Identifying the optimal treatment strategy in patients with resectable non-cardia gastric cancer

BACKGROUND

Multimodal treatment strategy including perioperative chemotherapy (PEC), postoperative chemoradiation therapy (POCR), and postoperative chemotherapy (POC) has been accepted as the standard of care in gastric cancer (GC). The ideal sequence and type of therapy remain undetermined.

METHOD

The National Cancer Database was examined from 2006 to 2016 to identify patients with resectable non-cardia gastric cancer. Patient outcomes were compared based on the receipt of PEC, POCR, and POC. This comparison was repeated in a sub-group of patients who received optimal treatment. Optimal treatment was defined as initial chemotherapy within 45 days of diagnosis, resection within 45 days of diagnosis, negative margins, adjuvant chemotherapy within 90 days of resection and standard radiation dose (45 Gy). Kaplan-Meier test, log-rank test, and multivariable analysis (MVA) were performed.

RESULTS

We identified 9589 patients. Median survival was greater in the PEC group followed by POCR and POC (60.6, 42.3, and 31.2 months, respectively). On MVA, factors associated with worse overall survival included age above median (≥ 63 years), Charlson-Deyo score of ≥ 1, non-academic/research program, poorly differentiated/undifferentiated grade, positive margins, and positive lymph nodes. Both PEC and POCR were associated with improved survival when compared to POC (HR 0.78 and 0.79; p < 0.001). When compared with PEC, no significant difference was noted with POCR (HR 1.01; p = 0.987). These results were maintained in optimally treated cohort (n = 3418).

CONCLUSION

In patients with resectable non-cardia gastric cancer, both perioperative chemotherapy and postoperative chemoradiation therapy were associated with improved survival when compared to postoperative chemotherapy. No difference was noted between perioperative chemotherapy and postoperative chemoradiation therapy. These results were maintained in the optimally treated cohort.

The Association between Peptic Ulcer Disease and Gastric Cancer: Results from the Stomach Cancer Pooling (StoP) Project Consortium

BACKGROUND

Gastric cancer (GC) is the fifth most common type of cancer and the fourth most common cause of cancer-related mortality. Although the risk of GC and peptic ulcer disease (PUD) is known to be increased by H. pylori infection, evidence regarding the direct relationship between PUD and GC across ethnicities is inconclusive. Therefore, we investigated the association between PUD and GC in the Stomach cancer Pooling (StoP) consortium.

METHODS

History of peptic ulcer disease was collected using a structured questionnaire in 11 studies in the StoP consortium, including 4106 GC cases and 6922 controls. The two-stage individual-participant data meta-analysis approach was adopted to generate a priori. Unconditional logistic regression and Firth's penalized maximum likelihood estimator were used to calculate study-specific odds ratios (ORs) and 95% confidence intervals (CIs) for the association between gastric ulcer (GU)/duodenal ulcer (DU) and risk of GC.

RESULTS

History of GU and DU was thoroughly reported and used in association analysis, respectively, by 487 cases (12.5%) and 276 controls (4.1%), and 253 cases (7.8%) and 318 controls (6.0%). We found that GU was associated with an increased risk of GC (OR = 3.04, 95% CI: 2.07-4.49). No association between DU and GC risk was observed (OR = 1.03, 95% CI: 0.77-1.39).

CONCLUSIONS

In the pooled analysis of 11 case-control studies in a large consortium (i.e., the Stomach cancer Pooling (StoP) consortium), we found a positive association between GU and risk of GC and no association between DU and GC risk.

Regional and racial disparity in proximal gastric cancer survival outcomes 1996-2016: Results from SEER and China National Cancer Center database

BACKGROUND

Given the growing incidence and aggressive biological behavior of proximal gastric cancer (PGC) as reported, it is important to understand which regional or racial populations are at poor prognosis so that interventions can be treated appropriately. We sought to explore regional treatment differences as well as racial genes influence survival outcomes in China and the US patients with PGC.

METHODS

PGC patients defined as tumors with the epicenter located in cardia (C16.0) or fundus (C16.1) from 1996 to 2016 were identified from the Surveillance Epidemiology and End Results (SEER) in the United States as well as data from a high-volume National Cancer Center Database in China. Overall survival (OS) curves were plotted for different regional or racial groups, respectively, using the Kaplan-Meier method and compared statistically using the log-rank test. Differentially expressed genes (DEGs) analysis was performed using TCGA database.

