Histological evaluation for chemotherapeutic responses of metastatic lymph nodes in gastric cancer

Role of pathological tumor regression grade of lymph node metastasis following neoadjuvant chemotherapy in locally advanced gastric cancer

AIMS

To confirm whether the pathological response of lymph node metastasis (LNM) to neoadjuvant chemotherapy (NCT) can predict the prognosis of patients with gastric cancer (GC).

METHODS

A total of 979 patients with locally advanced GC were included. χ2 test was used to analyze the relationship between LNM TRG and clinicopathological factors. Cox proportional hazards model was used to analyze the relationship between LNM TRG, clinicopathological factors, and overall survival (OS).

RESULTS

A total of 21,162 lymph nodes were evaluated, with 237 patients (35.4%) in the response group and 433 patients (64.6%) in the non-response group. The non-responsive group was strongly associated with higher ypT, ypN, ypTNM, primary tumor (PT) TRG (all p < 0.001), positive cancer nodules (p = 0.001), and more distant LNM location (p < 0.001). Patients with the same PT TRG but different LNM TRG had different prognosis. There was no difference in OS between the responding and non-responding groups of LNM at location 2, 3, and M. YpN, tumor location, and LNM location were independent prognostic factors.

CONCLUSIONS

The combination of LNM TRG and PT TRG could better predict patient prognosis. Lymph node dissection should be routinely performed after NCT to provide the reference of radical resection.

Short-term and long-term outcomes of patients with gastric cancer during versus before the COVID-19 pandemic: cohort study using propensity score matching method

BACKGROUND

The negative effects of the novel coronavirus disease 2019 (COVID-19) pandemic on patients with gastric cancer are poorly understood. This study was designed to compare the short-term and long-term outcomes of patients with gastric cancer in the same period before and during the COVID-19 pandemic.

METHODS

We retrospectively collected consecutive patients with definite diagnosis of gastric cancer at our center between 1 January and 30 June of 2019 (Before COVID-19) and 2020 (During COVID-19). A comparison was made between the number of patients and their characteristics before and during the COVID-19 epidemic. Propensity score matching (PSM) at 1:1 ratio was performed to evaluate the outcomes of patients that underwent laparoscopic radical gastrectomy in two groups.

RESULT

The total number of patients diagnosed with gastric cancer during the COVID-19 pandemic increased by 21.4%, compared to that before the COVID-19 pandemic. AII the qualified patients were divided Before COVID-19 Pandemic group (BCP n = 99) and During COVID-19 Pandemic group (DCP n = 118). PSM yielded 81 patients with comparable baseline characteristics into each group. Compared to the BCP group, the DCP group had longer surgery time(P = 0.011), more blood loss(P = 0.015), longer postoperative hospital stay(P = 0.002). No statistical differences were observed in terms of type of resection, number of retrieved lymph nodes (LNs), pathology, short-term and long-term complications (P > 0.05).

CONCLUSION

Patients diagnosed with gastric cancer during the COVID-19 pandemic had comparable short-term outcomes and long-term complications, but worse peri-operative outcomes, compared to that before the COVID-19 pandemic. Further research is needed to investigate long-term outcomes.

Nodal downstaging to ypN0 after neoadjuvant chemotherapy positively impacts on survival of cT4N+ GC/GEJ patients

BACKGROUND

The prognostic value of histomorphologic regression in primary gastric and gastroesophageal cancers (GC/GEJ) has been previously established, however, the impact of lymph node (LN) regression on survival still remains unclear.

METHODS

A prospectively maintained database was reviewed to identify cT4N+ gastric and gastroesophageal cancers (GC/GEJ) after NAC (neoadjuvant chemotherapy). Patients were categorized into two groups based on LN status: cN+/ypN0 (downstaged N0) and cN+/ypN+ (persistent N+), long-term survival were analyzed using Kaplan-Meier survival estimates.

RESULTS

In total, 125 patients with cT4N+ GC/GEJ underwent NAC followed by surgery were enrolled. A total of 39 patients (31.2%) had cN+/ypN0 (ypN0) disease, 86 patients (68.8%) had cN+/ypN+ (ypN+) disease. Prognosis in ypN+ patients was significantly worse than those in ypN0 group for 3- and 5-year overall survival (OS) (p < 0.05). The 3-year OS was 83%, 44% in ypN0 and ypN+ group, respectively. The 5-year OS was 75%, 35% in ypN0 and ypN+ group, respectively. Multivariable analysis suggested that multivisceral resection (hazard ratio [HR] = 0.33, 95% confidence interval [CI]: 0.14-0.76, p = 0.009), and ypN+ (HR = 3.42, 95% CI: 1.15-10.13, p =0.027) were independent prognostic factors for OS.

