decades, the incidence of diffuse cancer historically comprising poorly cohesive cells-GC (PCC-GC) and including signet ring cell cancer is rising. Literature concerning PCC-GC is scarce and unclear, mostly due to a large variety of historically used definitions and classifications. Compared to other histological subtypes of GC, PCC-GC is nevertheless characterized by a distinct set of epidemiological, histological and clinical features which require a specific diagnostic and therapeutic approach. The aim of this review was to provide an update on the definition, classification and therapeutic strategies of PCC-GC. We focus on the updated histological definition of PCC-GC, along with its implications on future treatment strategies and study design. Also, specific considerations in the diagnostic management are discussed. Finally, the impact of some recent developments in the therapeutic management of GC in general such as the recently validated taxane-based regimens (5-Fluorouracil, leucovorin, oxaliplatin and docetaxel), the use of hyperthermic intraperitoneal chemotherapy as well as pressurized intraperitoneal aerosol chemotherapy and targeted therapy have been reviewed in depth for their relative importance for PCC-GC in particular.

Neoadjuvant docetaxel, oxaliplatin and S-1 therapy for the patients with large type 3 or type 4 gastric cancer (OGSG1902): protocol of a multi-center, phase II study

BACKGROUND

Large type 3 and type 4 gastric cancers have extremely poor prognoses. To address this, neoadjuvant chemotherapy may be a promising approach. The phase III JCOG0501 study, conducted to confirm the superiority of neoadjuvant S-1 plus cisplatin followed by D2 gastrectomy over upfront surgery, showed no survival benefit for neoadjuvant S-1 plus cisplatin. In Korea, the PRODIGY study, which was a phase III study of neoadjuvant docetaxel plus oxaliplatin plus S-1 (DOS) followed by surgery and adjuvant S-1 versus surgery and adjuvant S-1 for gastric cancer of T2-3N+ or T4Nany, showed that progression-free survival (PFS) was significantly superior in the neoadjuvant DOS arm. Therefore, DOS therapy may be a promising candidate for preoperative chemotherapy for large type 3 or type 4 gastric cancer.

METHODS

Preoperative docetaxel 40 mg/m2 and oxaliplatin 100 mg/m2 will be intravenously administered on day1 every three weeks. S-1 will be orally administered 80 mg/m2 on days 1-14 of a 21-day cycle. Patients will receive three courses of treatment and gastrectomy with ≥D2 lymph node dissection. Postoperative S-1 plus docetaxel therapy (DS) will be administered according to the JACCRO GC-07 (START-2) study. The primary endpoint is the 3-year PFS rate. Secondary endpoints include PFS time, overall survival time, pathological response rate, response rate according to RECIST version1.1, proportion of completion of neoadjuvant chemotherapy, R0 resection rate, proportion of completion of surgery, proportion of completion of protocol treatment, proportion of negative conversion of CY, adverse event occurrence rate, and nutritional evaluation. The null hypothesis for the 3-year PFS rate is 45% and the expected value is 60%. The total sample size is 46 considering that the registration period and follow-up period are two and three years, respectively.

DISCUSSION

This is a prospective, multicenter, single-arm, open-label, phase II trial assessing the efficacy and safety of preoperative DOS and postoperative DS for large type 3 or type 4 gastric cancer. The results will inform future phase III trials and are expected to lead to new treatment strategies for large type 3 or type 4 gastric cancer.

TRIAL REGISTRATION

Registered with Japan Registry of Clinical Trials on October 11, 2019 ( jRCTs051190060 ).