RESULTS

Finally, the cohort consistent of 40973 PGC patients who enrolled in SEER database (n = 36305) or China National Cancer Center (n = 4668), and divided into 4 racial groups: Chinese (n = 5179), Black (n = 2429), White (n = 31185), and Others (n = 2096). After controlling for confounding variables, racial factors were independently associated with poor survival included Black ethnicity (HR = 1.376, 95% CI: 1.066-1.7760, p = 0.014) and White ethnicity (HR = 1.262, 95% CI: 1.005-1.583, p = 0.045) when compared to Chinese ethnicity in total PGC patients. Even in the same region for only US group, Chinese PGC patients also showed better prognosis.

CONCLUSIONS

In conclusion, we demonstrated the different survival outcomes of PGC patients in different regions or races from two high-volume database SEER and China National Cancer Center database. These survival differences are likely influenced by a number of factors (e.g., access to screening, quality of gastrectomy, neo/adjuvant therapy, and biological genes itself). More importantly, a better understanding of these disparities could lead to interventions that may help to abolish these disparities.

Helicobacter pylori-negative Gastric Cancer

<i>Helicobacter pylori (H. pylori)</i>-negative gastric cancer is diagnosed when gastric malignancies are found in patients in <i>H. pylori</i>-naïve stomachs. There are four types of noncardiac <i>H. pylori</i>-negative gastric cancers. The signet ring cell-type poorly cohesive carcinoma is most common, followed by the chief cell-predominant type gastric adenocarcinoma of the fundic gland. Extremely well-differentiated adenocarcinoma of the corpus and well-differentiated pyloric gland cancers are rare outside Japan because of country-specific differences in diagnostic criteria. In endemic areas of <i>H. pylori</i> infection, strict criteria are required for diagnosing an <i>H. pylori</i>-naïve stomach. Both invasive and noninvasive <i>H. pylori</i> tests should show negative results in a subject without a history of <i>H. pylori</i> infection. Furthermore, the serum pepsinogen (PG) assay and endoscopic findings of the background gastric mucosa are required to discriminate subjects with past infections owing to spontaneous regression or unintended eradication of <i>H. pylori</i>. There should be no gastric corpus atrophy (PG I ≤70 ng/mL and PG I/II ≤3.0). Gastroscopy should reveal a regular arrangement of collecting venules without gastric xanthoma, metaplastic gastritis, or advanced atrophy over the angle. On biopsy, there should be no gastric atrophy, intestinal metaplasia, neutrophils, or <i>H. pylori</i> infiltration, and only a mild degree of mononuclear cell infiltration is permitted. The types and characteristics of noncardiac <i>H. pylori</i>-negative gastric cancers are summarized in this review, along with current diagnostic challenges found in Korea.

Disaggregating Data on Pacific Islander Gastric Cancer Patients Reveals Survival Disparity

PURPOSE

The incidence and prognosis of Pacific Islanders with gastric cancer is not well documented as previous studies have often aggregated this population with Asians. The purpose of our study was to describe patient and tumor characteristics, as well as prognostic factors of Pacific Islanders with gastric cancer.

METHODS

Patients diagnosed with gastroesophageal junction or gastric adenocarcinoma between 2000 and 2014 were identified in the tumor registry of the largest hospital in Hawaii. Overall survival of Asians, Whites, and Pacific Islanders were calculated using the Kaplan-Meier method and log-rank test. Cox proportional hazards regression models were constructed to assess predictors of survival adjusting for clinical and pathological factors.

RESULTS

A total of 615 patients were included in the final analysis. Pacific Islanders were found to present at a younger age, were more often uninsured or had Medicaid insurance, and were diagnosed with a higher stage of cancer compared to their Asian and White counterparts. Pacific Islanders were less likely to undergo surgery even after adjusting for stage. Race was a prognostic factor and survival was lowest among Pacific Islanders, but only if the model was unadjusted for treatment.

CONCLUSIONS

We present an analysis of the largest cohort of Pacific Islander gastric cancer patients. Pacific Islanders have different sociodemographic characteristics and inferior survival compared to Asian patients and should be independently studied.

Rates of lymph node metastasis and survival in T1a gastric adenocarcinoma in Western populations

BACKGROUND AND AIMS

EMR and endoscopic submucosal dissection (ESD) are widely accepted in Asia for treatment of early gastric cancer (EGC). Few studies have examined lymph node (LN) metastasis of EGC in Western populations. We sought to examine EGC and LN metastasis in a heterogeneous Western population.

METHODS

Patients with surgically resected, histologically confirmed American Joint Committee on Cancer T1a gastric adenocarcinoma were identified in the Surveillance, Epidemiology, and End Results (SEER) database from 2002 to 2012. Patients were excluded if they had stage IV disease, had multiple primary cancers, or received neoadjuvant therapy. Rates of LN metastasis were calculated, and survival analyses were performed.