CONCLUSION

Nodal downstaging is an important hallmark representing the effectiveness of NAC for GC/GEJ, and it positively impacts on survival of these patients.

Pattern of lymph node metastases in gastric cancer: a side-study of the multicenter LOGICA-trial

BACKGROUND

The relation between gastric cancer characteristics and lymph node (LN) metastatic patterns is not fully clear, especially following neoadjuvant chemotherapy (NAC). This study analyzed nodal metastatic patterns.

METHODS

Individual LN stations were analyzed for all patients from the LOGICA-trial, a Dutch multicenter randomized trial comparing laparoscopic versus open D2-gastrectomy for gastric cancer. The pattern of metastases per LN station was related to tumor location, cT-stage, Lauren classification and NAC.

RESULTS

Between 2015-2018, 212 patients underwent D2-gastrectomy, of whom 158 (75%) received NAC. LN metastases were present in 120 patients (57%). Proximal tumors metastasized predominantly to proximal LN stations (no. 1, 2, 7 and 9; p < 0.05), and distal tumors to distal LN stations (no. 5, 6 and 8; OR > 1, p > 0.05). However, distal tumors also metastasized to proximal LN stations, and vice versa. Despite NAC, each LN station (no. 1-9, 11 and 12a) showed metastases, regardless of tumor location, cT-stage, histological subtype and NAC treatment, including station 12a for cT1N0-tumors. LN metastases were present more frequently in diffuse versus intestinal tumors (66% versus 52%; p = 0,048), but not for cT3-4- versus cT1-2-stage (59% versus 51%; p = 0.259). However, the pattern of LN metastases was similar for these subgroups.

CONCLUSIONS

The extent of lymphadenectomy cannot be reduced after NAC for gastric cancer. Although the pattern of LN metastases is related to tumor location, all LN stations contained metastases regardless of tumor location, cT-stage (including cT1N0-tumors), histological subtype, or NAC treatment. Therefore, D2-lymphadenectomy should be routinely performed during gastrectomy in Western patients.

Short-Term Clinical Efficacy of Neoadjuvant Chemotherapy Combined With Laparoscopic Gastrectomy for Locally Advanced Siewert Type II and III Adenocarcinoma of the Esophagogastric Junction: A Retrospective, Propensity Score-Matched Study

Background

Laparoscopic gastrectomy (LG) has been increasingly used for the treatment of locally advanced Siewert type II and III adenocarcinoma of the esophagogastric junction (AEG). However, whether LG can achieve the same short-term efficacy in the treatment of patients who receive neoadjuvant chemotherapy (NACT) remains controversial. Thus, the aim of this study was to investigate the clinical outcomes of NACT combined with LG for Siewert type II and III AEG.

Methods

This retrospective study identified patients with locally advanced Siewert type II and III AEG diagnosed between May 2011 and October 2020 using the clinical tumor-node-metastasis (cTNM) staging system. The short-term outcomes were compared between the matched groups using a 1:3 propensity score matching (PSM) method, which was performed to reduce bias in patient selection.

Results

After PSM, 164 patients were selected, including 41 in the NACT group and 123 in the LG group. The baseline characteristics were similar between the two groups. Compared with the LG group, the NACT group exhibit a smaller tumor size and significantly less advanced pathological tumor classification and nodal classification stages. The time to first flatus of the NACT group was significantly shorter, but the hospital stay was significantly longer than that of the LG group. The NACT group showed similar overall (29.3% vs 25.2%, P=0.683), systemic (24.4% vs 21.1%, P=0.663), local (12.2% vs 9.8%, P=0.767), minor (19.5% vs 19.5%, P=1.000) and major (9.8% vs 5.7%, P=0.470) complications as the LG group. Subgroup analyses showed no significant differences in most stratified parameters. Operation time≥ 300 minutes was identified as an independent risk factor for overall complications. Age≥ 60 years was identified as an independent risk factor for major complications.

Conclusion

NACT combined with LG for AEG does not increase the risk of postoperative morbidity and mortality compared with LG.

