Tumor Regression Grade in Gastric Cancer After Preoperative Therapy

Safety and efficacy of a programmed cell death 1 inhibitor combined with oxaliplatin plus S-1 in patients with Borrmann large type III and IV gastric cancers

BACKGROUND

Gastric cancer (GC) is the fifth most common and the fourth most lethal malignant tumour in the world. Most patients are already in the advanced stage when they are diagnosed, which also leads to poor overall survival. The effect of postoperative adjuvant chemotherapy for advanced GC is unsatisfactory with a high rate of distant metastasis and local recurrence.

AIM

To investigate the safety and efficacy of a programmed cell death 1 (PD-1) inhibitor combined with oxaliplatin and S-1 (SOX) in the treatment of Borrmann large type III and IV GCs.

METHODS

A retrospective analysis (IRB-2022-371) was performed on 89 patients with Borrmann large type III and IV GCs who received neoadjuvant therapy (NAT) from January 2020 to December 2021. According to the different neoadjuvant treatment regimens, the patients were divided into the SOX group (61 patients) and the PD-1 + SOX (P-SOX) group (28 patients).

RESULTS

The pathological response (tumor regression grade 0/1) in the P-SOX group was significantly higher than that in the SOX group (42.86% vs 18.03%, P = 0.013). The incidence of ypN0 in the P-SOX group was higher than that in the SOX group (39.29% vs 19.67%, P = 0.05). The use of PD-1 inhibitors was an independent factor affecting tumor regression grade. Meanwhile, the use of PD-1 did not increase postoperative complications or the adverse effects of NAT.

CONCLUSION

A PD-1 inhibitor combined with SOX could significantly improve the rate of tumour regression during NAT for patients with Borrmann large type III and IV GCs.

NESC Multicenter Phase II Trial in the Preoperative Treatment of Gastric Adenocarcinoma with Chemotherapy (Docetaxel-Cisplatin-5FU+Lenograstim) Followed by Chemoradiation Based 5FU and Oxaliplatin and Surgery

PURPOSE

Preoperative chemoradiation (CRT) is expected to increase the rate of curative resection and complete histological response. In this trial, we investigated the efficacy of a neoadjuvant CRT regimen in gastric adenocarcinoma (NCT01565109 trial).

MATERIALS AND METHODS

Patients with stage IB to IIIC gastric adenocarcinoma, endoscopy ultrasound and computed tomography-scan diagnosed, were eligible for this phase II trial. Neoadjuvant treatment consisted of 2 cycles of chemotherapy with DCF (docetaxel, cisplatin, and 5-fluorouracil [5FU]) followed by preoperative CRT with oxaliplatin, continuous 5FU and radiotherapy (45 Gy in 25 fractions of 1.8 Gy, 5 fractions per week for 5 weeks) administered before surgery. R0-resection rate, pathological complete response (pathCR) rate, and survival (progression-free survival [PFS] and overall survival [OS]) were evaluated as primary endpoints.

RESULTS

Among 33 patients included, 32 patients (97%) received CRT and 26 (78.8%) were resected (R0 resection for all patients resected). Among resected patients, we report pathCR in 23,1% and pathologic major response (tumor regression grade 2 according to Mandard's classification) in 26,9%. With a median follow-up duration of 5.82 years (range, 0.4 to 9.24 years), the estimated median OS for all 33 patients was not reached; 1-, 3-, and 5-year OS rates were 85%, 61%, and 52%, respectively. Among resected patients, those whose histological response was tumor grade regression (TRG) 1-2 had significantly better OS and PFS rates than those with a TRG 3-4-5 response (p=0.019 and p=0.016, respectively).

CONCLUSION

Promising results from trials involving preoperative chemoradiation followed by surgery in gastric cancer need to be further evaluated in a phase III trial.

