Is retrieval of at least 15 lymph nodes sufficient recommendation in early gastric cancer?

Impact of Removal of Lymph Nodes on Survival in Stage I-III Gastric Signet-Ring Cell Cancer: The More, the Better?

BACKGROUND

There is an ongoing debate over the prognostic value of the number of examined lymph nodes (ELNs) in cases of gastric signet-ring cell cancer (GSRCC). In this study, we sought to evaluate the correlation between the number of ELNs and the prognosis of GSRCC and identify the optimal number of ELNs.

METHODS

A total of 1020 patients diagnosed with GSRCC between 2011 and 2018 in the National Cancer Center database were identified. Clinicopathological characteristics were retrospectively collected, and optimal cutoff values of ELNs were calculated by using X-tile. The impact of different ELNs on overall survival (OS) was compared by using Kaplan-Meier curves. We used univariate and multivariate Cox and subgroup analyses to explore the relationship between ELNs and OS. Furthermore, nonlinear correlations were investigated by using restricted cubic splines (RCSs).

RESULTS

X-tile showed that the optimal cutoff value of ELNs was 22. The 5-year OS was higher for patients with ELNs > 22 (vs. ELNs ≤ 22, 66.9% vs. 74.9%, P = 0.026). Multivariate Cox analyses showed that high ELNs were associated with superior OS (hazard ratio = 0.56, 95% confidence interval 0.43-0.74, P < 0.001). In subgroup analyses, the significant association between tumor size > 4 cm, and TNM III stage was still observed. The RCS regression model showed a U-shaped dose-response nonlinear relationship between ELNs and OS; the inflection point, as well as the lowest risk points, corresponded to 44-52 ELNs.

CONCLUSIONS

A U-shaped, nonlinear correlation with inflection points of 44-52 ELNs between ELNs and prognosis in GSRCC was identified.

Evaluation of Nationwide Trends in Nodal Sampling Guideline Adherence for Gastric Cancer: 2005-2017

INTRODUCTION

Surgical resection is the primary curative treatment for localized gastric cancer. A multitude of research supports surgical nodal sampling guidelines. Though there are known disparities in adherence to nodal sampling, it is unclear how hospital program-level disparities have changed over time. The purpose of this study is to evaluate trends in program-level disparities in adherence to gastric cancer nodal sampling guidelines.

METHODS

Patients who underwent resection of gastric cancer from 2005 to 2017 were identified in the National Cancer Database. Patients treated at academic programs were compared to those treated at nonacademic programs, and rates and trends of adherence to nodal sampling guidelines (defined as ≥15 lymph nodes) were determined. Adjusted multivariable analysis was used to determine likelihood of nodal sampling adherence while controlling for sociodemographic, clinical, hospital, and travel distance characteristics.

RESULTS

A total of 55,421 patients were included with 27,201 (49.1%) of patients meeting adherence criteria for lymph node sampling. Academic programs treated 44.4% of the total cohort. Overall, lymph node sampling criteria were met in 59.2% of patients treated at high-volume academic programs and 37.0% of patients treated at low-volume nonacademic programs (incidence rate ratios 0.67, 95% confidence interval 0.63-0.72 versus high-volume academic programs). Adherence rates improved from 2005 to 2017 for both low-volume nonacademic programs (27.8% in 2005 to 50.1% in 2017) and high-volume academic programs (46.0% in 2005 to 69.8% in 2017, P < 0.001).

CONCLUSIONS

Though adherence rates have improved from 2005 to 2017, high-volume academic programs were more likely to adhere to lymph node sampling guidelines for gastric cancer.

Predictive value of 18F-FDG PET/CT multi-metabolic parameters and tumor metabolic heterogeneity in the prognosis of gastric cancer

OBJECTIVE

We aimed to investigate the predictive value of pre-treatment 18F-FDG PET/CT multi-metabolic parameters and tumor metabolic heterogeneity for gastric cancer prognosis.

