Clonality analysis of neuroendocrine cells in gastric adenocarcinoma

Neuroendocrine differentiation and serotonin expression in oesophageal adenocarcinomas after neoadjuvant therapy: correlation with clinicopathological features and outcome

AIMS

Oesophageal adenocarcinoma (EAC) is a glandular or mucinous epithelial malignancy that can show immunohistochemical evidence of neuroendocrine differentiation (NED) and express the hormone serotonin. The objective of this study was to correlate the presence of NED and serotonin with clinicopathological characteristics and patient outcome after neoadjuvant chemoradiation.

METHODS AND RESULTS

A retrospective cohort of patients treated between 2002 and 2021 was established and included 218 oesophagectomy specimens with residual tumour. Representative full-face sections of tumour were stained for synaptophysin, chromogranin-A and serotonin by immunohistochemistry, and staining results were correlated with disease-free survival (DFS) and overall survival (OS). In total, 129 (59%) tumours showed evidence of NED, defined as immunohistochemical expression of synaptophysin or chromogranin-A, while 40 (18%) showed evidence of NED and expressed serotonin. Patients with neuroendocrine-positive tumours had significantly shorter median OS compared to those with neuroendocrine-negative tumours (22.5 versus 48.8 months, P = 0.006), but similar median DFS (13.3 versus 17.8 months, P = 0.34). Using Cox regression, the association between NED and OS was significant in univariate [hazard ratio (HR) = 1.68, 95% confidence interval (CI) = 1.16-2.45] and multivariate (HR = 1.65, 95% CI = 1.08-2.52) analysis. Patients with serotonin-expressing tumours had similar median OS (21.7 versus 25.9 months, P = 0.24) and DFS (7.3 versus 15.6 months, P = 0.12) compared to those with NED but lacking serotonin. Using Cox regression, serotonin expression was associated with reduced OS in univariate (HR = 1.62, 95% CI = 1.06-2.47) but not multivariate (HR = 1.03, 95% CI = 0.64-1.65) analysis.

CONCLUSIONS

Our findings support NED as independent predictor of OS in EAC after neoadjuvant chemoradiation. While a subset of tumours with NED expressed serotonin, this did not provide additional prognostic information.

Synaptophysin and chromogranin A expression analysis in human tumors

The expression of the neuroendocrine markers synaptophysin and chromogranin A was analyzed by immunohistochemistry in 14,584 samples from 103 different tumor types and subtypes in a tissue microarray format. At least one of these markers was found to be positive in 96.7% of tumors from various subtypes of neuroendocrine neoplasms. In non-neuroendocrine tumors, synaptophysin and/or chromogranin A staining was seen in 6.3% (n = 584), specifically in 41 of 88 non-neuroendocrine tumor entities. Basal cell carcinomas of the skin (50% positive for chromogranin A alone) and adrenocortical carcinomas (91.7% positive for synaptophysin alone) stood out due to a frequent expression of only one specific marker. A subdivision of non-neuroendocrine neoplasms revealed "neuroendocrine differentiation" most commonly in adenocarcinomas from the female genital tract (18.9%), from pancreatico-/hepato-/biliary tract (15.8%) and the prostate (14.9%) while it was rare in urothelial (1.0%) and squamous cell carcinomas (0.6%). A comparison with clinico-pathological parameters of tumor aggressiveness did not suggest a clinical significance of neuroendocrine marker expression in 204 endometrium cancers, 249 pancreatic adenocarcinomas, 233 gastric adenocarcinomas and 1,182 colorectal adenocarcinomas. Within a cohort of 1,073 breast cancers of no special type, synaptophysin positivity was seen in 4.9% of cases and it was significantly linked to advanced tumor stage (p = 0.0427), high tumor grade (p = 0.0319) and loss of estrogen receptor expression (p = 0.0061) but unrelated to patient outcome. In conclusion, "neuroendocrine differentiation" can be observed in many different tumor types with non-neuroendocrine morphology. Evidence for a statistically significant association (p < 0.0001) between such a "neuroendocrine differentiation" and tumor aggressiveness could not be found.

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

Purpose

The significance of neuroendocrine differentiation (NED) in gastric carcinoma (GC) is controversial, leading to ambiguous concepts in traditional classifications. This study aimed to determine the prognostic threshold of meaningful NED in GC and clarify its unclear features in existing classifications.

Materials and Methods

Immunohistochemical staining for synaptophysin, chromogranin A, and neural cell adhesion molecule was performed for 945 GC specimens. Survival analysis was performed using the log-rank test and univariate/multivariate models with percentages of NED (P_NED) and demographic and clinicopathological parameters.

Results

In total, 275 (29.1%) cases were immunoreactive to at least 1 neuroendocrine (NE) marker. GC-NED was more common in the upper third of the stomach. P_NED, and Borrmann's classification and tumor, lymph node, metastasis stages were independent prognostic factors. The cutoff P_NED was 10%, beyond which patients had significantly worse outcomes, although the risk did not increase with higher P_NED. Tumors with ≥10% NED tended to manifest as Borrmann type III lesion with mixed/diffuse morphology and poorer histological differentiation; the NE components in this population mainly grew in insulae/nests, which differed from the predominant growth pattern (glandular/acinar) in GC with <10% NED.