Treatment Response Predictors of Neoadjuvant Therapy for Locally Advanced Gastric Cancer: Current Status and Future Perspectives

Neoadjuvant chemotherapy (NAC) for locally advanced gastric cancer (LAGC) has been recognized as an effective therapeutic option because it is expected to improve the curative resection rate by reducing the tumor size and preventing recurrence of micrometastases. However, for patients resistant to NAC, not only will operation timing be delayed, but they will also suffer from side effects. Thus, it is crucial to develop a comprehensive strategy and select patients sensitive to NAC. However, the therapeutic effect of NAC is unpredictable due to tumor heterogeneity and a lack of predictive biomarkers for guiding the choice of optimal preoperative treatment in clinical practice. This article summarizes the related research progress on predictive biomarkers of NAC for gastric cancer. Among the many investigated biomarkers, metabolic enzymes for cytotoxic agents, nucleotide excision repair, and microsatellite instability, have shown promising results and should be assessed in prospective clinical trials. Noninvasive liquid biopsy detection, including miRNA and exosome detection, is also a promising strategy.

A multicenter, open-label, single-arm phase I trial of neoadjuvant nivolumab monotherapy for resectable gastric cancer

BACKGROUND

Nivolumab monotherapy has demonstrated superior efficacy in advanced unresectable gastric cancer (GC), but its impact on resectable GC remains unknown. This phase I study aimed to evaluate safety, feasibility, and potential biomarkers of neoadjuvant nivolumab monotherapy in resectable GC.

METHODS

Untreated, resectable, cT2 or more advanced gastric adenocarcinomas with clinical stage I, II, or III were treated with two doses of nivolumab before gastrectomy. Patients were excluded if their tumors may be applicable to neoadjuvant chemotherapy. The primary endpoint was the incidence of adverse event (AE) categories of special interest.

RESULTS

All of the 31 enrolled patients completed 2 doses of nivolumab monotherapy. While 30 (97%) patients underwent surgery with curative intent, 1 patient discontinued before the planned surgical intervention because of a newly emerging liver metastasis. Seven patients (23%) had nivolumab treatment-related AEs, and one patient had a treatment-related AE of grade 3-4. The incidences of treatment-related AE categories of special interest ranged from 0 to 6%. Notable surgical complications included two cases of grade 3 anastomotic leakage and two cases of pancreatic fistula. The major pathologic response (MPR) assessed by the independent pathology review committee was achieved in five (16%) patients, of which one patient had a pathologic complete response. The MPR was mostly observed in patients with positive PD-L1 expression, high microsatellite instability, and/or high tumor mutation burden.

CONCLUSIONS

Neoadjuvant nivolumab monotherapy is feasible with an acceptable safety profile and induces a MPR in certain patients with resectable GC. (Registration: clinicaltrials.jp, JapicCTI-183895).

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.

Neoadjuvant apatinib combined with oxaliplatin and capecitabine in patients with locally advanced adenocarcinoma of stomach or gastroesophageal junction: a single-arm, open-label, phase 2 trial

BACKGROUND

Adding anti-angiogenics to neoadjuvant chemotherapy for localized gastric cancer is recognized as a promising strategy, but its clinical value remains to be defined.

METHODS

This single-center, single-arm, phase 2 trial included patients with locally advanced (cT3/4aN+M0) adenocarcinoma of the stomach or gastroesophageal junction (GEJ) who received three cycles of intravenous oxaliplatin (135 mg/m² on day 1), oral capecitabine (1000 mg/m² twice daily on days 1 to 14), and oral apatinib for 21 days (250 mg once daily in the first two cycles, and further increased to 500 mg daily in the third cycle based on whether any adverse event of grade 3 or worse occurred), and an additional cycle of oxaliplatin plus capecitabine, followed by gastrectomy with D2 lymphadenectomy. The primary endpoint was the proportion of patients who achieved an objective response according to RECIST version 1.1.