Nomogram for predicting pathological response to neoadjuvant treatment in patients with locally advanced gastric cancer: Data from a phase III clinical trial

PURPOSE

This study aimed to establish a nomogram using routinely available clinicopathological parameters to predict the pathological response in patients with locally advanced gastric cancer (LAGC) undergoing neoadjuvant treatment.

MATERIALS AND METHODS

We conducted this study based on the ongoing Neo-CRAG trial, a prospective study focused on preoperative treatment in patients with LAGC. A total of 221 patients who underwent surgery following neoadjuvant chemotherapy (nCT) or neoadjuvant chemoradiotherapy (nCRT) at Sun Yat-sen University Cancer Center between June 2013 and July 2022 were included in the analysis. We defined complete or near-complete pathological regression and ypN0 as good response (GR), and determined the prognostic value of GR by Kaplan-Meier survival analysis. Eventually, a nomogram for predicting GR was developed based on statistically identified predictors through multivariate logistic regression analysis and internally validated by the bootstrap method.

RESULTS

GR was confirmed in 54 patients (54/221, 24.4%). Patients who achieved GR had a longer progression-free survival and overall survival. Then, five independent factors, including pretreatment tumor differentiation, clinical T stage, monocyte count, CA724 level, and the use of nCRT, were identified. Based on these predictors, the nomogram was established with an area under the curve (AUC) of 0.777 (95% CI, 0.705-0.850) and a bias-corrected AUC of 0.752.

CONCLUSION

A good pathological response after neoadjuvant treatment was associated with an improved prognosis in LAGC patients. The nomogram we established exhibits a high predictive capability for GR, offering potential value in devising personalized and precise treatment strategies for LAGC patients.

Oncological risk of proximal gastrectomy for proximal advanced gastric cancer after neoadjuvant chemotherapy

PURPOSE

This study assesses the metastasis rate of the key distal lymph nodes (KDLN) that are not routinely dissected in proximal gastrectomy, aiming to explore the oncological safety of proximal gastrectomy for upper gastric cancer who underwent neoadjuvant chemotherapy.

METHODS

We analyzed a cohort of 150 patients with proximal locally advanced gastric cancer (cT3/4 before chemotherapy) from two high-volume cancer centers in China who received preoperative neoadjuvant chemotherapy (NAC) and total gastrectomy with lymph node dissection. Metastasis rate of the KDLN (No.5/6/12a) and the risk factors were analyzed.

RESULTS

Key distal lymph node metastasis was detected in 10% (15/150) of patients, with a metastasis rate of 6% (9/150) in No. 5 lymph nodes, 6.7% (10/150) in No. 6 lymph nodes, and 2.7% (2/75) in No. 12a lymph nodes. The therapeutic value index of KDLN as one entity is 5.8. Tumor length showed no correlation with KDLN metastasis, while tumor regression grade (TRG) emerged as an independent risk factor (OR: 1.47; p-value: 0.04). Of those with TRG3 (no response to NAC), 80% (12/15) was found with KDLN metastasis.

CONCLUSION

For cT3/4 proximal locally advanced gastric cancer patients, the risk of KDLN metastasis remains notably high even after NAC. Therefore, proximal gastrectomy is not recommended; instead, total gastrectomy with thorough distal lymphadenectomy is the preferred surgical approach.

Tumor regression grade combined with post-therapy lymph node status: A novel independent prognostic factor for patients treated with neoadjuvant therapy followed by surgery in locally advanced gastroesophageal junction and gastric carcinoma

BACKGROUND

Tumor regression grade (TRG) is a measure of histopathological response to neoadjuvant therapy (NAT). Post-therapy lymph node (ypN) metastasis was reported as a prognostic factor. However, the evaluation of the treatment effectiveness of NAT has not been well studied. Here, we explored whether TRG combined with ypN status could be a prognostic factor for gastroesophageal junction (GEJ) and gastric cancer (GC). Besides, we aimed at making clear the association of different neoadjuvant regimens with different TRG and ypN status.

