Characteristics and Survival of Gastric Cancer Patients with Pathologic Complete Response to Preoperative Therapy

Characterizing Patients with ypT0N1 Gastric Adenocarcinoma Within the AJCC Staging System

INTRODUCTION

The standard of care for gastric cancer in the United States involves perioperative chemotherapy. While most post-therapy pathologic staging results are concordant (i.e. ypT+N+ or ypT0N0), patients occasionally display discordant results, such as ypT0N1. Herein, we characterized the survival of patients with ypT0N1 staging to better determine their categorization within the American Joint committee on Cancer (AJCC) staging system.

METHODS

Using the National Cancer Database (NCDB), we queried all patients diagnosed with gastric adenocarcinoma from 2004 to 2021 who received neoadjuvant chemotherapy. Patients were stratified by their ypTNM stage: (1) ypT0N0; (2) ypT+N0; (3) ypT+N1; and (4) ypT0N1. Multivariable Cox proportional hazard regression was used to assess 5- and 10-year survival between ypTNM stages.

RESULTS

A total of 28,985 patients received neoadjuvant chemotherapy, of whom 2378 (8.2%) had ypT0N0, 9402 (32.4%) had ypT+N0, 5339 (18.4%) had ypT+N1, and 318 (1.1%) had ypT0N1 staging. Overall, patients had a median age of 64 years, with the majority being male (74.9%) or White (82.2%). Additionally, 50.2% received care from an academic center, and 53.3% received neoadjuvant chemotherapy and radiotherapy. On multivariable analysis, patients with ypT0N1 had a 105% higher risk for mortality within 5 years (adjusted hazards ratio [aHR] 2.05, 95% confidence interval [CI] 1.69-2.50) and 86% increased risk within 10 years (aHR 1.86, 95% CI 1.54-2.23) when compared with ypT0N0.

CONCLUSION

Patients with stage ypT0N1 disease have worse 5- and 10-year outcomes than those with node-negative disease. Thus, their survival pattern most closely matches patients with ypstage IIB and III disease.

Impact of pCR after neoadjuvant chemotherapy and radical D2 dissection in locally advanced gastric cancers: Analysis of 1001 cases

BACKGROUND

Advances in perioperative chemotherapy have improved outcomes in patients with gastric cancers (GC). This strategy leads to tumour downstaging and may result in a pathologic complete response (pCR). The study aimed to evaluate the predictors of pCR and determine the impact of pCR on long-term survival.

METHODS

At the Department of Gastrointestinal and HPB Oncology at the Tata Memorial Centre, Mumbai, 1001 consecutive patients with locally advanced GCs undergoing radical resection following neoadjuvant chemotherapy from January 2005 to June 2022 were included.

RESULTS

At a median follow-up of 61 months, the median OS was 53 months with a 5-year OS of 46.8 %. Ninety-five patients (9.49 %) realized pCR. Non-signet and well-differentiated histology were associated with pCR. pCR was significantly associated with improved OS, 5-year OS 79.2 % vs 43.2 % (HR 0.30, p < 0.001). On multivariable analysis, the realization of pCR and completion of adjuvant chemotherapy had superior OS. Whereas, signet-ring histology, linitis-like tumours, and high lymph node ratio had adverse outcomes.

CONCLUSION

Tumour grade and signet-ring histology predict achievement of pCR in locally advanced GCs after neoadjuvant chemotherapy. Patients with pCR have significantly improved survival. Future neoadjuvant strategies should focus on enhancing pCR rates to improve overall outcomes.

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.