RESULTS

Between April 28, 2017, and October 23, 2019, 37 patients were screened and 35 participants were included. Of the 32 patients assessable for efficacy and safety, objective responses were achieved in 25 (78.1%; 95% confidence interval [CI], 60.0% to 90.7%) patients. Thirty-one (96.9%) patients received R0 resection, two (6.3%) patients achieved pathological complete response, and 11 (34.4%) patients achieved pathological response. At the data cutoff date (September 30, 2021), the median event-free survival was 42.6 (95% CI, 16.2 to not reached) months, and the median overall survival was not reached. The most common grade 3 or 4 treatment-emergent adverse events were hypertension (9/32, 28.1%), thrombocytopenia (7/32, 21.9%), and neutropenia (5/32, 15.6%). Seven (21.9%) patients developed surgical complications, and the most common one was intra-abdominal abscess (4/32, 12.5%).

CONCLUSIONS

The concomitant use of apatinib, oxaliplatin, and capecitabine as neoadjuvant therapy showed promising efficacy and manageable safety profile in patients with locally advanced adenocarcinoma of the stomach or GEJ, and further phase 3 study is warranted.

TRIAL REGISTRATION

This study was registered with ClinicalTrial.gov ( NCT03229096 ).

Maximum standardized uptake value change rate before and after neoadjuvant chemotherapy can predict early recurrence in patients with locally advanced esophageal cancer: a multi-institutional cohort study of 220 patients in Japan

BACKGROUND

Neoadjuvant chemotherapy (NAC) followed by esophagectomy can improve the prognosis of locally advanced esophageal cancer (LAEC). However, LAEC reportedly recurred in 17-21% of patients within 6 months post surgery. Thus, current treatment strategies may be inadequate for LAECs with poor prognosis. Preoperative identification of patients with poor prognosis might aid in modification of treatment strategies. This study aimed to evaluate the usefulness of the maximum standardized uptake value change rate (ΔSUV_max) in predicting treatment effects on the primary lesion, prognosis, and LAEC recurrence.

METHODS

This study involved 220 esophageal cancer patients who underwent esophagectomy after NAC at three facilities in Japan. The optimal cut-off point for ΔSUV_max in predicting tumor regression grade (TRG) was calculated and used to assess the correlation between ΔSUV_max and postoperative survival.

RESULTS

The optimal cut-off point for ΔSUV_max was 0.5. The 5-year overall survival rate in patients with ΔSUV_max ≥ 0.5 was significantly higher than that in patients with ΔSUV_max < 0.5 (71.5% vs. 50.5%, P = 0.001). Multivariate analysis identified ΔSUV_max (hazards ratio, 0.496; P = 0.004) as an independent prognostic factor. Among 199 patients evaluated for recurrence, 24 (12.1%) showed recurrence within 6 months post surgery. Univariate analysis revealed ΔSUV_max as the only predictor for early recurrence (odds ratio, 0.222; P = 0.004).

CONCLUSION

ΔSUV_max before and after NAC is clinically useful as it could help predict TRG, survival outcome, and early recurrence within 6 months post esophagectomy and is easily obtainable in general clinical practice. We believe that it may also help determine suitable treatment strategies for LAEC.

Effects of perioperative eicosapentaenoic acid‑enriched oral nutritional supplement on the long‑term oncological outcomes after total gastrectomy for gastric cancer

Basic and clinical reports have suggested that eicosapentaenoic acid (EPA) exhibits anti-tumor activity. The present study evaluated whether perioperative EPA could improve the survival of patients with localized gastric cancer as a key secondary endpoint of a randomized clinical study. The present study was designed as multicenter, open-label, superiority, randomized trial to confirm the preventive effect of EPA on body weight loss after total gastrectomy for gastric cancer. Eligible patients were randomized to either the standard-diet group (EPA-off group) or EPA-on group by a centralized dynamic method. An EPA-enriched supplement (ProSure^®) was given to the EPA-on group in addition to their standard diet. This supplement included 600 kcal with 2.2 g/day of EPA. Among the 126 patients who were randomized, 123 patients (EPA-off group, n=60; EPA-on group, n=63) were examined in the survival analyses. All background factors were well balanced between the two groups. The 3-year and 5-year overall survival rates were 74.6 and 67.8%, respectively, in the EPA-off group, and 77.8 and 76.2% in the EPA-on group. There was no significant difference between the EPA-off and EPA-on groups (hazard ratio, 0.77; P=0.424). In the subgroup analysis, the hazard ratio was 0.39 in patients who received neoadjuvant chemotherapy and 0.57 in patients with nodal metastasis. In conclusion, a clear survival benefit of perioperative EPA was not observed in localized gastric cancer. The value of EPA should be further tested in a future study in patients with unfavorable advanced gastric cancer. Clinical trial number: UMIN000006380; date of registration, September 21, 2011.