METHODS

376 patients with GEJ or GC accepting NAT in Peking University Cancer Hospital were retrospectively collected from January 1, 2003 to June 30, 2021. According to TRG and ypN status, patients were innovatively categorized into four groups: TRG0N0, TRG1-3N0, TRG0-1N+, and TRG2-3N+. We applied Kaplan-Meier method and log-rank test to testify the differences in disease free survival (DFS) and overall survival (OS) among four groups. Univariate and multivariate analyses were performed to examine the relationships between TRG combined with ypN status and prognosis.

RESULTS

We observed significant survival differences among the four groups (p < 0.001, respectively). Median DFS and OS of patients with TRG0N0, TRG1-3N0, and TRG0-1N+ were not reached, whereas these of patients with TRG2-3N+ were 17.37 months (95% CI, 14.14-20.60 months) and 39.97 months (95% CI, 27.05-52.89 months). TRG combined with ypN status was still an independent predictor for both DFS (p < 0.001) and OS (p < 0.001) in multivariate analysis. Chi-squared test showed TRG combined with ypN status was significantly associated with different preoperative treatments (p < 0.001). Patients receiving immunotherapy achieved the highest TRG0N0 rate (31.9%).

CONCLUSION

Our results demonstrate that TRG combined with ypN status is a novel independent predictor of both DFS and OS in resectable, locally advanced GEJ and GC. Neoadjuvant immunotherapy achieved the highest TRG0N0 rate.

Two-photon imaging reveals histopathological changes in the gastric tumor microenvironment induced by neoadjuvant treatment

There is a close association between tumor response and survival in gastric cancer patients after receiving neoadjuvant treatment. An accurate and rapid assessment of therapeutic efficacy would be helpful for subsequent treatments and individual prognosis. At present, pathological examination is the gold standard for evaluating treatment response, however, it requires additional staining and the process is tedious, labor-intensive, as well as time-consuming. Here, we introduce a label-free imaging technique, two-photon imaging, to evaluate histopathological changes induced by pre-operative therapy, with a focus on assessing tumor regression as well as stromal response. Imaging data show that two-photon imaging allows label-free, rapid visualization of various aspects of pathological alterations in tumor microenvironment such as fibrotic reaction, inflammatory cell infiltration, mucinous response, isolated residual tumor cells. Moreover, a semi-automatic image processing approach is developed to extract the collagen morphological features, and statistical results show that there are significant differences in collagen area, length, width, cross-link space between the gastric cancer tissues with and without treatment. With the advent of a portable, miniaturized two-photon imaging device, we have enough reason to believe that this technique will become as an important auxiliary diagnostic tool in assessing neoadjuvant treatment response and thereby tailoring the most appropriate therapy strategies for the patients.

Borrmann Type Predicts Response to Preoperative Therapy in Advanced Gastric Cancer

PURPOSE

The Borrmann classification system is widely used to classify advanced gastric cancer (GC). No studies have focused on the relationship between Borrmann type and response to preoperative therapy.

METHODS

Patients with advanced GC who received preoperative therapy followed by curative-intent gastrectomy from September 2016 through September 2021 were identified. Clinicopathologic characteristics were compared by Borrmann type. Logistic regression models were fit to analyze the relationship between Borrmann type and pCR rate.

RESULTS

Of the 227 patients who underwent gastrectomy during the period studied, 73 had pretreatment endoscopic images available for analysis. We classified the tumors as follows: Borrmann type 1, 4 (6%); type 2, 17 (23%); type 3, 33 (45%); and type 4, 19 (26%). Nine patients (12%) achieved pCR; 6 of these (67%) had type 1/2 GC and 3 (33%) had type 3. Multivariable logistic regression showed that Borrmann type 3/4 was the only independent factor associated with pCR (odds ratio 0.12; p = 0.023), but 2-year overall survival rates did not differ by Borrmann type (p = 0.216).

CONCLUSION

Patients with Borrmann type 3/4 advanced GC have a lower likelihood of achieving pCR after preoperative therapy than those with type 1/2 GC. Determining the Borrmann type preoperatively can guide treatment decision-making.