Tumor downstaging after neoadjuvant chemotherapy determines survival after surgery for gastric adenocarcinoma

BACKGROUND

Since 2006, surgery combined with perioperative chemotherapy is the standard of care for resectable gastric adenocarcinoma in Europe. Specific effects of neoadjuvant chemotherapy remain unknown. The aim was to evaluate the rate of tumor downstaging and its impact on survival in patients undergoing curative resection after neoadjuvant chemotherapy (NeoCT) for gastric adenocarcinoma.

MATERIAL AND METHODS

All patients treated in a curative intent for gastric or esophagogastric junction adenocarcinomas between 1996 and 2016 in our high-volume center were retrospectively included. Tumor downstaging after NeoCT was defined as ypTN inferior to cTN. The accuracy of clinical staging was evaluated in patients treated by upfront surgery before 2006.

RESULTS

During the study period, 491 patients were operated for gastric adenocarcinoma, and 449 patients were finally analyzed. Among the 163 (36.3%) patients who received NeoCT, 61 (37.4%) had tumor downstaging. Overall survival and disease-free survival were longer in patients with tumor downstaging compared to patients without it (5-year survival: 84.8% vs 49.7%; P = .002 and 61.7% vs 43.4%; P = .054). In multivariate analysis tumor downstaging was an independent prognosis factor for better overall survival (HR = 5.258; P = .002) and disease-free survival (HR = 2.286; P = .028). Moreover, 45.5% of patients staged cT1-T2N0, in whom upfront surgery was performed, were understaged and ultimately had a more advanced tumor on pathological analysis.

CONCLUSION

Response to neoadjuvant chemotherapy constitutes a major prognostic factor for overall and disease-free survival. In the absence of predictive factors for tumor downstaging, the indication for perioperative chemotherapy should remain broad, in particular because of the low accuracy of pretherapeutic staging and therefore the high risk of understaging tumors.

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.

Short-term outcomes of laparoscopic versus open total gastrectomy after neoadjuvant chemotherapy: a cohort study using the propensity score matching method

Background

Until now, little is known about the benefit of laparoscopic total gastrectomy (LTG) after neoadjuvant chemotherapy (NACT). This study was designed to compare the safety and efficacy of the LTG versus the open total gastrectomy (OTG) approach after NACT treatment in patients with advanced gastric cancer (AGC).

Methods

This study involved a cohort of 145 patients with AGC who underwent total gastrectomy after NACT at our centre between April 2013 and August 2018 including 24 cases of LTG and 121 OTG. The baseline characteristics were matched based on 1:2 balanced propensity score-matching method.

Results

Sixty-nine marched cases were finally analysed (23 LTG vs. 46 OTG). All patients underwent R0 resection. Compared to the OTG group, the LTG group had a longer surgery duration (P<0.001), but a shorter incision length (P<0.001) and less intravenous patient-controlled analgesia (IV-PCA) time after surgery (P=0.027). No statistical differences were observed in terms of blood loss, retrieved lymph nodes (LNs), resection margin, length of stay, postoperative pain intensity, and complications (P>0.05).

Conclusions

LTG had comparable safety and histological findings to OTG after NACT in the perioperative period; however, LTG is less invasive and patients can benefit from less IV-PCA use. Further research is needed to investigate long-term effects.

Keywords

Gastric cancer (GC); neoadjuvant chemotherapy (NACT); safety; laparoscopic technique.

Significance of tumour regression in lymph node metastases of gastric and gastro-oesophageal junction adenocarcinomas

The presence of lymph node (LN) metastases is one of the most important negative prognostic factors in upper gastrointestinal carcinomas. Tumour regression similar to that in primary tumours can be observed in LN metastases after neoadjuvant therapy. We evaluated the prognostic impact of histological regression in LNs in 480 adenocarcinomas of the stomach and gastro‐oesophageal junction after neoadjuvant chemotherapy. Regressive changes in LNs (nodular and/or hyaline fibrosis, sheets of foamy histiocytes or acellular mucin) were assessed by histology. In total, regressive changes were observed in 128 of 480 patients. LNs were categorised according to the absence or presence of both residual tumour and regressive changes (LN−/+ and Reg−/+). 139 cases were LN−/Reg−, 28 cases without viable LN metastases revealed regressive changes (LN−/Reg+), 100 of 313 cases with LN metastases showed regressive changes (LN+/Reg+), and 213 of 313 metastatic LN had no signs of regression (LN+/Reg−). Overall, LN/Reg categorisation correlated with overall survival with the best prognosis for LN−/Reg− and the worst prognosis for LN+/Reg− (p < 0.001). LN−/Reg+ cases had a nearly significant better outcome than LN+/Reg+ (p = 0.054) and the latter had a significantly better prognosis than LN+/Reg− (p = 0.01). The LN/Reg categorisation was also an independent prognostic factor in multivariate analysis (HR = 1.23; 95% CI 1.1–1.38; p < 0.001). We conclude that the presence of regressive changes after neoadjuvant treatment in LNs and LN metastases of gastric and gastro‐oesophageal junction cancers is a relevant prognostic factor.

