Histologic and immunohistochemical analyses of α-fetoprotein--producing cancer of the stomach. Am J Surg Pathol. 2012;36:56-65. [PMID: 22173117 DOI: 10.1097/pas.0b013e31823aafec]

α‑Fetoprotein‑positive hepatoid adenocarcinoma of the stomach and a new classification: A case report

α-Fetoprotein (AFP)-producing gastric carcinoma (AFPGC) is a rare subtype of gastric cancer (GC) with controversial classification methods. Hepatoid adenocarcinoma of the stomach (HAS) is another rare subtype of GC. Its definition intersects with that of AFPGC, but it is much rarer. The present report describes the case of an elderly patient with GC and AFPGC and HAS features in a serum test and pathology, respectively, and proposes a new classification of GC subtypes based on histological and AFP-producing features. A 75-year-old woman presented with a history of polydipsia and polyuria for over a decade and dizziness for 1 day. Serum AFP levels gradually elevated from 183.70 to 397.70 ng/ml in 1 month after the patient's first clinic visit. Subsequent pathological findings from endoscopic biopsy samples confirmed a hepatoid focus with positive immunohistochemical staining for AFP. The patient underwent a laparoscopic-assisted radical total gastrectomy and esophagojejunal Roux-en-Y anastomosis, and the serum AFP levels decreased to the normal range after the surgery. The present case indicates the diagnostic value of both the serum AFP level and pathological examinations in the diagnosis of AFPGC and HAS, and also highlights the contemporary circumstances of the vague classification based on different criteria for these two subtypes. Furthermore, the present report proposes a new classification considering both histological and AFP-producing features (using both serum biomarkers and immunohistochemistry tests) to cover all cases encompassed by AFPGC and HAS under all definition methods. This new method would give more precise diagnoses and add value to the subsequent treatment decision-making.

Alpha-fetoprotein producing endometrioid carcinoma arising in an adenomyoma of the uterus

We report a case of alpha-fetoprotein-producing endometrioid carcinoma (AFP-EC) that originated within an adenomyoma of the uterine corpus. A 76-year-old Japanese woman was incidentally discovered to have a uterine tumor along with multiple lung nodules. Upon surgical removal of the uterus, it was revealed that the tumor was situated within the adenomyoma. The tumor exhibited microfollicular structures and solid growth patterns, with hyaline globules, clear cell glands, and primitive tumor cells. Immunohistochemical analysis indicated the presence of germ cell markers, including AFP, SALL4, and glypican3, leading to final diagnosis of AFP-EC. Histopathologically, AFP-ECs exhibit characteristics similar to those of AFP-producing neoplasms in other organs. Furthermore, a nomenclature issue arises when distinguishing AFP-ECs from yolk sac tumors of the endometrium in older patients due to their shared features. The concept of retrodifferentiation or neometaplasia suggests that "endometrioid carcinoma with yolk sac tumor differentiation" or "endometrioid carcinoma with a primitive phenotype" may serve as more fitting terms for the diverse spectrum of AFP-producing neoplasms in the endometrium. In conclusion, this case underscores the diagnostic challenges posed by AFP-ECs arising from adenomyomas and emphasizes the need for refining the nomenclature and classification of AFP-producing neoplasms within the endometrium.

Case report and literature analysis: pancreatic hepatoid carcinoma with multiple lymph node metastases progressing to liver metastasis after pancreaticoduodenectomy

Hepatoid carcinoma is an extrahepatic primary tumor displaying characteristics reminiscent of hepatocellular carcinoma differentiation, which is found in various organs, such as the stomach, ovaries, gallbladder, and pancreas. Reports of pancreatic hepatoid carcinoma remain scarce. Consequently, understanding of this disease remains a priority, with no established consensus on its diagnosis and management. Here, we reported the case of a 45-year-old woman diagnosed with hepatoid carcinoma located in the pancreatic head, accompanied by multiple lymph node metastases. Following pancreaticoduodenectomy, the patient developed liver metastases within 3 months. Subsequently, she underwent adjuvant therapy consisting of Teysuno and Durvalumab following microwave ablation for the liver metastases. Remarkably, the patient has survived for one year without significant disease progression. This case underscores the potential efficacy of immunotherapy as a promising treatment option for pancreatic hepatoid carcinoma. Further research and clinical trials are warranted to explore the optimal management strategies for this rare and challenging malignancy.

An Interesting Case of Alpha-Fetoprotein (AFP)-Producing Pancreaticoduodenal Tumor

Alpha-fetoprotein (AFP) is considered one of the best-known predictive serum markers, playing a crucial role in cancer investigation and subsequent treatment. In most adult cells, the production of this marker is suppressed after embryogenesis. However, its increased level raises concerns about underlying malignant conditions, which provide a valuable diagnostic tool for medical professionals in oncology. The existing AFP-producing adenocarcinomas exhibit unique clinical characteristics, including high malignancy and early metastatic potential, which result in poorer outcomes. To illustrate these characteristics, we decided to describe a case report of a 70-year-old African American female with a significantly elevated level of AFP. Further pathology results confirmed a duodenal adenocarcinoma versus adenocarcinoma from the pancreas. While AFP-producing adenocarcinoma has multiple underlying molecular mechanisms that correlate with poor prognosis, definitive treatment based on molecular pathways has yet to be defined. Therefore, further research is needed for new therapeutic modalities.

Unusual or Uncommon Histology of Gastric Cancer

This review comprehensively examines the diverse spectrum of gastric cancers, focusing on unusual or uncommon histology that presents significant diagnostic and therapeutic challenges. While the predominant form, tubular adenocarcinoma, is well-characterized, this review focuses on lesser-known variants, including papillary adenocarcinoma, micropapillary carcinoma, adenosquamous carcinoma, squamous cell carcinoma (SCC), hepatoid adenocarcinoma, gastric choriocarcinoma, gastric carcinoma with lymphoid stroma, carcinosarcoma, gastroblastoma, parietal cell carcinoma, oncocytic adenocarcinoma, Paneth cell carcinoma, gastric adenocarcinoma of the fundic gland type, undifferentiated carcinoma, and extremely well-differentiated adenocarcinoma. Although these diseases have different nomenclatures characterized by distinct histopathological features, these phenotypes often overlap, making it difficult to draw clear boundaries. Furthermore, the number of cases was limited, and the unique histopathological nature and potential pathogenic mechanisms were not well defined. This review highlights the importance of understanding these rare variants for accurate diagnosis, effective treatment planning, and improving patient outcomes. This review emphasizes the need for ongoing research and case studies to enhance our knowledge of these uncommon forms of gastric cancer, which will ultimately contribute to more effective treatments and better prognostic assessments. This review aimed to broaden the pathological narrative by acknowledging and addressing the intricacies of all cancer types, regardless of their rarity, to advance patient care and improve prognosis.

Exploring the molecular characteristics of the malignant potential of gastric adenocarcinoma with enteroblastic differentiation

AIMS

Gastric adenocarcinoma with enteroblastic differentiation (GAED) is a rare subset of alpha-fetoprotein (AFP)-producing carcinomas with poor prognosis. However, the molecular features associated with the malignant potential of GEAD remain partially elucidated.

