Clinical impact of lymphadenectomy extent in resectable gastric cancer of advanced stage

The Anti-Tumor Effect of Nab-Paclitaxel Proven by Patient-Derived Organoids

Background

Nab-paclitaxel has been widely used in treating breast cancer and pancreatic patients for its low toxicity and high efficiency. However, its role in gastric cancer (GC) remains ambiguous. The aim of our study was to test the anti-tumor activity of nab-paclitaxel using GC patient-derived organoids.

Methods

By using the organoid culture system, we describe the establishment of human gastric cancer organoid lines from surgical samples of three patients with gastric cancer. The consistency of these organoids with original cancer tissues was evaluated by histopathological examination. The characteristics of the cancer organoids were tested using immunofluorescence (IF) staining. Using organoids, the anti-tumor efficiencies of nab-paclitaxel, 5-Fu and epirubicin were compared by CCK8 assay and Annexin V-FITC/PI staining.

Results

Three organoids were successfully established and passaged. The morphology of the established GC organoids was consistent with original cancer tissues. The IC50 of nab-paclitaxel was 3.68 μmol/L in hGCO1, 2.41 μmol/L in hGCO2 and 2.91 μmol/L in hGCO3, which was significantly lower than those of 5-FU (72.99 μmol/L in hGCO1, 28.32 μmol/L in hGCO2 and 2.91 μmol/L in hGCO3) and epirubicin (25.85μmol/L in hGCO1, 15.15 μmol/L in hGCO2 and 7.60 μmol/L in hGCO3). When each organoid lines were treated with nab-paclitaxel for increasing period of time, the percentage of the apoptotic cells in each organoid increased accordingly.

Conclusion

Nab-paclitaxel showed strong anti-tumor activity and had the potential to become front-line drug for treating GC patients. Gastric cancer organoid may be a good tool to predict in vivo response to drugs.

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.

A Gastric Cancer Peptide GX1-Modified Nano-Lipid Carriers Encapsulating Paclitaxel: Design and Evaluation of Anti-Tumor Activity

Aim

The aim of this study was to develop a GX1-modified nanostructured lipid carrier (NLCs) and to evaluate its ability to improve the anti-gastric cancer tumor effects of paclitaxel (PTX).

Main Methods

The GX1-modified NLCs were synthesized and loaded with PTX (GX1-PTX-NLCs) by emulsion solvent evaporation technique. The anti-tumor activity and pharmacodynamics were then evaluated by in vitro cell studies and animal experiments.

Key Findings

The GX1-modified NLCs were successfully synthesized and confirmed by ¹H NMR and MALDI-TOF-MS. PTX-loaded NLCs produced particles with average size distribution less than or equal to 222 nm and good drug loading and entrapment efficiency. In vitro studies demonstrated that GX1-PTX-NLCs had a more obvious inhibitory effect on Co-HUVEC cells than PTX and unmodified PTX-NLCs. The cellular uptake results also showed that GX1-PTX-NLCs were largely concentrated in Co-HUVEC cells, and the uptake rates of GX1-PTX-NLCs in Co-HUVEC were higher than those of the free drug and the PTX-NLC. In vivo studies demonstrated that GX1-PTX-NLCs possess strong anti-tumor effect and showed higher tumor growth inhibition and lower toxicity in nude mice.

Significance

These results suggest that GX1-modified NLCs enhanced the anti-tumor activity of PTX and reduced its toxicity effectively. GX1-PTX-NLCs may be considered as a potent drug delivery system for therapy of gastric cancer.

Topographic lymph node staging system shows prognostic superiority compared to the 8th edition of AJCC TNM in gastric cancer. A western monocentric experience

INTRODUCTION

The current Tumor Node Metastasis staging system (TNM) for gastric cancer classifies the extent of lymph node metastasis based upon the number of lymph nodes involved. Choi et al. have recently proposed a new anatomical classification based upon the regionality of the involved nodes. This new classification seems to have a better predictive prognostic value than the traditional one. We investigated the prognostic role of the new anatomical based classification, reviewing our institutional gastric cancer database.

METHODS

We performed a retrospective chart review of 329 patients who underwent gastrectomy at our Institution from 2003 to 2017. We excluded from data analysis any patient with distant metastases at the time of first diagnosis and or surgery, pathology other than adenocarcinoma, lymphadenectomy less than D2, impossibility to identify location of lymph nodes (LNs) on pathological report and neoadjuvant chemotherapy. The extent of D2 lymphadenectomy was defined according to Japanese Gastric Cancer Association criteria. LN metastasis were reclassified into three topographic groups (lesser, greater curvature, and extraperigastric nodes) and staged according to Choi. The new N stage was combined with the current pT according to the 8th edition of TNM and a new hybrid TNM stage was established. All patients were followed up until June 2019. The prognostic performance of the new stage and of the current anatomical numeric based system (TNM) was analyzed and assessed by the C-index, AIC and likelihood ratio χ² value.

RESULTS

In predicting both Overall Survival (OS) and Disease free Survival (DFS) the new N stage and the new TNM staging system had the highest C-index and likelihood ratio χ2 value and the lowest Akaike Information Criterion (AIC), showing a better accuracy and displaying a better prognostic performance.

CONCLUSIONS

Our study is the first from the Western world to compare the new hybrid classification, based on the anatomical location of metastatic nodes, to the 8th of American Joint Committee on Cancer (AJCC) TNM staging system. Our findings on a small, monocentric sample suggest that hybrid topographic lymph node staging system is more accurate than TNM.

Variation in Adequate Lymph Node Yield for Gastric, Lung, and Bladder Cancer: Attributable to the Surgeon, Pathologist, or Hospital?

BACKGROUND

The Commission on Cancer recently released quality-of-care measures regarding adequate lymphadenectomy for colon, gastric, lung, and bladder cancer. There is currently little information regarding variation in adequate lymph node yield (ALNY) for gastric, lung, and bladder cancer.

METHODS

The New York State Cancer Registry and Statewide Planning and Research Cooperative System were queried for stage I-III gastric, stage I-II lung, and stage II-III bladder cancer resections from 2004 to 2014. Hierarchical models assessed factors associated with ALNY (gastric ≥ 15; lung ≥ 10; bladder ≥ 2). Additionally, the proportions of variation attributable to surgeons, pathologists, and hospitals were estimated among Medicare patients.

RESULTS

Among 3716 gastric, 18,328 lung, and 1512 bladder cancer resections, there were low rates of ALNY (gastric = 53%, lung = 36%, bladder = 67%). When comparing 2004-2006 and 2012-2014, there was significant improvement in ALNY for gastric cancer (39% vs. 68%), but more modest improvement for lung (33% vs. 38%) and bladder (65% vs. 71%) cancer. Large provider-level variation existed for each organ system. After controlling for patient-level factors/variation, the majority of variation was attributable to hospitals (gastric: surgeon = 4%, pathologist = 2.8%, hospital = 40%; lung: surgeon = 13.8%, pathologist = 1.5%, hospital = 18.3%) for gastric and lung cancer. For bladder cancer, most of the variation was attributable to pathologists (surgeon = 3.3%, pathologist = 10.5%, hospital = 6.2%).