Conclusions

GC with ≥10% NED should be classified as a distinct subtype because of its worse prognosis, and more attention should be paid to the necessity of additional therapeutics for NE components.

Analysis of Gastric Carcinoma With Neuroendocrine Character

The clinical significance of gastric adenocarcinoma with neuroendocrine differentiation is unclear because of its rarity. The aim of this study was to suggest a treatment strategy for this tumor. A total of 10 resected gastric tumors with neuroendocrine character, including 3 neuroendocrine carcinomas (NECs) and 7 adenocarcinomas with neuroendocrine differentiation, were retrospectively reviewed regarding tumor characteristics and therapeutic outcomes. The gastric adenocarcinomas with neuroendocrine differentiation had high rates of lymph node metastasis and vessel invasion, and showed the poor prognoses as NEC. The median survival time (MST) was 13 months. Preoperative and postoperative chemotherapy tended to prolong the MST compared with operation alone (112.5 versus 5 months; P = 0.058). Moreover, chemotherapy for postoperative recurrence significantly contributed to improving prognosis (MST, 15 versus 7 months; P = 0.025). Gastric adenocarcinoma with neuroendocrine differentiation had equivalently high potential malignancy as NEC. More aggressive treatment should be considered for this tumor according to NEC.

miR-135a inhibits tumor metastasis and angiogenesis by targeting FAK pathway

Tumor metastasis has been the major cause of recurrence and death in patients with gastric cancer. Here, we find miR-135a has a decreased expression in the metastatic cell lines compared with its parental cell lines by analyzing microRNA array. Further results show that miR-135a is downregulated in the majority of human gastric cancer tissues and cell lines. Decreased expression of miR-135a is associated with TNM stage and poor survival. Besides, regaining miR-135a in gastric cancer cells obviously inhibits tumor growth, migration, invasion and angiogenesis by targeting focal adhesion kinase (FAK) pathway. Bioinformatics analysis and molecular experiments further prove that miR-135a is a novel downstream gene of tumor suppressor p53. Blocking FAK with its inhibitor can also enhance miR-135a expression through inducing p53. In summary, this study reveals the expression and function of miR-135a in gastric cancer and uncovers a novel regulatory mechanism of miR-135a.

A Previously Undescribed Presentation of Mixed Adenoneuroendocrine Carcinoma

We report a case of mixed adenoneuroendocrine carcinoma (MANEC) of stomach with tubular adenoma and well-differentiated neuroendocrine tumor (WD-NET) in the primary tumor in the stomach giving rise to biphenotypic regional nodal metastases. A 35-year-old woman with abdominal pain was found to have a 1.8-cm gastric lesion, diagnosed as WD-NET (intermediate grade) on the biopsy. The resection specimen contained residual WD-NET; there was also a gastric adenoma adjacent to the NET and nodal metastasis with both adeno- and neuroendocrine components. The tumor was classified as MANEC. Of note, the entire gastric tissue was submitted and multiple deeper levels of the adenomatous lesion were examined; no adenocarcinoma was present in the primary lesion. While association of gastric adenoma with neuroendocrine neoplasm is rare, presence of biphenotypic metastasis originating from such a lesion is highly unusual and to the best of our knowledge has not been reported.

Detection of microsatellite instability in gastric cancer and dysplasia tissues

OBJECTIVE

We aimed to investigate the association between gastric cancer and microsatellite instability (MSI) in the present study.

METHOD

Phenol-chloroform method was employed for DNA extraction from the cancer tissues of 65gastric cancer patients and the dysplasia tissues and normal control tissues of 32 non-gastric cancer patients. The microsatellite loci Bat25, Bat26, D2S123, D5S346 and D17S250 were detected by using PCR-SSCP silver staining technique, and the MSI of the gastric cancer tissues and the precancerous tissues was analyzed.

RESULTS

Of 65 gastric cancer cases, MSI was detected in 43 cases, with the detection rate of 66.2%. There were 13 cases showing MSI-H and 30 cases showing MSI-L, accounting for 30.2% and 69.8%, respectively. Among 32 cases of dysplasia tissues, MSI was detected in 10 cases, with the detection rate of 31.3%. Two cases of dysplasia tissues showed MSI-H and 8 cases showed MSI-L, accounting for 20.0% and 80.0%, respectively.

CONCLUSION

Gastric cancer patients had a high detection rate of MSI. It is speculated that MSI is another molecular mechanism of carcinogenesis and may serve as a sensitive diagnostic indicator of gastric cancer.

Boveri at 100: cancer evolution, from preneoplasia to malignancy

In the 100 years since the publication of Boveri's manuscript, 'Concerning the origin of human tumours', we have seen many advances in our understanding of how tumours originate, develop and progress. However, reading this article now, it is possible to find conclusions, or more often predictions, of what we now consider basic tenets of tumour biology. These include predicting the stochastic nature of the malignant change and that all tumours are necessarily of clonal origin, perhaps the basis of the modern concepts of field cancerization, of tumour heterogeneity and the clonal evolution of tumours. Modern researchers rarely refer to this paper, yet as a source of ideas it must rank amongst the landmarks in tumour biology of the last 100 years.