METHODS

Seventy-one patients with gastric cancer were included. All patients underwent 18F-FDG PET/CT whole-body scans prior to treatment and had pathologically confirmed gastric adenocarcinomas. Each metabolic parameter, including SUVmax, SUVmean, MTV, and TLG, was collected from the primary lesions of gastric cancer in all patients, and the slope of the linear regression between the MTV corresponding to different SUVmax thresholds (40% × SUVmax, 80% × SUVmax) of the primary lesions was calculated. The absolute value of the slope was regarded as the metabolic heterogeneity of the primary lesions, expressed as the heterogeneity index HI-1, and the coefficient of variance of the SUVmean of the primary lesions was regarded as HI-2. Patient prognosis was assessed by PFS and OS, and a nomogram of the prognostic prediction model was constructed, after which the clinical utility of the model was assessed using DCA.

RESULTS

A total of 71 patients with gastric cancer, including 57 (80.3%) males and 14 (19.7%) females, had a mean age of 61 ± 10 years; disease progression occurred in 27 (38.0%) patients and death occurred in 24 (33.8%) patients. Multivariate Cox regression analysis showed that HI-1 alone was a common independent risk factor for PFS (HR: 1.183; 95% CI: 1.010-1.387, P < 0.05) and OS (HR: 1.214; 95% CI: 1.016-1.450, P < 0.05) in patients with gastric cancer. A nomogram created based on the results of Cox regression analysis increased the net clinical benefit for patients. Considering disease progression as a positive event, patients were divided into low-, intermediate-, and high-risk groups, and Kaplan-Meier survival analysis showed that there were significant differences in PFS among the three groups. When death was considered a positive event and patients were included in the low- and high-risk groups, there were significant differences in OS between the two groups.

CONCLUSION

The heterogeneity index HI-1 of primary gastric cancer lesions is an independent risk factor for patient prognosis. A nomogram of prognostic prediction models constructed for each independent factor can increase the net clinical benefit and stratify the risk level of patients, providing a reference for guiding individualized patient treatment.

Clinical implications of micro lymph node metastasis for patients with gastric cancer

BACKGROUND

Lymph node size is considered as a criterion for possible lymph node metastasis in imageology. Micro lymph nodes are easily overlooked by surgeons and pathologists. This study investigated the influencing factors and prognosis of micro lymph node metastasis in gastric cancer.

METHODS

191 eligible gastric cancer patients who underwent D2 lymphadenectomy from June 2016 to June 2017 in the Third Surgery Department at the Fourth Hospital of Hebei Medical University were retrospectively analyzed. Specimens were resected en bloc and the postoperative retrieval of micro lymph nodes was carried out by the operating surgeon for each lymph node station. Micro lymph nodes were submitted for pathological examination separately. According to the results of pathological results, patients were divided into the "micro-LNM (micro lymph node metastasis)" group (N = 85) and the "non micro-LNM" group (N = 106).

RESULTS

The total number of lymph nodes retrieved was 10,954, of which 2998 (27.37%) were micro lymph nodes. A total of 85 (44.50%) gastric cancer patients had been proven to have micro lymph node metastasis. The mean number of micro lymph nodes retrieved was 15.7. The rate of micro lymph node metastasis was 8.1% (242/2998). Undifferentiated carcinoma (90.6% vs. 56.6%, P = 0.034) and more advanced Pathological N category (P < 0.001) were significantly related to micro lymph node metastasis. The patients with micro lymph node metastasis had a poor prognosis (HR for OS of 2.199, 95% CI = 1.335-3.622, P = 0.002). For the stage III patients, micro lymph node metastasis was associated with shorter 5-year OS (15.6% vs. 43.6%, P = 0.0004).

CONCLUSIONS

Micro lymph node metastasis is an independent risk factor for poor prognosis in gastric cancer patients. Micro lymph node metastasis appears to be a supplement to N category in order to obtain more accurate pathological staging.