CONCLUSIONS

ALNY rates are low for gastric, lung, and bladder cancer, with only modest improvement over time for lung and bladder cancer. Given that the proportion of variation attributable to the surgeon, pathologist, and hospital is different for each organ system, future quality improvement initiatives should target the underlying causes, which vary by individual organ system.

Extranodal soft tissue metastasis as an independent prognostic factor in gastric cancer patients aged under 70 years after curative gastrectomy

Background

Accumulating evidence confirms the potential prognostic value of extranodal soft tissue metastasis (ESTM) in patients with solid cancers. The aim of this study was to elucidate the potential relationship between ESTM and lymph node (LN) metastasis, demonstrate clinicopathological predictive prognostic factors for ESTM and LN metastasis, and identify the prognostic value of ESTM for gastric cancer (GC) patients aged under 70 years.

Methods

A total of 580 GC patients who underwent the curative resection between 2003 and 2011 were included to identify if ESTM is essential to improve the accuracy of prognostic evaluation of the GC patients postoperatively. Overall survival rates were tested by Kaplan-Meier analysis. Univariate and multivariate analyses were applied to clarify the independent prognostic factors. Logistic regression analysis was adopted to clarify the risk factors for evaluating the presence of ESTM and LN metastasis. After cut-point survival analysis, the GC patients were divided into three subgroups based on the number of ESTM and then incorporated into the pTNM stage of gastric carcinoma to identify the possibility and necessity of incorporating ESTM into staging.

Results

ESTM was associated with advanced pT, pN and pTNM categories, large tumour size and the presence of signet-ring cell (SRC) variants. Survival analyses revealed that ESTM was associated with the OS and was an independent prognostic predictor in this GC patient cohort. Logistic regression analysis proved that ESTM and pT stage are significantly correlated with LN metastasis. Additionally, the ESTM was incorporated into the eighth edition of the pTNM classification and the prognostic evaluation of pTNME classification were calculated directly, and the results indicated that ESTM can reduce the stage migration.

Conclusions

ESTM is a significant independent predictor of survival in GC patients. To achieve R0 surgery, lymph nodes, soft tissues, fascia and adipose tissue should be resected en bloc at the same time as lymph node dissection. ESTM should be incorporated into pTNM staging according to the number retrieved from postoperative samples.

Predictors of outcomes in patients with gastric cancer treated with contemporary multimodality strategies-a single institution experience

Background

While gastric cancer is a leading cause of cancer-related mortality in Eastern Europe and Asia, it is less common in the United States. Recommendations regarding optimal treatment of non-metastatic gastric cancer with regard to type and extent of surgery, choice and sequence of chemotherapeutic agents, and use of radiation therapy vary somewhat depending on geographic location. There is paucity in the literature for direct comparison of various practices. To determine how variability in treatment practices affects patient outcomes, we conducted a retrospective study in patients with gastric cancer who had multimodality treatment for non-metastatic gastric cancer.

Methods

We gathered clinical data (patient demographics, pathology reports, type of surgical intervention, chemotherapy, and radiation therapy) for patients diagnosed with gastric adenocarcinoma who underwent gastrectomy at five sites from 2010-2017 using Electronic Health Records and California Cancer Registry databases. Medical chart reviews were conducted to validate patient outcomes. We performed multivariate Cox regression analyses to determine predictors for cancer recurrence and survival. We also performed logistic regression analyses to determine predictors of positive resection margins and hospitalization.

Results

One hundred and sixteen patients met eligibility criteria to be included. Mean age was 65.7±11.6 years. About 65.5% were male. The most common ethnicities were Asian (44.0%) and Caucasian (37.9%). About 58.6% of the patients had localized disease (defined as pT1-3, pN0) and the remaining 41.4% had loco-regional disease (i.e., pT4 or pN+). About 41.4% of the tumors were diffuse, 27.6% intestinal, 12.0% mixed, and 19.0% unknown histology. Surgery included laparoscopic (94.8%) and open gastrectomy (5.2%). Chemotherapy and radiation therapy were given in 51.7% and 19.0% of the patients, respectively. After a median follow-up time of 19 months after gastrectomy, 16.4% of patients had recurrence and 19.8% had died. Patients who had loco-regional tumors were more likely to have recurrence and death than those who had localized tumors (hazard ratios =7.0, P=0.0228 for recurrence and hazard ratios =3.3, P=0.0160 for death). Positive resection margins were seen in 9% of the patients and were associated with diffuse histology (odds ratio =6.6, P=0.0207). Hospitalization within six months of gastrectomy was seen in 22% of the patients. Peri-operative chemotherapy was the only significant predictor for re-hospitalization (odds ratio =3.5, P=0.0415).

Conclusions

In this contemporary cohort of patients with localized gastric cancer, only the pathological stage was significantly associated with survival while positive resection margins were associated with diffuse histology. Closer monitoring of patients undergoing perioperative chemotherapy within 6 months of surgery is warranted based on our observation of higher rate of re-hospitalization.

Effects of epidural combined with general anesthesia versus general anesthesia alone in gastric cancer surgery: a propensity score matching analysis

BACKGROUND

This study was conducted retrospectively to investigate the survival of patients undergoing gastric cancer surgery with epidural combined with general anesthesia (EGA) and general anesthesia alone (GA).

METHODS

We retrospectively analyzed 596 patients with gastric cancer who were scheduled for radical resection. Propensity score matching was performed at a 1:1 ratio between GA (n=97) and EGA (n=97) to reduce selection bias. Univariate and multivariate analyses were used to identify factors significantly correlated with recurrence and/or metastasis and prognosis. The 5-year overall survival rates of patients receiving EGA and GA alone were compared.

RESULTS

After the propensity scores were matched, there were 97 patients who underwent EGA and 97 patients who underwent GA. For the entire population, reconstruction type, pN stage, and complications were significantly correlated with prognosis based on multivariate analyses. For patients with a recurrence and/or metastasis, lymphadenectomy and pN stage were shown to be independent prognostic factors by multivariate analysis.

CONCLUSIONS

In summary, patients might benefit from EGA as a result of better analgesic and anti-inflammatory effects, fewer postoperative complications, higher safety, and a lower rate of metastasis and recurrence is conducive to postoperative recovery in patients with gastric cancer.

Intraoperative Surrogate Indicators of Gastric Cancer Patients' Long-Term Prognosis: The Number of Lymph Nodes Examined Relates to the Lymph Node Noncompliance Rate

BACKGROUND

The number of examined lymph nodes (ExLNs) and the rate of lymph node (LN) noncompliance are two independent indicators for evaluating the oncological efficacy for radical gastric cancer (GC) surgery. There are no studies to prove the relationship between these two indicators and their influence on the long-term prognosis of GC patients.

METHODS

The clinicopathological data of 1872 patients with radical GC resection with pathological stage pT2-4N0-3M0 from June 2007 to June 2013 were retrospectively analyzed. Noncompliance was defined as patients with more than one or more LN stations absence as described in the protocol for lymphadenectomy in the Japanese Gastric Cancer Association.

