Prognostic Threshold of Neuroendocrine Differentiation in Gastric Carcinoma: a Clinicopathological Study of 945 Cases

Clinicopathological characteristics of gastric neuroendocrine neoplasms: A comprehensive analysis

OBJECTIVE

This study aimed to explore the clinicopathological characteristics and prognostic implications of gastric neuroendocrine neoplasms (g-NENs).

METHODS

A retrospective enrollment of 142 patients diagnosed with g-NENs was conducted at Zhejiang Cancer Hospital between January 1, 2007 and December 31, 2021. The study compared essential clinicopathological features and survival rates. Additionally, the prognosis of gastric neuroendocrine carcinomas/mixed neuroendocrine-non-neuroendocrine neoplasms (g-NEC/MiNEN) were contrasted with those of gastric adenocarcinoma (GAC) and signet ring cell carcinoma (SRCC).

RESULTS

The study comprised a total of 142 g-NENs cases, with a male-to-female ratio of approximately 2:1. The 5-year survival rates for g-NEC and g-MiNEN were 26.7% and 35.2%, respectively. Corresponding 5-year survival rates for G1 and G2 were observed at 100% and 80.0%, respectively. g-NEC/MiNEN showed a significantly worse prognosis compared to g-NET (p < 0.001). g-NEC/MiNEN exhibited a poor prognosis compared to GAC (p < 0.001), and within poorly differentiated GAC, g-NEC/MiNEN demonstrated a worse prognosis (p = 0.007). Additionally, patients receiving postoperative adjuvant therapy exhibited notably prolonged overall survival (OS) in the case of g-NEC/MiNEN (p = 0.010).

CONCLUSION

In short, the prognosis of g-NEC/MiNEN was worse than that of g-NET, GAC and poorly differentiated GAC, but this group benefit from postoperative adjuvant therapy.

Correlation of Neuroendocrine Differentiation with a Distinctively Suppressive Immune Microenvironment in Gastric Cancer

INTRODUCTION

Neuroendocrine neoplasms (NENs) harbored significantly suppressive tumor immune microenvironments (TIMEs). However, the immunological effects of neuroendocrine differentiation (NED) on non-NENs, such as gastric cancer (GC), were unknown.

METHODS

Between pure gastric cancer (PGC) and GC-NED, TIME features were scored based on expression data and validated on serial whole-tissue sections of surgical samples, with tertiary lymphoid structures (TLSs) and the extra-TLS zone evaluated independently using multi-marker immunohistochemical staining. Risk analyses of TIME features on tumor behaviors were performed in GC-NED. The universal immunological effects of NED were explored preliminarily in adenocarcinomas arising in other organs.

RESULTS

Based on over 11,500 annotated TLSs and 2,700 extra-TLS zones, compared with PGC, GC-NED harbored a distinctively more suppressive TIME characterized by increased but immature TLSs, with higher naïve B-cell and follicular regulatory T-cell densities and downregulated TLS maturation-related cell ratios inside TLSs; increased naïve B-cell and regulatory T-cell densities; and a high proportion of exhausted T cells in the extra-TLS zone. The upregulated tumor PD-L1 expression and its close correlations with TLS formation and maturation were remarkable exclusively in GC-NED. TIME features, especially those regarding TLSs, were significantly correlated with tumor growth and invasion. The desynchrony between TLS formation and maturation and increased naïve or regulatory immune cell infiltration was observed in adenocarcinomas of the colorectum, pancreas, lung, and prostate.

CONCLUSION

NED highlighted a distinct GC entity with more suppressive TIME features correlated with tumor behaviors, indicating a cohort that would benefit more from immunotherapies.

Clinicopathological Features and Postoperative Survival Analysis of Gastric Carcinoma with Neuroendocrine Differentiation

Objectives

This study aims at investigating the differences of clinicopathological features and postoperative prognosis in three different types of neuroendocrine differentiation-related gastric cancers.