Changes in Oncological Surgical Principles Driven by Advances in Preoperative Treatments

From a surgical point of view, the development of preoperative oncological treatment has had a profound effect on the surgical treatment trends of cancer as well as on the outcomes of cancer patients. Consequently, these changes have challenged formerly entrenched oncological surgical principles. In our short report, we aimed to summarize the main shifts regarding the surgical principles of cancer treatment due to the development of preoperative oncological therapy in recent years. As a result of successful preoperative treatment, surgeons may perform less radical surgeries, the required free resection margin has been narrowed down to a few millimeters in dimension and preoperative treatment is justified in both definitely resectable tumors and in oligometastatic tumors as well. For prognosis assessment, the post-preoperative oncological treatment stage is now considered decisive, rather than the pretreatment stage as previously thought. Other changes include the introduction of the watch and wait strategy and the reverse order of treatment of the primary tumor and metastasis. Observing the continuously improving outcomes of cancer patients and the developments in oncological treatment modalities, a further expansion of the indication of preoperative treatments is to be expected.

T1 Gastric Cancer is Associated With a High Incidence of Regional Lymph Node Metastases

INTRODUCTION

Early stage gastric cancer, particularly T1 disease, is associated with high recurrence-free and overall survival rates following resection with curative intent. However, rare cases of T1 gastric cancer have nodal metastasis and this is associated with poor outcomes.

METHODS

Data from gastric cancer patients treated with surgical resection and D2 lymph node (LN) dissection at a single tertiary care institution from 2010 to 2020 were analyzed. Patients with early stage (T1) tumors were assessed in detail to identify variables associated with regional LN metastasis including histologic differentiation, signet ring cells, demographics, smoking history, neoadjuvant therapy, and clinical staging by endoscopic ultrasound (EUS). We used standard statistical techniques including Mann-Whitney U and Chi-squared tests.

RESULTS

Of 426 patients undergoing surgery for gastric cancer, 34% (n = 146) were diagnosed with T1 disease on surgical pathology. Among 146 T1 (T1a, T1b) gastric cancers, 24 patients [(17%) T1a (n = 4), T1b (n = 20)] had histologically confirmed regional LN metastases. The age at diagnosis ranged between 19 and 91 y and 54.8% were male. Prior smoking status was not associated with nodal positivity (P = 0.650). Of the 24 patients with positive LN on final pathology, seven patients received neoadjuvant chemotherapy. EUS was performed on 98 (67%) of the 146 T1 patients. Of these patients, 12 (13.2%) had positive LN on final pathology; however, none (0/12) were detected on preoperative EUS. There was no association between node status on EUS and node status on final pathology (P = 0.113). The sensitivity of EUS for N status was 0%, specificity was 84.4%, negative predictive value was 82.2% and positive predictive value was 0%. Signet ring cells were identified in 42% of node negative T1 tumors and 64% of node positive T1 tumors (P = 0.063). For LN positive cases on surgical pathology, 37.5% had poor differentiation, 42% had lymphovascular invasion, and regional nodal metastases were associated with increasing T stage (P = 0.003).

CONCLUSIONS

T1 gastric cancer is associated with a substantial risk (17%) of regional LN metastasis, when pathologically staged following surgical resection and D2 lymphadenectomy. Clinically staged N+ disease by EUS was not significantly associated with pathologically staged N+ disease in these patients.

Hyperthermic intraperitoneal chemotherapy (HIPEC) as adjuvant and therapeutic options for patients with advanced gastric cancer at high risk of recurrence or established peritoneal metastases: a single-centre experience

Peritoneal metastases from gastric cancer (PM-GC) have a detrimental prognostic impact on survival and there is a lack of consensus regarding treatment. Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) may offer a chance for prolonged survival as compared to standard chemotherapy. This study aims to present our experience in the management of GC with CRS and HIPEC. This is a single-centre retrospective study. Patients were divided into two groups: patients with GC at high risk for developing PM-GC (adjuvant HIPEC group) and patients with PM-GC or positive peritoneal cytology (therapeutic CRS and HIPEC group). Overall survival (OS) and disease-free survival (DFS) were considered as outcome measures. A total of 41 patients with a GC primary received surgery and HIPEC: 14 patients (34.1%) were in the adjuvant HIPEC group, while 27 patients (65.9%) were in the therapeutic CRS and HIPEC group. In the adjuvant HIPEC group, the 1- and 3-year OS were 85.7% and 71.4%, while 1- and 3-year DFS were 71.4% and 64.3%, respectively. In the therapeutic CRS and HIPEC group, OS was 60.3% and 35.1% at 1 and 3 years, whereas 1- and 3-year DFS were 38% and 32.6%, respectively. Univariate survival analysis of patients in the therapeutic CRS and HIPEC group showed that the presence of lymph node metastasis and signet ring cell histology predicted worse OS, while PCI > 12 and lymph node metastasis were associated with decreased DFS. Treatment of highly selected patients with GC at high risk of peritoneal recurrence or established PM with CRS and HIPEC showed satisfactory results in terms of OS and DFS.