RESULTS

Among 1872 patients, 941 (50.3%) had complete LN compliance, 469 (25.1%) had minor LN noncompliance, and 462 (24.6%) had major LN noncompliance. Logistic regression analysis showed that cT staging and ExLNs were independent risk factors for LN noncompliance. In the whole group, Kaplan-Meier survival curve elucidated that overall survival (OS) differences of ExLNs ≤ 25 and ExLNs > 25 were statistically significant (p < 0.001). Stratified analysis of LN noncompliance elucidated no statistically significant difference in OS of these two group. Multivariate COX regression analysis suggested that LN noncompliance was an independent prognostic factor for OS, whereas ExLNs was no longer an independent prognostic factor for OS.

CONCLUSIONS

The increase number of ExLNs can improve the OS of GC patients, which depends on the decrease of LN noncompliance rate. As surrogate indicators for long-term prognosis of GC patients, LN noncompliance rate was better than ExLNs number.

Management of Gastric Adenocarcinoma for General Surgeons

Gastric cancer is one of the most common cancers in the world, despite declining incidence of the disease in the United States. Because of the rare occurrence of the disease in the United States, there is significant treatment variance in use of diagnostic modalities, neoadjuvant/adjuvant therapies, and surgical techniques. The survival of patients with gastric cancer in the United States is significantly lower than those of Asian countries where the diagnosis is made at an earlier stage and uniform high-quality treatment is delivered. This article reviews pearls and pitfalls of multidisciplinary management of the gastric adenocarcinoma for best outcomes.

How Should We Measure the Quality of Lymphadenectomy for Gastric Cancer? Anatomical Versus Numerical Criterion

AIM

To compare anatomical with numerical criterion to measure the quality of lymphadenectomy for gastric cancer.

PATIENTS AND METHODS

We analyzed 447 gastric cancer patients with resectable tumor stage (R0 resection) with at least 16 examined lymph nodes.

RESULTS

Of 447 patients, 82.6% underwent D2 lymphadenectomy for a median of total examined lymph nodes of 28. The 7-year disease-specific survival rate for the whole sample was 71.4%. Survival was significantly different between patients treated with D2 and D1 lymphadenectomy (77.4% versus 44.3%; p < 0.001) and between patients with total examined lymph nodes ≥ 28 and < 28 (74.5% versus 62.3%; p = 0.041). Anatomical criterion significantly differentiated 7-year survival in patients stratified according to a numerical parameter.

CONCLUSION

We should still consider the anatomical criterion as the best item to measure the quality of lymphadenectomy for gastric cancer.

Greater negative lymph node count predicts favorable survival of patients with breast cancer in the setting of neoadjuvant chemotherapy and mastectomy

Aim: Adequate lymph node evaluation is recommended in patients with malignant tumors. However, the role of negative lymph nodes (NLNs) remains unclear in breast cancer (BC), especially in patients who have received neoadjuvant chemotherapy and mastectomy. Materials & methods: A total of 435 patients were included in the analysis. On multivariate analysis, NLN count was an independent predictor of 5 year disease-free survival and 5 year overall survival. Results: Patients with NLN count <10 showed significantly worse 5 year disease-free survival than those with NLN count ≥10 (34.8 and 78.2%; p = 0.000); the corresponding 5 year overall survival rates were also significantly different (52.0 and 82.7%; p = 0.000). Conclusion: This is the first study that confirms the relationship between NLN count and prognosis of patients in the setting of neoadjuvant chemotherapy and mastectomy. More NLNs imply better prognosis.

Evaluating Dissemination of Adequate Lymphadenectomy for Gastric Cancer in the USA

BACKGROUND

Adequate lymphadenectomy (AL) of 15+ lymph nodes comprises an important component of gastric cancer surgical therapy. Despite endorsement by the National Comprehensive Cancer Network and the Committee on Cancer, initial adoption of this paradigm has been relatively slow. The current analysis sought to perform an adjusted time-trend evaluation of the factors associated with AL and its dissemination.

METHODS

Utilizing the 2004-2015 National Cancer Database, 28,985 patients were identified who underwent gastrectomy for adenocarcinoma. An adjusted time-trend analysis was performed to estimate the adoption of AL overall. Multivariable logistic regression was utilized to assess factors associated with these observed trends. Interactions and stratified models determined disparate effects in vulnerable populations (older adults, ethnic minorities, low socioeconomic status).

RESULTS

The adjusted time-trend analysis demonstrated an overall 30% increase (28.8 to 58.7%) in receipt of AL (OR 1.10 increase/year; 95%CI 1.09-1.10) from 2004 to 2015. This trend persisted even after stratifying the models by age, race/ethnicity, and income (OR 1.07-1.12; p < 0.05). Slowest rates of adoption were seen amongst hospitals in the Midwest census region (OR 1.08, CI 1.06-1.90) and comprehensive community hospitals (OR 1.08, CI 1.06-1.91) and with African-American patients (OR 1.09, CI 1.06-1.11) (all p < 0.05).

CONCLUSION

This multi-center evaluation demonstrates increased adoption of AL during gastric cancer surgery in the USA overall and amongst vulnerable populations, although regional and racial disparities were observed. Future studies are needed to investigate reasons underlying racial and regional differences in receipt of AL.

Insufficient lymph node assessment in gastric adenocarcinoma

BACKGROUND

This study aimed to investigate the sufficient (≥ 16) lymph node assessment in 449 patients with gastric adenocarcinoma and literature review.

METHODS

Four hundred and forty-nine patients with pathologically confirmed locoregional invasive gastric adenocarcinoma from 2004 to 2013 were included. A standard surgical resection was performed for all the patients with (n = 16) or without (n = 433) neoadjuvant treatment.

RESULTS

In this study, 301 men and 148 women with a median age of 58 (range 21-88) years were included. The median total numbers of examined lymph nodes were 9 (range 0-55). Ninety-five patients (21.2%) had adequate (≥ 16) lymph node examination, and 70 patients (15.6%) had no examined lymph nodes. In univariate analysis, total or near total gastrectomy (P <  0.001), advanced node stage (P < 0.001), primary tumor size > 6 cm (P < 0.001), and the presence of perineural invasion (P = 0.039) were associated with more average number of examined lymph nodes. On multivariate analysis, node stage (P < 0.001) and type of surgery (P = 0.008) were independent predictive factors.

CONCLUSION

In this study, approximately one in five patients with gastric adenocarcinoma had sufficient lymph node assessment. More studies are suggested for identifying a true inadequate lymph node dissection from insufficient lymph node assessment.

Current status of adjuvant chemotherapy for gastric cancer

Although radical gastrectomy is a standard treatment for advanced gastric cancer, recurrence remains high. After several large-scale controlled studies have shown the beneficial effects of adjuvant chemotherapy, that treatment emerged as a standard option for advanced gastric cancer after gastrectomy. However, various guidelines from different countries have suggested different adjuvant chemotherapies. Understanding the differences between guidelines is very important for investigating further therapeutic strategies. Fortunately, because there are many ongoing studies about new regimens for adjuvant treatment, it is expected that patients with gastric cancer after surgery will have better outcome.