Extended Lymphadenectomy for Gastric Cancer in the Neoadjuvant Era: Current Status, Clinical Implications and Contentious Issues

Despite its decreasing incidence, gastric cancer remains an important global healthcare problem due to its overall high prevalence and high mortality rate. Since the MAGIC and FNLCC/FFCD trials, the neoadjuvant chemotherapy has been recommended throughout Europe in gastric cancer. Potential benefits of preoperative treatments include a higher rate of R0 resection achieved by downstaging the primary tumor, a likely effect on micrometastases and isolated tumor cells in the lymph nodes, and, as a result, improved cancer-related survival. Nevertheless, distortion of anatomical planes of dissection, interstitial fibrosis, and sclerotic tissue changes may increase surgical difficulty. The collection of at least twenty-five lymph nodes after neoadjuvant therapy would seem to ensure removal of undetectable node metastasis and reduce the likelihood of locoregional recurrence. It is not what you take but what you leave behind that defines survival. Therefore, para-aortic lymph node dissection is safe and effective after neoadjuvant chemotherapy, in both therapeutic and prophylactic settings. In this review, the efficacy of adequate lymph node dissection, also in a neoadjuvant setting, has been investigated in the key studies conducted to date on the topic.

Clinical significance of the number of retrieved lymph nodes in early gastric cancer with submucosal invasion

The prognosis of early gastric cancer (EGC) with submucosal invasion is favorable; however, several cases of recurrence have been reported even after curative gastrectomy. This study aimed to investigate risk factors and evaluate the clinical significance of the number of retrieved lymph nodes (LNs) in EGC with submucosal invasion. We retrospectively analyzed the data of 443 patients with gastric cancer with submucosal invasion after curative gastrectomy for recurrent risk factors. Recurrence was observed in 22 of the 443 gastric cancer patients with submucosal invasion. In the univariate analysis, the risk factors for recurrence were the number of retrieved LNs ≤ 25 and node metastasis. In the multivariate analysis, retrieved LNs ≤ 25 (hazard ratio [HR] = 5.754, P-value = .001) and node metastasis (HR = 3.031, P-value = .029) were independent risk factors for recurrence after curative gastrectomy. Body mass index was related to retrieved LNs ≤ 25 in univariate and multivariate analyses (HR = .510, P = .002). The number of retrieved LNs and node metastases were independent risk factors for EGC with submucosal invasion. For EGC with submucosal invasion, retrieved LNs > 25 are necessary for appropriate diagnosis and treatment.

Pathological Nodal Staging Score for Gastric Signet Ring Cell Carcinoma: A Clinical Tool of Adequate Nodal Staging

Background: Gastric signet ring cell carcinoma (GSRCC) is a subset of gastric cancer with distinct histological and inconsistent prognosis outcome. Currently, the association between the adequate regional lymph node and proper nodal staging in GSRCC is rarely noticed. Materials and methods: Clinical data of GSRCC were retrieved from the Surveillance, Epidemiology, and End Results database. Beta-binomial distribution model was employed for the estimation of the probability of missing nodal disease, followed by the development of a nodal staging score (NSS). Results: A total of 561 GSRCC patients were included in this study, with 193 in lymph node-negative and 368 in lymph node-positive diagnoses. As the number of examined lymph nodes increased, the probability of missing nodal disease decreased rapidly, with T stage-specific curves. The probability of missing nodal disease in T4 was lower than that in T1. NSS calculation indicated that T1 stage patients commonly had NSS > 0.8. However, with the NSS of T2−T4 to reach 0.8, the number of examined lymph node was required to be larger than 12 in T2, 17 in T3 and 27 in T4. NSS ≥ 0.75 (quantile 75%) subgroup in T2−T4 subgroups tended to have better outcome; however, without significant prognostic value. Conclusions: NSS is served as a reliable and feasible tool in adequate nodal staging of GSRCC with statistical basis and provides further evidence for clinical decision making.

Grossing of Gastrointestinal Specimens: Best Practices and Current Controversies

The proper handling of the gross specimen is imperative, as it is the most important first step in providing excellent patient care. Our diagnoses depend on the correct description and submission of tissue sections for histologic analysis. A logical and problem-solving approach to handling the gross specimen is presented.

Retrieval of 30 Lymph Nodes Is Mandatory for Selected Stage II Gastric Cancer Patients

Background

According to the 8th edition AJCC staging manual, a least of 16 lymph nodes retrieval (LNRs) is the minimal requirement for lymph nodes (LNs) dissection of gastric cancer surgery. Previous studies have shown that increasing the number of LNRs (≥30) prolongs survival for selected patients. However, the necessity of retrieving 30 or more LN for stage II gastric cancer patients is still under debate.