METHODS AND RESULTS

In this study, the relationship between clinicopathological parameters and aggressive biological behaviour was analysed in 37 patients with GAED. The results showed that GAED tended to infiltrate the deep layer of the gastric wall and possessed more frequent vascular invasion than conventional gastric adenocarcinoma (CGA) (P < 0.001). All distant metastases were observed in the GAED group, not the CGA group (P < 0.001). High HER2 expression was found in nearly 24.32% of the informative cases, and none showed EBV-encoded RNA positivity or deficient mismatch repair. The most frequently mutated gene in GAED was p53. Programmed cell death-ligand 1 (PD-L1) immunostaining revealed 13 patients with a combined positive score (CPS) ≥ 5 (65%, 13 of 20). Thus, based on these molecular markers (immunostaining, in situ hybridisation and mutation analysis), GAED may be classified as a unique subgroup of the chromosomal instability subtype with HER2+ /EBV- /MSS/TP53+ /PD-L1+ . Next-generation sequencing analyses showed that mutations in the TOPI, ELOA and NOTCH3 genes were found only in GAED, and abnormally expressed genes in GAED were significantly enriched in hepatocellular carcinoma-, gland development-, and gastric cancer-related pathways.

CONCLUSION

The HER2+ /EBV- /MSS/TP53+ /PD-L1+ profile and hepatocellular carcinoma-related pathways may be significant in the malignant potential of GAED. In addition to anti-HER2 therapy, immune check-point inhibitors may be an effective treatment option for patients with GAED.

Clinicopathological characteristics of gastric adenocarcinoma with enteroblastic differentiation and gastric adenocarcinoma with enteroblastic marker expression

Gastric adenocarcinoma (GA) with enteroblastic differentiation (GAED) is an aggressive carcinoma histologically characterized by a glycogen-rich clear cytoplasm and fetal gut-like structures. GAED shows the expression of at least one of the following enteroblastic markers (EMs): glypican-3 (GPC3), spalt-like transcription factor 4 (SALL4), and α-fetoprotein (AFP). Despite the absence of clear cytoplasm, we often encounter GA with EMs expression (GA with EM); however, the clinicopathological characteristics of GA with EM remain unclear. Immunohistochemical (IHC) expression of three EMs (AFP, GPC3, and SALL4) was examined on tissue microarray. According to the status of the clear cytoplasm of tumor cells, GAs showing IHC expression of EMs were classified as either GAED or GA with EM, and this analysis categorized 688 GAs into 94 GAEDs (13.7%), 58 GAs with EM (8.4%), and 536 conventional GAs (CGAs). Both GAED and GA with EM showed frequent lymphovascular invasion, lymph node metastasis, and liver metastasis compared to CGA. However, a higher frequency of venous invasion, but not of lymphatic invasion, was noted for GAED in comparison to CGA. GAED and GA with EM showed similar overall survival. GAED had significantly poorer prognosis than CGA; however, not for GA with EM. Furthermore, GA showing EM expression had a worse prognosis than CGA. Interestingly, GA showing EM-positive group was more aggressive than CGA group as they had frequent venous invasion and liver metastasis despite its smaller tumor size. GAED and GA with EM can be clinically classified as aggressive tumors but pathologically they seem to be slightly different.

Gastric Carcinoma With Sebaceous Differentiation and SALL4 Expression

A sebaceous carcinoma is rarely seen in extracutaneous sites. We present a 75-year-old man who was admitted with epigastralgia and melena. Endoscopic examination revealed an ulcer on the posterior wall of the gastric antrum, and distal gastrectomy was performed. Histopathological examination revealed thin to thick trabeculae of polygonal cells with scattered foci of foamy cells, whereas Sudan 3 staining showed lipid vacuoles. Immunohistochemistry was positive for both p40 and SALL4. After considering these findings, we suggest sebaceous differentiation as the diagnosis. To the best of our knowledge, this is the first case of gastric carcinoma with sebaceous differentiation.

Combined tubular adenocarcinoma, neuroendocrine carcinoma and adenocarcinoma with enteroblastic differentiation arising in Barrett esophagus

Adenocarcinoma (AC) with neuroendocrine carcinoma (NEC) or enteroblastic (ENT) differentiation rarely develops in Barrett's esophagus (BE). A 76-year-old man was diagnosed with Barrett's AC (cT1bN0M0) and underwent thoracoscopic esophagectomy. A type 0-IIc + 0-Is lesion measuring 26 × 21 mm was macroscopically observed on a background of long segment BE (pT1bN0M0). The tumor comprised three different histological types of carcinoma (NEC, AC with ENT differentiation and moderately differentiated AC). NEC showed positivity for synaptophysin, chromogranin A and insulinoma-associated protein 1 with a Ki-67 index of 60.6%. ENT tumors were immunopositive for AFP and sal-like protein 4, and focally immunopositive for human chorionic gonadotrophin. The amounts of NEC, ENT and AC were 40%, 40% and 20%, respectively. p53 expression was positive throughout the tumor. Rb expression was negative at the NEC, but positive at the ENT and AC. CD4 and CD8 densities were lower in the NEC segment than in the AC and ENT segments, and PD-L1 expression was negative throughout the tumor. Early cancer arising in BE with a combination of tubular AC, ENT tumors and NEC is very rare. Our observations might contribute to understanding the carcinogenetic pathways and tumor microenvironment of NEC and ENT tumors.

Yolk Sac Tumor Originating From Cervical Adenocarcinoma: A Case Predominated by Enteroblastic Differentiation

The fetal gut-like phenotype can be found in yolk sac tumors and adenocarcinomas with enteroblastic differentiation (AEBDs). We report a cervical yolk sac tumor in a 44-yr-old woman. The tumor has similar morphology, immunophenotype, and molecular features to the AEBD of the digestive system. The tumor showed a glandular-predominant growth pattern, composed of columnar cells with clear glycogen-rich cytoplasm. The microcystic/reticular architecture or Schiller-Duval bodies were not found in the tumor. Immunohistochemically, the tumor cells were positive for p16, glypican-3 (GPC3), spalt-like transcription factor 4 (SALL4), CDX-2, and p53. TP53 mutation was identified by next-generation sequencing, and human papillomavirus (HPV) 35 was detected by HPV DNA polymerase chain reaction. In the present case, the adenocarcinoma cells in the superficial cervical glandular epithelium and the nonclear glandular components proved the existence of somatic components. The positivity of p16 and HPV also supports that the present case originates from an HPV-associated adenocarcinoma. The yolk sac tumor should be thought of as "germ cell differentiation" from a somatic carcinoma. This kind of yolk sac tumor arising from somatic-type adenocarcinoma in the female genital tract may be the counterpart of AEBD in the digestive tracts and adenocarcinomas with fetal gut-like morphology in other organs. The tumor might be more aggressive than conventional adenocarcinoma, pathologists should highlight the existence of the enteroblastic component in the pathologic report.

Hepatoid adenocarcinoma of the stomach: CT findings

Objective

To analyze the CT findings of hepatoid adenocarcinoma of the stomach (HAS) and improve the diagnosis accuracy of this condition.

Methods

The CT images of 22 pathologically confirmed HAS patients were analyzed retrospectively. We investigated the location of lesions, morphology, enhancement features, area of invasion into surrounding organs, lymph node metastasis, and venous tumor thrombus.

Results

Among the 22 patients (17 men and 5 women, the mean age was 61.41 ± 9.83 years ranging from 36 to 80 years) with HAS; the morphology of tumors included mass (n = 5), focal ulcer (n = 7), and infiltrating ulcer (n = 10). Extraserous fat was invaded in 12 cases. Enhancement scans showed continuous enhancement in all cases. The CT values of unenhanced scan, the arterial phase, and the portal venous phase are 30.36 ± 6.46, 60.91 ± 17.80, and 75.64 ± 22.09 (Hounsfield Unit, HU), respectively. In six cases, the tumor infiltrated the surrounding organs: liver (n = 1), pancreas (n = 2), and both liver and pancreas (n = 3). In 16 out of 22 patients (72.3%), suspicious lymph node metastasis at CT imaging has then been confirmed by pathological specimens. Intrahepatic metastasis was found in 14 cases. Seven patients had venous tumor thrombus: three patients developed tumor thrombus in the main trunk and intrahepatic branches of the portal vein and two patients in the portal vein, splenic vein, and superior mesenteric vein simultaneously.