Gastric cancer surgery: historical background and perspective in Western countries versus Japan

Gastrectomy plus D2 lymphadenectomy plays a decisive role in the management of resectable gastric cancer in Japan. Before recent advances in chemotherapy, Japanese surgeons considered that extensive surgery involving extended lymphadenectomy with combined resection of neighboring organ(s) was required to eliminate any possible lymphatic cancer spread and improve patient survival. This approach differs radically from that in Western countries, which aim to improve survival outcomes by multidisciplinary approaches including perioperative chemotherapy and/or radiotherapy with limited lymph node dissection. However, a randomized controlled trial conducted in Japan found that more extensive lymphadenectomy including the para-aortic lymph nodes provided no survival benefit over D2 lymphadenectomy. Splenic hilum dissection with splenectomy also failed to show superiority over the procedure without splenectomy in patients with proximal gastric cancer, except in cases with tumor invasion of the greater curvature. Furthermore, bursectomy recently demonstrated similar outcomes to omentectomy alone. Although "D2 lymphadenectomy" as carried out in Japan contributes to low local recurrence rates and good survival outcomes, the results of randomized controlled trials have led to a decreased extent of surgical resection, with no apparent adverse effects on survival outcome. Notably, gastrectomy with D2 dissection has tended to become acceptable for advanced gastric cancer in Western countries, based on the latest results of the Dutch D1D2 trial. Differences in surgical practices between the West and Japan have thus lessened and procedures are becoming more standardized. Japanese D2 lymphadenectomy for advanced gastric cancer is evolving toward more minimally invasive approaches, while consistently striving to achieve the optimal surgical extent, thereby promoting consensus with Western counterparts.

Impact of age on stage-specific mortality in patients with gastric cancer: A long-term prospective cohort study

Controversies exist regarding the impact of age on gastric cancer-related mortality according to cancer stage. In our prospective cohort study, we evaluated the impact of age on stage-specific mortality in patients with gastric cancer. Between 2002 and 2006, patients with newly diagnosed gastric cancer were recruited from two university-affiliated hospitals in Korea. Follow-up data were updated regularly based on medical records and telephone surveys. Patients were classified into four subgroups according to age: <50, 50-59, 60-69, and 70-79 years. A total of 448 patients were followed up for 81.6 months (interquartile range, 25.0-139.3 months). The number of patients with stage I, II, III, and IV disease was 247, 74, 88, and 39, respectively. Overall, age was an independent risk factor for gastric cancer-specific mortality (hazard ratio [HR], [95% confidence interval (CI)]: 1.53 [0.91-2.57], 1.88 [1.21-2.91], and 2.64 [1.69-4.14] in the 50-59, 60-69, and 70-79 years groups, respectively, with the <50 years group as reference). In patients with stage I and II gastric cancer, the 70-79 years group was associated with a significantly higher rate of cancer-specific mortality than the <50 years group (stage I: HR [95% CI], 9.55 [2.11-43.12]; stage II: HR [95% CI], 7.17 [2.32-22.18]). However, age was not an independently associated factor for cancer-specific mortality in patients with stage III and IV gastric cancer. Although age was an independent risk factor for gastric cancer-related mortality in patients with gastric cancer, its impact may differ depending on the stage of cancer.

Postoperative dynamic survival of gastric cancer patients: A multi-institutional, international analysis of 22 265 patients

BACKGROUND

How to best evaluate the disease-specific survival (DSS) of gastric cancer (GC) survivors over time is unclear.

METHODS

Clinicopathological data from 22 265 patients who underwent curative intend resection for GC were retrospectively analyzed. Changes in the patients' 3-year conditional disease-specific survival (CS3) were analyzed. We used time-dependent Cox regression to analyze which variables had long-term effects on DSS and devised a dynamic predictive model based on the length of survival.

RESULTS

Based on 1-, 3-, and 5-year survivorships, the CS3 of the population increased gradually from 62% to 68.1%, 83.7%, and 90.6%, respectively. Subgroup analysis showed that the CS3 of patients who had poor prognostic factors initially demonstrated the greatest increase in postoperative survival time (eg, N3b: 26.6%-84.1%, Δ57.5% vs N0: 84.1%-93.3%, Δ9.2%). Time-dependent Cox regression analysis showed the following predictor variables constantly affecting DSS: age, the number of examined lymph nodes (LNs), T stage, N stage, and site (P < .05). These variables served as the basis for a dynamic prediction model.

CONCLUSIONS

The influence of prognostic factors on DSS and CS3 changed dramatically over time. We developed an effective model for predicting the DSS of patients with GC based on the length of survival time.

Updates on Management of Gastric Cancer

PURPOSE OF REVIEW

Gastric adenocarcinoma is the fifth most common and the third most lethal cancer worldwide. Surgery is the only chance of cure, but recurrence is common, even with complete resection.

RECENT FINDINGS

Advances in diagnosis and staging, genomic classification, surgical resection and treatment of peritoneal disease, systemic chemotherapy and chemoradiation, and targeted and immune therapies have led to the current multidisciplinary approach to gastric adenocarcinoma. Treatment of gastric cancer is rapidly evolving in an effort to combat this challenging disease.

A homogenized approach to classify advanced gastric cancer patients with limited and adequate number of pathologically examined lymph nodes

Background

The prognosis of gastric cancer patients with a limited number of pathologically examined lymph nodes (eLN, < 16) is dismal compared to those with adequately eLN (≥ 16), yet they are still classified within the same subgroups using the American Joint Committee on Cancer (AJCC) staging system. We aimed at formulating an easy-to-adopt and clinically reliable stratification approach to homogenize the classification for these two categories of patients.

Methods

Patients staged according to the 8th AJCC pathological nodal (N) and tumor-node-metastasis (TNM) classification were stratified into a Limited and Adequate eLN cohort based on their number of pathologically examined LNs. The statistical differences between the 5-year overall survival (OS) rates of both cohorts were determined and based on which, patients from the Limited eLN cohort were re-classified to a proposed modified nodal (N′) and TNM (TN′M) classification, by matching their survival rates with those of the Adequate eLN cohort. The prognostic performance of the N′ and TN′M classification was then compared to a formulated lymph-node-ratio-based nodal classification, in addition to the 8th AJCC N and TNM classification.

Results

Significant heterogeneous differences in 5-year OS between patients from the Limited and Adequate eLN cohort of the same nodal subgroups were identified (all P < 0.001). However, no significant differences in 5-year OS were observed between the subgroups N0, N1, N2, and N3a of the Limited eLN cohort when compared with N1, N2, N3a, and N3b from the Adequate eLN cohort, respectively (P = 0.853, 0.476, 0.114, and 0.230, respectively). A novel approach was formulated in which only patients from the Limited eLN cohort were re-classified to one higher nodal subgroup, denoted as the N′ classification. This re-classification demonstrated superior stratifying and prognostic ability as compared to the 8th AJCC N and lymph-node-ratio classification (Akaike information criterion values [AIC]: 12,276 vs. 12,358 vs. 12,283, respectively). The TN′M classification also demonstrated superior prognostic ability as compared to the 8th AJCC TNM classification (AIC value: 12,252 vs. 12,312).

Conclusion

The proposed lymph node classification approach provides a clinically practical and reliable technique to homogeneously classify cohorts of gastric cancer patients with limited and adequate number of pathologically examined lymph nodes.

Development and External Validation of Web-Based Models to Predict the Prognosis of Remnant Gastric Cancer after Surgery: A Multicenter Study

BACKGROUND

Remnant gastric cancer (RGC) is a rare malignant tumor with poor prognosis. There is no universally accepted prognostic model for RGC.