A real-life analysis on the indications and prognostic relevance of perioperative chemotherapy in locally advanced resectable gastric adenocarcinoma

BACKGROUND AND PURPOSE

Perioperative chemotherapy (periCTX) based on the "MAGIC" scheme has become a standard treatment in Europe for locally advanced oesophagogastric cancer. We assessed implementation and long-term oncological outcomes of MAGIC periCTX for locally advanced gastric cancer.

METHODS

Population-based cohort study of all patients with locally advanced gastric cancer undergoing surgical resection with curative intent in Catalonia and Navarra (the first two autonomous communities included in the EURECCA Upper GI Spanish Working Group) between January 2011 and December 2013. The main variable was the percentage of patients treated with MAGIC periCTX. Kaplan-Meier analysis and Cox proportional hazards model were used to assess the survival benefit of periCTX.

RESULTS

Among 814 patients, 217 (26.6%) received periCTX (especially patients more likely to receive it: aged < 70 years, with proximal tumors, low anesthetic risk, and cT3-4/cN+ clinical stage). 35% did not complete perioperative chemotherapy, with no relationship with age. PeriCTX showed no effect on postoperative morbimortality. Histological tumor regression was more often absent or poor (38.2%) than total or almost total (27.8%), although clinico-pathological lymph-node downstaging was higher than expected by staging inaccuracy (38.7% vs. 24.2%). PeriCTX was associated with a better survival only in cT3-4 and cN+ patients, showing less prognostic relevance than optimal oncological surgery with D2 lymphadenectomy.

CONCLUSIONS

Only 26.6% of locally advanced resectable gastric cancer patients received PeriCTX. Pathological response was poor, although some degree of nodal downstaging was observed. Survival benefit of periCTX was limited to cT3-4 and cN+ patients, being less relevant than D2 lymphadenectomy.

Downstaging of lymph node metastasis after neoadjuvant intraperitoneal and systemic chemotherapy in gastric carcinoma with peritoneal metastasis

PURPOSE

The aim of the present study was to evaluate the clinical features and prognosis of lymph node metastasis (LNM) in gastric cancer patients with peritoneal metastasis (PM) after neoadjuvant intraperitoneal and systemic chemotherapy.

METHODS

A total of 69 gastric cancer patients with PM and LNM who received neoadjuvant intraperitoneal and systemic chemotherapy (NIPS) of intraperitoneal docetaxel (DXT) and cisplatin (CDDP); intravenous chemotherapy of DXT and CDDP and oral S-1in Kishiwada Tokushukai Hospital between January 2008 and February 2017. After surgical resection, the response of LNMs was studied to confirm the effect of NIPS on LNMs.

RESULTS

After NIPS, 197 lymph nodes (LNs) (42.5%) were graded as G3, the progression in LNMs were significantly better than in the primary tumors. Until the last follow-up, 1-year overall survival rate was 82.6%, and the median survival period was 22.0 ± 3.7 months. In the group of patients who had achieved a more than 50% G3 grade of the response of LNMs, the median survival period is 38 months; in the less than 50% G3 grade group, it is 14 months, that is a significantly different result. Multivariate analyses showed that the factors PCI, Post-therapeutic N status and response of the LNMs were found to be as independent prognostic factors.

CONCLUSION

Downstaging of LNMs were achieved in patients of gastric cancer with PM who received NIPS. Downstaging of LNMs after NIPS is related with the prognosis of gastric cancer and should be valued in subsequent surgery for gastric cancer with peritoneal and lymph nodes metastasis.

Unnecessity of lymph node regression evaluation for predicting gastric adenocarcinoma outcome after neoadjuvant chemotherapy

BACKGROUND

Neoadjuvant chemotherapy has been applied worldwide to improve the survival of patients with gastric adenocarcinoma (GAC). The evaluation of histological regression in primary tumors is valuable for predicting prognosis. However, the prognostic effect of regression change in lymph nodes (LNs) remains unclear.