Conclusion

The CT scans of HAS often show a thickened gastric wall and infiltrating ulceration. Infiltration into extraserosal fat is often seen. Enhancement scans show a continuous and progressive enhancement of lesions. Lymph node metastasis, intrahepatic metastasis, and portal vein tumor thrombus are common in HAS patients.

Early hepatoid adenocarcinoma of the stomach with signet ring cell carcinoma: A case report and clinicopathological features

Background

Hepatoid adenocarcinoma of the stomach (HAS) is a rare subtype of gastric cancer with poor prognosis, and its clinicopathological features are not well understood, so the pathology from the clinical biopsy is easily misdiagnosed, especially for special or atypical HAS. We present an extremely rare early HAS with signet ring cell carcinoma and evaluate its clinicopathological features.

Case presentation

A 51-year-old female patient of Chinese Han ethnicity with upper abdominal pain for 5 years and worsened abdominal pain for 1 month was admitted to our hospital. Esophagogastroduodenoscopy showed a submucosal tumor-like elevated lesion with central depression in the greater curvature of the junction between the antrum and body. Histopathological examination from the biopsy revealed medium-low-differentiation adenocarcinoma with signet ring cell carcinoma. Radical gastrectomy was performed, and the final diagnosis was early HAS with signet ring cell carcinoma.

Conclusions

HAS with signet ring cell carcinoma is a special type of HAS and extremely rare. It is first presented for this extremely rare type of HAS, which contributes to strengthen the understanding for the clinicopathological characteristics of HAS and especially promote early detection of HAS.

Treatment efficacy of ramucirumab-containing chemotherapy in patients with alpha-fetoprotein producing gastric cancer

BACKGROUND

Alpha-Fetoprotein Producing Gastric Cancer (AFPGC) is an aggressive subgroup of gastric cancer. Recently ramucirumab has shown survival benefits in hepatocellular carcinoma, but only in those with higher Alpha-Fetoprotein (AFP) levels. However, the efficacy of ramucirumab-containing chemotherapy in AFPGC remains unclear.

METHODS

We retrospectively assessed 352 patients who received ramucirumab-containing chemotherapy between June 2015 and December 2019. AFPGC was defined when serum AFP levels were elevated at diagnosis and correlated with the disease state during treatment. Non-AFPGC was defined when serum AFP levels were normal at diagnosis.

RESULTS

Among the 352 patients, 28 patients were defined as AFPGC and 246 patients were defined as non-AFPGC. AFPGC was characterized by high frequency of liver metastasis and low frequency of peritoneal metastasis compared to non-AFPGC. Ramucirumab containing chemotherapy showed higher response rates in AFPGC (39.1% vs 24.8%, p = 0.198) and disease control rates (86.9% vs 61.5%, p = 0.028) than those of non-AFPGC, respectively. Median progression-free survival (PFS) was 5.5 months (95%CI 3.9-7.1) in AFPGC and 4.0 months (95%CI 3.6-4.6) in non-AFPGC (HR: 0.91, 95% CI 0.61-1.36, p = 0.66), and median overall survival (OS) was 10.7 months (95% CI 7.4-20.8) in AFPGC and 9.2 months (95% CI 8.1-10.4) in non-AFPGC (HR: 0.72, 95% CI 0.48-1.08, p = 0.11), respectively. In multivariate analysis, AFPGC was not a negative prognostic factor both for PFS and OS.

CONCLUSION

Ramucirumab containing chemotherapy showed higher response and comparable survival in AFPGC compared to those of non-AFPGC. Considering the generally poor prognosis of AFPGC, ramucirumab-containing chemotherapy might be a promising treatment option in AFPGC.

Alpha-Fetoprotein-Producing Esophageal Adenocarcinoma With Enteroblastic, Yolk Sac Tumor-Like, and Hepatoid Carcinoma Differentiation: A Rare Case and Literature Review

We report a case of a 65-year-old man with alpha-fetoprotein (AFP)-producing esophageal adenocarcinoma that microscopically consisted of a polymorphous blend of enteroblastic, yolk sac-like, and hepatoid carcinoma components of variable proportions. No histological evidence of Barrett's esophagus was identified. Two weeks post-endoscopic mucosal mass resection, the serum AFP level was 1434.6 ng/mL. The patient underwent radiation and chemotherapy but developed metastatic lung lesions. At 18 months post-resection, the patient is alive. AFP-producing esophageal adenocarcinoma is a rare entity. We reviewed reported cases for clinicopathological features, treatment strategies, and prognosis.

Hepatoid carcinoma and related entities of the extrahepatic bile duct: A clinicopathological study of four cases

Hepatoid carcinoma or related entities (HPC/RTs) are extremely rare, especially in the extrahepatic bile duct (EHBD). Only a few case reports have been published. We analyzed the clinicopathological features of HPCs/RTs in EHBD. HPC/RT of extrahepatic cholangiocarcinoma (eCCA) cases were selected based on the histological characteristics and immunohistochemical detection of spalt-like transcription factor 4 (SALL4) and/or alpha-fetoprotein (AFP). Four HPC/RT cases arose in the distal but not in the perihilar EHBD. The four patients with HPC/RT included one female and three males with a median age of 77 years. There are various macroscopic types of HPC/RT. The predominant histological features were two solid-type carcinomas that mimicked hepatocellular carcinoma and two well-differentiated tubular adenocarcinomas. Immunohistochemically, SALL4 and glypican-3 were expressed in all cases, and AFP was expressed in one case. Cancer cell phenotypes included intestinal, pancreatobiliary, and mixed pancreatobiliary and intestinal types. Focal neuroendocrine differentiation and severe perineural and lymphovascular invasions were also observed. HPC/RT recurred in two patients within 2 years, and one patient died 13 months postoperatively. It is suggested that the HPC/RT of EHBD shares common characteristics with HPC/RT arising in various organs, and has some unique characteristics. HPC/RT of EHBD might be more aggressive than conventional eCCA.

Loss of ARID1A expression is associated with systemic inflammation markers and has important prognostic significance in gastric cancer

BACKGROUND

The tumor suppressor gene AT-rich interactive domain 1A (ARID1A) and systemic inflammatory response (SIR) have been reported to be related to the sensitivity to immunotherapy. This study intended to explore the relationship between ARID1A expression and SIR, and to further elucidate the prognostic value of ARID1A expression in gastric cancer (GC).

METHODS

The mRNA and protein expression of ARID1A were detected in 272 formalin-fixed paraffin-embedded (FFPE) tumor tissues. The data of nine systemic inflammation markers were collected 1 week before gastrectomy. Univariate and multivariate COX analysis were used to screen out independent predictors of GC.

RESULTS

Negative expression of ARID1A protein was related to GC with deficient mismatch repair (dMMR) (p = 0.033), positive programmed cell death-ligand 1 (PD-L1) (p = 0.005) and lower albumin level (p = 0.0064). Low expression of ARID1A mRNA was common in GC with abnormal E-cadherin (p = 0.020) and a higher platelet/lymphocyte ratio (PLR) (p = 0.0391). Multivariate COX analysis showed that the expression of ARID1A protein (p = 0.023), age (p = 0.004), T stage (p = 0.009) and N stage (p = 0.009) were independent predictors of GC. The nomogram established by independent predictors can accurately evaluate the survival risk of patients with GC.