Significance of Preoperative Prognostic Nutritional Index in the Perioperative Management of Gastric Cancer

BACKGROUND

Malnutrition leads to accelerated tumor progression through the suppression of tumor immunity. The present study examined the significance of the preoperative prognostic nutritional index (PNI) for predicting postoperative survival outcomes in gastric cancer (GC).

METHODS

A total of 447 patients who underwent curative gastrectomy for GC were included in the present study. PNI was calculated as 10 × serum albumin (g/dl) + 0.005 × total lymphocyte counts (per mm³). The prognostic impact of preoperative PNI was examined using two multivariate analysis models.

RESULTS

The optimal cutoff value of preoperative PNI for predicting overall survival (OS) was 48 based on a receiver operating characteristic curve. The 5-year OS rate was 59.5% in the PNI<48 group and 91.3% in the PNI≥48 group (p<0.001). In the first multivariate survival analysis where all explanatory variables were composed of preoperative factors alone, a PNI<48 (hazard ratio [HR] 3.33; 95% confidence interval [CI] 2.01-5.56, p<0.001), upper-third GC and cT2-T4 were identified as independent indicators of a poor OS. In the second survival analysis where explanatory variables were composed of preoperative, intraoperative, and pathological factors, a PNI<48 (HR 2.80; 95% CI 1.65-4.78, p<0.001), hypertension, open gastrectomy, intraoperative blood loss≥100g, pT2-T4, and pN+ were independent prognostic factors.

CONCLUSION

Preoperative PNI may be a useful predictor of postoperative survival outcomes both before and immediately after surgery in GC. Appropriate perioperative interventions and the meticulous surveillance of GC relapse are necessary for patients with PNI<48.

Clinical impact of gastrectomy for gastric cancer patients with positive lavage cytology without gross peritoneal dissemination

BACKGROUND

The prognosis of gastric cancer patients with positive lavage cytology without gross peritoneal dissemination (P0CY1) is poor. The survival benefit of gastrectomy for these patients has not been established.

PATIENTS AND METHODS

In this population-based cohort study, we investigated the impact of radical gastrectomy with lymph node dissection for P0CY1 patients. Patients who were diagnosed with Stage IV gastric cancer from 2008 to 2015 in all nine cancer-designated hospitals in a tertiary medical area were listed. Patients who were diagnosed with histologically proven adenocarcinoma in both the primary lesion and lavage cytology during the operation or a diagnostic laparoscopic examination were enrolled. Patients with a gross peritoneal lesion or other metastatic lesions were excluded. The primary outcome was the adjusted hazard ratio (aHR) of gastrectomy for overall survival. We also evaluated the survival time in patients who underwent gastrectomy or chemotherapy in comparison to patients managed without primary surgery or with best supportive care.

RESULTS

One hundred patients were enrolled. The aHR (95% confidence interval) of gastrectomy was 0.677 (0.411-1.114, p = 0.125). The median survival time in patients who received gastrectomy (n = 74) was 21.7, while that in patients managed without primary surgery (n = 30) was 20.5 months (p = 0.155). The median survival time in patients who received chemotherapy (n = 76) was 23.0 months, while that in patients managed without chemotherapy was 8.6 months (p < 0.001).