METHODS

We analyzed data for 253 RGC patients who underwent radical gastrectomy from 6 centers. The prognosis prediction performances of the AJCC7th and AJCC8th TNM staging systems and the TRM staging system for RGC patients were evaluated. Web-based prediction models based on independent prognostic factors were developed to predict the survival of the RGC patients. External validation was performed using a cohort of 49 Chinese patients.

RESULTS

The predictive abilities of the AJCC8th and TRM staging systems were no better than those of the AJCC7th staging system (c-index: AJCC7th vs. AJCC8th vs. TRM, 0.743 vs. 0.732 vs. 0.744; P>0.05). Within each staging system, the survival of the two adjacent stages was not well discriminated (P>0.05). Multivariate analysis showed that age, tumor size, T stage, and N stage were independent prognostic factors. Based on the above variables, we developed 3 web-based prediction models, which were superior to the AJCC7th staging system in their discriminatory ability (c-index), predictive homogeneity (likelihood ratio chi-square), predictive accuracy (AIC, BIC), and model stability (time-dependent ROC curves). External validation showed predictable accuracies of 0.780, 0.822, and 0.700, respectively, in predicting overall survival, disease-specific survival, and disease-free survival.

CONCLUSIONS

The AJCC TNM staging system and the TRM staging system did not enable good distinction among the RGC patients. We have developed and validated visual web-based prediction models that are superior to these staging systems.

Proposed Modification of the 8th Edition of the AJCC Staging System for Gastric Cancer

Background: The American Joint Committee on Cancer (AJCC) staging system has been the standardized staging system for malignancies since the first edition in 1987. The 8th edition of gastric cancer was released in 2016, and is expected to be used in clinical practice in 2018. The aim of this study was to improve this new gastric cancer staging system. Methods: We conducted median overall survival analyses in a cohort of 8359 gastric cancer patients from the Surveillance, Epidemiology, and End Results (SEER) database (2004-2014) via Kaplan-Meier curves and log-rank tests, and proposed a modified staging system based on median OS. The concordance index (C-index) was conducted to evaluate the predictive accuracy. Results: Using the 8th AJCC staging system, the median OS of patients at the same stage varied widely between the different substages, especially in stage III. Despite the definitions of T, N, and M, substages in the modified staging system were regrouped based on median OS. The C-index of stage III patients with the modified staging system [0.579, 95% confidence interval (CI) 0.564-0.593] was higher than the 8th AJCC staging system (0.567, 95% CI 0.552-0.581). Moreover, we divided these patients into two groups according to their examined lymph node counts (≥15 or 1-14), and studied the effectiveness of the modified staging system in the two groups. Conclusions: The modified 8th AJCC staging system for gastric cancer proposed in this study generates better prognostic stratifications and may be evaluated for further update. Abbreviations:AJCCAmerican Joint Committee on CancerOSOverall SurvivalSEERSurveillance, Epidemiology, and End Results.

Does Noncompliance in Lymph Node Dissection Affect Oncological Efficacy in Gastric Cancer Patients Undergoing Radical Gastrectomy?

BACKGROUND

Few reports have examined the prognosis of or possible remedial treatments for patients with noncompliant D2 lymphadenectomy. We investigated the effect of noncompliance in lymph node (LN) dissection on long-term survival in gastric cancer (GC) patients after radical gastrectomy and explored intervention measures.

METHODS

Clinicopathological data were retrospectively analyzed in 2401 patients who underwent radical gastrectomy for GC. Noncompliance was defined as patients with more than one empty LN station, as described in the protocol of the Japanese GC Association.

RESULTS

The overall noncompliance rate was 49.1%. The 3-year overall survival (OS) rate was significantly better in compliant than noncompliant patients (74.0% vs. 60.1%, P < 0.001). Univariate and multivariate analyses revealed that noncompliance was an independent risk factor for OS. Logistic regression analysis demonstrated that extent of gastrectomy, primary tumor site, history of intraperitoneal surgery, body mass index, and open gastrectomy were independent preoperative predictive factors for noncompliance. Cox analysis demonstrated that age, pT, pN, and extent of gastrectomy independently affected OS in patients with noncompliant lymphadenectomy. However, OS was significantly better in the compliant than noncompliant group regardless of the recommendation for chemotherapy. Stratified analysis demonstrated that OS was significantly better in chemotherapy patients than in patients without chemotherapy and stage II patients (pT1N2/N3M0 and pT3N0M0) in whom chemotherapy was not recommended.

CONCLUSIONS

Noncompliance is an independent risk factor after radical gastrectomy for GC. Adjuvant chemotherapy improved the prognosis of patients with pT1N2/N3M0 and pT3N0M0 disease who underwent noncompliant D2 lymphadenectomy.

A Simplified Two-Step Technique for Extended Lymphadenectomy During Resection of Gastroesophageal Malignancy: Early Results Compared to En Bloc Dissection

BACKGROUND

Extended lymph node dissection (ELND) remains an important component of curative intent resection of mid-stage gastric cancer (GC). Benefits include enhanced staging accuracy, extending regional disease control, and optimizing potential curability. ELND during gastrectomy remains underutilized in US centers due to a low prevalence of GC operations.

METHODS

The traditional en bloc ELND was modified into a two-step technique to facilitate greater ease of dissection with better exposure. After completion of the gastrectomy component, retrogastric nodes are dissected in a separate, contiguous specimen. Resulting data were compared to outcomes after en bloc resection.

RESULTS

Of 179 consecutive patients undergoing gastrectomy, 129 underwent an ELND (73%). There were 97 men and 32 women, with a median age of 64 years (range 24-98). The median total LN count was 25 (3-86). The two-step dissection yielded an average of 18.3 (± 8.5 S.D.) perigastric and 12.1 (± 5.8) retrogastric nodes. Two-step LND was associated with lower estimated blood loss (265 vs. 448 ml, p = 0.0005), lower transfusion requirements (6 vs. 28%, p = 0.007), greater mean total LN counts (30 vs. 26, p = 0.03), and a greater rate of obtaining at least 15 or 20 LNs (91 vs. 77% and 83 vs. 65%, p = 0.05). Major morbidity (overall 16%), length of stay, and survival outcomes were not different.

CONCLUSIONS

The two-step LND technique as described was found to be associated with favorable operative and postoperative outcome parameters and an excellent LN yield. It can be recommended for standard ELND indications in the absence of macroscopically abnormal LNs.

Nodal staging score and adequacy of nodal staging

Aims

The number of lymph nodes (LNs) excised in patients with pathologic N0 is limited, and it is very likely that there will be recessive node disease after surgery, so they are at risk of understaging. The purpose of the present study is to develop a nodal staging score (NSS) in a mathematical way to assess the likelihood that a pathologic N0 gastric cancer (GCa) patient has, indeed, no occult nodal disease after surgery.

Patients and methods

A total of 14,033 stage I-III GCa patients were identified from Surveillance, Epidemiology and End Results database for analysis. A beta-binomial model was fitted to calculate the probability of missing a nodal disease. This probability is then used to calculate the NSS.