CONCLUSIONS

The loss of ARID1A protein expression was associated with the dMMR subtype and high expression of PD-L1 in GC. Negative ARID1A protein and low expression of mRNA were associated with aberrant systemic inflammatory markers. The expression of ARID1A protein had important prognostic significance in GC.

Carcinosarcoma of the stomach: four cases that expand the morphologic spectrum of gastric cancer with a primitive phenotype

Carcinosarcoma of the stomach is a rare neoplasm characterized by the presence of both epithelial and mesenchymal malignant components. We describe four examples with a focus on the characterization of the epithelial components and the histogenetic implications for this unique tumor. All patients were men aged 40-79 years. All patients developed metastatic disease, and three of them died 4-19 months after the diagnosis. Sarcomatous elements included poorly differentiated spindle cell sarcoma without distinctive differentiation (n = 4), chondrosarcoma (n = 2), and rhabdomyosarcoma (n = 1). In two cases, the sarcomatous component was recognized only in metastatic lesions. Notably, carcinomatous components were characterized by multilineage and primitive cellular differentiation, including carcinoma with enteroblastic (n = 4), hepatoid (n = 3), yolk sac tumor-like (n = 1), trophoblastic (n = 1), and neuroendocrine (n = 1) differentiation, as well as conventional tubular adenocarcinoma (n = 4). On immunohistochemistry, all four cases showed varying degrees of positive expression of primitive phenotypic markers, including alpha-fetoprotein (AFP), glypican-3, or SALL4. All tumors showed mutant patterns of p53 staining, exhibiting either diffusely positive or completely negative staining. On the basis of these findings, at least some gastric carcinosarcomas are likely to be derived from carcinoma with a primitive phenotype, including AFP-producing adenocarcinoma. Our observations suggest that sarcomatous differentiation, as well as multilineage differentiation of epithelial components, may represent increased cellular plasticity of gastric carcinoma with a primitive phenotype.

New substituted molecular classifications of advanced gastric adenocarcinoma: characteristics and probable treatment strategies

Background

Gastric adenocarcinoma (GA) is a heterogeneous tumor, and the accurate classification of GA is important. Previous classifications are based on molecular analysis and have not focused on GA with the primitive enterocyte phenotype (GAPEP), a unique subtype with a poor prognosis and frequent liver metastases. New substituted molecular (SM) classifications based on immunohistochemistry (IHC) are needed.

Methods

According to the IHC staining results, we divided 582 cases into six types: mismatch repair deficient (dMMR), Epstein-Barr virus associated (EBVa), the primitive enterocyte phenotype (PEP), the epithelial mesenchymal transition (EMT) phenotype, not otherwise specified/P53 mutated (NOS/P53m) and not otherwise specified/P53 wild-type (NOS/P53w). We analyzed the clinicopathological features, the immune microenvironment (PD-L1, CD8) and expression of HER2 and VEGFR2 of those types.

Results

There were 31 (5.3%) cases of the dMMR type, 13 (2.2%) cases of the EBVa type, 44 (7.6%) cases of the PEP type, 122 (21.0%) cases of the EMT type, 127 (21.8%) cases of the NOS/P53m type and 245 (42.1%) cases of the NOS/P53w type. Patients with the dMMR type had the best survival (P < 0.001). Patients with the EBVa type were younger (P < 0.001) and had higher PD-L1 and CD8 expression (P < 0.001) than other patients. Patients with the EMT type exhibited poor differentiation and a higher rate of abdominal metastasis. Patients with the NOS/P53m and PEP types had the worst survival rates and the highest PD-L1/HER2/VEGFR2 expression levels among all patients (P < 0.001).

Conclusion

Different SM classifications have different clinicopathological features and expression patterns, which indicate the probable clinical treatment strategies for these subtypes.

Alpha-fetoprotein can promote gastric cancer progression via upregulation of metastasis-associated colon cancer 1

High serum alpha-fetoprotein (AFP) level is a predictor of poor prognosis in patients with gastric cancer (GC). AFP-producing GC (AFP-GC) is an aggressive subtype of GC characterized by a high incidence of liver metastasis and high c-Met expression. High expression of metastasis-associated colon cancer 1 (MACC1), which is the transcription activator of c-Met, also predicts a poor prognosis of GC. c-Met is known to be involved in tumor progression into malignant invasive phenotypes. Considering that high c-Met expression is simultaneously positively correlated with high AFP and MACC1 expression levels and that high expression of AFP or MACC1 predicts poor prognosis in GC, we hypothesized that an interaction may exist between AFP and MACC1. In the present study, GC cell lines with AFP-overexpression, MACC1-downregulation and the combination of both transfections were used as experimental models. The relative mRNA and protein expression of c-Met, AFP and MACC1 were analyzed using reverse transcription quantitative PCR and western blotting, respectively. Cell viability was evaluated using Cell Counting Kit-8 assay. Cell invasion and cell migration were examined using Transwell migration assay with and without Matrigel, respectively. The results demonstrated that, compared with the control group, the mRNA and protein expression of MACC1was significantly elevated in the AFP-overexpressed group and in the group with AFP overexpressed and MACC1 downregulated. Furthermore, a significantly enhanced cell viability, migration and invasion were observed in the AFP-overexpressing group, whereas opposite effects were found in the MACC1-downregulating group. In summary, the results from this study indicated that AFP may promote GC progression by stimulating MACC1. This finding may help illustrating the aggressive behaviors of GC in patients with high AFP serum level and AFP-GC.

α-Fetoprotein-Producing Endometrial Carcinoma Is Associated With Fetal Gut-Like and/or Hepatoid Morphology, Lymphovascular Infiltration, TP53 Abnormalities, and Poor Prognosis: Five Cases and Literature Review

The clinicopathological, immunohistochemical, and molecular characteristics of α-fetoprotein (AFP)-producing endometrial carcinoma (AFP+ EC) are poorly understood. From 284 cases of endometrial carcinoma in our pathology archive, we identified five cases (1.8%) of AFP+ EC with fetal gut–like (4/5) and/or hepatoid (2/5) morphology. All cases exhibited lymphovascular infiltration. In addition, 24 cases of endometrial carcinoma with elevated serum AFP levels were retrieved from the literature. The patient age ranged from 44 to 86 years (median: 63). Of 26 cases whose FIGO (International Federation of Gynecology and Obstetrics) stage and follow-up information was available (mean follow-up 24 months), 15 were stage I or II and 11 were stage III or IV. Even in stage I or II disease, death or relapse occurred in more than half of the patients (8/15). Detailed analysis of our five cases revealed that, on immunohistochemistry, AFP+ EC was positive for SALL4 (4/5), AFP (3/5), and HNF1β (4/5) in >50% of neoplastic cells and negative for estrogen and progesterone receptors (5/5), PAX8 (4/5), and napsin A (5/5). Four cases exhibited aberrant p53 immunohistochemistry and were confirmed to harbor TP53 mutations by direct sequencing. No mutation was found in POLE, CTNNB1, or KRAS. In conclusion, AFP+ EC merits recognition as a distinct subtype of endometrial carcinoma, which occurs in 1.8% of endometrial carcinoma cases, are associated with TP53 abnormalities, exhibit lymphovascular infiltration, and can show distant metastasis even when treated in early stage.