Comparison of response evaluation criteria in solid tumors and tumor regression grade in evaluating the effect of preoperative systemic therapy of gastric cancer

BACKGROUND

Both Response Evaluation Criteria in Solid Tumors (RECIST) and tumor regression grade (TRG) play key roles in evaluating tumor response. We analyzed the consistency of TRG and RECIST 1.1 for gastric cancer (GC) patients and compared their prognostic values.

METHODS

Patients with GC who received preoperative chemotherapy or chemoimmunotherapy and had records of TRG from December 2013 to October 2021 were enrolled retrospectively. TRG 0-1 and 2-3 are considered as corresponding to complete response (CR)/partial response (PR) and stable disease (SD)/progress disease (PD) in RECIST 1.1, respectively. The primary endpoints were disease-free survival (DFS) and overall survival (OS). The consistency of RECIST and TRG was examined by kappa statistics. Survival analysis was performed using the Kaplan Meier method.

RESULT

One hundred fifty seven GC patients were enrolled, including 125 with preoperative chemotherapy and 32 with chemoimmunotherapy. Among them, 56 patients had measurable lesions. Only 19.6% (11/56) of the patients had consistent results between RECIST 1.1 and TRG. TRG was correlated with both OS and DFS (P = 0.02 and 0.03, respectively) while response according to RECIST1.1 was not (P = 0.86 and 0.23, respectively). The median DFS had not reached in the TRG 0-1 group and was 16.13 months in TRG 2-3 group. TRG 2-3 was associated with young age and peritoneal or liver metastasis. Besides, preoperative chemoimmunotherapy had a significantly higher pCR rate than chemotherapy alone (34.4% vs 8.0%, P < 0.001).

CONCLUSION

TRG was in poor agreement with RECIST 1.1. TRG was better than RECIST 1.1 in predicting DFS and OS for GC patients who received preoperative therapy.

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.

Understanding the association between clinical staging accuracy, treatment response, and survival among gastric cancer patients through Bayesian analysis

BACKGROUND

Neoadjuvant therapy (NAT) improves survival among patients with locally advanced gastric cancer (GC), but it remains unclear whether its benefit is contingent on treatment response.

METHODS

This is a national cohort study of stage Ib-III GC patients in the National Cancer Data Base (2006-2015) treated with upfront resection or NAT followed by surgery. Bayesian analysis was used for NAT patients to ascertain staging concordance and to account for down-staging. We used multivariable Cox regression to evaluate the association between staging concordance, treatment, response to NAT, and survival.

RESULTS

The cohort included 13 340 patients treated at 1124 hospitals. Staging concordance ranged from 86.1% for cT3-4N+ to 34.7% for cT2N0 patients. Relative to accurately staged patients treated with upfront surgery, NAT was associated with a decreased risk of death if there was disease down-staging among those with cT1-2N+ (hazard ratio [HR]: 0.43 [0.30-0.61]), cT3-4N0 (HR: 0.69 [0.54-0.88]), and cT3-4N+ (HR: 0.51 [0.48-0.58]) tumors, and in the absence of down-staging among cT3-4N+ patients (HR: 0.83 [0.74-0.92]). Conversely, NAT without down-staging increased the risk of death among those with intermediate-stage disease.