Results

The probability of missing a nodal disease is decreased with increasing LNs examined across all pT stages. Seven and 24 LNs removed and examined was enough for an NSS of 90% in pT1 and pT2 patients, respectively, ensuring a high confidence of correct nodal negative classification. Twenty-three and 31 LNs examined in pT3 and pT4 patients could also maintain the NSS at 80%, respectively. NSS had a significant impact on patients' survival across all pT stages (all Ps <0.0001).

Conclusion

The probability that GCa patients are free of true nodal disease could be provided by NSS-based prediction, which is conducive to postoperative decision and survival surveillance. In addition, NSS can define a subtle standard on how many LNs examined are enough for adequate staging dependent on pT stages. However, at least 16 LNs examined is the standard recommendation to date.

Optimal Timing for Postsurgical Adjuvant Therapy in Patients with Gastric Cancer: A Propensity Score Matching Study

Background:In clinical trials, adjuvant therapy (AT) has been shown to improve the prognosis in patients with gastric adenocarcinoma who undergo curative gastrectomy and adequate lymph node dissection. However, the optimal timing for initiating AT is still unclear.

Method:We collected data from 538 patients with stage II-III gastric cancer who underwent curative gastrectomy and AT in two tertiary hospitals from 2006 to 2013. Patients were divided into the early group (≤8 weeks, n=393) and the late group (>8 weeks, n=145), based on the interval between gastrectomy and initiation of AT. Propensity score matching was applied according to baseline characteristics.

Results:After 1:1 propensity score matching, an even distribution of characteristics in both groups (143:143) was achieved. The 5-year overall survival (OS) rates were 56.6% and 40.2% in the matched early and late groups, respectively (p=0.062), while the corresponding 5-year recurrence-free survival (RFS) rates were 57.6% and 46.4%, respectively (p=0.028). The time to AT initiation was correlated with RFS and had a positive association with OS. The 5-year distant metastasis-free survival was also significantly better (HR 0.682, 95% CI 0.472-0.985, p=0.040), suggesting an early AT results in a better outcome in patients.

Conclusion:We observed that initiation of AT within 8 weeks of curative gastrectomy produces better disease control and may contribute to better overall survival.

Comparison of oncological benefits of deep neuromuscular block in obese patients with gastric cancer (DEBLOQS_GC study): A study protocol for a double-blind, randomized controlled trial

PURPOSE

Many studies have demonstrated the advantage of maintaining intraoperative deep neuromuscular block (NMB) with sugammadex. This trial is designed to evaluate the impact of muscle relaxation during laparoscopic subtotal gastrectomy on the oncological benefits, particularly in obese patients with gastric cancer.

MATERIALS AND METHODS

This is a double-blind, randomized controlled multicenter prospective trial. Patients with clinical stage I-II gastric cancer with a body mass index of 25 and over, who undergo laparoscopic subtotal gastrectomy will be eligible for trial inclusion. The patients will be randomized into a deep NMB group or a moderate NMB group with a 1:1 ratio. A total of 196 patients (98 per group) are required. The primary endpoint is the number of harvested lymph nodes, which is a critical index of the quality of surgery in gastric cancer treatment. The secondary endpoints are surgeon's surgical condition score, patient's sedation score, and surgical outcomes including peak inspiratory pressure, operation time, postoperative pain, and morbidity.

DISCUSSION

This is the first study that compares deep NMB with moderate NMB during laparoscopic gastrectomy in obese patients with gastric cancer. We hope to show the oncologic benefits of deep NMB compared with moderate NMB during subtotal gastrectomy.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov (NCT03196791), date of registration: October 10, 2017.

Prognostic significance of metastatic lymph node ratio: the lymph node ratio could be a prognostic indicator for patients with gastric cancer

Background

To demonstrate the prognostic significance and value of lymph node ratio (LNR) and evaluate the possibility of becoming a new indicator to enhance the current Union for International Cancer Control (UICC)/American Joint Committee on Cancer (AJCC) tumor, lymph node, metastasis (TNM) staging system.

Methods

Our retrospective study included 221 patients who got gastric cancer and underwent curative gastrectomy between 2005 and 2012 at the Fourth Hospital Affiliated of China Medical University. The log-rank test was used to compare the clinicopathological variables. The Kaplan-Meier method and Cox proportional hazard regression model was used to perform the univariate analysis and multivariate statistical survival analysis.

Results

The patients with a better differentiated pathological type; an earlier stage of T staging, N staging, and TNM staging; and a lesser LNR would have a longer survival time according to the univariate analysis. As for the multivariate analysis, the Grade, T stage, N stage, and LNR had the statistical significance. Both in group 1 (the number of lymph nodes examined ≥ 15, namely LN ≥ 15) and group 2 (LN < 15), the LNR had statistical significance and the median survival time would decrease with the increase of the LNR. It was still statistically significant between group LNR1 and group LNR2 which were regrouped by the new cut-off value.

Conclusion

The LNR could estimate the prognosis of patients with curative gastrectomy regardless of the number of lymph nodes examined. Thus LNR could become a new indicator to enhance the current TNM stage system.

Clinical trends and effects on quality metrics for surgical gastroesophageal cancer care

Background

Surgical therapy of mid-stage gastric cancer (GC) and other neoplastic conditions requiring gastric resection remains at the center of curative outcomes, while epidemiologic changes and multimodality treatment options have evolved rapidly. Putative quality metrics for gastrectomy such as R0 rate, total lymph node (LN) count or postoperative morbidity may depend partly on changing disease and treatment patterns, and deserve evaluation under various practice conditions.

Methods

Data within a U.S.-based single surgical oncologist's practice over 15 years were prospectively recorded and retrospectively analyzed for clinicopathologic factors, operative treatment aspects and outcomes. Trends and spectrum changes over three time intervals were analyzed with contingency analysis and continuous data comparative statistics.

Results

Of 179 patients undergoing gastric resection, 119 were male and 60 female, with a median age of 63 years (range, 24-98 years). Resections included 56 total, 56 subtotal/distal, 30 proximal and 37 segmental gastrectomies. Diagnoses included 96 GCs, 31 gastroesophageal (GE) junction (GEJ) cancers, 21 GI stromal tumors (GISTs), and 31 other conditions. Significant trends from first towards last time interval were observed for resection type (16% to 32% proximal, 9% to 30% segmental, P=0.0003), curative intent (76% to 98%, P=0.002), diagnosis (5% to 42% GEJ cancer, P<0.0001) and preoperative therapy use (0% to 58%, P<0.0001), among others. Intraoperative aspects showed significantly reduced blood loss (median: 500 to 150 mL) and transfusion requirements (39% to 4%), and an increased use of minimally invasive techniques over time (all at P<0.001). Among patients undergoing curative intent GC resection with LN dissection, total LN counts remained steady (mean: 26), while the number of involved LNs decreased (9.0 to 3.7, P=0.0003) and the R0 resection rate increased from 74% to 85% (P=0.05). The number of specimens with >15 LNs examined increased from 69.0% to 92.5% (P=0.022). At the same time, spleen preservation rate (91% overall) and major morbidity (16%) remained unchanged throughout. Postoperative length of stay decreased from a median of 12 to 8 days (P<0.0001).