Clinicopathological and molecular characteristics of the alpha-fetoprotein-producing gastric cancer: emphasis on two major subtypes

Alpha-fetoprotein-producing gastric cancer (AFPGC) is associated with high invasion and poor prognosis, but has not been well-documented due to its rarity. To develop the understanding of AFPGC, and further facilitate its clinical decision-making and treatment, we performed clinicopathological and molecular characterization of AFPGC and its two major subtypes, namely, gastric adenocarcinoma with enteroblastic differentiation (GAED) and hepatoid adenocarcinoma (HAC). The clinicopathological and molecular characteristics of AFPGC patients (n = 54) were mainly investigated by immunohistochemistry and next-generation sequencing (NGS) approaches. AFPGC exhibited a higher incidence of lymphatic and vascular invasion than conventional gastric adenocarcinoma (CGA). Despite various morphological patterns, there was mostly no evident difference in clinicopathological characteristics between the GAED and HAC subtypes. Target-enriched NGS profiling of disease mutation landscapes discovered 17 differentially mutated genes between AFPGC and CGA. The AFPGC patients carrying ZNF217 mutations had poorer overall survival than the ZNF217 wildtype. Furthermore, ATR showed a significantly higher mutation rate in GAED than in HAC. Overall, our study of clinicopathological characteristics shed light on the differences between CGA and AFPGC, as well as the relationships between the GAED and HAC subtypes of AFPGC. Furthermore, mutation landscape profiling revealed potential diagnostic and prognostic markers for AFPGC and its two subtypes.

Both the serum AFP test and AFP/GPC3/SALL4 immunohistochemistry are beneficial for predicting the prognosis of gastric adenocarcinoma

BACKGROUND

Both gastric adenocarcinoma with primitive enterocyte phenotype (GAPEP) (including hepatoid adenocarcinoma) and alpha-fetoprotein (AFP)-producing gastric adenocarcinoma have poor prognoses. However, the value of the serum AFP test and AFP/glypican-3 (GPC3)/spalt-like transcription factor 4 (SALL4) immunohistochemistry is still not clear, and these two methods have not yet been thoroughly compared.

METHODS

We collected 421 consecutive non-neoadjuvant surgically or endoscopically resected gastric adenocarcinoma patients with serum AFP results before surgery (group A). We divided these cases into serum AFP-high (sAFP-H) and serum AFP-normal (sAFP-N) by serum AFP levels, and into GAPEP (expressing AFP, GPC3, or SALL4) and non-GAPEP (nGAPEP) by AFP/GPC3/SALL4 immunohistochemistry results. We also collected 12 non-resected gastric adenocarcinoma patients with serum AFP ≥ 7 ng/mL before treatment (group B). We analyzed these patients' clinicopathological characteristics and prognoses.

RESULTS

Seventeen (4.04%) patients in group A were sAFP-H. These patients were younger and mainly had tubular adenocarcinoma with later pT (P = 0.014) and pN (P = 0.047) categories and more lymphovascular invasion (P < 0.001), perineural spread (P = 0.008), and metastases or recurrence (P < 0.001). For immunohistochemistry, 34 (8.08%) cases were GAPEP, and GAPEP cases also had later pT categories than nGAPEP cases (P = 0.001). Most group B patients with elevated serum AFP (especially > 1000 ng/mL) had simultaneous metastases, mainly liver metastases. Both the serological method and immunohistochemical method were useful for predicting prognosis (AUC _sAFP = 0.625, AUC _A/G/S-IHC = 0.723, z statistic = 1.726, P = 0.084). The serum AFP level (especially > 1000 ng/mL) is more specific (100%), and immunohistochemistry is more sensitive (50%).

CONCLUSION

Both the serum AFP level and immunohistochemical expression of AFP/GPC3/SALL4 can be used to indicate a poor prognosis for gastric adenocarcinoma.

Whole-exome sequencing of alpha-fetoprotein producing gastric carcinoma reveals genomic profile and therapeutic targets

Alpha-fetoprotein producing gastric carcinoma (AFPGC) is a rare and aggressive subtype of gastric cancer. However, little is known about the genomic features of this disease. We perform whole-exome sequencing analysis of AFPGC, and identify 34 significantly mutated genes. Somatic copy number alterations analysis reveals several significant focal amplifications (e.g. 19q12, 17q12) and focal deletions (e.g. 1p36.11, 9p21.3), and some of these negatively affect the patient prognosis. Comparative analyses reveal that AFPGC has distinct genomic features from gastric cancer of The Cancer Genome Atlas as well as four molecular subtypes. Several frequently altered genes with potential as therapeutic targets are identified in AFPGC. Further analysis reveals that AFPGC with amplification of CCNE1 at 19q12 and/or ERBB2 at 17q12 show poorer survival and more aggressive. Subsequently, based on our established patient-derived xenograft models for AFPGC, translational research is performed and the therapeutic value of targeting CCNE1 and ERBB2 is validated. In this work, we provide an understanding of genomic characteristics of AFPGC and propose a platform to explore and validate the genome-guided personalized treatment for this disease.

Hepatoid Adenocarcinoma of the Stomach: Current Perspectives and New Developments

Hepatoid adenocarcinoma of the stomach (HAS) is a rare malignant tumor, accounting for only 0.17-15% of gastric cancers. Patients are often diagnosed at an advanced disease stage, and their symptoms are similar to conventional gastric cancer (CGC) without specific clinical manifestation. Morphologically, HAC has identical morphology and immunophenotype compared to hepatocellular carcinoma (HCC). This is considered to be an underestimation in diagnosis due to its rare incidence, and no consensus is reached regarding therapy. HAS generally presents with more aggressive behavior and worse prognosis than CGC. The present review summarizes the current literature and relevant knowledge to elaborate on the epidemic, potential mechanisms, clinical manifestations, diagnosis, management, and prognosis to help clinicians accurately diagnose and treat this malignant tumor.

Two cases of gastric adenocarcinoma with enteroblastic differentiation resected by endoscopic submucosal dissection

Gastric adenocarcinoma with enteroblastic differentiation (GAED) is rare, highly malignant, and has higher vascular invasion and metastasis rates than conventional differentiated gastric cancer (CDGC). We report two cases of GAED that underwent curative resection by endoscopic submucosal dissection (ESD). Case 1 was an 82-year-old man with an elevated lesion in the gastric cardia. Biopsy revealed well-differentiated tubular adenocarcinoma. Pathological diagnosis of the ESD specimen revealed intramucosal gastric cancer without lymphovascular invasion (LVI). Although the surface layer of the lesion showed well and moderately differentiated tubular adenocarcinoma, clear cytoplasmic cancer cells positive for Sal-like protein-4 (SALL4) and Glypican-3 were found in a part of the deep layer. Therefore, GAED was diagnosed as present in a part of the whole lesion and covered with CDGC. Case 2 was an 83-year-old man with an elevated lesion in the gastric angulus. Biopsy revealed papillary and well-differentiated tubular adenocarcinomas. Pathological diagnosis of the ESD specimen revealed intramucosal gastric cancer without LVI. The entire lesion was occupied by papillary and tubular cancer cells, and had clear vesicles. Pure GAED was diagnosed, because the cells were SALL4 positive. In both cases, resection was curative despite the difference in pathological features.