CONCLUSIONS

NAT is associated with improved survival for GC, but it seems to be contingent on treatment response among patients with intermediate-stage disease.

ENDOSCOPIC CHARACTERISTICS OF PATIENTS WITH COMPLETE PATHOLOGICAL RESPONSE AFTER NEOADJUVANT CHEMOTHERAPY FOR GASTRIC AND ESOPHAGOGASTRIC JUNCTION ADENOCARCINOMAS

Background:

Gastric and esophagogastric junction adenocarcinoma are responsible for approximately 13.5% of cancer-related deaths. Given the fact that these tumors are not typically detected until they are already in the advanced stages, neoadjuvancy plays a fundamental role in improving long-term survival. Identification of those with complete pathological response (pCR) after neoadjuvant chemotherapy (NAC) is a major challenge, with effects on organ preservation, extent of resection, and additional surgery. There is little or no information in the literature about which endoscopic signs should be evaluated after NAC, or even when such re-evaluation should occur.

Aim:

To describe the endoscopic aspects of patients with gastric and esophagogastric junction adenocarcinomas who underwent NAC and achieved pCR, and to determine the accuracy of esophagogastroduodenoscopy (EGD) in predicting the pCR.

Methods:

A survey was conducted of the medical records of patients with these tumors who were submitted to gastrectomy after NAC, with anatomopathological result of pCR.

Results:

Twenty-nine patients were identified who achieved pCR after NAC within the study period. Endoscopic responses were used to classify patients into two groups: G1-endoscopic findings consistent with pCR and G2-endoscopic findings not consistent with pCR. Endoscopic evaluation in G1 was present in an equal percentage (47.4%; p=0.28) in Borrmann classification II and III. In this group, the predominance was in the gastric body (57.9%; p=0.14), intestinal subtype with 42.1% (p=0.75), undifferentiated degree, 62.5% (p=0.78), Herb+ in 73.3% (p=0.68). The most significant finding, however, was that the time interval between NAC and EGD was longer for G1 than G2 (24.4 vs. 10.2 days, p=0.008).

Conclusion:

EGD after NAC seems to be a useful tool for predicting pCR, and it may be possible to use it to create a reliable response classification. In addition, the time interval between NAC and EGD appears to significantly influence the predictive power of endoscopy for pCR.

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.

Shifting sands: the role of radiotherapy for patients with gastric and gastroesophageal adenocarcinoma

Gastric adenocarcinoma, a leading cause of cancer-related mortality worldwide, is treated primarily with surgical resection in the non-metastatic setting. However, the optimal role and sequencing of adjunctive therapies, including radiotherapy (RT) as well as systemic therapy, remains unclear. A complex milieu of trials spanning several decades has evaluated different treatment strategies for gastric cancer, including the role of RT. In this review, we summarize the trial-level evidence for the diverse gastric cancer treatment paradigms. Despite initial success, postoperative RT has not shown a clear benefit in modern prospective studies in the setting of more aggressive surgical nodal dissection. On the other hand, the role of preoperative RT in optimizing oncologic outcomes for gastric cancer patients remains relatively under-explored; ongoing trials assessing preoperative RT aim to illuminate the optimal treatment strategy for non-metastatic gastric cancer patients.

Role of CT in the prediction of pathological complete response in gastric cancer after neoadjuvant chemotherapy

OBJECTIVE

To explore which computed tomography (CT) features can predict pathological complete response (pCR) (ypT0N0) after neoadjuvant chemotherapy (NAC) in patients with gastric adenocarcinoma (GC).

MATERIALS AND METHODS

This study reviewed an institutional database of patients who underwent resection of GC after NAC and identified patients with pCR from January 2010 to December 2013. The correlations between pre-chemotherapy and post-chemotherapy CT features and pCR were analyzed.

