Potential benefit of resection for stage IV gastric cancer: a national survey

Identification of optimal primary tumor resection candidates for metastatic gastric cancer: Nomograms based on propensity score matching

BACKGROUND

This study sought to develop and validate nomograms for screening patients with metastatic gastric cancer (mGC) who are candidates for primary tumor resection (PTR) and evaluating the prognosis of mGC patients after PTR.

METHODS

From 2010 to 2016, we screened mGC patients with complete data from the Surveillance, Epidemiology, and End Results (SEER) database. Depending on whether or not PTR was performed, we categorized patients into surgery and non-surgery groups. A 1:1 propensity score matching (PSM) analysis was used to balance the characteristics of the two groups. The endpoints were overall survival (OS) and cancer-specific survival (CSS). Two predictive nomograms were developed using logistic regression to assess the likelihood of benefit. Two additional prognostic nomograms were developed to assess prognosis in mGC patients after PTR by Cox regression. Finally, nomograms were evaluated using a variety of methodologies.

RESULTS

Our study included 3594 mGC patients who met the criteria. PTR was associated with improved OS and CSS time (median OS time after PSM: 15 vs. 7 months, P < 0.05; median CSS time after PSM: 17 vs. 7 months, P < 0.05). The OS-related predictive nomogram, including age, histologic type, grade, T stage, and chemotherapy, was developed. Moreover, the CSS-related predictive nomogram, including age, histologic type, grade, and chemotherapy, was developed. Sex, histologic type, grade, T stage, N stage, and chemotherapy were found to be correlated with OS. Furthermore, the CSS correlated with histologic type, grade, T stage, N stage, and chemotherapy. Both predictive and prognostic nomograms were found to be valuable and reliable after different types of validation.

CONCLUSION

Predictive nomograms were developed and validated for identifying the optimal PTR mGC candidates. Prognostic nomograms were developed and validated for assessing the prognosis of mGC patients after PTR.

Application of machine learning algorithm in predicting distant metastasis of T1 gastric cancer

Distant metastasis (DM) is relatively uncommon in T1 stage gastric cancer (GC). The aim of this study was to develop and validate a predictive model for DM in stage T1 GC using machine learning (ML) algorithms. Patients with stage T1 GC from 2010 to 2017 were screened from the public Surveillance, Epidemiology and End Results (SEER) database. Meanwhile, we collected patients with stage T1 GC admitted to the Department of Gastrointestinal Surgery of the Second Affiliated Hospital of Nanchang University from 2015 to 2017. We applied seven ML algorithms: logistic regression, random forest (RF), LASSO, support vector machine, k-Nearest Neighbor, Naive Bayesian Model, Artificial Neural Network. Finally, a RF model for DM of T1 GC was developed. The AUC, sensitivity, specificity, F1-score and accuracy were used to evaluate and compare the predictive performance of the RF model with other models. Finally, we performed a prognostic analysis of patients who developed distant metastases. Independent risk factors for prognosis were analysed by univariate and multifactorial regression. K-M curves were used to express differences in survival prognosis for each variable and subvariable. A total of 2698 cases were included in the SEER dataset, 314 with DM, and 107 hospital patients were included, 14 with DM. Age, T-stage, N-stage, tumour size, grade and tumour location were independent risk factors for the development of DM in stage T1 GC. A combined analysis of seven ML algorithms in the training and test sets found that the RF prediction model had the best prediction performance (AUC: 0.941, Accuracy: 0.917, Recall: 0.841, Specificity: 0.927, F1-score: 0.877). The external validation set ROCAUC was 0.750. Meanwhile, survival prognostic analysis showed that surgery (HR = 3.620, 95% CI 2.164-6.065) and adjuvant chemotherapy (HR = 2.637, 95% CI 2.067-3.365) were independent risk factors for survival prognosis in patients with DM from stage T1 GC. Age, T-stage, N-stage, tumour size, grade and tumour location were independent risk factors for the development of DM in stage T1 GC. ML algorithms had shown that RF prediction models had the best predictive efficacy to accurately screen at-risk populations for further clinical screening for metastases. At the same time, aggressive surgery and adjuvant chemotherapy can improve the survival rate of patients with DM.