AIM

To confirm whether the evaluation of regression change in LNs could predict the prognosis of GAC patients who received neoadjuvant chemotherapy followed by surgery.

METHODS

In this study, we evaluated the histological regression of resected LNs from 192 GAC patients (including those with esophagogastric junction adenocarcinoma) treated with neoadjuvant chemotherapy. We classified regression change and residual tumor in LNs into four groups: (A) true negative LNs with no evidence of a preoperative therapy effect, (B) no residual metastasis but the presence of regression change in LNs, (C) residual metastasis with regression change in LNs, and (D) metastasis with minimal or no regression change in LNs. Correlations between regression change and residual tumor groups in LNs and regression change in the primary tumor, as well as correlations between regression change in LNs and clinicopathological characteristics, were analyzed. The prognostic effect of regression change and residual tumor groups in LNs was also analyzed.

RESULTS

We found that regression change and residual tumor groups in LNs were significantly correlated with regression change in the primary tumor, tumor differentiation, ypT stage, ypN stage, ypTNM stage, lymph-vascular invasion, perineural invasion and R0 resection status. Regression change and residual tumor groups in LNs were statistically significant using univariate Cox proportional hazards analysis, but were not independent predictors. For patients who had no residual tumor in LNs, the 5-year overall survival (OS) rates were 67.5% in Group A and 67.4% in Group B. For the patients who had residual tumors in LNs, the 5-year OS rates were 28.2% in Group C and 39.5% in Group D. The patients in Groups A+B had a significantly better outcome than the patients in Groups C+D (P < 0.01). No significant differences in survival were found between Groups A and B, or between Groups C and D.

CONCLUSION

The existence of residual tumor in LNs, rather than regression change in LNs, is useful for predicting the prognosis after neoadjuvant chemotherapy in GAC patients. In practice, it may not be necessary to report regression change in LNs.

The prognostic value of negative lymph node count for patients with gastric cancer who received preoperative radiotherapy

Negative lymph node (NLN) count provides accurate prognostic information in patients with gastric cancer. However, it is unclear whether NLN still has prognostic value for patients received preoperative radiotherapy. In this study, Surveillance, Epidemiology, and End Results Program (SEER)-registered gastric cancer patients were used for analysis. Clinicopathological characteristics and survival time were collected. Univariate and multivariate Cox proportional hazards models were used to assess the risk factors for survival. NLN count was validated as an independent prognostic factor in both univariate and mulivariate analysis (P < 0.001). X-tile plots identified 12 as the optimal cutoff value to divide the patients into high and low risk subsets in terms of survival rate. Nomogram based on cancer-specific survival was successfully established according to all significant factors. The C-index was 0.630 (95% CI: 0.605–0.655). Subgroup analysis showed that NLN count was a prognosis factor for patients with advanced gastric cancer (stage ypII and ypIII). In conclusion, our results firmly demonstrated that NLN count was an independent prognostic factor for patients with gastric cancer who received preoperative radiotherapy. It provides more accurate prognostic information especially for patients with advanced gastric cancer (stage ypII and ypIII). Nomograms based on cancer-specific survival could be recommended as practical models to evaluate prognosis.

Gastric Cancer Maximum Tumour Diameter Reduction Rate at CT Examination as a Radiological Index for Predicting Histopathological Regression after Neoadjuvant Treatment: A Multicentre GIRCG Study

Aim

To investigate the role of maximum tumour diameter (D-max) reduction rate at CT examination in predicting histopathological tumour regression grade (TRG according to the Becker grade), after neoadjuvant chemotherapy (NAC), in patients with resectable advanced gastric cancer (AGC).

Materials and Methods

Eighty-six patients (53 M, mean age 62.1 years) with resectable AGC (≥T3 or N+), treated with NAC and radical surgery, were enrolled from 5 centres of the Italian Research Group for Gastric Cancer (GIRCG). Staging and restaging CT and histological results were retrospectively reviewed. CT examinations were contrast enhanced, and the stomach was previously distended. The D-max was measured using 2D software and compared with Becker TRG. Statistical data were obtained using “R” software.

Results

The interobserver agreement was good/very good. Becker TRG was predicted by CT with a sensitivity and specificity, respectively, of 97.3% and 90.9% for Becker 1 (D-max reduction rate > 65.1%), 76.4% and 80% for Becker 3 (D-max reduction rate < 29.9%), and 70.8% and 83.9% for Becker 2. Correlation between radiological and histological D-max measurements was strongly confirmed by the correlation index (c.i.= 0.829).