Integrated clinicopathological and immunohistochemical analysis of gastric adenocarcinoma with hepatoid differentiation: an exploration of histogenesis, molecular characteristics, and prognostic markers

In addition to hepatoid adenocarcinoma (HAC), gastric adenocarcinoma with enteroblastic differentiation (GAED) and common adenocarcinoma (COM) could also show hepatoid differentiation, which presents a poor prognosis. To elucidate the histogenesis and development of gastric cancer with hepatoid differentiation, we identified 55 cases by histological morphology and a panel of markers, including α-fetoprotein (AFP), Glypican 3 (GPC3) and SALL4, then clinicopathological parameters, pathomorphological characteristics, mucin phenotypes, molecular features, Immunoscore and survival analysis were assessed. A mixture of three types (COM + GAED + HAC) was most commonly observed in the same case, and typical transitions between each histological subtype were frequently seen. Hyaline globule and pink amorphous substance were often present. HER2 was amplified in 21.8% of cases. All the tumors showed intestinal phenotype (69.1%) and mixed gastric/intestinal phenotype (30.9%) and were all defined to chromosomal instable (CIN)/genomically stable (GS) group. Considering that 83.6% cases presented TP53 gene mutation phenotype and 61.8% cases showed ≥10% aberrant E-cadherin expression, the precise molecule classification is ambiguous. Survival analysis showed that patients with high SALL4 expression, high preoperative serum AFP level, or low Immunoscore had a significantly poor overall survival (OS). Moreover, SALL4, HER2, and Immunoscore had an independent influence on OS. In conclusion, we suggest that the development of gastric adenocarcinoma with hepatoid differentiation might a continuously progressive profile: from intestinal-type COM adenocarcinoma to GAED and then HAC. CIN/GS subtypes might be where they belonged. SALL4, HER2, and Immunoscore may be potential therapeutic targets.

Efficacy and safety of apatinib for the treatment of AFP-producing gastric cancer

BACKGROUND

Alpha-fetoprotein-producing gastric cancer (AFPGC) poses a therapeutic challenge worldwide because of its poor prognosis. This study aimed to evaluate the efficacy and safety of antiangiogenic drug apatinib in advanced AFPGC in a real-world setting.

METHODS

From September 2015 to December 2017, twenty-one patients identified with AFPGC from the clinical trial AHEAD-G202, an open-label, prospective, multicenter, non-interventional study of apatinib for advanced metastatic gastric cancer, were enrolled to perform this analysis. Patients received oral apatinib as monotherapy or combination therapy. A treatment cycle was defined as 28 days. The primary outcome was progression-free survival (PFS) and overall survival (OS), and the secondary outcomes included safety, objective response rate (ORR), and disease control rate (DCR).

RESULTS

Twenty patients were evaluated for the apatinib efficacy analysis. The ORR of apatinib was 10%, whereas the DCR was 70%. The median PFS was 3.5 months [95%confidence interval (CI): 2.34-4.66]. The median OS was 4.5 months (95%CI: 3.49-5.51). Median OS of AFPGC patients without carcinoembryonic antigen (CEA) elevation achieved 30.8 months. CEA elevation was considered to be a potential independent predictive factor for OS (P = 0.030) and PFS (P = 0.047) by the analysis of multivariate analysis. The most common grade 3 to 4 adverse events (AEs) were hypertension (4.8%), hand-foot syndrome (4.8%), anorexia (4.8%), and vomiting and nausea (4.8%).

CONCLUSION

Apatinib showed promising efficacy and an acceptable safety profile in patients with advanced AFPGC. Antiangiogenic therapy may be a good strategy for the treatment of AFPGC as a rare sub-type of gastric cancer.

TRIAL REGISTRATION

AHEAD-G202 (NCT02668380).

Alpha-Fetoprotein-Producing Gastric Cancer with Nonbiliary Pancreatitis

Alpha-fetoprotein (AFP)-producing gastric cancer (AFPGC) is a rare, aggressive tumor. In the absence of metastasis in diagnosis, close observation and long-term follow-up is needed to monitor and slow its progress. We report a young patient who presented with nonbiliary pancreatitis. Upon finding Virchow's nodule, we conducted tests and observed multiple lymph nodes and liver and pancreatic metastasis. We subsequently made a diagnosis of AFPGC. This study describes the different presentations of this rare but aggressive subtype of gastric cancer with a review of the literature.

Effect of Immune Checkpoint Inhibitors Plus Chemotherapy on Advanced Gastric Cancer Patients with Elevated Serum AFP or Hepatoid Adenocarcinoma

Purpose

Alpha-fetoprotein-producing gastric cancer (AFPGC) and hepatoid adenocarcinoma of stomach (HAS) are rare types of gastric cancer, with specific clinical manifestations and poor prognosis. The standardized treatment process of such cancers remains elusive. We aim to investigate the efficacy of immunotherapy combined with chemotherapy on patients with AFPGC or HAS.

Patients and Methods

AFPGC and HAS patients who underwent immunotherapy and/or chemotherapy as the first-line treatment at our institute from June 2016 to December 2018 were enrolled in this observational study. Their clinicopathological characteristics, serum AFP level and treatment methods were collected. The progression-free survival (PFS) and overall survival (OS) were analyzed and compared between patients who received immunotherapy plus chemotherapy and those received chemotherapy.

Results

A total of 21 patients with advanced AFPGC or HAS were included in the study and the median follow-up time was 28.0 months. Of the 21 patients, 7 patients received immunotherapy of PD-1 antibody (nivolumab) plus chemotherapy and 14 patients as control received chemotherapy with or without Herceptin/Apatinib. The median progression-free survival (mPFS) time was 5.0 months (4.3 months in the control group and 22.0 months in the immunotherapy group). The median overall survival (mOS) time of the control group was 16.0 months (14.0 months in chemotherapy alone subgroup, 20.0 months in chemotherapy plus Apatinib or Herceptin subgroup), while the mOS of patients receiving immunotherapy was not reached.

Conclusion

This study suggested PD-1 checkpoint inhibitor plus chemotherapy could benefit AFPGC and HAS patients. Its mechanism of action warrants further investigation.

Gastric adenocarcinoma with enteroblastic differentiation followed endoscopically: A case report

A 70-year-old man underwent endoscopy, which revealed a slightly depressed and elevated gastric cancer with suspected submucosal invasion of the mid gastric body. Biopsy specimens revealed differentiated tubular adenocarcinoma. We also detected lung and esophageal cancer and prioritized treatment of these lesions, and the patient underwent three endoscopies to monitor changes in gastric cancer. The tumor size and color remained unchanged; however, the marginal ridge was prominent, and the depressed area was deeper on subsequent evaluation. Total gastrectomy was performed 9 months after the first endoscopy. Histopathological examination of the resected specimens showed muscularis propria invasion, well-differentiated tubular adenocarcinoma involving the superficial mucosa, and tumor cells showing clear cytoplasm and a columnar or three-dimensional structure, between the deep mucosa and submucosa. The cells were immunopositive for Sal-like protein 4 and glypican 3; therefore, the patient was diagnosed with gastric adenocarcinoma with enteroblastic differentiation (GAED). This rare gastric cancer variant constituted approximately 70% of the entire lesion, and we observed significant lymphovascular invasion and lymph node metastasis. GAED is a rare histopathological subtype of gastric cancer described in recent years. Few cases of this tumor are reported to date; therefore, our study significantly contributes to the literature.