RESULTS

Eleven of 199 patients with GC who achieved ypT0N0 status after NAC were classified as the pCR group in this study. After matching pCR (n = 11) and non-pCR patients (n = 44) in the ratio of 1:4, a total of 55 cases were analyzed. The binary logistic regression analysis showed that the post-chemotherapy short diameter of the largest lymph node and tumor thickness ratio reduction were independent predictors of pCR, with an area under the curve (AUC) of 0.94 on the receiver operating characteristic (ROC) curve analysis.

CONCLUSION

Two CT features, including the short diameter of the largest lymph node post-chemotherapy and tumor thickness ratio reduction, are good predictors of pCR after NAC in patients with GC.

The Prognostic Value of Postoperative Lymph Node Ratio in Gastric Adenocarcinoma Patients Treated With Neoadjuvant Chemotherapy

Objective

In this study, we aimed to investigate the prognostic value of postoperative lymph node ratio (LNR)in locally advanced gastric cancer (GC) patients receiving neoadjuvant chemotherapy (NACT).

Methods

LNR was calculated as the ratio of positive LNs to the total LNs removed. The receiver operating characteristic (ROC) curve was plotted to estimate the cut-off value of LNR for recurrence. The area under the curve of LNR was 0.714 (95% CI: 0.604-0.825, p<0.001) with 60% sensitivity and >0.255 with 76% specificity. Patients were grouped as group I (≤0.255) and group II (>0.255).

Results

In this study, 157 GC patients were included (39.5% female and 60.5% male). Of the patients, 97 (61.8%) were in group I and 60 (38.2%) were in group II. Disease‑free survival (DFS) was not reached in group I, and it was 16 months in group II (p<0.001). Overall survival (OS) was 58 months in group I and 28 months in group II (p>0.001). In multivariate analysis, lymphovascular invasion, neoadjuvant response, adjuvant treatment, and LNR were found to be the factors associated with DFS and OS (p<0.05).

Conclusion

In our study, it was observed that LNR can predict survival rates better than LN staging.

Towards Personalization in the Curative Treatment of Gastric Cancer

Gastric cancer is the fifth most common cancer worldwide and has a high mortality rate. In the last decades, treatment strategy has shifted from an exclusive surgical approach to a multidisciplinary strategy. Treatment options for patients with resectable gastric cancer as recommended by different worldwide guidelines, include perioperative chemotherapy, pre- or postoperative chemoradiotherapy and postoperative chemotherapy. Although gastric cancer is a heterogeneous disease with respect to patient-, tumor-, and molecular characteristics, the current standard of care is still according to a one-size-fits-all approach. In this review, we discuss the background of the different treatment strategies in resectable gastric cancer including the current standard, the specific role of radiotherapy, and describe the current areas of research and potential strategies for personalization of therapy.

Preoperative Therapy Regimen Influences the Incidence and Implication of Nodal Downstaging in Patients with Gastric Cancer

Purpose

Nodal downstaging after preoperative therapy for gastric cancer has been shown to impart excellent prognosis, but this has not been validated in a national cohort. The role of neoadjuvant chemoradiation (NACR) in nodal downstaging remains unclear when compared with that of neoadjuvant chemotherapy alone (NAC). Furthermore, it is unknown whether the prognostic implications of nodal downstaging differ by preoperative regimen.

Materials and Methods

Using the National Cancer Database, overall survival (OS) duration was compared among natural N0 (cN0/ypN0), downstaged N0 (cN+/ypN0), and node-positive (ypN+) gastric cancer patients treated with NACR or NAC. Factors associated with nodal downstaging were examined in a propensity score-matched cohort of cN+ patients, matched 1:1 by receipt of NACR or NAC.

Results

Of 7,426 patients (natural N0 [n=1,858, 25.4%], downstaged N0 [n=1,813, 24.4%], node-positive [n=3,755, 50.4%]), 58.2% received NACR, and 41.9% received NAC. The median OS durations of downstaged N0 (5.1 years) and natural N0 (5.6 years) patients were similar to one another and longer than that of node-positive patients (2.1 years) (P<0.001). In the matched cohort of cN+ patients, more recent diagnosis (2010–2015 vs. 2004–2009) (odds ratio [OR], 2.57; P<0.001) and NACR (OR, 2.02; P<0.001) were independently associated with nodal downstaging. The 5-year OS rate of downstaged N0 patients was significantly lower after NACR (46.4%) than after NAC (57.7%) (P=0.003).