Aim

This study aims to explore the impact of retrieving 30 or more lymph nodes on the survival of stage II cancer patients.

Methods

A total of 1,177 patients diagnosed with stage II gastric cancer were enrolled in this study. The clinicopathological parameters and the impact of different LNRs (<30 or ≥30) and positive lymph node ratio (NR) on overall survival (OS) were retrospectively analyzed.

Results

The mean number of LNRs was 34 ± 15. A total of 44% (518/1,177) of patients had an LNRs <30, while 56% (659/1,177) of patients had an LNRs ≥30. The 5-year survival rate was 81% for all patients, 76% for the LNRs <30 group, and 86% for LNRs ≥30 group, respectively (P = 0.003). The survival benefit of retrieving 30 lymph nodes was significant in certain subgroups: age >60 years/male/underwent total gastrectomy/stage IIB. For N+ patients, higher NR was significantly correlated with poor survival.

Conclusion

The survival benefit of retrieving 30 LNs varies in different subgroups. An LNRs of 30 is mandatory for selected stage II gastric cancer patients.

Effect of Surgical Approach on Node Harvest in Gastrectomy: Analysis of the National Cancer Database

BACKGROUND

Gastrectomy is the cornerstone of treatment for gastric cancer. Recent studies demonstrated significant surgical outcome advantages for patients undergoing minimally invasive versus open gastrectomy. Lymph node harvest is an indicator of adequate surgical resection, and greater harvest is associated with improved staging and patient outcomes. This study evaluated lymph node harvest based on surgical approach.

METHODS

Gastric adenocarcinoma patients were identified from NCDB who underwent gastrectomy between 2010 and 2016. Patients were classified by surgical approach into three cohorts: robotic, laparoscopic, or open gastrectomy. Clinical and demographic data were collected. Lymph node harvest was compared with univariate analysis and multivariable generalized linear mixed model. Univariate analysis with propensity matching was also performed to control for differences in patient population across cohorts.

RESULTS

We identified 10,690 patients that underwent gastrectomy for gastric adenocarcinoma, with 68% males and median age of 66 (IQR 5774) years. 7161 (67%) underwent open, 2841 (26.6%) laparoscopic, and 688 (6.4%) robotic gastrectomy. Multivariable analysis revealed robotic was associated with a significantly higher median node harvest (18, IQR 1326) compared to laparoscopic (17, IQR 1125) and open gastrectomy (16, IQR 1023). Laparoscopic was also associated with significantly higher node harvest then open gastrectomy. Propensity-matched analysis (6950 patients) showed robotic gastrectomy was still associated with significantly higher node harvest (18, IQR 1226) compared to laparoscopic (17, IQR 1125) and open (17, IQR 1124); however, laparoscopic and open were not significantly different.

CONCLUSION

Robotic approach is associated with increased node harvest compared to laparoscopic and open approach in gastrectomy patients.

Effect of Surgical Approach on Node Harvest in Robotic Gastrectomy

There has been increasing utilization of minimally invasive surgical approaches. This study evaluates the effect of surgical approach on total lymph node harvest in gastrectomy. Patients undergoing gastrectomy for gastric adenocarcinoma between 2007 and 2018 were reviewed retrospectively. Data collected included age, gender, race, BMI, neoadjuvant therapy, tumor stage, surgical approach, and total number of lymph nodes harvested. The total number of harvested lymph nodes for open, laparoscopic, and robotic gastrectomy was compared using the Kruskal-Wallis test for univariate analysis and a Poisson regression model for multivariable analysis. One hundred four patients were identified. Median node harvest for open, laparoscopic, and robotic approaches were 16, 17, and 36, respectively. Multivariable analysis controlling for gender, BMI, pathological T stage, and year of operation demonstrates that surgical approach is statistically significantly associated with lymph node harvest ( F = 83.4, P < 0.0001). In multivariable analysis, robotic approach was associated with greater lymph node harvest than both open ( P < 0.0001) and laparoscopic ( P < 0.0001) approaches, whereas laparoscopic approach was associated with greater lymph node harvest than open ( P < 0.0001) approach. These data demonstrate that for patients undergoing gastrectomy for gastric adenocarcinoma at our institution, robotic approach is associated with greater lymph node harvest than both laparoscopic and open approaches.