Conclusions

This experience represents some variable practice patterns within a clinicopathologic spectrum of GE diseases. Postoperative or oncologic quality metrics have been sustained or did improve, which would support their utility for various practice settings; they compare favorably to other published U.S. experiences during the same time period.

Reevaluation of laparoscopic versus open distal gastrectomy for early gastric cancer in Asia: A meta-analysis of randomized controlled trials

BACKGROUND

The benefits and risks of laparoscopic distal gastrectomy (LADG) are not yet sufficiently clear for acceptance as a standard treatment of early gastric cancer. Previous meta-analyses were not powered to reach definitive conclusions.

MATERIALS AND METHODS

Randomized controlled trials comparing LADG with open distal gastrectomy (ODG) for early gastric cancer in Asia and published between January 1994 and January 2018 were retrieved from PubMed, Embase, the Cochrane Library, and Google Scholar. Patient characteristics, oncological safety and efficacy, and surgical safety were evaluated following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and Grading of Recommendations Assessment, Development and Evaluation guidelines (GRADE) guidelines. Trial Sequential Analysis (TSA) reduced random error and reinforced the reliability and strength of evidence.

RESULTS

Eight trials including 2666 participants were selected. LADG benefits were an 11.6 cm shorter incision (95% CI: -13.31 to -9.88 cm; P < 0.0001), 103.81 ml less blood loss (95% CI: -133.68 to -73.94; P < 0.0001), 1.73 times less analgesic use (95% CI: -2.21 to -1.24; P < 0.0001), 0.51 days shorter time to first flatus (95% CI: -0.88 to -0.15 days; P = 0.006), lower risk of wound dehiscence (RR = 0.24, 95% CI: 0.08-0.78; P = 0.02), lower risk of surgical adverse events (RR = 0.69, 95% CI: 0.53-0.91; P = 0.008), and lower risk of respiratory complications (RR = 0.40; 95% CI: 0.20-0.79; P = 0.009) than ODG. LADG had 2.22 fewer resected lymph nodes (95% CI: -4.33 to -0.12; P = 0.04) and 76.61 min longer procedures (76.61 min, 95% CI: 57.74-95.47 min; P < 0.0001).

CONCLUSIONS

In Asian patients, LADG had similar mortality and oncological safety, better surgical safety, less operative morbidity, less trauma, and faster recovery than ODG. It has a high role to play in node-negative cases due to better short-term outcomes but less nodal harvest. It is a recommended alternative treatment for experienced surgeons in high-volume centers.

Lymphovascular invasion as a predictor for lymph node metastasis and a prognostic factor in gastric cancer patients under 70 years of age: A retrospective analysis

BACKGROUND

Accumulating evidence has confirmed the potential prognostic value of LVI in patients with cancers. This aim of the current study was to clarify the potential relationship between LVI and lymph node metastasis, establish predictive clinicopathologic prognostic factors for LVI and lymph node metastasis, and determine the prognostic significance of LVI for patients younger than 70 years with resected gastric cancer.

METHODS

Overall survival rates were calculated using Kaplan-Meier analysis. Differences in proportions of patients were tested with the χ² test. Univariate and multivariate analyses were applied to identify independent prognostic factors. Logistic regression analysis was employed to identify the risk factors predicting the presence of LVI and LN metastasis.

RESULTS

Univariate analysis led to the identification of tumor size, LVI and pN stage as factors significantly correlated with prognosis. Multivariate analysis demonstrated that tumor size, LVI, pN stage, and number of LNs retrieved are independent prognostic factors for the entire population. Logistic regression analysis proved that LVI and pT stage were significantly associated with LN metastasis.

CONCLUSION

LVI is an independent prognostic factor predicting LN metastasis and a strongly independent predictor of survival for patients with resected gastric cancer. We recommend that LVI should be taken into account as an important adjuvant prognostic factor, specially for pN0 cases with inadequate LNs retrieved. And the maximum number of LNs possible should be retrieved for optimal staging, especially for patients with higher cT stage.

Characteristics of advanced gastric cancer with negative or only perigastric lymph node metastasis in elderly patients

OBJECTIVES

After gastrectomy with extended lymph node (LN) dissection, the damage of celiac plexus seems to cause of disorder of eating habits. To clarify the indication of gastrectomy with limited LN dissection for elderly patients, the pathological characteristics of advanced gastric cancer in elderly patients were examined in this study.

METHODS

Forty-seven patients aged ≥80 years with advanced gastric cancer (deeper than pT2) who underwent curative gastrectomy from 1998 to 2015 were enrolled. Patients were classified into two groups by extent of LN metastasis: Group A, with N0 or only perigastric LN metastasis (n = 33); Group B, LN metastasis beyond the perigastric area (n = 14). Pathological factors were then evaluated.

RESULTS

No significant differences were observed in age, sex, body mass index, American Society of Anesthesiologists physical status classification, serum level of carcinoembryonic antigen, surgical procedure, extent of LN dissection, and number of dissected LNs. Pathological findings showed no significant differences in tumor location, macroscopic type, histologic type, and lymphovascular invasion. However, significant differences were observed in tumor maximum diameter at the cut-off level of 40 mm (Group A: ≤40 mm, n = 10 and >40 mm, n = 23; Group B: ≤40 mm, n = 0 and >40 mm, n = 14; P = 0.02).

CONCLUSION

In the elderly patients, LN metastasis in advanced gastric cancer of ≤40 mm in diameter was limited to be within the perigastric area. Gastrectomy with only perigastric LN dissection may be adopted in these patients.

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.

Age-specific effects on the prognosis after surgery for gastric cancer: A SEER population-based analysis

Prognosis of age at diagnosis for gastric cancer (GC) has been investigated in a few studies with inconclusive results. To assess the survival of GC across different age groups, we searched the Surveillance, Epidemiology, and End Results (SEER) database (1988-2010) and identified 10,092 patients undergoing gastrectomy. Analyses of the associations between age and 5-year GC-specific survival (GCSS) were carried out using the Kaplan-Meier method and Cox regression model. When the 50-59 year age group was used as reference group, patients younger than 50 years suffered similar survival rates, and the risk of death increased for patients older than 60 years (hazard ratio [HR], 1.11; 95% confidence interval [CI], 1.02-1.20), peaking for ages > 80 years (HR, 1.60; 95% CI, 1.46-1.76). Overall, HRs of 5-year GCSS increased steadily with age, even when age was evaluated as a continuous variable. We assessed the survival differences associated with age between three groups, using the cut-off ages of 30 and 50 years. Compared with the elderly group, a high survival rate was observed in the mid-age group, but not in the youngest group. Stratified analysis for sex, race, tumor site, histology and clinical stage yielded consistent results. This study shows that the prognosis of GC varies with age, and young GC patients appear to have a favorable GCSS after surgical treatment. Further studies are warranted to verify our findings.

Lymph node staging systems in patients with gastric cancer treated with D2 resection plus adjuvant chemotherapy

Background: The optimal nodal staging scheme for gastric cancer remains unsettled. We compared the prognostic performances of the metastatic lymph node, lymph node ratio, and log odds of metastatic lymph nodes based on nomograms among 801 patients with D2-resected gastric cancer treated with adjuvant chemotherapy.