Pathologic Tumor Regression is Associated With Improved Survival in Pancreatic Cancer

OBJECTIVES

The advent of effective chemotherapy regimens has increased the use of neoadjuvant multiagent chemotherapy in pancreatic cancer. However, the effect of tumor downstaging with neoadjuvant treatment on survival is unclear.

METHODS

Retrospective study included all resected patients with pancreatic adenocarcinoma who underwent neoadjuvant chemotherapy with FOLFIRINOX or gemcitabine/Abraxane. Downstaging was quantified using (1) difference between presenting AJCC clinical and final pathologic stage and (2) College of American Pathologists (CAP) Tumor Regression Grading Schema.

RESULTS

Eighty-seven patients met inclusion criteria. FOLFIRINOX was the most common regimen, 63.2% vs 21.8%. Change in regimen occurred in 15% of patients. Downstaging based on a difference in AJCC stage group occurred in only 4.6%. In contrast, 45.2% were classified as downstaged by the CAP Tumor Regression of 0-2. Downstaging was similar for FOLFIRINOX gemcitabine/Abraxane (64.7 vs 53.6, P = .12) using the CAP criteria. On univariate analysis, treatment regimen (gemcitabine/Abraxane vs FOLFIRINOX, median survival 27 vs 29 mo; HR 1.57, P = .2) had similar survival. Downstaging by the AJCC stage was not associated with improved survival (HR 1.51, P = .4). However, there was a survival benefit for those downstaged by the CAP Tumor Regression Grading Schema, the median survival of 41 mo vs 25 mo; HR 3.05, P = .009. Improved survival 3.32 (1.35-8.16), P = .009) was maintained on multivariate analysis.

CONCLUSION

Survival is significantly improved in those downstaged, as assessed by the CAP Tumor Regression Schema. Downstaging is an important prognostic variable that can help with joint decision making for clinicians and patients.

Comparison of the predictive value of pathological response at primary tumor and lymph node status after neoadjuvant chemotherapy in locally advanced gastric cancer

BACKGROUND

Preoperative chemotherapy has been increasingly used in locally advanced gastric cancer (LAGC). However, the prognostic factors are still insufficient. This study aimed to investigate the prognostic significance of pathological response of the primary tumor to neoadjuvant chemotherapy (NACT) and the lymph node status after NACT.

METHODS

Data from 160 patients with LAGC treated with NACT followed by gastrectomy and met the inclusion criteria between March 2016 and December 2019 were retrospectively reviewed. Pathological evaluation after NACT was based on the grade of pathological response of the primary tumor and the status of lymph node. Survival curves for overall survival (OS) and disease-free survival (DFS) were estimated using the Kaplan-Meier method, and the log-rank test was used to compare survival difference. Univariate and multivariate analyses for prognostic factors were based on the Cox regression.

RESULTS

Among 160 selected cases, 90 had pathological response (PR), while 70 had no pathological response (nPR) to NACT. Smaller tumor size was presented in PR group, which also had lower level of signet ring cell features, compared to nPR group (all p < 0.05). Based on the status of lymph nodes, nodal status (-) group showed smaller tumor size, lower depth of tumor invasion, better differentiated degree, lower level of signet ring cell features, lower rate of lymphatic and venous invasion and less advanced ypTNM stage (all p < 0.05). Survival was equivalent between PR and nPR group (all p > 0.05), while patients with no lymph node metastasis had better DFS than that with lymph node metastasis (HR 0.301, 95% CI 0.194-0.468, p = 0.002). Multivariable Cox regression analysis identified that lymph node status after NACT was an independent prognostic factor associated with survival (OS: hazard ratio 1.756, 95% CI 1.114-3.278, p = 0.029; DFS: hazard ratio 1.901, 95% CI 1.331-3.093, p = 0.012).

CONCLUSION

Lymph node status is a potential independent prognostic factor for LAGC patients treated with NACT and may be more efficient than pathological response in primary tumor.