Indications for adjuvant chemotherapy in patients with AJCC stage IIa T3N0M0 and T1N2M0 gastric cancer-an east and west multicenter study

PURPOSE

To determine the indications for adjuvant chemotherapy (AC) in patients with stage IIa gastric cancer (T3N0M0 and T1N2M0) according to the 7th American Joint Committee on Cancer (AJCC).

METHODS

A total of 1593 patients with T3N0M0 or T1N2M0 stage gastric cancer were identified from the Surveillance, Epidemiology, and End Results (SEER) database for the period 1988.1-2012.12. Cox multiple regression, nomogram and decision curve analyses were performed. External validation was performed using databases of the Fujian Medical University Union Hospital (FJUUH) (n = 241) and Italy IMIGASTRIC center (n = 45).

RESULTS

Cox multiple regression analysis showed that the risk factors that affected OS in patients receiving AC were age > 65 years old, T1N2M0, LN dissection number ≤ 15, tumor size > 20 mm, and nonadenocarcinoma. A nomogram was constructed to predict 5-year OS, and the patients were divided into those predicted to receive a high benefit (points ≤ 188) or a low benefit from AC (points > 188) according to a recursive partitioning analysis. OS was significantly higher for the high-benefit patients in the SEER database and the FJUUH dataset than in the non-AC patients (Log-rank < 0.05), and there was no significant difference in OS between the low-benefit patients and non-AC patients in any of the three centers (Log-rank = 0.154, 0.470, and 0.434, respectively). The decision curve indicated that the best clinical effect can be obtained when the threshold probability is 0-92%.

CONCLUSION

Regarding the controversy over whether T3N0M0 and T1N2M0 gastric cancer patients should be treated with AC, this study presents a predictive model that provides concise and accurate indications. These data show that high-benefit patients should receive AC.

Does Lymphadenectomy with at Least 15 Perigastric Lymph Nodes Retrieval Promise an Improved Survival for Gastric Cancer: A Retrospective Cohort Study in Southern China

Background: Specific guidelines recommend at least 15 or 16 lymph nodes (LNs) be examined to adequately assess nodal category of gastric cancer (GC), but the requirement for minimum number of regional LNs retrieval is not mentioned. This study aims to investigate survival significance from various numbers of perigastric (N1) LNs retrieval and to determine an optimal number harvested in such region.

Study design: From April 1994 to March 2012, 1003 resectable GC patients with at least 15 LNs examined were included. Patients with at least 15 N1 nodes retrieval were assigned into study group, with the rest into control group. The 5-year overall survival (OS) rate was compared between two groups, and an optimal number of examined N1 nodes was detected by a survival joinpoint analysis.

Results: 635 (63.3%) patients in study group had median 22 (range, 15-75) N1 nodes and 3 (range, 0-74) positive N1 nodes retrieval, with median 10 (range, 0-14) N1 nodes and 1 (range, 0-29) metastatic N1 nodes examined in control group. The number of N1 nodes retrieval was associated with tumor location (P=0.007), tumor stage (P<0.001) and total number of harvested LNs (r=0.691, P<0.001). Median survival time (79.0 vs. 72.0 months, P=0.462) and actual 5-year OS rate (41.0% vs. 39.2%, P=0.463) were slightly improved in study group compared with control group, with significance obtained via stage-by-stage analysis. The joinpoint analysis indicated that at least seven N1 nodes retrieval achieved survival significance (81.0 vs. 35.0 months, P=0.036), with survival superiority remained until reaching up to 15 N1 nodes.

Conclusion: Adequate retrieval of perigastric LNs is essential for radical gastrectomy. A harvest of at least 7-15 perigastric LNs could achieve long-term survival benefit for GC patients.