CONCLUSION

Gastrectomy was not effective for improving the survival time in patients with P0CY1 gastric cancer. Surgeons should prioritize the performance of chemotherapy over surgery as the initial treatment.

The jury is still out on peri-operative vs. adjuvant chemotherapy for distal gastric cancer

Randomized control trials have established systemic therapy as an integral part of treatment for gastric cancer, but the ideal sequence of surgery and chemotherapy is not known. In the West, peri-operative chemotherapy (based on MAGIC and FLOT4 trials) is the standard of care vs. in the East, D2 gastrectomy followed by adjuvant chemoradiation (based on ARTIST trial) or adjuvant chemotherapy (based on S-1 and CLASSIC trials) is more common. In this issue, Singh et al. ask if perioperative chemotherapy or adjuvant chemotherapy portends a survival advantage specifically for patients with resectable distal gastric cancer who underwent D2 lymphadenectomy.¹.

Intraperitoneal Chemotherapy as Adjuvant or Perioperative Chemotherapy for Patients with Type 4 Scirrhous Gastric Cancer: PHOENIX-GC2 Trial

The prognosis of patients with type 4 scirrhous gastric cancer remains poor due to a high risk of peritoneal metastasis. We have previously developed combined chemotherapy regimens of intraperitoneal (IP) paclitaxel (PTX) and systemic chemotherapy, and promising clinical efficacy was reported in gastric cancer with peritoneal metastasis. Herein, a randomized, phase III study is proposed to verify the efficacy of IP PTX to prevent peritoneal recurrence. Gastric cancer patients with type 4 tumors and without apparent distant metastasis, including peritoneal metastasis, will be randomized for standard systemic chemotherapy or combined IP and systemic chemotherapy based on peritoneal lavage cytology findings. Those with negative peritoneal cytology will receive radical gastrectomy and adjuvant chemotherapy of S-1 plus docetaxel (control arm), or S-1 plus intravenous and IP PTX (experimental arm). Those with positive peritoneal cytology will receive three courses of S-1 plus oxaliplatin (control arm), or S-1 plus oxaliplatin and IP PTX (experimental arm). Subsequently, they undergo gastrectomy and receive postoperative chemotherapy of S-1 plus docetaxel (control arm), or S-1 plus intravenous and IP PTX (experimental arm). The primary endpoint is disease free survival after a 3-year follow-up period. Secondary endpoints are overall survival, survival without peritoneal metastasis, safety, completion rate, curative resection rate, and histological response of preoperative chemotherapy. A total of 300 patients are to be enrolled.

Development of a Quantitative Diagnostic Criterion for Gastric Linitis Plastica: Findings From a Large Single-Institutional Study

Gastric linitis plastica (GLP) is a descriptive term but lacks a quantitative definition. Several relatively quantitative criteria had been proposed, such as tumor involving a limit of one-third or two-thirds of the gastric surface. However, these criteria needed doctors to subjectively judge tumor infiltration area, which made diagnosis difficult to be objective and reproducible. This study aimed to propose a quantitative diagnostic criterion for distinguishing GLP. We performed a retrospective cohort study of 2,907 patients with Borrmann III and IV gastric cancer (GC) who underwent gastrectomy between 2011 and 2018 in our center. The Kaplan–Meier curves showed that patients with an observed tumor size more than 8 cm had obviously lower overall survival (OS) and disease-free survival (DFS) rates than those with a size less than 8 cm(p < 0.001; p < 0.001). However, there was no significantly different prognosis of patients with tumor sizes between more than 8 cm and more than 10 cm (p = 0.248; p = 0.534). Moreover, patients with tumor sizes greater than 8 cm more presented with advanced stage and had extremely poor 3-year OS and DFS (31.4%; 29.3%), with a stronger propensity toward peritoneal metastasis. Therefore, we considered patients’ observed tumor size more than 8 cm as a critical value for distinguishing the prognosis of Borrmann III and IV GC. Furthermore, we proposed an observed tumor size more than 8 cm as a quantitative diagnostic criterion for GLP on the premise of satisfying the originally descriptive and pathological definition regardless of Borrmann type.