Conclusions

Downstaged N0 patients have the same prognosis as natural N0 patients. Nodal downstaging occurred more frequently after NACR; however, the survival benefit of nodal downstaging after NACR may be less than that when such is achieved by NAC.

Which is the optimal management for locally advanced gastric cancer patients with TRG 0 and 1 after R0 resection?

Background

Neoadjuvant chemotherapy (NAC) followed by surgery currently offers promise as a strategy for patients with locally advanced gastric cancer (GC). However, there is limited evidence to guide treatment for TRG 0 and 1 patients with locally advanced GC after R0 resection. This study set out to explore the optimal management for TRG 0 and 1 patients with locally advanced GC after R0 resection.

Methods

The retrospective data of 154 TRG 0 and 1 patients with locally advanced GC following R0 resection who were treated between January 2012 and December 2018 were collected and analyzed. The Kaplan-Meier method was used to estimate the survival rate. Multivariate analysis was performed using the Cox proportional hazards model.

Results

The median follow-up was 34.1 (range, 6.6–90.9) months. Six patients (3.9%) were lost during follow-up. Of the 27 patients who experienced relapse, 12 died, including 2 patients who died of non-neoplastic causes. The 5-year recurrence-free survival (RFS) and 5-year overall survival (OS) were 71.6% (95% CI: 68.5–79.6) and 82.9% (95% CI: 76.9–86.1) for the whole cohort, respectively. Univariate analysis revealed that patients with carcinoembryonic antigen (CEA) <5.0 ng/ml after NAC (77.7% vs. 20.1%, P<0.001), distal gastrectomy (91.7% vs. 67.5%, P=0.046) had higher 5-year RFS. Meanwhile, combined resection (55.6% vs. 73.1%, P=0.042), major complications (42.7% vs. 80.50%, P<0.001), and lymph node metastasis (ypN+) (52.0% vs. 83.7%, P<0.001) had lower 5-year RFS. The multivariate analysis showed that CEA level after NAC (HR =2.876, 95% CI: 1.051–7.872, P=0.040), major complications (HR =2.432, 95% CI: 1.062–5.567, P=0.035), and lymph node metastasis (ypN+) (HR =3.183, 95% CI: 1.242–8.161, P=0.016) were independent prognostic factors.

Conclusions

TRG 0 and 1 patients with local GC after R0 resection following NAC had a good prognosis, especially patients with CEA <5.0 ng/mL after NAC, and those without major complications or lymph node metastasis. Monotherapy or no chemotherapy may offer options for treating TRG 0 and 1 patients without adverse prognostic factors.

Prognostic Significance of Complete Pathologic Response Obtained with Chemotherapy Versus Chemoradiotherapy in Gastric Cancer

BACKGROUND

Few studies have compared the survival advantage of complete pathologic response (cPR) achieved through neoadjuvant chemotherapy (nCT) versus neoadjuvant chemoradiotherapy (nCRT) in gastric adenocarcinoma. Our study utilizes a large national cancer database to address this question.

PATIENTS AND METHODS

This is a retrospective review of patients with clinical stage I to III gastric adenocarcinoma from 2004 to 2013 who received nCT or nCRT. Patients who achieved cPR were selected. Associations were evaluated using Mann-Whitney U and Fisher's exact tests. Survival information was summarized using standard Kaplan-Meier methods, where estimates of the median and 5-year survival rates were estimated with 95% confidence intervals.