Prognostic value of computed tomography radiomics features in patients with gastric cancer following curative resection

OBJECTIVES

The present study aimed to investigate the clinical prognostic significance of radiomics signature (R-signature) in patients with gastric cancer who had undergone radical resection.

METHODS

A total of 181 patients with gastric cancer who had undergone radical resection were enrolled in this retrospective study. The association between the R-signature and overall survival (OS) was assessed in the primary cohort and verified in the validation cohort. Furthermore, the performance of a radiomics nomogram integrating the R-signature and significant clinicopathological risk factors was evaluated.

RESULTS

The R-signature, which consisted of six imaging features, stratified patients with gastric cancer who had undergone radical resection into two prognostic risk groups in both cohorts. The radiomics nomogram incorporating R-signature and significant clinicopathological risk factors (T stage, N stage, and differentiation) exhibited significant prognostic superiority over clinical nomogram and R-signature alone (Harrell concordance index, 0.82 vs 0.71 and 0.82 vs 0.74, respectively, p < 0.001 in both analyses). All calibration curves showed remarkable consistency between predicted and actual survival, and decision curve analysis verified the usefulness of the radiomics nomogram for clinical practice.

CONCLUSIONS

The R-signature could be used to stratify patients with gastric cancer following radical resection into high- and low-risk groups. Furthermore, the radiomics nomogram provided better predictive accuracy than other predictive models and might aid clinicians with therapeutic decision-making and patient counseling.

KEY POINTS

• Radiomics can stratify the gastric cancer patients following radical resection into high- and low-risk groups. • Radiomics can improve the prognostic value of TNM staging system. • Radiomics may facilitate personalized treatment of gastric cancer patients.

Adjuvant Therapy is Associated with Improved Survival in pT1N1 Gastric Cancer in a Heterogeneous Western Patient Population

BACKGROUND

Two recent South Korean studies showed adjuvant therapy (AT) was not associated with improved survival in pT1N1 gastric adenocarcinoma (GAC). We established the prognostic utility of lymph node status, determined the pattern of use of AT, and compared survival stratified by type of AT in pT1N1 GAC in a Western patient population.

METHODS

We identified patients with pT1N0 and pT1N1 GAC using the National Cancer Database from 2004 to 2012. Clinicopathologic variables, treatment regimens, and overall survival (OS) were compared.

RESULTS

We compared 4516 (86.6%) pT1N0 to 696 (13.4%) pT1N1 patients. pT1N1 tumors were larger (median size 2.5 vs. 1.8 cm, p < 0.001), more often poorly differentiated (56.2% vs. 39.6%, p < 0.001), and had higher median retrieved lymph nodes (RLN) (14 vs. 12, p < 0.001) compared with pT1N0. pT1N1 was associated with worse median overall survival (OS) (6.9 vs. 9.9 years for pT1N0, p < 0.001). pN1 was independently associated with worse OS (hazard ratio [HR] 2.17, 95% confidence interval [CI] 1.84-2.56). Increased RLN was associated with improved OS (HR 0.73, 95% CI 0.65-0.83). Among pT1N1 patients, 330 (47.4%) had observation (OBS), 77 (11.1%) received adjuvant chemotherapy (ACT), 68 (9.8%) received adjuvant radiation therapy (ART), and 221 (31.8%) received adjuvant chemoradiation therapy (ACRT). ACT and ACRT were independently associated with improved OS (HR 0.37, 95% CI 0.22-0.65 and HR 0.40, 95% CI 0.28-0.57).

CONCLUSIONS

pN1 was associated with worse survival and RLN ≥ 15 was associated with improved survival in pT1 GAC. ACT and ACRT were independently associated with improved survival in pT1N1 gastric cancer suggesting a valuable role in Western patients.

Are the indications for postoperative radiotherapy in the NCCN guidelines for patients with gastric adenocarcinoma too broad? A study based on the SEER database

Background

The types of patients with gastric adenocarcinoma (GA) for whom postoperative radiotherapy can improve the disease-specific survival rate (DSS) remain controversial. This study aims to explore the ideal indications.

