Determination of the optimal cutoff percentage of residual tumors to define the pathological response rate for gastric cancer treated with preoperative therapy (JCOG1004-A)

Therapeutic strategy for scirrhous type gastric cancer

Scirrhous-type gastric cancer (SGC) is a rare but well-recognized subset of resectable gastric cancer (GC), accounting for ⁓10% of cases. Despite its long history of clinical recognition dating back to the pre-1900s, SGC remains one of the most challenging GC subtypes to treat. Traditionally, SGC has been clinically defined as Borrmann type 4 GC, with histological classifications such as signet ring cell carcinoma or diffuse-type histology serving as alternative diagnostic criteria. Therapeutic advancements for SGC have largely focused on locally advanced or oligometastatic disease, yet no SGC-specific treatment has been established. The phase III JCOG0501 trial failed to demonstrate a survival benefit of neoadjuvant S-1 plus cisplatin for Borrmann type 4 and large type 3 GC. Recent developments in biomarker-driven therapies may redefine SGC by molecular subtypes, with CLDN18.2-targeted therapy emerging as a potential option for some SGC cases. However, as the landscape of medical oncology evolves, SGC may not remain a distinct therapeutic entity. The focus should shift toward understanding the intrinsic biology of SGC. Treatment development for SGC is expected to continue advancing, becoming increasingly stratified based on molecular abnormalities while maintaining a commitment to addressing unmet needs, such as early-onset GC and GC with symptomatic peritoneal dissemination.

Prospects for the application of pathological response rate in neoadjuvant therapy for gastric cancer

With the annual increase in the incidence and mortality rates of gastric cancer, it has gradually become one of the significant threats to human health. Approximately 90% of gastric cancer patients are diagnosed with adenocarcinoma. Although the 5-year survival rate for early-stage gastric cancer can exceed 90%, due to its concealed symptoms, less than half of the patients are eligible for radical surgical treatment upon diagnosis. For gastric cancer patients receiving palliative treatment, the current expected survival time is only about one year. In China, the majority of gastric cancer patients, accounting for about 80% of the total, are in the locally advanced stage. For these patients, radical surgery remains the primary treatment option; however, surgery alone is often inadequate in controlling tumor progression. In the pivotal MAGIC study, the recurrence rate was as high as 75%, and similar results were obtained in the French ACCORD07-FFCD9703 study. Numerous clinical trials are currently exploring preoperative neoadjuvant therapy for patients with locally advanced gastric cancer. Data indicates that preoperative neoadjuvant therapy can not only reduce the size of the local tumor but also shrink surrounding lymph nodes, thereby downstaging the tumor and improving the R0 resection rate. Additionally, it can decrease tumor cell activity and eliminate potential micrometastases. The emergence of various immunotherapies has ushered in a new era for neoadjuvant treatment options for gastric cancer.

Efficacy and safety of S-1 plus oxaliplatin combined with apatinib and camrelizumab as neoadjuvant therapy for patients with locally advanced gastric or gastroesophageal junction adenocarcinoma: a protocol for a single-arm phase II trial

Gastric cancer, as the fifth most diagnosed malignancy and the fourth leading cause of cancer-related death globally, remains a significant health concern. The potential effect of the programmed death-1 (PD-1) inhibitor, when used alongside chemotherapy and antiangiogenic agents in neoadjuvant therapy for gastric cancer, has yet to be explored in the published literature. This study aims to evaluate the efficacy and safety of the S-1 plus oxaliplatin (SOX) regimen when combined with apatinib and camrelizumab (SOXAC) as neoadjuvant therapy for patients with locally advanced gastric or gastroesophageal junction (GEJ) adenocarcinoma. A single-arm, open-label, single-center phase II clinical trial has been designed to evaluate the safety and efficacy of the SOXAC regimen as neoadjuvant therapy for patients diagnosed with locally advanced gastric or GEJ adenocarcinoma (cT2-3N + M0 or T4NxM0). Eligible patients are to receive 2 cycles of SOXAC and 1 cycle of SOX regimen with camrelizumab (SOXC) as neoadjuvant therapy prior to radical surgery, and 3 cycles of SOXC as postoperative adjuvant therapy. The primary endpoint is major pathological remission (MPR), while secondary endpoints include pathological complete response (pCR) rate, R0 resection rate, objective response rate (ORR), operation-related outcomes, and safety. The SOX regimen remains a leading choice for neoadjuvant chemotherapy in Eastern countries. Recent studies suggest that combining chemotherapy, targeted agents, and immune checkpoint inhibitors can enhance the antitumor immune response. This phase II clinical trial seeks to assess the safety and efficacy of the SOXAC regimen as neoadjuvant therapy for patients with locally advanced resectable gastric or GEJ adenocarcinoma, while also exploring the correlation between biomarkers and efficacy.Trial Registration Chinese Clinical Trial Registry (ChiCTR): ChiCTR2200062285 ( https://www.chictr.org.cn/ ).

Prognostic factors and significance of postoperative adjuvant chemotherapy in patients with advanced gastric cancer undergoing neoadjuvant chemotherapy followed by gastrectomy

PURPOSE

In Japan, gastrectomy with D2 lymph node dissection and postoperative adjuvant chemotherapy are the standard treatments for locally advanced gastric cancer. Neoadjuvant chemotherapy (NAC) is not affected by postgastrectomy syndromes or postoperative complications. This multicenter retrospective study investigated the prognostic factors and significance of postoperative adjuvant chemotherapy in patients with advanced gastric cancer who underwent NAC followed by gastrectomy.

METHODS

Consecutive patients (n = 221) with advanced gastric cancer who underwent NAC followed by curative surgery were enrolled in this study. Prognostic factors including postoperative adjuvant chemotherapy were investigated using univariate and multivariate analyses.

RESULTS

A multivariate analysis revealed that pathological lymph node metastasis (ypN) status and postoperative adjuvant chemotherapy were independent prognostic factors for the overall and relapse-free survival. Forty-five patients (20.4%) did not receive postoperative adjuvant chemotherapy. There were no significant differences between patients with and without adjuvant chemotherapy for all factors, except age. The most common reason for not undergoing postoperative adjuvant chemotherapy was a poor condition (n = 23).

CONCLUSIONS

ypN status and postoperative adjuvant chemotherapy were independent prognostic factors in gastric cancer patients who underwent NAC followed by curative gastrectomy. It is important to maintain the patient's condition during NAC and the perioperative period so that they can receive postoperative adjuvant chemotherapy.