Alpha-Fetoprotein-Producing Early Gastric Cancer with Intramucosal Hepatoid and Fetal Enteric Differentiation

Alpha-fetoprotein (AFP)-producing gastric carcinomas (AFPGCs) are relatively rare tumors known to have a poor prognosis and commonly found as advanced lesions. Histologically, AFPGCs have been described as having hepatoid and fetal enteric (enteroblastic) morphology and are associated with conventional adenocarcinomas. Prior studies reported a hepatoid component present only in invasive areas and hypothesized that AFPGCs may develop hepatoid features during the process of tumor invasion. We report three cases of AFP-producing early gastric cancer which had an intramucosal hepatoid component. Immunohistochemistry showed that the hepatoid component was diffusely immunoreactive for SALL4, AFP, arginase-1, and HepPar1, and focally for CDX2 and PDX1. An intramucosal transition between the hepatoid component and conventional intramucosal adenocarcinoma was identified. Two patients also had a coexistent fetal enteric component, which was admixed with a hepatoid component. Although at an early stage one patient subsequently developed liver metastasis and a second patient was suspected of having liver metastasis, these were not biopsy-proven. The latter patient had a previous history of hepatocellular carcinoma (HCC) and SALL4 was used on the HCC to distinguish metastatic/further HCC from a gastric metastatic primary with hepatoid differentiation.

Early gastric cancer involving a pure enteroblastic differentiation component that was curatively resected via endoscopic submucosal dissection

Gastric adenocarcinoma with enteroblastic differentiation (GAED) is a very rare variant of alpha-fetoprotein-producing gastric cancer (AFPGC). GAED is histologically characterized by cuboidal or columnar cells, which resemble those found in the primitive gut and have clear cytoplasm. In previously reported cases, GAED exhibit more aggressive behavior, as well as AFPGC, than conventional gastric cancer, such as marked lymphovascular invasion, lymph node metastasis, and liver metastasis. And also GAED was usually located in a deep mucosal layer and was covered by a conventional adenocarcinoma (CA) component. Based on these findings, GAED is considered to develop from CA during the process of tumor invasion and proliferation. We present a very rare case of early-stage GAED achieved curatively resected via endoscopic submucosal dissection, in which the lesion was composed of a pure enteroblastic differentiation component without a CA component.

Hepatoid adenocarcinoma of the stomach: Thirteen case reports and review of literature

BACKGROUND

The aim of the present study was to examine the clinical characteristics of hepatoid adenocarcinoma of the stomach (HAS) and its diagnosis, treatment, and prognosis.

CASE SUMMARY

A retrospective analysis of 13 HAS cases was performed. The mean age of the 13 patients was 66.08 years, and 10 of the 13 patients were male. Prior to treatment, the alpha-fetoprotein levels in the serum were elevated in 7 patients, the tumour was located in the distal or gastric body in 11 patients, and the gastroscopy pathological results showed that 3 patients had poorly differentiated tumours and that 8 patients had moderately/poorly differentiated tumours. Abdominal CT scans showed local stomach wall thickening, and enlarged lymph nodes were visible around the stomach in 8 patients. Of the 13 patients, 11 underwent radical surgery. The clinical pathological staging was as follows: Stage II in 2 cases; stage III in 8 cases; and stage IV in 1 case. A total of 3 patients were lost to follow-up. Otherwise, as of the last follow-up, 3 patients had survived for 56 mo, and the other 7 patients failed to achieve long-term survival (survival period of 1-56 mo).

CONCLUSION

HAS is a special type of gastric cancer, and the prognosis of HAS has improved compared with past prognoses. Measurement of alpha-fetoprotein, early diagnosis, active surgical treatment, and application of new diagnostic and treatment techniques are conducive to improving the prognosis of HAS.

Hepatoid Adenocarcinoma of Stomach: Emphasis on the Clinical Relationship with Alpha-Fetoprotein-Positive Gastric Cancer

Aims. Both hepatoid adenocarcinoma of stomach (HAS) and alpha-fetoprotein-positive gastric cancer (AFPGC) are rare but aggressive subtypes of gastric cancer, but few studies focus on the clinicopathologic differences and prognostic factors between them because of their rarity and histologic overlap. And the significance of AFP level in HAS prognosis was not well studied. Methods. 41 patients with AFPGC and 52 patients with HAS were included in this study. The clinicopathologic features were compared by Chi-square analysis. Prognostic factors for overall survival (OS) and disease-free survival (DFS) were analyzed with the Kaplan-Meier method. Results. The patients with HAS were of a younger age compared with AFPGC, and nearly 60% of tumor located in the gastric antrum and the gastric fundus of cardia. The OS of AFPGC was shorter than that of HAS, due to a higher rate of metastasis. Furthermore, the survival analysis showed that HAS with high AFP expression (AFPHigh HAS) had a significantly poorer OS compared to HAS with low AFP expression (AFPLow HAS) (P=0.046). Conclusions. Compared with AFPGC, the patients of HAS were of a younger age and had less rate of liver and other organ metastasis. The serum AFP level was a sensitive prognostic indicator for OS. Therefore, much attention should be paid to AFPHigh HAS in clinical practice.

Human germ cell tumours from a developmental perspective

Human germ cell tumours (GCTs) are derived from stem cells of the early embryo and the germ line. They occur in the gonads (ovaries and testes) and also in extragonadal sites, where migrating primordial germ cells are located during embryogenesis. This group of heterogeneous neoplasms is unique in that their developmental potential is in effect determined by the latent potency state of their cells of origin, which are reprogrammed to omnipotent, totipotent or pluripotent stem cells. Seven GCT types, defined according to their developmental potential, have been identified, each with distinct epidemiological and (epi)genomic features. Heritable predisposition factors affecting the cells of origin and their niches likely explain bilateral, multiple and familial occurrences of the different types of GCTs. Unlike most other tumour types, GCTs are rarely caused by somatic driver mutations, but arise through failure to control the latent developmental potential of their cells of origin, resulting in their reprogramming. Consistent with their non-mutational origin, even the malignant tumours of the group are characterized by wild-type TP53 and high sensitivity for DNA damage. However, tumour progression and the rare occurrence of treatment resistance are driven by embryonic epigenetic state, specific (sub)chromosomal imbalances and somatic mutations. Thus, recent progress in understanding GCT biology supports a comprehensive developmental pathogenetic model for the origin of all GCTs, and provides new biomarkers, as well as potential targets for treatment of resistant disease.

Hemorrhagic Gastric Metastasis from Hepatocellular Carcinoma Successfully Treated Using Coil Embolization of the Left Gastric Artery

A 62-year-old man initially underwent transcatheter arterial chemoembolization for the treatment of hepatocellular carcinoma (HCC). One year after the initial treatment, he developed anemia. Upper gastrointestinal endoscopy revealed irregularly elevated tumors in the lower anterior gastric body, which were diagnosed to be metastasis from HCC. Left gastric artery coil embolization was performed to prevent sustained bleeding, and his anemia partially improved. In addition to direct invasion, hematogenous metastasis to the stomach from HCC is possible and therefore should be considered during treatment. Transcatheter arterial embolization for gastric metastasis is an effective treatment method which achieves a good degree of hemostasis in patients without any surgical indications.

Gastric adenocarcinoma with enteroblastic differentiation should be differentiated from hepatoid adenocarcinoma: A study with emphasis on clear cells and clinicopathologic spectrum

BACKGROUND

In gastric cancer, clear cells are preferentially found in gastric adenocarcinoma with enteroblastic differentiation (GAED) and hepatoid adenocarcinoma (HAC). The distinction between GAED and HAC is difficult because of their rarity and histologic overlap.

METHODS

To elucidate identification of gastric adenocarcinoma with clear cells as GAED or HAC, survival analyses were performed in 28 GAED, 26 HAC, and 1107 conventional adenocarcinoma cases. Cells of origin were assessed by investigating the expression of oncofetal proteins (α-FP, glypican-3, SALL4), in addition to gastric (MUC5AC, MUC6), and intestinal (MUC2, CD10, CDX-2) cell markers.