Methods

Patients in the Surveillance, Epidemiology, and End Results (SEER) database with T3–4Nx or TxN+ GA from January 1988 to December 2012 were included and divided into a postoperative chemoradiotherapy group (Group R) and a postoperative chemotherapy group (Group C). We established a nomogram to predict DSS and then divided entire patient cohort into low-risk and high-risk groups based on the DSS predicted by the nomogram.

Results

The Cox multiple regression analysis demonstrated that various risk factors affected DSS for Group R. Based on these risk factors, a nomogram for predicting DSS was established. The decision curve indicated that the best clinical effect could be obtained when the threshold probability was 0–58%. The patients were then divided into low-risk (< 69 points) and high-risk (≥ 69 points) groups according to the five-year DSS predicted. DSS was significantly better for Group R than for Group C for high-risk patients (P < 0.001) but was similar for low-risk patients (P = 0.732).

Conclusion

At present, the National Comprehensive Cancer Network (NCCN) guidelines may include an overly broad range of indications for postoperative radiotherapy for patients with GA. For intestinal GA patients with a postoperative pathologic stage of T1 N1 who are younger than 65 years, have had more than 15 lymph nodes dissected, and have received postoperative chemotherapy, postoperative radiotherapy should not be recommended.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-4957-6) contains supplementary material, which is available to authorized users.

External validation of a modified 8th AJCC TNM system for advanced gastric cancer: Long-term results in southern China

BACKGROUND

The 8th edition of AJCC TNM staging manual for gastric cancer (GC) has been validated by several studies. A modified staging system based on it and total harvested number of lymph nodes (LNs; cutoff: 30) is suggested to improve predictive capacities for advanced GC. This study is designed to validate the modified method using a single-center database in Southern China.

METHODS

Clinical data from 684 GC patients with stage II and III according to the 7th edition between 2001 and 2012 were reviewed. A modified staging system was applied to restage the cohort. The three staging systems were compared in terms of prognostic performance on long-term survival.

RESULTS

The median follow-up period of this cohort was 52 (range, 6-180) months, with a median 5-year overall survival rate of 52.4%. Stage migration was observed in 159 (23.2%) patients according to the 8th edition of TNM staging, and another migration was observed in 108 (15.8%) patients according to the modified TNM staging system. Compared with the modified staging system, both 7th and 8th edition of AJCC TNM staging systems did not prove survival concordance on stage IIIA (7th edition) and stage IIIC (8th edition) when <30 LNs were examined. The survival performance between two AJCC staging systems had no significant improvement (c-index, 0.607 vs. 0.609), with the best prognostic stratification obtained using the modified staging method (c-index, 0.631).

CONCLUSIONS

The modified staging system on basis of the 8th AJCC classification and the number of harvested LNs could provide an optimal predictive capacities for advanced gastric cancer.

Comparison of perioperative chemotherapy with adjuvant chemoradiotherapy for resectable gastric cancer: findings from a population-based study

Background

Both perioperative chemotherapy (PC) and adjuvant chemoradiotherapy (CRT) improve survival in resectable gastric cancer; however, these treatments have never been formally compared. Our objective was to evaluate treatment trends and compare survival outcomes for gastric cancer patients treated with surgery and either PC or CRT.

Methods

We performed a retrospective population-based cohort study between 2007 through 2013 using California Cancer Registry data. Patients diagnosed with stage IB-III gastric adenocarcinoma and treated with total or partial gastrectomy were eligible for this study. Based on the type of treatment received, patients were grouped into surgery-only, PC, or CRT. Primary and secondary outcomes were overall survival (OS) and gastric cancer-specific survival (GCCS) respectively. Mortality hazards ratios (HRs) for each of these outcomes were computed using propensity score weighted and covariate-adjusted Cox regression models, stratified by clinical node status.