Improving individualised therapies in localised gastro-oesophageal adenocarcinoma

Despite our increased understanding of the biological and molecular aspects of gastro-oesophageal tumourigenesis, the identification of prognostic or predictive factors remains challenging. Patients with resectable gastric and oesophageal adenocarcinoma are often treated similarly after surgical resection, regardless of their tumour biology, clinical characteristics, and histological treatment response. Substantial progress has been made in the past 5 years in managing patients with gastric or oesophageal adenocarcinoma, including the use of immune checkpoint inhibitors and new targeted therapies, leading to substantial improvements in clinical outcomes. These advancements have primarily been established in advanced and metastatic disease, while the management framework for local and locoregional disease is just beginning to shift. We provide an overview of existing data on biomarkers and tumour-related and host-related factors that are relevant to stratify patients into low-risk and high-risk recurrence groups, both before and after surgery, paving the way for more personalised treatment approaches.

Microscopic tumor mapping of post-neoadjuvant therapy pancreatic cancer specimens to predict post-surgical recurrence: A prospective cohort study

BACKGROUND

Although various pathological grading systems are available for evaluating the response of pancreatic ductal adenocarcinoma (PDAC) to neoadjuvant therapy (NAT), their prognostic value has not been thoroughly validated. This study examined whether microscopic tumor mapping of post-NAT specimens could predict tumor recurrence.

METHODS

This prospective study enrolled 52 patients who underwent pancreaticoduodenectomy after NAT for PDAC between 2019 and 2021. Microscopic mapping was performed to identify residual tumor loci within the tumor bed using 4 mm2 pixels. Patients were divided into small extent (SE; n = 26) and large extent (LE; n = 26) groups using a cutoff value of 226 mm2. The diagnostic performance for predicting tumor recurrence was evaluated using receiver operating characteristic (ROC) curves.

RESULTS

Carbohydrate antigen 19-9 levels were normalised after NAT in more patients in the SE group (SE 21 [80.8%] vs. LE 13 [50.0%]; P = 0.041). Tumor size (P < 0.001), T stage (P < 0.001), positive lymph node yield (P = 0.024), and perineural invasion rate (P = 0.018) were significantly greater in the LE group. The 3-year disease-free survival rate was significantly lower in the LE group (SE 83.3% vs. LE 50.0%, P = 0.004). The area under the ROC curve for mapping extent was 0.743, which was greater than that of the other tumor response scoring systems.

CONCLUSIONS

Microscopic tumor mapping of the residual tumor in post-NAT specimens is a significant predictor of post-surgical recurrence, and offers better prognostic performance than the current grading systems.

Short-term outcomes of preoperative chemotherapy with docetaxel, oxaliplatin, and S-1 for gastric cancer with extensive lymph node metastasis (JCOG1704)

BACKGROUND

The prognosis for marginally resectable gastric cancer with extensive lymph node metastasis (ELM) remains unfavorable, even after R0 resection. To assess the safety and efficacy of preoperative docetaxel, oxaliplatin, and S-1 (DOS), we conducted a multicenter phase II trial.

METHODS

Eligibility criteria included histologically proven HER2-negative gastric adenocarcinoma with bulky nodal (bulky N) involvement around major branched arteries or para-aortic node (PAN) metastases. Patients received three cycles of docetaxel (40 mg/m2, day 1), oxaliplatin (100 mg/m2, day 1), and S-1 (80-120 mg/body, days 1-14), followed by gastrectomy with D2 plus PAN dissection. Subsequently, patients underwent postoperative chemotherapy with S-1 for 1 year. The primary endpoint was major (grade ≥ 2a) pathological response rate (pRR) according to the Japanese Classification of Gastric Carcinoma criteria.

RESULTS

Between October 2018 and March 2022, 47 patients (bulky N, 20; PAN, 17; both, 10) were enrolled in the trial. One patient was ineligible. Another declined any protocol treatments before initiation. Among the 45 eligible patients who initiated DOS chemotherapy, 44 (98%) completed 3 cycles and 42 (93%) underwent R0 resection. Major pRR and pathological complete response rates among the 46 eligible patients, including the patient who declined treatment, were 57% (26/46) and 24% (11/46), respectively. Common grade 3 or 4 toxicities were neutropenia (24%), anorexia (16%), febrile neutropenia (9%), and diarrhea (9%). No treatment-related deaths occurred.

CONCLUSIONS

Preoperative chemotherapy with DOS yielded favorable pathological responses with an acceptable toxicity profile. This multimodal approach is highly promising for treating gastric cancer with ELM.

Randomized phase II study comparing neoadjuvant 5-fluorouracil/oxaliplatin/docetaxel versus docetaxel/oxaliplatin/S-1 for patients with type 4 or large type 3 gastric cancer

Macroscopic type 4 and large type 3 gastric cancer, mostly overlapping with scirrhous or linitis plastica type, exhibit a highly invasive nature and show unfavorable prognosis after curative surgery, even with adjuvant chemotherapy. A randomized phase III trial (JCOG0501) failed to demonstrate a survival advantage of neoadjuvant chemotherapy with S-1 plus cisplatin for this population. The current authors initiated a randomized phase II study comparing neoadjuvant chemotherapy with 5-fluorouracil/oxaliplatin/docetaxel versus docetaxel/oxaliplatin/S-1 for type 4 and large type 3 gastric cancer. 76 patients are planned to be enrolled over two years. The primary end point is the proportion of patients with a pathological response (grade 1b or higher) and secondary end points include overall survival and adverse events. Clinical Trial Registration: jRCTs031230231 (rctportal.niph.go.jp).

Three-Year Outcomes of a Phase II Study of Perioperative Capecitabine Plus Oxaliplatin Therapy for Clinical SS/SE N1-3 M0 Gastric Cancer (OGSG 1601)

BACKGROUND

We previously reported the good feasibility and favorable efficacy of perioperative capecitabine plus oxaliplatin (CapeOx) in patients (pts) with clinical T3(SS)/T4a(SE) N1-3 M0 gastric cancer (GC) in a phase II study in which the pathological response rate, the primary endpoint, of 54.1% was demonstrated. Here, we report 3-year follow-up data.