Conclusions

D-max reduction rate in AGC patients may be helpful as a simple and reproducible radiological index in predicting TRG after NAC.

Prognostic impact of nodal status and therapeutic implications

The prognostic impact of lymph node (LN) metastases in gastric cancer is generally accepted. In primarily resected patients the pN-category and LN ratio are independent prognostic factors. Number of involved LNs, number of resected LNs, lymphangiosis and micrometastases also influence the prognosis significantly. To guarantee a proper D2 lymphadenectomy (LAD) at least 25 LNs according to the German S3 guidelines for the treatment of gastric cancer should be removed. Also in neoadjuvantly treated patients the ypN-category and LN ratio play an important prognostic role, despite the fact that UICC staging system was development based only on primarily resected patients. The role of response of LNs in neoadjuvantly treated patients is still unclear and needs further investigation. It seems to be less important than the response of the primary tumor. Limited data exists, suggesting that preoperative treatment might reduce the number of LNs involved and improve ypN-category. Due to further development in gastric cancer like laparoscopic resection and effective perioperative treatment in locally advanced tumor the role and the prognostic impact of LAD is again in the focus of discussion.

Role of histological regression grade after two neoadjuvant approaches with or without radiotherapy in locally advanced gastric cancer

Background:

The degree of histopathological response after neoadjuvant therapy in locally advanced gastric cancer (GC) is a key determinant of patients' long-term outcome. We aimed to assess the pattern of histopathological regression after two neoadjuvant approaches and its impact on survival times.

Methods:

Regression grade of the primary tumour (Becker criteria) and the degree of nodal response by a 4-point scale (grades A–D) were assessed. Grade A—true negative lymph nodes (LNs); grade B and C—infiltrated LNs with any or little evidence of nodal response; and grade D—complete pathological response in a previously infiltrated LN. A favourable pathological response was defined as Becker Ia–b and grade D.

Results:

From 2004 to 2014, 80 patients with GC (cT3–4/N+ by CT-scan/EUS) were treated with either preoperative chemotherapy (ChT, n=34) or chemoradiation (CRT, n=46). Patients in the CRT group had a higher likelihood of achieving a Becker Ia–b response (58 vs 32%, P=0.001), a grade D nodal regression (30 vs 6%, P=0.009) and a favourable pathological response (23 vs 3% P=0.019). Patients with a grade D nodal response had a longer 5-year PFS and OS compared with those with a grade B or C response. Patients with a baseline negative LN status had similar outcomes irrespective of the preoperative therapy received (5-year OS; ChT vs CRT, 58 vs 51%, P=0.92).

Conclusions:

Preoperative chemoradiation increases the likelihood of achieving favourable histopathological features that correlate with a 5-year OS>70% in GC patients.

Pristimerin inhibits growth and induces apoptosis of gastric cancer MGC803 and SGC7901 cells

AIM: To investigate the effects of pristimerin on the growth and apoptosis of gastric cancer MGC803 and SGC7901 cells, and to preliminarily explore its action mechanism.

METHODS: MGC803 and SGC7901 cells were cultured in vitro. After treatment with pristimerin, CCK-8 assay, Annexin V-FITC/PI staining, and cell cycle analysis were conducted to investigate the effects of pristimerin on the growth and apoptosis of MGC803 and SGC7901 cells, and then the mitochondrial membrane potential and Bax and Bcl-2 protein expression were determined by Rhodamine 123 staining and Western blot, respectively. Human gastric cancer MGC803 cells were transplanted to nude mice to establish an animal model, and the effect of pristimerin on tumor growth in this model was observed.

RESULTS: Pristimerin inhibited MGC803 and SGC7901 cell growth, with the IC₅₀ values of 8.5 and 12.6 μmol/L, respectively. Annexin-V/PI staining showed that pristimerin induced the apoptosis of MGC803 and SGC7901 cells in a dose-dependent manner. The cell cycle analysis revealed that pristimerin could induce a G₁-phase arrest. Treatment with pristimerin significantly decreased the mitochondrial membrane potential. Treatment with pristimerin increased the expression of Bax protein and decreased the expression of Bcl-2 in a concentration-dependent manner. Treatment with pristimerin could inhibit tumor growth in the nude mouse model.

CONCLUSION: Pristimerin could inhibit proliferation and induce apoptosis of gastric cancer MGC803 and SGC7901 cells, possibly by inducing the loss of mitochondrial membrane potential.