RESULTS

A total of 413 patients who had cPR were identified. Eighty-four patients received nCT and 329 patients received nCRT. Patients in the nCRT group had higher clinical stage (88.4% vs. 75.0%) and more proximal location of tumors (95.4% vs. 45.2%). The nCT group (n = 84) had a 94% 5-year survival rate, while the nCRT group's (n = 329) rate was 60% (p < 0.001). On Cox regression modeling using a propensity-weighted approach, nCT treatment was an independent predictor of improved overall survival (nCRT vs. nCT; HR 10.44, p < 0.001).

CONCLUSIONS

The use of nCT leads to a significant increase in overall survival in patients when compared with nCRT for those who achieved cPR in gastric adenocarcinoma. While this study is limited in identifying the cause for this difference in overall survival, this important finding nonetheless requires further investigation and should be considered in the development of future gastric cancer trials.

Impact of tumor regression grade on recurrence after preoperative chemoradiation and gastrectomy for gastric cancer

BACKGROUND AND OBJECTIVES

It is unknown whether the degree of response to preoperative therapy correlates with locoregional recurrence (LR) or distant recurrence (DR) after resection of gastric cancer.

METHODS

Patients who underwent resection of gastric adenocarcinoma following chemotherapy and chemoradiation (1995-2015) were reviewed. The tumor regression grade (TRG) was defined by the percentage of viable tumor cells in the specimen (TRG0 = 0%; TRG1 = 1%-2%; TRG2 = 3%-50%; TRG3 ≥ 50%). The relationships among TRG, recurrence-free survival (RFS), LR, and DR were examined.

RESULTS

Two hundred forty-seven patients met the inclusion criteria (TRG0, 52 [21%]; TRG1, 49 [20%]; TRG2, 98 [40%]; TRG3, 48 [19%]). LR and DR occurred in 6.1% and 32.0% of patients, respectively. No patient with TRG0 experienced LR. R1 resection (6%-15%) and LR (6%-8%) rates were similar among TRG1-3 patients. R1 resection was associated with LR (hazard ratio [HR], 17.85; P < .001). ypN status (HR, 2.44; P = .004) and linitis plastica (HR, 2.90; P < .001) were associated with DR. TRG was not independently associated with RFS, LR, or DR.

CONCLUSIONS

TRG0 imparted excellent local control. However, TRG1-3 patients had similar R1 resection rates and therefore similar LR. DR is associated with ypN status and linitis plastica, not TRG.

Preoperative Chemoradiation Versus Chemotherapy in Gastroesophageal Junction Adenocarcinoma

BACKGROUND

The incidence of lower esophageal and gastroesophageal junction adenocarcinoma has sharply increased over the past several decades and is a serious public health problem. Preoperative therapy with either chemotherapy or chemoradiation is recommended, but the optimal regimen is unknown. We used the National Cancer Database and propensity score matching to investigate whether preoperative chemoradiation therapy offers an advantage over chemotherapy alone for patients with these tumors.

METHODS

From the National Cancer Database esophageal and gastric dataset, we selected patients with either lower esophageal or gastric cardia adenocarcinomas who had undergone definitive resection after chemotherapy or chemoradiation. We used propensity score matching to balance groups based on the preoperative treatment they received. We then used conditional multivariable logistic regression and Cox proportional hazard models to examine the association between preoperative therapy regimen and pathological response, overall survival (OS), and postoperative outcomes.

RESULTS

Our study included 13,783 patients; 12,129 (89.0%) had received preoperative chemoradiation. Propensity score matching created 1650 pairs. Patients receiving chemoradiation were 2.7 (95% confidence interval, 1.29-3.23) times more likely to achieve complete response in the primary tumor than were those receiving chemotherapy alone; however, chemoradiation was not associated with improved OS (hazard ratio, 1.01; 95% confidence interval, 0.91-1.12). Short-term outcomes (length of stay, mortality, and readmissions) were similar between the 2 groups.

CONCLUSIONS

Preoperative chemoradiation was associated with a higher complete response rate in the primary tumor but not with improved OS in lower esophageal and gastroesophageal junction adenocarcinoma.