METHODS

The eligibility criteria included clinical T3(SS)/T4a(SE) N1-3 M0 GC according to the Japanese Classification of Gastric Carcinoma-3rd English Edition (JCGC). Three cycles of neoadjuvant CapeOx (capecitabine, 2000mg/m2 for 14 days; oxaliplatin, 130mg/m2 on day 1, every 3 weeks) were administered, followed by 5 cycles of adjuvant CapeOx after D2 gastrectomy. Three-year overall survival and relapse-free survival are presented here, and analyzed by cohorts based on pathologic response rate (pRR).

RESULTS

Thirty-seven pts were enrolled from July 2016 to May 2017, and fully evaluated for efficacy and toxicity. Thirty-three pts (89.2%) completed the planned three cycles of neoadjuvant CapeOx and underwent gastrectomy, with an R0 resection rate of 78.4% (n = 29). The overall survival (OS) rate and relapse-free survival (RFS) rate at 3 years was 83.8% (95% CI, 72.7-96.5%) and 73.0% (95% CI, 60.0-88.8%), respectively. Further, the 3-year OS rate in pts with pathological response of grade 1a (n = 13) and grade 1b or higher (n = 20) was 69.2% (95% CI: 48.2-99.5%) and 100.0%, respectively, based on JCGC. Pathological response rate was classified according to JCGC as follows: grade 0, the tumor was not affected; grade 1a, less than one-third of the tumor was affected; grade 1b, one to two thirds of the tumor was affected; grade 2, greater than or equal to two thirds was affected; and grade 3, no residual tumor. A pathological response was defined as grade 1b or greater.

CONCLUSION

Perioperative CapeOx showed good feasibility and favorable prognosis, especially in pts with pathological response of grade 1b or higher and was found to be useful in predicting prognosis. The data obtained using this novel approach warrant further investigation (Trial ID: UMIN000021641, jRCTs051180109).

Grading der Tumorregression gastrointestinaler Karzinome nach neoadjuvanter Therapie

Prä- oder perioperative Chemo- oder Radiochemotherapie und anschließende Resektion ist die Standardtherapie von lokal fortgeschrittenem Ösophagus‑, Magen- und Rektumkarzinom. Eine Tumorregressionsgraduierung (TRG, auch Tumorregressionsgrad) kategorisiert das Ausmaß der regressiven Veränderungen nach neoadjuvanter Behandlung. Für gastrointestinale Karzinome existieren mehrere TRG-Systeme, die sich entweder auf das Ausmaß der therapieinduzierten Fibrose im Verhältnis zum Resttumor oder den geschätzten Anteil des Resttumors im Bereich des ehemaligen Tumorareals beziehen. Ein ideales TRG-System zeigt eine signifikante Interobserverübereinstimmung und bietet relevante prognostische Informationen – in den meisten Fällen ist eine vollständige oder nahezu vollständige Regression nach neoadjuvanter Therapie mit verbesserter Prognose verbunden. In diesem Review werden die am häufigsten verwendeten TRG-Systeme für gastrointestinale Karzinome vorgestellt und diskutiert. Zudem werden aktuelle Punkte wie die Standardisierung der Angabe von TRGs und die Thematik der Regression bei Lymphknotenmetastasen im Kontext eines TRG-Systems behandelt.

Comparison of tumor regression grading systems for locally advanced gastric adenocarcinoma after neoadjuvant chemotherapy

BACKGROUND

Current tumor regression grade (TRG) evaluations are based on various systems which brings confusion for oncologists and pathologists when interpreting results. The recent six-tier system (JGCA2017-TRG) recommended by the Japanese Gastric Cancer Association (JGCA) is worth investigating, as four-tier TRG systems are favored in various parts of the world.

AIM

To compare the predictive accuracies of five published TRG systems.

METHODS

Data were retrospectively collected from patients with locally advanced gastric cancer (LAGC) who underwent neoadjuvant chemotherapy followed by D2 Lymphadenectomy between January 2005 and January 2014 at our institution. Outcomes were overall survival (OS) and disease-free survival (DFS), which were evaluated separately using the following TRG systems: JGCA2017, JGCA, Becker, AJCC/CAP, and Mandard.

RESULTS

All five published TRG systems were independent predictors for OS and DFS. Concordance indices of the JGCA2017, JGCA, Becker, AJCC/CAP-TRG, and Mandard systems were 0.651/0.648 0.652/0.649, 0.693/0.695, 0.688/0.685, and 0.674/0.675 for OS and DFS, respectively. The four-tier Becker system showed the highest c-index, which was significantly greater than that of the six-tier JGCA2017 and five-tier JGCA systems (P < 0.05 in OS and DFS). When residual tumor percentages were reset as: “no residual tumor”, < 10%, < 100%, and “no response”, the rearranged cutoff values achieved a maximum c-index with 0.728 for OS and 0.737 for DFS, which was superior to the other five systems.

CONCLUSION

The newly introduced six-tier JGCA-TRG system cannot increase prognostic stratification. The four-tier Becker system is more suitable for LAGC patients. A population-based study is warranted to define the optimal criterion for TRG in LAGC patients.

Interobserver agreement of a gastric adenocarcinoma tumor regression grading system that incorporates assessment of lymph nodes

Perioperative chemotherapy is increasingly used in combination with surgery for the treatment of patients with locally advanced, resectable gastric cancer. Histologic tumor regression grade (TRG) has emerged as an important prognostic factor; however, a common standard for its evaluation is lacking. Moreover, the clinical significance of regressive changes in metastatic lymph nodes (LNs) remains unclear. We conducted an international study to examine the interobserver agreement of a TRG system that is based on the Becker system for the primary tumors and additionally incorporates regression grading in LNs. Twenty observers at different levels of experience evaluated the TRG in 60 histologic slides (30 primary tumors and 30 LNs) based on the following criteria: for primary tumors, grade 1 represented complete response (no residual tumor), grade 2 represented <10%, grade 3 represented 10-50%, and grade 4 represented >50% residual tumor, as described by Becker et al. For LNs, grade "a" represented complete, grade "b" represented partial, and grade "c" represented no regression. The interobserver agreement was estimated using the Kendall's coefficient of concordance (W). Regarding primary tumors, agreement was good irrespective of the level of experience, reaching a W-value of 0.70 overall, 0.71 among subspecialized, and 0.71 among nonsubspecialized observers. Regarding LNs, interobserver agreement was moderate to good, with W-values of 0.52 overall, 0.64 among subspecialized, and 0.45 among nonsubspecialized observers. These findings indicate that the combination of the Becker TRG system with a three-tiered grading of regression in LNs generates a system that is reproducible. Future studies should investigate whether the additional information of TRG in LNs adds to the prognostic value of histologic regression grading in gastric cancer specimens.