Phase II study of neoadjuvant chemotherapy with S-1 plus oxaliplatin for gastric cancer clinical T4 or N2-3

In Japan, the standard treatment for stage II or III gastric cancer is D2 gastrectomy followed by administration of S-1 for one year. However, patients with stage III disease have unsatisfactory survival rates. The purpose of this study was to evaluate the efficacy and safety of neoadjuvant chemotherapy consisting of S-1 and oxaliplatin for advanced gastric cancer. Patients with cT4 or cN2-3 gastric cancer were scheduled to receive two courses of chemotherapy (130 mg/m² oxaliplatin on Day 1, 80 mg/m² S-1 per day twice daily for 14 days) followed by surgery. The primary endpoint was the R0 resection rate. The secondary endpoints were rates of completion of protocol treatment, pathological response, and adverse events; and 3-year overall survival, 5-year overall survival, and 5-year recurrence-free survival. Between May 2016 and March 2019, 30 patients were enrolled in the study, all of whom completed the protocol treatment. The R0 resection rate (primary endpoint) was 93.3% (95% confidence interval: 77.9-99.2). The pathological response rate was 63.3%. Grade 3-4 toxicities included anemia (3.3%), anorexia (6.7%), and fatigue (3.3%). Relative dose intensities were 91.2% and 94.2% for S-1 and oxaliplatin, respectively. Neoadjuvant S-1 and oxaliplatin is highly effective, achieving an acceptable R0 resection rate with relatively few severe toxicities and good compliance.Trial registration: Registry name: A prospective intervention study on the availability of preoperative SOX therapy for T4 or N2-3 gastric cancer. Trial ID: UMIN: UMIN000024656. https://upload.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R00002836.

History and emerging trends in chemotherapy for gastric cancer

Chemotherapy is indispensable for gastric cancer. For unresectable and/or recurrent gastric cancer, first-line chemotherapy consists of multidrug regimens including oral 5-FU agents such as S1/Xeloda and platinum preparations, as well as Trastuzumab, which is effective in HER2-positive cases. Second- and third-line chemotherapy regimens include taxanes, Ramucirumab (R-mab), and Nivolumab (N-mab), which have different mechanisms of action from first-line chemotherapy. R-mab is molecularly targeted to vascular endothelial growth factor receptor 2 in the host cells, but its indication is not conditional. For resectable gastric cancer, in Eastern countries, postoperative adjuvant chemotherapy has been successful, including S1, Docetaxel/S1 (DS), and Xeloda/Oxaliplatin (Xelox) regimens, whereas, in Western countries, the 5-FU/Leucovorin/Oxaliplatin/Docetaxel (FLOT) regimen was recently shown to be effective in the perioperative chemotherapy setting. Most recently, however, in Eastern countries, perioperative SOX was demonstrated to be effective in specific advanced gastric cancer. For stage IV gastric cancer, new therapeutic strategies have been proposed such as neoadjuvant chemotherapy and conversion surgery, and cures can be conditionally obtained. Recent genomic understanding of gastric cancer proposed a diversity of molecular targets by molecular profiling. Such optimized chemotherapy regimens, according to the specific clinical situations, have been rigorously established for the best survival of advanced gastric cancer.

PRODIGY: A Phase III Study of Neoadjuvant Docetaxel, Oxaliplatin, and S-1 Plus Surgery and Adjuvant S-1 Versus Surgery and Adjuvant S-1 for Resectable Advanced Gastric Cancer

Adjuvant chemotherapy after D2 gastrectomy is standard for resectable locally advanced gastric cancer (LAGC) in Asia. Based on positive findings for perioperative chemotherapy in European phase III studies, the phase III PRODIGY study (ClinicalTrials.gov identifier: NCT01515748) investigated whether neoadjuvant docetaxel, oxaliplatin, and S-1 (DOS) followed by surgery and adjuvant S-1 could improve outcomes versus standard treatment in Korean patients with resectable LAGC.