Methods

From January 1, 2015 to September 30, 2016, 47 patients diagnosed with neuroendocrine differentiation-related gastric cancers were collected from 1095 patients with gastric cancer who underwent surgical treatment in the Department of Gastrointestinal Surgery, Jiangsu Cancer Hospital. Patients were followed up regularly, and the last follow-up time was October 25, 2021. A total of 38 cases met the inclusion criteria and completed follow-up. The clinicopathological characters and immunohistochemical results of these three special pathological types of gastric cancer (adenocarcinoma with neuroendocrine differentiation, mixed adenoneuroendocrine carcinoma, and neuroendocrine carcinoma of the stomach) patients were compared. Tissues from these patients were tested with immunohistochemical markers synaptophysin (Syn), chromogranin A (CgA), and Ki-67. The Kaplan–Meier method and log-rank test were used to analyze the effect of different histological types of gastric cancer on overall survival (OS). The differences in positive rates of chromogranin A (CgA) and Ki-67 were analyzed by univariate Cox regression analysis as independent risk factors that may affect the survival of gastric cancer patients.

Results

Ki-67 and N staging were significantly correlated with OS in gastric cancer patients and were independent prognostic factors affecting the survival of gastric cancer patients. There was no statistical difference in OS between the two histopathological types (adenocarcinoma with neuroendocrine differentiation and mixed adenoneuroendocrine carcinoma) of gastric cancer patients. There were no significant differences in the positive rates of immunohistochemical markers Syn, CgA, and Ki-67 in gastric cancer patients with different histological types.

Conclusion

The combined detection of Syn and CgA is of great value for the diagnosis of neuroendocrine differentiation-related gastric cancers, Ki-67 is of significance for the prognosis prediction of neuroendocrine differentiation-related gastric cancers, regional lymph node metastasis has a great impact on tumor prognosis, and the N staging determines the necessity of postoperative adjuvant chemotherapy for patients with neuroendocrine differentiation-related gastric cancer.

Better Prognosis of Gastric Neuroendocrine Carcinoma Than Gastric Adenocarcinoma among Whites in the United States: A Propensity Score Matching Analysis Based on SEER

It was generally believed that the prognosis of gastric neuroendocrine carcinoma (GNEC) was worse than gastric adenocarcinoma (GAC). However, almost all previous studies compared the prognosis of GNEC and GAC based on East Asians. In this study, we evaluated the clinicopathological features and prognosis of GNEC and GAC in Whites. Patients with GNEC and GAC were identified from 2000 to 2018 in the Surveillance, Epidemiology, and End Results (SEER) database. We used propensity score matching (PSM) analysis to match the age, sex, TNM stage, and treatments received between GNEC and GAC, then compared the overall survival (OS) and cancer-specific survival (CSS) in the two types. A total of 392 cases of GNEC and 12,835 cases of GAC in Whites were recognized. After PSM, the 5-year OS rates of GNEC and GAC were 50.3% and 43.0%, respectively (p = 0.010). The 5-year CSS rates of GNEC and GAC were 57.4% and 50.1%, respectively (p = 0.012). Besides, multivariable cox regression analyses showed that GNEC was an independent predictor of improved OS (HR 0.719; 95% CI 0.607–0.853) and CSS (HR 0.691; 95% CI 0.571–0.835) in the matched data. The prognosis of GNEC was better than GAC in Whites, showing significant ethnic differences. Appropriate treatments and follow-up strategies for GNEC in Whites are probably different from East Asians. The potential genetic and molecular mechanisms need to be further explored.

Metastasis Prevalence and Survival of Patients with T1-2 Gastric Neuroendocrine Tumor Treated with Endoscopic Therapy and Surgery

BACKGROUND AND AIM

The selection criteria and long-term outcomes of endoscopic therapy (ET) for gastric neuroendocrine tumors (G-NETs) remain controversial.

METHODS

Using Surveillance, Epidemiology, and End Results (SEER) Program database, we assessed the prevalence of metastasis of early G-NETs and long-term outcomes of ET in G-NET patients with good/moderate differentiation and no muscularis propria (MP) involvement.

RESULTS

A total of 2207 patients with stage T1 and T2 G-NETs were included. The depth of invasion into MP [odds ratio (OR) 4.581, 95% confidence interval (CI) 2.571-8.162; P < 0.001] and size of > 20 mm (OR 5.656, 95% CI 2.002-15.975; P = 0.001) were significantly associated with metastasis. The 5-year overall survival (OS) and cancer-specific survival (CSS) of the ET group were similar to the surgery group (91.11% vs. 91.09%, P = 0.750; 99.26% vs. 99.01%, P = 0.173). In the multivariable Cox proportional hazards regression models adjusting for age, gender, race, year of diagnosis, SEER region, depth of tumor invasion, site of cancer, tumor size, and chemotherapy, procedures employed (ET or surgery) had no significant impact on the OS [hazard ratio (HR) 1.189; 95%CI 0.721-1.961; P = 0.498] and CSS (HR 0.684; 95% CI 0.021-22.727; P = 0.832).