Pathological complete response at the para-aortic nodes as a possible surrogate endpoint in gastric cancer surgery with para-aortic node dissection after neoadjuvant chemotherapy

PURPOSE

Gastric cancer with para-aortic node (PAN) metastasis has a chance to be cured with multidisciplinary treatment of D2 and PAN dissection (PAND) following neoadjuvant chemotherapy (NAC), but its prognosis remains unsatisfactory. To establish a better multidisciplinary treatment, a better surrogate endpoint is needed. The present study focused on a pathological complete response at the PANs alone as a new surrogate endpoint and evaluated its prognostic value.

METHODS

The study examined patients who received radical gastrectomy with D2 and PAND after NAC for gastric cancer with PAN metastasis from 2004 to 2015. The study compared five methods of evaluating the response to NAC: RECIST, clinical disappearance of PANs (cPAN), histological response of the primary tumor defined by Japanese Classification of Gastric Carcinoma (JCGC histological criteria) and Becker's criteria, and pathological disappearance of PANs (pPAN). The efficacy of these methods was compared using the hazard ratio (HR) for death between responders and non-responders.

RESULTS

Thirty-two patients were analyzed. The respective HR and 5-year overall survival rates of responders and non-responders were 1.316 and 49.1% vs. 60.0% by RECIST, 1.106 and 52.9% vs. 52.5% by cPAN, 0.246 and 71.3% vs. 28.6% by JCGC histological criteria, 0.239 and 76.2% vs. 36.8% by Becker's criteria, and 0.074 and 81.0% vs. 0.0% by pPAN.

CONCLUSIONS

A pathological complete response at the PANs had the lowest HR and clearly differentiated the survival, suggesting it might be a good surrogate endpoint for identifying future candidates for NAC in multidisciplinary treatment for gastric cancer with PAN metastasis.

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

BACKGROUND

Specific treatment strategies are sorely needed for scirrhous-type gastric cancer still, which has poor prognosis. Based on the promising results of our previous phase II study (JCOG0210), we initiated a phase III study to confirm the efficacy of neoadjuvant chemotherapy (NAC) in type 4 or large type 3 gastric cancer.

METHODS

Patients aged 20-75 years without a macroscopic unresectable factor as confirmed via staging laparoscopy were randomly assigned to surgery followed by adjuvant chemotherapy with S-1 (Arm A) or NAC (S-1plus cisplatin) followed by D2 gastrectomy plus adjuvant chemotherapy with S-1 (Arm B). The primary endpoint was overall survival (OS).

RESULTS

Between October 2005 and July 2013, 316 patients were enrolled, allocating 158 patients to each arm. In Arm B, in which NAC was completed in 88% of patients. Significant downstaging based on tumor depth, lymph node metastasis, and peritoneal cytology was observed using NAC. Excluding the initial 16 patients randomized before the first revision of the protocol, 149 and 151 patients in arms A and B, respectively, were included in the primary analysis. The 3-year OS rates were 62.4% [95% confidence interval (CI)  54.1-69.6] in Arm A and 60.9% (95% CI  52.7-68.2) in Arm B. The hazard ratio of Arm B against Arm A was 0.916 (95% CI  0.679-1.236).

CONCLUSIONS

For type 4 or large type 3 gastric cancer, NAC with S-1 plus cisplatin failed to demonstrate a survival benefit. D2 surgery followed by adjuvant chemotherapy remains the standard treatment.

Posttherapy topographical nodal status, ypN-site, predicts survival of patients who received neoadjuvant chemotherapy followed by curative surgical resection for non-type 4 locally advanced gastric cancer: supplementary analysis of JCOG1004-A

BACKGROUND

Perioperative treatment is an accepted standard approach for treating locally advanced gastric cancer (LAGC). Histopathological tumor regression with < 10% residual tumor is a globally accepted prognosticator in LAGC patients who received neoadjuvant chemotherapy (NAC) and curative surgery. However, despite a response of the primary tumor, a significant percentage of patients dies from recurrence and identification of those at risk for relapse remains challenging. We re-estimated the value of histopathological tumor regression as a prognosticator alongside other factors, especially posttherapy topographical nodal status, ypN-site.

PATIENTS AND METHODS

Individual patient data including clinicopathological variables were used from the four JCOG trials investigating NAC (JCOG0001, JCOG0002, JCOG0210, JCOG0405) for analyzing prognosticators in patients with curative surgery excluding those with type 4 AGC by univariable and multivariable Cox regression analyses.

RESULTS

Among 85 patients, 5-year overall survival (OS) was 46.0% [95% confidence interval (CI) 35.0-56.4] with a median follow-up of 3.2 years. On univariable analysis, histopathological tumor regression with ≥ 10% residual tumor and ypN-site 2-3 were negatively associated with OS [≥ 10% residual tumor: hazard ratio (HR) 2.60; 95% CI 1.22-5.54; P = 0.014; ypN2-3: HR 3.59; 95% CI 1.60-8.06; P = 0.002). On multivariable analysis, only ypN-site 2-3 was predictive of OS (HR 3.67; 95% CI 1.55-8.69; P = 0.003), whereas histopathological tumor regression with ≥ 10% residual tumor was not (HR 2.24; 95% CI 0.98-5.10; P = 0.055).

CONCLUSIONS

ypN-site may have greater impact on OS than histopathological tumor regression in patients who received NAC plus surgery for non-type 4 LAGC.

Primary results of a randomized two-by-two factorial phase II trial comparing neoadjuvant chemotherapy with two and four courses of cisplatin/S-1 and docetaxel/cisplatin/S-1 as neoadjuvant chemotherapy for advanced gastric cancer

AIM

Neoadjuvant chemotherapy (NAC) is promising to improve the survival of resectable gastric cancer. However, suitable regimen and treatment duration for NAC have not yet been established.

METHODS

We conducted a randomized phase II trial to compare two and four courses of neoadjuvant S-1/cisplatin (SC) and S-1/cisplatin/docetaxel(DCS) using a two-by-two factorial design for locally resectable advanced gastric cancer. Patients with M0 and either T4 or T3 in case of junctional cancer or scirrhous-type cancer received two or four courses of SC or DCS. Then, patients underwent D2 gastrectomy and adjuvant S-1 chemotherapy for 1 year. The primary endpoint was 3-year overall survival. The planned sample size was 120 eligible patients.