Clinicopathological Characteristics and Prognosis of cT1N0M1 Gastric Cancer: A Population-Based Study

Background

Distant metastasis of early gastric cancer is a rare subgroup and poorly understood. The present study is aimed at summarizing the clinicopathological characteristics, prognosis, and management of clinical T1N0M1 (cT1N0M1) gastric cancer.

Method

Between 2004 and 2015, patients diagnosed with cT1N0M1 gastric cancer were retrospectively analyzed using the Surveillance, Epidemiology, and End Results (SEER) database.

Results

A total of 1093 cT1N0M1 gastric cancer patients were identified. 49 patients (4.5%) received cancer-directed surgery, and 113 patients (10.4%) were managed with radiotherapy. Compared with the other stage IV diseases, a relatively high proportion of black population (19.9% vs. 15.8%), patients older than 60 years (63.1% vs. 57.8%), and adenocarcinoma (59.5% vs. 55.9%) were observed in the cT1N0M1 gastric cancer subgroup. Besides that, patients with cT1N0M1 had the characteristics of less poor differentiated or undifferentiated (54.3% vs. 61.7%). Patients with cT1N0M1 had worse cancer-specific survival (CSS) and overall survival (OS) as compared to the other metastatic gastric cancer patients (CSS: p = 0.002, OS: p = 0.001 for log-rank test). Intriguingly, patients with cT1N0M1 had poor prognosis as compared to patients with cT1N+M1 (CSS: p = 0.015, OS: p = 0.007 for log-rank test). The 3-year and 5-year CSS for patients with cT1N0M1 were 5.7% and 4.0%, respectively. The addition of surgery resulted in improved CSS (p < 0.001 for log-rank test) while radiotherapy was not associated with CSS (p = 0.756 for log-rank test) in patients with cT1N0M1. A multivariate Cox analysis showed that surgery (HR = 0.378, 95% CI: 0.255-0.562) and patients younger than 60 (HR = 0.745, 95% CI: 0.647-0.858) years were independent protective factors for these subgroup patients.

Conclusion

Patients with cT1N0M1 gastric cancer had distinctive clinicopathological characteristics and presented poor prognosis. Knowledge of these differences contributes to guiding clinical evaluation for metastatic gastric cancer patients. More aggressive therapeutic strategy should be highlighted for this subgroup.

Modest overall survival improvements from 1998 to 2009 in metastatic gastric cancer patients: a population-based SEER analysis

BACKGROUND

An increasing fraction of gastric cancer patients present with distant metastases at diagnosis. The objective of the present 11-year population-based trend analysis was to assess the survival rates in patients who underwent and in patients who did not undergo palliative gastrectomy.

METHODS

Patients with metastatic gastric cancer were identified from the Surveillance, Epidemiology, and End Results (SEER) database between 1998 and 2009. Time trend and impact of palliative gastrectomy on survival were assessed by both a multivariate Cox proportional hazards model and propensity score matching.

RESULTS

We identified 8249 patients with stage IV gastric cancer. The rate of metastatic disease increased from 31.0 % in 1998 to 37.5 % in 2009 (P < 0.001). The palliative gastrectomy rate dropped from 18.8 to 10.2 % (P = 0.004). The median survival for patients who underwent palliative gastrectomy (N = 1445, 17.4 %) and for patients who did not undergo palliative gastrectomy (N = 6804, 82.4 %) was 7 and 3 months, respectively. There was an increase in median overall survival from 2 months (1998) to 3 months (2009) in the no-gastrectomy group, and from 6.5 to 8 months in the gastrectomy group. The 3-year cancer-specific survival rates were 2.1 % (95 % confidence interval 1.7-2.5 %) for patients who did not undergo palliative gastrectomy and 9.4 % (95 % confidence interval 7.8-11.2 %) for patients who underwent palliative gastrectomy (P < 0.001). Palliative gastrectomy was associated with an increased cancer-specific survival in propensity-score-adjusted Cox regression analyses (hazard ratio 0.50, 95 % confidence interval 0.46-0.55, P < 0.001).