Tumor Regression Grade and Overall Survival following Gastrectomy with Preoperative Therapy for Gastric Cancer

BACKGROUND

Pre-/perioperative chemotherapy is well-established for management of locoregional gastric cancer (LRGC). The American Joint Committee on Cancer advocates histopathologic assessment of tumor regression grade (TRG) but does not endorse a specific schema. We sought to examine the prognostic value of the recently revised National Comprehensive Cancer Network (NCCN) definition of TRG specifying TRG0 as no disease in primary tumor or lymph nodes.

PATIENTS AND METHODS

Patients with clinical-stage T2+/N+/M0 LRGC receiving preoperative chemotherapy and curative-intent gastrectomy were identified (2000-2020). TRG using the current NCCN definition was retrospectively assigned. Factors associated with TRG were examined using ordinal logistic regression and overall survival (OS) was assessed using the Kaplan-Meier method and Cox regression.

RESULTS

Among 117 patients, the most common chemotherapy regimen was epirubicin, cisplatin, plus fluorouracil or capecitabine (ECF/ECX) (n = 48, 41%), followed by folinic acid, fluorouracil, and oxaliplatin (FOLFOX) (n = 30, 26%), and fluorouracil, leucovorin, oxaliplatin, plus docetaxel (FLOT) (n = 13, 11%). TRG3 was the most common histopathologic response (n = 68, 58%), followed by TRG2 (n = 25, 21%), TRG1 (n = 18, 15%), and, lastly, TRG0 (n = 6, 5.1%). The only preoperative factor independently associated with lower TRG was gastroesophageal junction tumor location (OR 0.24, p = 0.012). Higher TRG was independently associated with worse OS in a stepwise fashion (HR 1.49, p = 0.026). Posttreatment pathologic lymph node status was the strongest prognostic factor (HR 1.93, p = 0.026). Independent prognostic value of TRG and ypT stage could not be shown due to substantial overlap.

CONCLUSIONS

TRG using the contemporary NCCN definition is associated with OS in LRGC. TRG0 is uncommon but with excellent prognosis. ypN status is the strongest prognostic factor and the revised NCCN definition acknowledging this is appropriate.

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.

Prognostic value and clinicopathological correlation of the tumor regression grade in neoadjuvant chemotherapy for gastric adenocarcinoma: a retrospective cohort study

BACKGROUND

Neoadjuvant chemotherapy (NACT) and radical gastrectomy are the gold standard treatments for resectable advanced gastric cancer (GC). However, the prognostic value of the pathological tumor regression grade (TRG) of NACT remains controversial. This retrospective study aimed to investigate the correlation between the TRG after NACT and clinicopathological features as well as its prognostic value in advanced GC.

METHODS

In total, 551 patients with GC who received NACT combined with surgical resection at the Zhejiang Cancer Hospital from April 2004 to December 2019 were included. The demographic characteristics, treatment response, tumor characteristics, treatment regimens, and survival data were reviewed from the medical records of all patients. The Chi-square test was used to analyze the correlation between TRG and clinicopathological factors. Kaplan-Meier univariate analysis and Cox regression multivariate analysis were used to determine the independent risk factors affecting the prognosis of GC patients.

RESULTS

Among the 551 patients with advanced GC who accepted NACT treatment, 14 were determined to be in TRG 0, 98 in TRG 1, 257 in TRG 2, and 182 in TRG 3. Also, TRG was significantly correlated with the cT stage (P=0.015), ypT stage (P<0.001), ypN stage (P<0.001), ypTNM stage (P<0.001), vascular tumor thrombus (P<0.001), Borrmann classification (P=0.042), and lymph node ratio (LNR) (P<0.001). Furthermore, patients who had a good pathological response to NACT had a better prognosis, with a 3-year overall survival (OS) of 70.9% versus 48.8% in patients who had a poor pathological response. We also found that TRG (P=0.042, HR =1.65) was an independent prognostic factor affecting the OS of GC patients.