CONCLUSIONS

The long-term outcome of survival did not appear to differ between ET and surgery in G-NETs with good/moderate differentiation, ≤ 20 mm size, and no MP involvement.

Presentation and outcome of mixed neuroendocrine non-neuroendocrine neoplasms of the pancreas

BACKGROUND/OBJECTIVES

Mixed neuroendocrine non-neuroendocrine neoplasms (MiNEN) of the pancreas and periampullary region are extremely rare and heterogeneous malignancies. Literature is sparse, clinical management is not standardized and little is known about survival outcomes. The aim of this study was to identify pathological and radiological features of MiNEN and assess the outcome of surgical management.

METHODS

Patients undergoing surgery for pancreatic and periampullary MiNEN between 2001 and 2019 were retrospectively analysed based on a prospective database. Histological, radiological and clinical features were assessed. Survival was analysed in a nested case-control study and matched-pair analyses with pure neuroendocrine neoplasms (pNEN) and ductal adeno- or acinar cell carcinomas of the pancreas. A literature review with focus on survival after surgical resection was additionally performed.

RESULTS

Of 13 patients with MiNEN, 5 had acinar-MiNEN and 8 adeno-MiNEN. Two of 5 (40%) acinar-MiNEN and one adeno-MiNEN patients had liver metastases. All but one adeno-MiNEN (88%) showed preoperative radiological features of pancreatic adenocarcinoma, 3 of 5 (60%) acinar-MiNEN exhibited mainly neuroendocrine features. No surgical mortality was observed. The 5-year overall survival rate in all MiNEN was 40%. Five-year survival rate was 58% in adeno-MiNEN and comparable to that of matched ductal adenocarcinomas (36%) and pNEN (48%). Five-year overall survival rate was 20% in acinar-MiNEN, compared to 39% in acinar carcinoma patients and 59% in matched pNEN patients.

CONCLUSIONS

MiNEN are rare and difficult to distinguish from pure adenocarcinoma or neuroendocrine neoplasm preoperatively. Surgical resection would therefore be the treatment of choice in localized tumors.

Serum lipid levels correlate to the progression of gastric cancer with neuroendocrine immunophenotypes: A multicenter retrospective study

PURPOSE

Dyslipidemia was associated with gastric adenocarcinoma or neuroendocrine tumors, but its role in a more malignant entity, gastric cancer with neuroendocrine immunophenotypes (GCNEI), was unclarified. This study sought to explore the relationship between serum lipid levels and the biological behaviors of gastric cancer with neuroendocrine immunophenotypes (GCNEI).

METHODS

Patients with neuroendocrine carcinoma (NEC), GC with NEC components (GC-NEC), or GC expressing NE marker(s) but no NE morphology (GC-NENM) were enrolled from three centers. Their preoperative serum lipid levels, demographic, and clinicopathological information were analyzed and compared with those of patients with pure adenocarcinoma (PAC) or a background population selected from 10,061 health-check people by propensity-score matching.

RESULTS

A total of 342 GCNEI patients were enrolled. Compared with the background population, total cholesterol (TCHO) and high-density lipoprotein cholesterol (HDL-C) levels were lower in GCNEI. Compared with PAC, GC-NENM and GC-NEC showed lower triglyceride (TG) levels, while, carcinoma with NE morphology showed higher low-density lipoprotein cholesterol (LDL-C) levels. Among GCNEI subtypes, GC-NEC differed from the others by higher LDL-C and non-HDL-C levels. A higher LDL-C level and(or) lower TG, HDL-C levels correlated to higher stages or large tumor sizes in GC-NENM, and a lower HDL-C level correlated to large tumor sizes in GC-NEC. A higher LDL-C level, lower TG, HDL-C, and non-HDL levels increased the risk of GC-NEC, and lower TG, and HDL-C levels increased the risk of GC-NENM and NEC.

CONCLUSION

GCNEI had distinct and heterogeneous serum lipid patterns, which correlated to tumor development and progression.