CONCLUSION

On a population-based level, only modest improvements in prognosis for metastatic gastric cancer were observed in patients who underwent and in patients who did not undergo palliative gastrectomy. Considering the low rate of midterm survivors in both groups, only a small subgroup of patients benefits from palliative gastrectomy.

Prognostic factors in metastatic gastric cancer: results of a population-based, retrospective cohort study in Ontario

BACKGROUND

Stage IV gastric cancer is lethal, and little population-based research on prognostic factors has been performed in low-incidence countries. Therefore, we investigated the consistency of the associations of patient, disease and healthcare system factors identified in previous population-based research to understand their generalizability to other low-incidence populations.

METHODS

A population-based, retrospective cohort study of patients diagnosed with Stage IV gastric cancer in Ontario between 1 April 2005 and 31 March 2008 was performed. Kaplan-Meier methodology and the log-rank test were used for bivariate analysis. Multivariate Cox proportional hazard regression was performed. Hazard ratios (HRs) and 95% confidence intervals (CIs) are presented.

RESULTS

On multivariate analysis, patient, disease and healthcare system factors were independent predictors of survival. Increasing age per 10 years (HR 1.07; 95% CI 1.02-1.10), a tumor located in the gastroesophageal junction (HR 1.09; 95% CI 0.94-1.27) or middle of the stomach (HR 1.14; 95% CI 0.97-1.35), presence of carcinomatosis (HR 1.61; 95% CI 1.42-1.83) and a larger burden of metastatic disease (2-3 sites of metastatic disease: HR 1.17; 95% CI 1.03-1.32; ≥ 4 sites: HR 1.69; 95% CI 1.30-2.20) were associated with worse prognosis. Female gender, receipt of surgery, chemotherapy and radiotherapy and treatment from a high-volume, gastric cancer specialist were all associated with significantly better prognosis. In addition, there was evidence of significant geographic variation in survival.

CONCLUSION

This study provides supporting evidence for patient, disease and healthcare system prognostic factors in metastatic gastric cancer. Future work investigating the role of emerging molecular and biologic information will need to take these established prognostic factors into consideration.

Race Influences Stage-specific Survival in Gastric Cancer

Gastric adenocarcinoma studies show improved survival for Asians but have not reported stage-specific overall survival (OS) or disease-specific survival (DSS) by race. The Surveillance, Epidemiology and End Results database was queried for cases of gastric adenocarcinoma between 1998 and 2008. We evaluated OS and DSS by race and stage. Number of assessed lymph nodes was compared among surgical patients. Of 49,058 patients with complete staging data, 35,300 were white, 7709 were Asian, and 6049 were black. Asians had significantly better OS for all stages ( P < 0.001) and significantly better DSS for Stages I ( P < 0.0001) and II ( P = 0.0006). As compared with blacks, whites had significantly better DSS for Stages I ( P < 0.0001), II ( P = 0.0055), III ( P = 0.0165), and IV ( P < 0.0001). Among the 28,133 (57%) surgical patients, average number of evaluated lymph nodes was highest for Asians ( P < 0.0001). Among surgical patients with 15 or more nodes evaluated, DSS was worse in blacks with Stage I disease ( P < 0.05). Blacks with gastric adenocarcinoma have a worse DSS, which disappears when surgical treatment includes adequate lymphadenectomy. Race-associated survival differences for gastric adenocarcinoma might simply reflect variations in surgical staging techniques and socioeconomic factors.

Noncurative gastrectomy for gastric adenocarcinoma should only be performed in highly selected patients

BACKGROUND

The benefit of surgical resection in patients with incurable gastric adenocarcinoma is controversial.

METHODS

A total of 289 patients who presented with advanced or metastatic gastric cancer from 1995 to 2010 were retrospectively reviewed.