CONCLUSIONS

TRG plays a significant role in the prognostic value in neoadjuvant chemotherapy for gastric adenocarcinoma. Patients with higher cT stage, higher levels of pre-CA199 and pre-CA125 may have worse pathological response.

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.

Preoperative Chemoradiotherapy for Gastroesophageal Junction Adenocarcinoma Modified by PET/CT: Results of Virtual Planning Study

Background and Objectives: The treatment of gastroesophageal junction (GEJ) adenocarcinoma consists of either perioperative chemotherapy or preoperative chemoradiotherapy. Radiotherapy (RT) in the neoadjuvant setting is associated with a higher probability of resections with negative margins (R0) and better tumor regression rate, which might be enhanced by incrementing RT dose with potential impact on treatment results. This virtual planning study demonstrates the feasibility of increasing the dose to GEJ tumor and involved nodes using PET/CT imaging. Materials and Methods: 16 patients from the chemoradiotherapy arm of the phase II GastroPET study were treated by a prescribed dose of 45.0 Gray (Gy) in 25 fractions. PET/CT was performed before treatment. The prescribed dose was virtually boosted on PET/CT-positive areas to 54.0 Gy by 9 Gy in 5 fractions. Dose-volume histograms (DVH) were compared, and normal tissue complication (NTCP) modeling was performed for both dose schedules. Results: DVHs were exceeded in mean heart dose in one case for 45.0 Gy and two cases for 54.0 Gy, peritoneal space volume criterion V_45Gy < 195 ccm in three cases for 54.0 Gy and V_15Gy < 825 ccm in one case for both dose schedules. The left lung volume of 25 Gy isodose exceeded 10% in most cases for both schedules. The NTCP values for the heart, spine, liver, kidneys and intestines were zero for both schemes. An increase in NTCP value was for lungs (median 3.15% vs. 4.05% for 25 × 1.8 Gy and 25 + 5 × 1.8 Gy, respectively, p = 0.013) and peritoneal space (median values for 25 × 1.8 Gy and 25 + 5 × 1.8 Gy were 3.3% and 14.25%, respectively, p < 0.001). Conclusion: Boosting PET/CT-positive areas in RT of GEJ tumors is feasible, but prospective trials are needed.

Lymph Node Evaluation after Neoadjuvant Chemotherapy for Patients with Gastric Cancer

BACKGROUND

Adequate lymphadenectomy with at least 16 nodes retrieved at the time of gastrectomy is a quality measure recommended to ensure adequate staging. The minimum nodal retrieval recommended after receipt of neoadjuvant chemotherapy (NACT) is less defined.

METHODS

Patients with clinical stages 1 to 3 gastric adenocarcinoma who received NACT and surgical resection were identified from the 2004-2015 National Cancer Database. The optimal nodal harvest number was calculated with Cox spline regression modeling. Cohorts with a nodal harvest higher or lower than this number were 1:1 propensity score-matched. Overall survival (OS) was analyzed using Kaplan-Meier survival estimates.

RESULTS

Among 4337 patients receiving NACT, the optimal minimal nodal harvest at gastrectomy was 23 nodes. Compared with the patients who had fewer than 23 nodes retrieved, the patients with at least 23 nodes examined (n = 1073, 24.7%) were more likely to be female (26.1% vs 22%; p = 0.006) and non-white (29.3% vs 18.5%; p < 0.0001), to have a Charlson-Deyo score of 0 (71.5% vs 66.8%; p = 0.005), and to have undergone resection at an academic facility (67.9% vs 51.5%; p < 0.0001). The patients with at least 23 nodes examined had higher proportions of high-grade tumor (62% vs 57.4%; p = 0.030), pT3 or pT4 tumor (56.3% vs 48.7%; p < 0.0001), body tumor (21.3% vs 12.5%; p < 0.0001), or antrum/pylorus tumor (15.3% vs 11.4%; p < 0.0001). The patients with at least 23 nodes were more likely to have lymph node metastases identified (61% vs 51%; p < 0.0001). After matching, the patients with at least 23 nodes (n = 990) demonstrated an improved 5-year OS (57.9% vs 49%; p = 0.001).