Methods: When assessed as a continuous covariate, each nodal staging variable was incorporated into a prognostic nomogram with other significant prognosticators to predict the 5-year overall survival. The discriminatory abilities of the nomograms were compared using the concordance index. Patients were divided into subgroups using each nomogram, and the prognostic homogeneity of the nomograms was assessed using the Kaplan-Meier method with log-rank tests.

Results: The discriminatory abilities of the three nomograms were comparable (P > 0.05 for all pairwise comparisons). However, for patients within each lymph node ratio subgroup, overall survival was homogenous when stratified by subgroups of the other two staging schemes, while it differed significantly among the different lymph node ratio subgroups for patients within some of the other two staging subgroups.

Conclusion: The lymph node ratio-based staging scheme performs the best for the prediction of survival in patients with locally advanced gastric cancer treated with D2 resection followed by adjuvant chemotherapy.

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.

miR-542-3p Appended Sorafenib/All-trans Retinoic Acid (ATRA)-Loaded Lipid Nanoparticles to Enhance the Anticancer Efficacy in Gastric Cancers

PURPOSE

In this study, miR-542-3p appended SRF/ATRA-loaded solid lipid nanoparticle was successfully prepared and demonstrated for its therapeutic efficacy against gastric cancers.

METHODS

The particles were nanosized and typically spherical in shape. In vitro release study showed that release of ATRA was significantly slower compared to that of SRF from the NPs.

RESULTS

MTT assay showed that miR-542-3p have a strong inhibitory effect on the proliferation of MGC-803 cancer cells in a typical dose dependent manner. Nanocarrier encapsulation of SRF + ATRA induced a significantly higher cytotoxic effect compared to either individual drug or cocktail combinations indicating that the cellular uptake of different formulations was rate limiting factor in the therapeutic efficacy. Importantly, miR-542-3p-based miSRNP exhibited an extremely significant toxic effect compared to any other treated group. Importantly, miSRNP induced a significantly higher early (~55%) and late (~15%) apoptotic effect in gastric cancer cells. In vivo anticancer analysis results clearly suggest that nanoparticle encapsulation of combination of SRF and miRNA (with miRNA) will have greater antitumor efficacy in tumor mice.

CONCLUSION

Overall, unique combination of miRNA coupled with SRF + ATRA in a lipid nanocarrier could be a promising therapeutic approach in gastric cancer treatment.

Modified vs. standard D2 lymphadenectomy in distal subtotal gastrectomy for locally advanced gastric cancer patients under 70 years of age

The present study was conducted to investigate the prognosis and survival of patients with locally advanced gastric cancer who underwent distal subtotal gastrectomy with modified D2 (D1+) and D2 lymphadenectomy, under 70 years of age. The five-year overall survival rates of 390 patients were compared between those receiving D1+ and D2 lymphadenectomy. Univariate and multivariate analyses were used to identify factors that correlated with prognosis and lymph node metastasis. Tumor size (P=0.039), pT stage (P=0.011), pN stage (P<0.001), and lymphadenectomy (P=0.004) were identified as independent prognostic factors. Furthermore, tumor size (P=0.022), pT stage (P=0.012), and lymphadenectomy (P=0.028) were proven as independent factors predicting lymph node metastasis. In conclusion, cancers of larger size, higher pT stage, and with D1+ lymphadenectomy had a higher risk of lymph node metastasis. Standard D2 lymphadenectomy removes sufficient lymph nodes to improve staging accuracy and survival. Therefore, D2 lymphanectomy is recommended in distal subtotal gastrectomy for locally advanced gastric cancer, especially for cancers of larger size and higher pT stage.

Validation of the American Joint Commission on Cancer (8th edition) changes for patients with stage III gastric cancer: survival analysis of a large series from a Specialized Eastern Center

The 8th edition of the TNM was released in 2016 and included major revisions, especially for stage III. We aimed to compare the prognostic value of the 7th and 8th editions of the AJCC TNM classification for stage III gastric cancer. Clinical data from 1557 patients operated on for stage III gastric cancer according to the 7th edition between 2007 and 2014 were analyzed and compared using the 7th and 8th TNM classifications. A proposed staging system was established, and the three systems were compared in terms of prognostic performance. The stage shifted for 669 (42.96%) patients. It shifted from IIIA to IIIB (one patient, 0.06%), IIIB to IIIA (230 patients, 14.8%), IIIB to IIIC (94 patients, 6.0%), and IIIC to IIIB (344 patients, 22.1%). However, the new AJCC subgroupings did not prove distinctive for survival levels between T3N3aM0 (stage IIIB) and T3N3bM0 (stage IIIC) or between T4aN3aM0 (stage IIIB) and T4aN3bM0 (stage IIIC) when <30 lymph nodes (LNs) were resected. The performance of the 8th edition (c-index, 0.614; 95% confidence interval [CI], 0.596-0.633) revealed no relevant improvement compared to the 7th edition (c-index, 0.624; 95% CI, 0.605-0.643). The proposed staging system generated the best prognostic stratification. The 8th TNM edition may not provide better accuracy in predicting the prognosis of stage III gastric cancer. The proposed staging system, comprised of a combination of the number of LNs harvested and the 7th and 8th AJCC classifications, may improve predictive capacities for stage III gastric cancer.

Evolution in the surgical management of gastric cancer: is extended lymph node dissection back in vogue in the USA?

BACKGROUND

Gastric cancer remains a formidable treatment challenge. For decades, treatment consisted mostly of surgical intervention for this deadly disease. With improvements in the multi-disciplinary management of solid organ malignancies, the approach to this disease is being stepwise refined.

MAIN BODY

One of the prevalent controversies in the surgical management of gastric cancer rests on the need for adequate harvesting of lymph nodes. For decades, lymph node dissection is regarded as a staging technique useful in only upstaging the disease. The adoption of D2 lymphadenectomy has been particularly slow to mature. But with prevailing data from Asia consistently demonstrating a survival benefit from lymphadenectomy, it calls into question the notion of lymphadenectomy as being solely a staging procedure.

CONCLUSIONS

As gastric resection techniques are being better defined in western countries and surgical morbidities lowered on its execution, D2 lymphadenectomy is becoming more accepted as the new standard in the management of gastric cancer.

Increased pancreatic cancer survival with greater lymph node retrieval in the National Cancer Data Base

BACKGROUND

We evaluated the role of lymph node (LN) retrieval in pancreatic adenocarcinoma (PA) patients undergoing pancreaticoduodenectomy (PD).

METHODS

We utilized the National Cancer Data Base; Cox regression models and logistic regression models were used for statistical evaluation.

RESULTS

We evaluated 26,792 patients with PA who underwent PD. The mean LN retrieved in LN(-) patients was 10.8 vs 14.4 for LN(+) patients (P < 0.0001). Greater LN retrieval is an independent predictor of a negative microscopic margin and decreased length of stay. The median survival of LN(-) patients exceeded that of LN(+) patients (24.5 vs 15.1 months, P < 0.0001). Increasing LN retrieval is a significant predictor of survival in all patients, and in LN(-) patients. The relationship of increased LN retrieval and enhanced survival is a nearly linear trend.

CONCLUSIONS

Rather than demonstrating an inflection point that defines the extent of adequate lymphadenectomy, this dataset demonstrates an incremental relationship between LN retrieval and survival.