RESULTS

Between October 2011 and September 2014, 132 patients were assigned to CS (n = 66; 33 in 2-courses and 33 in 4-courses) and DCS (n = 66; 33 in 2-courses and 33 in 4-courses). The 3-year OS was 58.1% in CS and 60.0% in DCS with hazard ratio of 0.80 (95% CI, 0.48-1.34), while it was 53.1% in the two courses and 65.0% in the four courses with hazard ratio of 0.72 (95% CI, 0.43-1.22). In the survival analysis by duration in each regimen, the 3-year OS was 58.1% for both two and four courses in CS, while it was 48.5% for two courses of DCS and 71.9% for four courses of DCS.

CONCLUSIONS

Considering high 3-year OS, four courses DCS has a value to be tested in a future phase III study to confirm superiority of neoadjuvant chemotherapy for locally advanced gastric cancer.

Neoadjuvant chemotherapy plus surgery for high-risk advanced gastric cancer: long-term results of KDOG1001 trial

PURPOSE

The purpose of this study is to evaluate the long-term survival outcomes of KDOG1001 trial after a minimum follow-up of 3 years.

METHODS

Patients with bulky N2 lymph nodes, linitis plastica (type 4), or large ulcero-invasive-type tumors (type 3) received up to four 28-day cycles of DCS neoadjuvant chemotherapy (docetaxel at 40 mg/m², cisplatin at 60 mg/m² on day 1, and S-1 at 40 mg/m² twice daily for 2 weeks) followed by gastrectomy with D2 lymphadenectomy plus adjuvant S-1 therapy for 1 year. The final preplanned analysis of long-term outcomes including overall survival and relapse-free survival was conducted after minimum follow-up of 3 years. This trial is registered with the University Hospital Medical Information Network Clinical Trials Registry, number UMIN 000003642, and has been completed.

RESULTS

From May 2010 through January 2017, 40 patients were enrolled. All included patients underwent neoadjuvant chemotherapy with DCS followed by gastrectomy with D2 lymphadenectomy, and 32 (80%) completed adjuvant S-1 therapy for 1 year. After a median follow-up for surviving patients of 68 months at the last follow-up in January 2020, 3-year overall survival rate was 77.5% (95% confidence interval 62.1-87.9%), while 3-year relapse-free survival rate was 62.5% (95% confidence interval 46.8-76.0%).

CONCLUSION

Neoadjuvant chemotherapy with 4 cycles of DCS followed by D2 gastrectomy plus adjuvant S-1 was associated with relatively good long-term oncologic outcomes for patients with the high-risk gastric cancer.

Connection and distinction of tumor regression grading systems of gastrointestinal cancer

OBJECTIVES

As the neoadjuvant therapy has been successfully introduced in the treatment of gastrointestinal malignancies, the evaluation of therapeutic effectiveness is becoming increasingly important. Tumor-node-metastasis system has been widely applied. However, this system is mainly based on the location of residual tumor, but does not consider the amount of residual tumor. Tumor regression grading system, a quantitative method to assess the reaction of tumor to neoadjuvant treatment, could be used as a supplement to tumor-node-metastasis system and provide additional information on prognosis. To date, numerous gastrointestinal grading systems have been used in esophageal/esophagogastric junction carcinoma, gastric adenocarcinoma, colorectal cancer, and most of them were considered to associate with clinical outcomes.

MATERIALS AND METHODS

In this review, firstly, we expounded the importance of tumor regression grading systems, and summarized the histopathological changes after neoadjuvant therapy. Secondly, we introduced some commonly used gastrointestinal systems, as well as the relationships and nuance. Finally, we discussed pivotal issues about these systems. In this part, we explained the calculation methods based on grid points and square measures, discussed several factors leading to observer bias, containing the slice number and the grading tier number, and analyzed the factors that might affect clinical significance, covering anatomical location, the selection of survival index, and the tumor type.

RESULTS

Tumor regression grade systems could be divided into two main classifications, the relative amount of fibrosis and residual tumor, and the proportion of residual tumor in the tumor bed. However, the definitions of these systems were still need to be improved.

CONCLUSIONS

The tumor regression grading system is useful in evaluating tumor response to neoadjuvant therapy, but more work is needed to refine and unify the system.

Effect of apatinib plus neoadjuvant chemotherapy followed by resection on pathologic response in patients with locally advanced gastric adenocarcinoma: A single-arm, open-label, phase II trial

BACKGROUND

The evidence of combining neoadjuvant chemotherapy with targeted therapy for patients with locally advanced gastric cancer is inadequate. We conducted a single-arm phase II trial to evaluate the efficacy and safety of S-1, oxaliplatin and apatinib (SOXA) in patients with locally advanced gastric adenocarcinoma.

METHODS

Treatment-naïve patients received three preoperative cycles of S-1 (80-120 mg/day on days 1-14) and oxaliplatin (130 mg/m2 on day 1) and two cycles of apatinib (500 mg/day for 21 days) at 3-week intervals, followed by surgery. The primary end-point was pathologic response rate (pRR). This trial is registered at ChiCTR.gov.cn: ChiCTR-OPC-16010061.

RESULTS

Of 29 patients included, median age was 60 (range, 43-73) years; 20 (69.0%) were male. The pRR was 89.7% (95% confidence interval [CI], 72.7%-97.8%; 26 of 29 patients; P < 0.001) with 28 patients treated with surgery. All 29 patients were available for preoperative response evaluation, achieving an objective response rate of 79.3% (95% CI, 60.3%-92.0%) and a disease control rate of 96.6% (95% CI, 82.2%-99.9%). The margin-free resection rate was 96.6% (95% CI, 82.2%-99.9%). The pathologic complete response rate was 13.8% (95%CI, 1.2%-26.3%). Downstaging of overall TNM stage was observed in 16 (55.2%) patients. During neoadjuvant therapy, 10 (34.5%) patients had grade ≥III adverse events. No treatment-related death occurred. Surgery-related complications were observed in 12 of 28 (42.9%) patients.

CONCLUSION

SOXA followed by surgery in patients with locally advanced gastric adenocarcinoma showed favourable activity and manageable safety. A randomised controlled trial in locally advanced gastric or oesophagogastric junction adenocarcinoma is ongoing (ClinicalTrials.gov: NCT04208347).