CONCLUSIONS

The extent of lymphadenectomy during gastrectomy for gastric adenocarcinoma should not be reduced after NACT because adequate lymph node retrieval remains important for prognostication.

Development and Validation of a Computed Tomography-Based Radiomics Signature to Predict Response to Neoadjuvant Chemotherapy for Locally Advanced Gastric Cancer

IMPORTANCE

Neoadjuvant therapies have been shown to decrease tumor burden, increase resection rate, and improve the outcomes among patients with locally advanced gastric cancer (GC). However, not all patients are equally responsive; therefore, differentiating potential respondents from nonrespondents is clinically important.

OBJECTIVE

To use pretreatment computed tomography (CT)-pixelated feature-difference extraction techniques to identify diagnostically relevant features that could predict patients' response to neoadjuvant chemotherapy at diagnosis.

DESIGN, SETTING, AND PARTICIPANTS

This multicenter cohort study included patients with locally advanced GC who were treated from January 2010 to July 2017 at 2 hospitals in southern China (training cohort) and 1 hospital in northern China (external validation cohort). Their clinicopathological data, pretreatment CT images, and pathological reports were retrieved and analyzed. Data analysis was conducted from December 2017 to May 2021.

EXPOSURES

All patients underwent 2 to 4 cycles of fluorouracil in combination with a platinum-based neoadjuvant chemotherapy regimen. All gastrectomies were performed according to the Japanese Classification of Gastric Carcinoma (14th edition) guidelines.

MAIN OUTCOMES AND MEASURES

Reliability of clinicopathological and radiomics-based features were assessed with area under receiver operating characteristic curve (AUC) and Mann-Whitney U test.

RESULTS

A total of 323 patients (242 [74.9%] men; median [range] age, 58 [24-82] years) were included in the study, with 250 patients (77.4%) in the training cohort and 73 (22.6%) in the validation cohort. The baseline pretreatment characteristics of the training and validation cohorts were well-balanced. The number of respondents in the training and validation cohort was 122 (48.8%) and 40 (54.8%), respectively, and the number of nonrespondents was 128 (51.2%) and 33 (45.2%), respectively. No clinicopathological variables were significantly associated with treatment response. Using radiomics, 20 low-intercorrelated features from a total of 7477 features were used to construct a radiomics signature that demonstrated significant association with treatment response. Good discrimination performance of the radiomics signature for predicting treatment response in the training (AUC, 0.736; 95% CI, 0.675-0.798) and external validation (AUC, 0.679; 95% CI, 0.554-0.803) cohorts was observed. Decision curve analysis confirmed the clinical utility of the radiomics signature.

CONCLUSIONS AND RELEVANCE

In this study, the proposed radiomics signature showed potential as a clinical aid for predicting the response of patients with locally advanced GC before treatment, thereby allowing timely planning for effective treatments for potential nonrespondents.

Treatment Switch in Poor Responders with Locally Advanced Gastric Cancer After Neoadjuvant Chemotherapy

Background

Among locally advanced gastric cancer (LAGC) patients, poor response to initial neoadjuvant chemotherapy (NAC) is associated with unfavorable outcomes; however, changing the postoperative therapy regimen in this group of patients is unclear. We compared the poor responders who continued the original protocols with that of patients who switched treatment after NAC plus D2 gastrectomy.

Methods

Our study included LAGC patients who achieved tumor regression grade 3 according to the American Joint Committee on Cancer/College of American Pathologists system, after NAC, between December 2006 and December 2017 at our institution. Outcomes were overall survival (OS), progression-free survival (PFS), and adverse events during postoperative treatment. The propensity score matching method was used to match patients.