A good preoperative immune prognostic index is predictive of better long-term outcomes after laparoscopic gastrectomy compared with open gastrectomy for stage II gastric cancer in elderly patients

BACKGROUND

It remains inconclusive whether laparoscopic gastrectomy (LG) has better long-term outcomes when compared with open gastrectomy (OG) for elderly gastric cancer (EGC). We attempted to explore the influence of the immune prognostic index (IPI) on the prognosis of EGCs treated by LG or OG to identify a population among EGC who may benefit from LG.

METHODS

We included 1539 EGCs treated with radical gastrectomy from January 2007 to December 2016. Propensity score matching was applied at a ratio of 1:1 to compare the LG and OG groups. The IPI based on dNLR ≥ cut-off value (dNLR) and sLDH ≥ cut-off value (sLDH) was developed, characterizing two groups (IPI = 0, good, 0 factors; IPI = 1, poor, 1 or 2 factors).

RESULTS

Of the 528 EGCs (LG: 264 and OG: 264), 271 were in the IPI = 0 group, and 257 were in the IPI = 1 group. In the entire cohort, the IPI = 0 group was associated with good 5-year overall survival (OS) (p = 0.001) and progression-free survival (PFS) (p = 0.003) compared to the IPI = 1 group; no significant differences in 5-year OS and PFS between the LG and OG groups were observed. In the IPI = 1 cohort, there was no significant difference in OS or PFS between the LG and OG groups across all tumor stages. However, in the IPI = 0 cohort, LG was associated with longer OS (p = 0.015) and PFS (p = 0.018) than OG in stage II EGC, but not in stage I or III EGC. Multivariate analysis showed that IPI = 0 was an independent protective factor for stage II EGC receiving LG, but not for those receiving OG.

CONCLUSION

The IPI is related to the long-term prognosis of EGC. Compared with OG, LG may improve the 5-year survival rate of stage II EGC with a good IPI score. This hypothesis needs to be further confirmed by prospective studies.

Comparative Outcomes of Laparoscopic Gastrectomy and Open Gastrectomy for Scirrhous Gastric Cancer: A Multicenter Retrospective Cohort Study

Objective

A multicenter retrospective cohort study was performed to compare the outcomes of laparoscopic gastrectomy (LG) versus open gastrectomy (OG) for scirrhous gastric cancer (GC) as a unique subtype also known as type 4 gastric cancer or linitis plastica.

Background

Although data on the efficacy and safety of LG as an alternative to OG are emerging, the applicability of LG to scirrhous GC remains unclear.

Methods

Patients with clinical type 4 GC undergoing gastrectomy at 13 hospitals from 2005 to 2015 were retrospectively reviewed. As the primary endpoint, we compared overall survival (OS) between the LG and OG groups. To adjust for confounding factors, we used multivariate Cox regression analysis for the main analyses and propensity-score matching for sensitivity analysis. Short-term outcomes and recurrence-free survival were also compared.

Results

A total of 288 patients (LG, 62; OG, 226) were included in the main analysis. Postoperative complications occurred in 25.8% and 30.1%, respectively (P = 0.44). No significant difference in recurrence-free survival was observed (P = 0.72). The 5-year OS rates were 32.4% and 31.6% in the LG and OG groups, respectively (P = 0.60). The hazard ratio (LG/OG) for OS was 0.98 (95% confidence interval [CI], 0.65-1.43) in the multivariate regression analysis. In the sensitivity analyses after propensity-score matching, the hazard ratio for OS was 0.92 (95% CI, 0.58-1.45).

Conclusions

Considering the hazard ratios and 95% CIs for OS, LG for scirrhous GC was not associated with worse survival than that for OG.