Varying practices in tumor regression grading of gastrointestinal carcinomas after neoadjuvant therapy: results of an international survey

Tumor regression grading is routinely performed on neoadjuvantly treated gastrointestinal cancer resections. Challenges in tumor regression grading include grossing standards, multiple grading systems, and difficulty interpreting therapy-induced changes. We surveyed gastrointestinal pathologists around the world for their practices in handling neoadjuvantly treated gastrointestinal cancer specimens and reporting tumor regression using a 23-question online survey. Topics addressed grossing, histologic work-up, tumor regression grading systems, and degree of difficulty identifying and estimating residual cancer within treatment effect. Two-hundred three responses were received, including 173 participants who completed the entire questionnaire. Fifty percent of the participants were from Europe, 29% from North America, 10% from Australia, and 11% from other continents. Ninety-five percent routinely report a tumor regression grade and 92% have standardized grossing and histologic work-up: 27% always completely embed the entire tumor bed, 54% embed the complete tumor site if not a grossly apparent, large mass. Fifty-nine percent use hematoxylin & eosin alone for assessment; the remaining use additional stains. In North America and Australia, the American Joint Committee on Cancer (AJCC)/College of American Pathologists (CAP)/Ryan system is routinely used for gastroesophageal (71%) and rectal carcinomas (77%). In Europe, the Mandard system is common (36%) for gastroesophageal tumors, followed by AJCC/CAP/Ryan (22%), and Becker (10%); for rectal CA, the Dworak system (30%) is followed by AJCC/CAP/Ryan (24%) and Mandard (14%). This regional differences were significant (p < 0.001 each). Fifty-one percent prefer a four-tiered system. Sixty-six percent think that regressive changes in lymph nodes should be part of a regression grade. Sixty-nine percent consider identifying residual tumor straight-forward, but estimating therapy-induced fibrosis difficult (57%). Free comments raised issues of costs for work-up and clinical relevance. In conclusion, this multinational survey provides a comprehensive overview of grossing and histologic work-up with regards to tumor regression grading in gastrointestinal cancers with partly significant regional differences particularly between North America and Europe.

A Phase II Study of Perioperative Capecitabine plus Oxaliplatin Therapy for Clinical SS/SE N1-3 M0 Gastric Cancer (OGSG 1601)

LESSONS LEARNED

Perioperative capecitabine and oxaliplatin (CapeOx) therapy showed favorable efficacy with sufficient pathological response. Small sample size limited the statistical power of this result. Perioperative CapeOx therapy showed good feasibility. Further studies with larger sample size are required to validate this novel approach.

BACKGROUND

D2 gastrectomy followed by adjuvant S-1 is the standard therapy for patients (pts) with stage III gastric cancer (GC) in Japan; however, the outcome is not satisfactory. We examined the efficacy of perioperative capecitabine and oxaliplatin (CapeOx) in pts with GC.

METHODS

The eligibility criteria included confirmed clinical T3(SS)/T4a(SE) N1-3 M0 GC according to the Japanese Classification (JCGC; 3rd English Edition). Three cycles of neoadjuvant CapeOx (NAC; capecitabine, 2,000 mg/m2 for 14 days; oxaliplatin, 130 mg/m2 on day 1, every 3 weeks) were administered, followed by five cycles of adjuvant CapeOx (AC) after D2 gastrectomy. The primary endpoint was the pathological response rate (pRR) according to the JCGC (≥grade 1b).

RESULTS

Thirty-seven pts were enrolled on CapeOx. An R0 resection rate of 78.4% (n = 29) and a pRR of 54.1% (n = 20, p = .058; 90% confidence interval [CI], 39.4-68.2) were demonstrated. Among 27 pts who initiated AC, 21 (63.6%) completed the treatment. Grade 3-4 toxicities during NAC included neutropenia (8%), thrombocytopenia (8%), and anorexia (8%) and during AC included neutropenia (37%), diarrhea (4%), and anorexia (4%).

CONCLUSION

Perioperative CapeOx showed good feasibility and favorable efficacy with sufficient pathological response, although statistical significance at .058 did not reach the commonly accepted cutoff of .05. The data obtained using this novel approach warrant further investigations.

A Phase II study of preoperative chemotherapy with docetaxel, oxaliplatin and S-1 in gastric cancer with extensive lymph node metastasis (JCOG1704)

Background: Although surgical resection is necessary to cure the locally advanced gastric cancer, it is sometimes difficult for extensive nodal metastasis such as para-aortic nodal disease or bulky nodal metastasis around the major gastric branched arteries. We had conducted several Phase II studies and clarified preoperative chemotherapy with doublet regimen followed by surgery markedly improved the survival for this disease. Recently, preoperative chemotherapy with docetaxel, oxaliplatin and S-1 (DOS) showed promising efficacy and acceptable feasibility for resectable advanced gastric cancer. Aim: To describe the design and rationale for the multi-institutional, single-arm, Phase II trial of systemic chemotherapy with DOS followed by surgery in advanced gastric cancer with extensive lymph node metastasis (JCOG1704). If efficacy and safety of DOS can be shown, we will conduct a Phase III trial comparing preoperative DOS and current standard cisplatin and S-1. Trial registration: jRCTs031180028.

Pathological features and survival analysis of gastric cancer patients with positive surgical margins: A large multicenter cohort study

OBJECTIVE

To investigate the factors related to positive surgical margins of gastric cancer and their correlation with the prognosis of these patients.

METHODS

The clinicopathological data of gastric cancer patients undergoing gastrectomy were collected, and the relationship between surgical margins status and patient outcome was analyzed.

RESULTS

A total of 10080 patients were included, among which 311 (3.1%) had positive surgical margins. pT3-4, pN+ and M1 were independent risk factors for positive margins, and a tumor in the middle of the stomach was a protective factor (p < 0.05). The 5-year overall survival (OS) rates of the patients with positive and negative margins after propensity score matching (PSM) were 24.2% and 36.8%, respectively (p < 0.001). For M0 patients, the 5-year OS of the margin-positive patients was lower than that of the margin-negative patients, and was higher than that of patients with M1. For the M1 patients, no statistically significant difference in 5-year OS was noted between patients with positive and negative margins. Age, positive margins, tumor location, pN+, and M1 were independent prognostic factors for OS in patients undergoing gastrectomy, and pN2-3 and M1 stages were independent prognostic factors for patients with positive surgical margins. Postoperative chemotherapy could improve the 5-year OS in pN2-3 and M1 margin-positive patients (p < 0.05).