RESULTS

Ten patients (3.5 %) required emergent surgery at presentation and were excluded from further analyses. Patients who underwent nonemergent surgery at presentation (n = 110, 38.1 %) received either gastric resection (group A, n = 46, 42 %) or surgery without resection (group B, n = 64, 58 %). Procedures in group A included distal gastrectomy (n = 25, 54 %), total gastrectomy (n = 17, 37 %), and proximal/esophagogastrectomy (n = 4, 9 %). Procedures in group B included laparoscopy (n = 17, 27 %), open exploration (n = 25, 39 %), gastrostomy and/or jejunostomy tube (n = 12, 19 %), and gastrojejunostomy (n = 10, 16 %). Group A required a stay in the intensive care unit or additional invasive procedure significantly more often than group B (15 vs. 2 %, p = 0.009). Four patients in group A (8.7 %) and three patients in group B (4.7 %) died within 30 days of surgery (p = 0.45). When the 110 patients who underwent nonemergent surgery (groups A and B) were compared to nonoperatively managed patients (group C, n = 169, 58 %), median overall survival did not significantly differ (8.6 vs. 9.2 vs. 7.7 months; p > 0.05). Three patients in group B (4.7 %) and three in group C (1.8 %) ultimately required an operation for their primary tumor.

CONCLUSIONS

Patients with gastric adenocarcinoma who present with advanced or metastatic disease not amenable to curative resection infrequently require emergent surgery. Noncurative resection is associated with significant perioperative morbidity and mortality as well as limited overall survival, and should therefore be performed judiciously.

Adherence to national guidelines for gastric cancer in the Netherlands: a retrospective population-based audit

In May 2009, a new clinical practice guideline for gastric cancer was released in the Netherlands. To determine the impact of this guideline, we evaluated trends in patterns of care, thereby focusing on the use of perioperative chemotherapy, the adequacy of lymphadenectomy and the proportion of non-curative resections. For our evaluation, we retrospectively collected information from the Netherlands Cancer Registry on 2,511 patients diagnosed with primary adenocarcinoma of the stomach during the period July 2008-June 2010, excluding tumors of the cardia. After comparing clinical management for patients diagnosed from July 2008 to June 2009 with that for patients diagnosed from July 2009 to June 2010, we conclude that our indicators for guideline adherence did not show major change, except for the proportion of patients that received an adequate lymphadenectomy (examination of ≥10 lymph nodes), which increased from 49% to 58% (p = 0.005), this increase being more pronounced for high-volume hospitals (p = 0.006). Preoperative chemotherapy was given in 45% of patients and 25% of resections was non-curative. For the total study population, the resection rate was 41% and 30-day mortality was 5.7%. However, this measure may underestimate the real operative risk for gastric cancer patients given supplementary information on postdischarge death and prolonged hospital stay.

Gastric malignancy: surgical management

PURPOSE OF REVIEW

To highlight the recent changes and development in the surgical management of gastric adenocarcinoma. There is significant development in the field. However, issues like extent of resection, lymphadenectomy, and minimal access approach are still to be refined for clinical and oncological effectiveness and safety.

RECENT FINDINGS

The outcomes of surgical treatment of gastric adenocarcinoma are improving due to several factors, including specialist unit settings, refinement of the surgical techniques, improved adequacy of lymphadenectomy and some other minor factors such as multidisciplinary team approach and the use of perioperative chemotherapy or radiotherapy. The most hot issue in the past year's literatures is the use of minimal access surgery for resection and lymphadenectomy. The trend of studies is supporting minimal access approach for limited, subtotal and even total gastrectomy.

SUMMARY

The outcomes of surgical treatment of gastric adenocarcinoma are improving. Minimal access approach to treat gastric adenocarcinoma is evolving and continuing to have a substantial role in current surgical practice. The potential role of minimal access surgery, surgical resectional techniques, extent of lymphadenectomy and setting of specialized units and multidisciplinary team approach have stimulated an active research.