RESULTS

Of 923 patients in the cohort, 72 (7.8%) had at least 1 positive LN on final pathology. When stratified by race, Asian/Pacific Islanders (APIs) demonstrated the lowest rate of LN metastases (n = 17/327, 5.2%), followed by Hispanics (n = 12/171, 7.0%), whites (n = 27/278, 9.7%), and blacks (n = 16/147, 10.9%). The highest rates of stage IA disease were observed in API (93.9%) and Hispanic (92.4%) patients, followed by white (89.9%) and black (87.1%) patients (P = .04). Survival analysis of T1a gastric cancer patients by race/ethnicity showed that 5-year overall survival was highest for API patients (API, 88%; Hispanic, 81%; black, 79%; and white, 77%; P < .01).

CONCLUSIONS

The rate of LN metastasis in T1a gastric cancers in the United States is higher than the rates reported in Asia. Survival outcomes in T1a gastric cancers varied significantly by race, suggesting that definitive endoscopic treatment may not be appropriate for all patients in the United States.

Treatment and outcomes of gastric cancer among United States-born and foreign-born Asians and Pacific Islanders

BACKGROUND

The authors investigated whether stage at diagnosis, cancer treatments, and survival of Asian and Pacific Islander (API) gastric cancer patients in the United States vary by birthplace.

METHODS

The authors studied 6454 API and 10,099 non-Hispanic white (NHW) patients diagnosed with gastric cancer from the Surveillance, Epidemiology, and End Results program between 1992 and 2005. In descriptive analyses, stage, receipt of adequate lymph node examination (ALNE), and surgery were compared among US-born APIs, foreign-born (FB) APIs, and NHWs. Multivariate polytomous logistic and proportional hazards regression models were used to assess differences in cancer stage and survival, respectively, adjusted for clinical and demographic factors.

RESULTS

As a group, APIs were more likely than NHWs to present with earlier-stage diagnoses and receive surgery and ALNE (P < .001). However, FB (adjusted odds ratios [aOR], 0.79; 95% confidence interval [CI], 0.73-0.86) but not US-born APIs (aOR, 1.05; 95% CI, 0.92-1.20) were significantly more likely to present at earlier stages than NHWs. Compared with NHW patients, FB and US-born APIs were more likely to receive surgery (adjusted risk ratio [aRR], 1.06; 95% CI, 1.03-1.09 and aRR, 1.09; 95% CI, 1.03-1.14, respectively) and ALNE (aRR, 1.29; 95% CI, 1.19-1.41 and aRR, 1.14; 95% CI, 1.00-1.32, respectively). In fully adjusted models, FB (adjusted relative hazard ratios [aHR], 0.86; 95% CI, 0.82-0.90) but not US-born APIs (aHR, 0.96; 95% CI, 0.89-1.04) had more favorable survival than NHWs.

CONCLUSIONS

The earlier-stage diagnosis, more complete surgical treatment, and improved survival of Asians and Pacific Islanders with gastric cancer may result from less aggressive tumors or more prompt recognition and thorough evaluation of early symptoms. Further study of these factors could improve outcomes for all patients with gastric cancer.

Different pathological features and prognosis in gastric cancer patients coming from high-risk and low-risk areas of Italy

OBJECTIVE

To compare clinicopathological features and long-term outcome in gastric cancer patients coming from high-risk and low-risk areas of Italy.

SUMMARY BACKGROUND DATA

Better survival rates have been reported from countries with higher incidence of gastric cancer.

METHODS

Data regarding 829 patients coming from Tuscany (group A) and 143 patients coming from Southern Italy (group B) were analyzed. Mean follow-up time was 56 +/- 57 months; it was 85 +/- 63 months in surviving patients or not tumor-related deaths. Prognostic factors were investigated by multivariate analysis with Cox proportional hazard model after verifying the assumption of proportionality of the risk associated with covariates.

RESULTS

Lauren diffuse-mixed histotype, younger age, extended lymphadenectomy, and advanced stages were more common in group B. Gastric cancer-related 10-year survival probability was 48% in group A versus 29% in group B (log-rank test: P < 0.001). By multivariate analysis, geographic area was confirmed as a significant prognostic factor (hazard ratio for group B vs. group A: 1.52, 95% confidence interval: 1.12-2.06, P = 0.006). The influence of this factor on long-term survival was independent from other clinical, surgical, and pathologic factors, and was notable in neoplasms involving the serosa (10-year survival probability: 15% in group A vs. 3% in group B, log-rank test: P = 0.005).

CONCLUSIONS

Patients coming from low-risk area of Italy showed distinct pathologic features, more advanced stage, and worse prognosis when compared with patients coming from high-risk area. These findings may be indicative of different tumor biology, and may contribute to partly explain worldwide geographic variability in prognosis reported in different series.