CONCLUSION

The prognosis of M0 gastric cancer patients with positive surgical margins is poor, and it is recommended that these patients should undergo routine intraoperative frozen-section pathological examination to reduce the risk of positive surgical margins.

Area of residual tumor (ART) can predict prognosis after post neoadjuvant therapy resection for pancreatic ductal adenocarcinoma

An increasing number of patients with pancreatic ductal adenocarcinoma (PDAC) have undergone resection after neoadjuvant therapy (NAT). We have reported Area of Residual Tumor (ART) as a useful pathological assessment method to predict patient outcomes after post NAT resection in various cancer types. The aim of this study was to assess the prognostic performance of ART in PDAC resected after NAT. Sixty-three patients with PDAC after post NAT resection were analyzed. The viable residual tumor area was outlined and the measurement of ART was performed using morphometric software. The results were compared with those of the College of American Pathologist (CAP) regression grading. Of 63 cases, 39 (62%) patients received chemoradiation therapy and 24 (38%) received chemotherapy only. The median value of ART was 163 mm2. Large ART with 220 mm2 as the cut-off was significantly associated with lymphatic invasion, vascular invasion and perineural invasion, while CAP regression grading was not associated with any clinicopathological features. By multivariate analysis, large ART (≥220 mm2) was an independent predictor of shorter relapse free survival. Together with our previous reports, an ART-based pathological assessment may become a useful method to predict patient outcomes after post NAT resection across various cancer types.

Does neoadjuvant chemotherapy cancel out the negative survival impact induced by surgical complications after gastrectomy?

BACKGROUND

Postoperative infectious complications (ICs) are associated with a poor prognosis following gastric cancer surgery. Neoadjuvant chemotherapy (NAC) targeting scirrhous-type or bulky nodal disease reportedly exerts a prophylactic effect on the negative impact of ICs. However, a recent study clearly showed that NAC for scirrhous-type disease had no survival benefit. We investigated this prophylactic effect and significant interactions among subgroups of histological response, macroscopic type, and bulky nodal disease.

METHODS

We examined 115 patients who received NAC followed by radical gastrectomy between January 2008 and December 2015. The overall survival (OS) and disease-free survival (DFS) were compared between those with and without ICs. Our cohort included 62 with type 4/giant type 3, 44 with bulky nodal disease/para-aortic nodal disease, and 25 with other diseases.

RESULTS

A histological response was observed in 80 patients (69.5%). Thirty three (28.7%) developed ICs. There was no significant difference in the OS [hazard ratio (HR) 0.96; 95% confidence interval (CI) 0.47-1.99, p = 0.920] or DFS (HR 0.74; 95% CI 0.40-1.38, p = 0.342) by the presence of ICs. The HR was 1.00 in patients who had no response to NAC (grade 0/1a) and 0.95 in those who responded to NAC (grade 1b/2/3). No subgroups showed significant interactions for the OS.

CONCLUSIONS

NAC may cancel out the negative impact of morbidity on the survival in advanced gastric cancer patients. The prophylactic effects by NAC do not depend on the tumor type or histological response.

Pathological response measured using virtual microscopic slides for gastric cancer patients who underwent neoadjuvant chemotherapy

BACKGROUND

Although pathological response is a common endpoint used to assess the efficacy of neoadjuvant chemotherapy (NAC) for gastric cancer, the problem of a low rate of concordance from evaluations among pathologists remains unresolved. Moreover, there is no globally accepted consensus regarding the optimal evaluation. A previous study based on a clinical trial suggested that pathological response measured using digitally captured virtual microscopic slides predicted patients’ survival well. However, the pathological concordance rate of this approach and its usefulness in clinical practice were unknown.

AIM

To investigate the prognostic utility of pathological response measured using digital microscopic slides in clinical practice.

METHODS

We retrospectively evaluated pathological specimens of gastric cancer patients who underwent NAC followed by surgery and achieved R0 resection between March 2009 and May 2015. Residual tumor area and primary tumor beds were measured in one captured image slide, which contained the largest diameter of the resected specimens. We classified patients with < 10% residual tumor relative to the primary tumorous area as responders, and the rest as non-responders; we then compared overall survival (OS) and relapse-free survival (RFS) between these two groups. Next, we compared the prognostic utility of this method using conventional Japanese criteria.

RESULTS

Fifty-four patients were evaluated. The concordance rate between two evaluators was 96.2%. Median RFS of 25 responders and 29 non-responders was not reached (NR) vs 18.2 mo [hazard ratio (HR) = 0.35, P = 0.023], and median OS was NR vs 40.7 mo (HR = 0.3, P = 0.016), respectively. This prognostic value was statistically significant even after adjustment for age, eastern cooperative oncology group performance status, macroscopic type, reason for NAC, and T- and N-classification (HR = 0.23, P = 0.018). This result was also observed even in subgroup analyses for different macroscopic types (Borrmann type 4/non-type 4) and histological types (differentiated/undifferentiated). Moreover, the adjusted HR for OS between responders and non-responders was lower in this method than that in the conventional histological evaluation of Japanese Classification of Gastric Carcinoma criteria (0.23 vs 0.39, respectively).

CONCLUSION

The measurement of pathological response using digitally captured virtual microscopic slides may be useful in clinical practice.

Area of residual tumor is a robust prognostic marker for patients with rectal cancer undergoing preoperative therapy

The aim of this study was to elucidate differences in the histological features of rectal cancer between patients treated with preoperative chemoradiotherapy and those treated with preoperative chemotherapy. Area of residual tumor (ART) was also evaluated for its utility as a potential prognostic marker between them. Sixty‐eight patients with rectal cancer who underwent sphincter‐saving surgery were enrolled in this study. Of these, 39 patients received preoperative chemoradiotherapy (CRT group) and 29 patients received preoperative (neoadjuvant) chemotherapy (NAC group). Area of residual tumor was determined by using morphometric software. Tumors in the two groups were compared for differences in their histological features and clinical outcomes. Tumors in the CRT and NAC groups varied greatly with regard to their histological features after preoperative therapy. Tumors in the CRT group showed more marked fibrosis than those in the NAC group. The total ART were significantly smaller in tumors in the CRT group than those in the NAC group. However, in circumferential resection margin‐negative pathologic stage 0‐III cases, clinical outcomes were not statistically different between the CRT and NAC groups. Both ART and pathologic TNM classification were associated with clinical outcome in preoperative CRT and NAC groups, but Dworak regression grade and fibrotic change were not. Tumors in those undergoing preoperative CRT and NAC were shown to differ significantly in their histological features. Area of residual tumor‐based assessment may provide useful prognostic information, regardless of preoperative therapy.