Results

Of 2,146 patients who underwent surgical resection, 1,067 had surgery-only, while 771 and 308 received PC or CRT, respectively. Median OS was 25, 33, and 52 months for surgery-only, PC, and CRT, respectively; P<0.001. Overall, patients treated with PC had significantly poorer survival compared to CRT (HR =1.45; 95% CI: 1.22-1.73). PC was also associated with higher mortality in patients with signet ring histology (HR =1.66; 95% CI: 1.21-2.28) and clinical node negative cancer (HR =1.85; 95% CI: 1.32-2.60). Survival was not different between PC vs. CRT in clinical node positive patients (HR =1.29; 95% CI: 0.84-2.08). Of note, the percentage of patients receiving PC increased from 17.5% in 2007-2008, to 41.5% in 2013-2014; P<0.001.

Conclusions

Despite the rapid adoption of PC, overall, CRT is associated with better survival than PC. Specifically, clinical node negative and signet ring histology patients had better survival when treated with CRT compared to PC. Based on these findings, we recommend against indiscriminate adoption of PC and consideration for CRT over PC in clinical node negative patients.

The retrieval of at least 25 lymph nodes should be essential for advanced gastric cancer patients with lymph node metastasis: A retrospective analysis of single-institution database study design: Cohort study

BACKGROUND

Recently, increased evidence have shown that the better prognosis of gastric cancer (GC) patients was associated with the larger number of retrieved lymph nodes (RLNs), but the optimal number of RLNs remains controversial. In the present study, we investigated whether adequate LN retrieval (≥15) was necessary to evaluate the prognosis of patients and attempted to propose an appropriate cutoff-point for the number of RLNs.

METHODS

We reviewed 2246 GC patients who underwent radical gastrectomy in our research institution between January 1986 and January 2008. All patients were divided into several groups based on the number of RLNs. The prognostic outcomes of different patient groups were compared and clinicopathologic features were analyzed.

RESULTS

In the present study, our results indicated that ≥15 RLNs showed a better survival outcome than inadequate LN retrieval (<15), regardless of the node-negative or node-positive GC patients (P < 0.001). For the more advanced GC patients (T2-T4 stage, N1-N3 stage, and stage II-stage III), the retrieval of 25-29 LNs could provide a better survival benefit compared with <25 or ≥30 RLNs (P < 0.05). In addition, for the patients who underwent proximal or total gastrectomy, the superior prognosis was still observed in the patient group with 25-29 RLNs.

CONCLUSION

The minimal goal of 15 RLNs may not be enough to accurately evaluate prognosis of all patients and at least 25 RLNs should be necessary for advanced GC patients with lymph node metastasis.

Lymphadenectomy with Optimum of 29 Lymph Nodes Retrieved Associated with Improved Survival in Advanced Gastric Cancer: A 25,000-Patient International Database Study

BACKGROUND

Gastric adenocarcinoma is an aggressive disease with frequent lymph node (LN) metastases for which lymphadenectomy results in a survival benefit. In the US, the National Comprehensive Cancer Network guidelines recommend D2 lymphadenectomy or a minimum of 15 LNs retrieved. However, retrieval of only 15 LNs is considered by most international guidelines as inadequate. We sought to evaluate the survival benefits associated with a more complete lymphadenectomy.

STUDY DESIGN

An international database was constructed by combining gastric cancer cases from the Surveillance, Epidemiology, and End Results program database (n = 13,932) and the Yonsei University Gastric Cancer database (n = 11,358) (total n = 25,289). Kaplan-Meier survival analysis was performed along with Joinpoint analysis to obtain the optimal number of LNs to retrieve based on survival. Prognostic significance of number of nodes retrieved was then confirmed with univariate and multivariate analyses.

RESULTS

Analysis for both mean and median survival yielded 29 LNs removed as the Joinpoint. This was confirmed with multivariate analysis, where 15 retrieved LNs cutoff fell out of the model and 29 retrieved LNs remained intact, with a hazard ratio of 0.799 (95% CI 0.759 to 0.842; p < 0.001). Stage-stratified Kaplan-Meier analysis for a cutoff point of 29 LNs also demonstrated a statistically significant improvement in survival.

CONCLUSIONS

Joinpoint analysis has allowed for the creation of a model demonstrating the point at which additional dissection would not provide additional benefit. This large international dataset analysis demonstrates that the maximal survival advantage is seen by performing a lymphadenectomy with a minimum of 29 LNs retrieved.