Results

Overall, 160 patients were enrolled in the final analysis set, including 21 switched cases and 139 non-switched cases. A 1:2 matched cohort (21 switching vs. 42 non-switching) was generated to eliminate all confounding factors. No statistical differences were observed in OS and PFS, either in the whole patients (OS: log-rank p = 0.804; PFS: log-rank p = 0.943) or in the matched cohort (OS: log-rank p = 0.907; PFS: log-rank p = 0.670) between the two groups. Patients with changed regimens had a significantly higher rate of peripheral neurotoxicity (p = 0.045). Contrarily, a lower rate of overall adverse events was observed in the non-switching group with marginal significance (p = 0.069).

Conclusion

Adjusting to a non-cross-resistant regimen only by post-NAC pathological evaluation may not be sufficient for designing an effective treatment route for LAGC poor responders. Treatment change required a more scrutinized clinical track, which involved a multifaceted assessment.

Supplementary Information

The online version contains supplementary material available at 10.1245/s10434-021-10087-x.

Prognostic value of pathological tumor regression grade in locally advanced gastric cancer: New perspectives from a single-center experience

BACKGROUND AND OBJECTIVE

Perioperative chemotherapy (PC) with radical surgery represents the gold standard of treatment for resectable advanced gastric cancer (GC). The prognostic value of pathological tumor regression grade (TRG) induced by neoadjuvant chemotherapy (NACT) is not clearly established. This study aimed to investigate the correlation between TRG and survival in GC.

METHODS

Patients affected by advanced GC undergoing PC and radical surgery were considered. TRG was assessed for each patient according to Becker's grading system. The correlation between TRG and survival was investigated.

RESULTS

One-hundred patients were selected; 25 showed a good response (GR) (TRG 1a/1b), while 75 had a poor response (PR) (TRG 2/3) to NACT. GR patients showed better disease-free survival (DFS) (52 vs. 19 months, p < .001) and disease-specific survival (DSS) (57 vs. 25 months, p < .0001) when compared to PR patients. On univariate analysis, TRG, lymph node ratio (LNR), tumor size, grading, and post-neoadjuvant therapy TNM stage were significantly correlated with survival. On multivariate analysis, TRG, LNR and tumor size were independent prognostic factors for DFS and DSS.

CONCLUSIONS

TRG, LNR, and tumor size are independent prognostic factors for DFS and DSS in patients with advanced GC undergoing NACT.

Nomogram for Predicting Survival in Advanced Gastric Cancer after Neoadjuvant Chemotherapy and Radical Surgery

BACKGROUND

Neoadjuvant chemotherapy (NAC) with subsequent radical surgery has become a popular treatment modality for advanced gastric cancer (AGC) worldwide. However, the survival benefit is still controversial, and prognostic factors remain undetermined.

AIM

To identify clinical parameters that are associated with the survival of AGC patients after NAC and radical surgery and to establish a nomogram integrating multiple factors to predict survival.

METHODS

We reviewed the medical profiles of 215 AGC patients who received NAC and radical resection, and clinical parameters concerning NAC, surgery, pathological findings, and adjuvant chemotherapy were analyzed using a Cox regression model to determine their impact on survival. Based on these factors, a nomogram was developed and validated.

RESULTS

The overall 1-year and 3-year survival rates were 85.8% and 55.6%, respectively. Younger age (<60 years old), increased examined lymph nodes (exLNs), successful R0 resection, the achievement of pathological complete response (pCR), and acceptance of adjuvant chemotherapy were positive predictors of survival. The C-index of the established nomogram was 0.785. The area under receiver operating curve (ROC) at 1/3 years of prediction was 0.694/0.736, respectively. The model showed an ideal calibration following internal bootstrap validation.

CONCLUSION

A nomogram predicting survival after NAC and surgery was established. Since this nomogram exhibited satisfactory and stable predictive power, it can be inferred that this is a practical tool for predicting AGC patient survival after NAC and radical surgery.