Tumor regression grading of gastrointestinal cancers after neoadjuvant therapy

Neoadjuvant therapy has been successfully introduced in the treatment of locally advanced gastrointestinal malignancies, particularly esophageal, gastric, and rectal cancers. The effects of preoperative chemo- or radiochemotherapy can be determined by histopathological investigation of the resection specimen following this treatment. Frequent histological findings after neoadjuvant therapy include various amounts of residual tumor, inflammation, resorptive changes with infiltrates of foamy histiocytes, foreign body reactions, and scarry fibrosis. Several tumor regression grading (TRG) systems, which aim to categorize the amount of regressive changes after cytotoxic treatment in primary tumor sites, have been proposed for gastroesophageal and rectal carcinomas. These systems primarily refer to the amount of therapy-induced fibrosis in relation to the residual tumor (e.g., the Mandard, Dworak, or AJCC systems) or the estimated percentage of residual tumor in relation to the previous tumor site (e.g., the Becker, Rödel, or Rectal Cancer Regression Grading systems). TRGs provide valuable prognostic information, as in most cases, complete or subtotal tumor regression after neoadjuvant treatment is associated with better patient outcomes. This review describes the typical histopathological findings after neoadjuvant treatment, discusses the most commonly used TRG systems for gastroesophageal and rectal carcinomas, addresses the limitations and critical issues of tumor regression grading in these tumors, and describes the clinical impact of TRG.

A phase II study of preoperative chemotherapy with docetaxel, cisplatin, and S-1 followed by gastrectomy with D2 plus para-aortic lymph node dissection for gastric cancer with extensive lymph node metastasis: JCOG1002

BACKGROUND

Gastric cancer with extensive lymph node metastasis is commonly considered unresectable, with a poor prognosis. We previously reported the results of the use of cisplatin and S-1 as preoperative chemotherapy for gastric cancer with extensive lymph node metastasis; docetaxel, cisplatin, and S-1 (DCS) have now been investigated for the same purpose.

METHODS

Patients received two or three 28-day cycles of DCS therapy (docetaxel at 40 mg/m² and cisplatin at 60 mg/m² on day 1, S-1 at 40 mg/m² twice daily for 2 weeks) followed by gastrectomy with D2 plus para-aortic nodal dissection. After R0 resection, S-1 chemotherapy was given for 1 year. The primary end point was the response rate (RR) to preoperative chemotherapy determined by central peer review according to the Response Evaluation Criteria in Solid Tumors version 1.0. The planned sample size was 50, with one-sided alpha of 10 %, power of 80 %, expected RR of 80 %, and threshold of 65 %.

RESULTS

Between July 2011 and May 2013, 53 patients were enrolled, of whom 52 were eligible. The clinical RR was 57.7 % [30/52, 80 % confidence interval 47.9-67.1 %, p = 0.89], and R0 resection was achieved in 84.6 % of patients (44/52). Common grade 3 or grade 4 adverse events during DCS therapy were leukocytopenia (18.9 %), neutropenia (39.6 %), and hyponatremia (15.1 %). The common grade 3 or grade 4 surgical morbidity was abdominal infection (10.2 %). The pathological RR was 50.0 % (26/52).

CONCLUSIONS

Preoperative DCS therapy was feasible but did not show a sufficient RR. Preoperative cisplatin and S-1 therapy is still considered the tentative standard treatment for this population until survival results are known.

Feasibility of neoadjuvant S-1 and oxaliplatin followed by surgery for resectable advanced gastric adenocarcinoma

PURPOSE

In Japan, the administration of S-1 following D2 gastrectomy is a standard treatment for stage II/III gastric cancer (GC). However, the survival of stage IIIB/IIIC GC remains unsatisfactory. To improve this, we conducted a multicenter phase II study to evaluate the safety and efficacy of a neoadjuvant S-1 and oxaliplatin regimen (SOX) followed by surgery targeted at stage III GC.

METHODS

Oxaliplatin was administered intravenously (130 mg/m(2)) on day 1, and S-1 was administered orally (40 mg/m(2), twice a day) for 14 days followed by a seven-day rest period. After three cycles of therapy, D2 gastrectomy was performed.

RESULTS

A total of 14 patients were enrolled and completed the protocol treatment. Grade 3/4 toxicities included thrombocytopenia (21.4 %), anorexia (14.3 %), and diarrhea (7.1 %). Seven patients (50 %) underwent total gastrectomy, and seven patients underwent distal gastrectomy. Grade 3/4 surgical complications included pancreatic fistula (21.4 %) and lung infection (7.1 %). The pathological response rate was 85.7 %.

CONCLUSION

Although our data are limited and preliminary, neoadjuvant SOX followed by surgery can be performed safely with a high pathological response rate in patients with resectable advanced GC. Further investigation of this neoadjuvant approach is warranted.

Gastric adenocarcinoma with para-aortic lymph node metastasis: a borderline resectable cancer?

Dissection of the para-aortic lymph nodes (PAN) had once been enthusiastically explored at dedicated centers throughout Japan. Reflecting the results of a randomized trial, however, the current standard surgery for advanced resectable gastric cancer does not include systematic dissection of the PAN. Gastric cancer with PAN metastases, currently considered distant metastases, is classified as Stage IV, and according to the algorithm of the Japanese guidelines, is not indicated for surgery with curative intent. Historical data indicates, however, that a certain proportion of long-term survivors can be introduced among patients with PAN metastasis through D2 + PAN dissection. The Japan Clinical Oncology Group launched a series of phase II trials exploring a strategy employing neoadjuvant chemotherapy followed by D2 + PAN dissection for patients radiologically diagnosed to harbor metastases to the PAN. The campaign was successful, with 57% of these patients surviving for 5 years after two cycles of neoadjuvant S-1/CDDP followed by surgery. This strategy is now the tentative standard, mentioned in the 4th version of the Japanese Gastric Cancer Treatment Guidelines as one of the current clinical questions, and could be replaced by a more powerful combination chemotherapy or treatment employing more or longer cycles of chemotherapy in the future. The relevance of the strategy consisting of neoadjuvant chemotherapy followed by D2 + PAN dissection and its fundamental difference from the concept of conversion therapy are discussed herein with reference to the literature.