Current status and future perspectives on neoadjuvant therapy in gastric cancer

Gastric cancer, with high morbidity and mortality rates, is one of the most heterogeneous tumors. Radical gastrectomy and postoperative chemotherapy are the standard treatments. However, the safety and efficacy of neoadjuvant therapy (NAT) need to be confirmed by many trials before implementation, creating a bottleneck in development. Although clinical benefits of NAT have been observed, a series of problems remain to be solved. Before therapy, more contributing factors should be offered for choice in the intended population and ideal regimens. Enhanced computed tomography (CT) scanning is usually applied to evaluate effectiveness according to Response Evaluation Criteria in Solid Tumors (RECIST), yet CT scanning results sometimes differ from pathological responses. After NAT, the appropriate time for surgery is still empirically defined. Our review aims to discuss the abovementioned issues regarding NAT for GC, including indications, selection of regimens, lesion assessment and NAT-surgery interval time.

Different risk factors for three major recurrence patterns of pathological stage II or III gastric cancer patients who completed adjuvant S-1 monotherapy

INTRODUCTION

After curative gastrectomy followed by 1-year adjuvant S-1 monotherapy for pathological stage (pStage) II or III gastric cancer, some patients experience peritoneal, hematogenous, or lymph nodal recurrence. However, risk factors for each recurrence pattern despite completed adjuvant S-1 monotherapy remain unclear. The aim of this study was to determine which factors influence each recurrence type after curative gastrectomy followed by 1-year adjuvant S-1 monotherapy.

MATERIALS AND METHODS

A total of 380 patients with pStage II or III gastric cancer who completed 1-year adjuvant S-1 monotherapy after R0 gastrectomy between January 2008 and December 2013 were enrolled in this study. The risk factors that were associated with peritoneal, hematogenous, and lymph nodal recurrence were investigated by univariate and multivariate analyses.

RESULTS

Eighty (21.1%) of 380 patients developed recurrence. As the first site, peritoneal, hematogenous, and lymph nodal recurrence occurred in 42 (11.1%), 26 (6.8%), and 12 (3.2%) patients, respectively. In multivariate analysis, peritoneal metastasis was associated with signet ring cell carcinoma (P < 0.001), pT4 (P = 0.001), and pN3 (P < 0.001), while hematogenous recurrence was associated with pN3 (P = 0.019) and later initiation of S-1 (P = 0.013), and lymph nodal recurrence was associated with pN3 (P = 0.002).

CONCLUSION

The risk factors for peritoneal, hematogenous, and lymph nodal recurrence in pStage II or III gastric cancer patients who complete adjuvant S-1 monotherapy differ. This information may be helpful for daily surveillance of recurrence in post-operative and chemotherapeutic patients. Furthermore, it may be a useful reference to develop novel perioperative chemotherapy.

Essential updates 2019/2020: Perioperative and surgical management of gastric cancer

Perioperative and surgical management of gastric cancer have been changing as pivotal phase II trials and landmark phase III trials offer new insights to the existing knowledge. The results of many landmark trials have been published or presented in the past year, many of which have changed or will change current clinical practice. For example, FLOT4 has completely changed the regimen of perioperative chemotherapy in Europe. Furthermore, evidence for minimally invasive surgery for clinical Stage I was firmly established by KLASS-01 and JCOG0912 for distal gastrectomy and CLASS-02, KLASS-03, and JCOG1401 for total gastrectomy. Moreover, promising results were provided by CLASS-01 and KLASS-02 for locally advanced gastric cancer. For adjuvant chemotherapy, JACCRO GC-07 (START-2) has provided a new doublet regimen for pathological Stage III, which is often refractory to chemotherapy. Conversely, JCOG0501 poses a significant challenge for advanced tumors, such as large type 3 and scirrhous (type 4) tumors. In this review, we briefly review recent updates and discuss future perspectives of gastric cancer treatment.