RESULTS

Clinically, HAC showed frequent (57.5%) distant metastasis (mostly in the liver) at the time of diagnosis compared to GAED (P < 0.001). On pathology, all 28 GAED had a predominantly tubulopapillary growth pattern while 24 HAC displayed a predominantly hepatoid growth pattern. In survival analyses, patients with HAC had significantly shorter overall and recurrence-free survival (mean: 25 months, and 53 months, respectively) compared to those with GAED (mean: 107 months, and 118 months, respectively) (P < 0.001). HAC with clear cells showed diffuse and strong expression of all oncofetal proteins (α-FP, glypican-3, and SALL4), were highly positive for CDX-2, and were negative for CD10, MUC6, MUC5AC, and MUC2, suggesting an intestinal mucin phenotype and hepatoid features. In contrast, GAED showed focal expression of one or two oncofetal proteins and commonly expressed CD10, CDX-2, and MUC6 but not MUC2 and MUC5AC, suggesting both gastric antral/intestinal mucin phenotype and focal enteroblastic differentiation. SALL4 was diffusely and strongly positive in HAC, while it was heterogeneously expressed in GAED.

CONCLUSIONS

In conclusion, although rare, HAC with clear cells should be differentiated from GAED based on the poor prognosis, diffuse and strong oncofetal protein expression, and intestinal mucin phenotype.

Expression of Glypican 3 is an Independent Prognostic Biomarker in Primary Gastro-Esophageal Adenocarcinoma and Corresponding Serum Exosomes

Exosomes are nano-sized membranous vesicles of endosomal origin that carry nucleic acids, lipids and proteins. The cargo of exosomes is cell origin specific and the release of these exosomes and uptake by an acceptor cell is seen as a vital element of cell-cell communication. Here, we sought to investigate the diagnostic and prognostic value of the expression of glypican 3 (GPC3) on primary gastro-esophageal adenocarcinoma (GEA) tissue (tGPC3) and corresponding serum exosomes (eGPC3). Circulating exosomes were extracted from serum samples of 49 patients with GEA and 56 controls. Extracted exosomes were subjected to flow cytometry for the expression of eGPC3 and GPC3 expression on primary GEA tissue samples was determined by immunohistochemistry and correlated to clinicopathological parameters. We found decreased eGPC3 levels in GEA patients compared to healthy controls (p < 0.0001) and high tGPC3 expression. This was significantly associated with poor overall survival (high vs. low eGPC3: 87.40 vs. 60.93 months, p = 0.041, high vs. low tGPC3: 58.03 vs. 84.70 months, p = 0.044). Cox regressional analysis confirmed tGPC3 as an independent prognostic biomarker for GEA (p = 0.02) and tGPC3 expression was validated in two independent cohorts. Our findings demonstrate that eGPC3 and tGPC3 can be used as potential diagnostic and prognostic biomarkers for GEA.

Clinicopathological features and prognosis of AFP-producing colorectal cancer: a single-center analysis of 20 cases

Background: High serum levels of alpha-fetoprotein (AFP) are observed in some gastrointestinal cancers. However, primary AFP-producing colorectal cancer (CRC) is extremely rare and causes confusion among clinicians. In this study, we analyzed the clinicopathological features and clinical outcomes of AFP-producing CRC and provide a brief view of this rare carcinoma.

Patients and methods: Twenty patients with AFP-producing CRC were enrolled at the Fudan University Shanghai Cancer Center from 2012 to 2015. Clinical information, including serum AFP and CEA levels, and outcomes were collected. Tumors were divided into three histologic types: the common adenocarcinoma (COM) type, mucinous adenocarcinoma type and hepatoid type (HPT). Immunohistochemical (IHC) staining of GPC3, Hepa-1, SALL4 and Arg-1 was performed. Additionally, mutations of the KRAS, NRAS and BRAF genes were examined. Finally, another 40 stage-matched patients with traditional CRC were enrolled as controls for survival analysis.

Results: AFP-producing CRC was more likely to occur in males (60%) and arose mainly from the ascending (40%) and sigmoid (35%) colon. In addition, the majority of patients with AFP-producing CRC had poor differentiation (50%), advanced local invasion (80%) and lymph node (LN) metastasis (60%). Synchronous distant metastasis was commonly observed (35%). Interestingly, serum AFP levels were closely associated with LN metastasis. Histopathologically, the COM type was the most common pattern. In IHC staining, the HPT pattern was the most distinct due to high positivity rates of GPC3, Hepa-1 and Arg-1. One patient had mismatch repair deficiency, and another had a KRAS mutation. Patients with AFP-producing CRC had worse progression-free and overall survival than patients with traditional CRC.

Conclusion: AFP-producing CRC has unique clinical and histopathological characteristics, showing an aggressive biological behavior and worse prognosis than traditional CRC.

Gastric hepatoid adenocarcinomas are a genetically heterogenous group; most tumors show chromosomal instability, but MSI tumors do exist

The Cancer Genome Atlas Research Network classified gastric adenocarcinoma into four molecular subtypes: (1) Epstein-Barr virus-positive (EBV), (2) microsatellite-instable (MSI), (3) chromosomal instable (CIN), and (4) genomically stable (GS). The molecular subtypes of gastric hepatoid adenocarcinomas are still largely unknown. We analyzed 52 hepatoid adenocarcinomas for the expression of surrogate markers of molecular subtypes (MLH1, p53, and EBER in situ hybridization) and some biomarkers (p21, p16, Rb, cyclin D1, cyclin E, β-catenin, Bcl-2, IMP3, ARID1A and HER2), and mutations of TP53, CTNNB1, KRAS, and BRAF. We analyzed 36 solid-type poorly differentiated adenocarcinomas as a control group. Hepatoid adenocarcinomas were categorized as follows: EBV group (EBER-positive), no cases (0%); MSI group (MLH1 loss), three cases (6%); "CIN or GS" (CIN/GS) group (EBER-negative, MLH1 retained), 49 cases (94%). In the CIN/GS group, most of the tumors (59%) had either p53 overexpression or TP53 mutation and a coexisting tubular intestinal-type adenocarcinoma component (90%), suggesting that most hepatoid adenocarcinomas should be categorized as a true CIN group. Hepatoid adenocarcinomas showed relatively frequent expressions of HER2 (score 3+/2+: 21%/19%). Hepatoid adenocarcinomas showed shorter survival, more frequent overexpressions of p16 (67%) and IMP3 (98%) than the control group. None of hepatoid adenocarcinomas had KRAS or CTNNB1 mutations except for one case each, and no hepatoid adenocarcinomas had BRAF mutation. In conclusion, gastric hepatoid adenocarcinomas are a genetically heterogenous group. Most hepatoid adenocarcinomas are "CIN," but a small number of hepatoid adenocarcinomas with MSI do exist. Hepatoid adenocarcinomas are characterized by overexpressions of p16 and IMP3.

Frequent loss of heterozygosity of SMAD4 locus and prognostic impacts of SMAD4 immunohistochemistry in gastric adenocarcinoma with enteroblastic differentiation

Gastric adenocarcinoma with enteroblastic differentiation (GAED) is a rare variant of gastric adenocarcinoma. Clinicopathologically, GAED is known to be aggressive and is characterized by frequent vascular invasion, lymphatic invasion, and liver metastasis even in early stages. SMAD4 was identified as a frequently deleted gene in GAED by copy number variation analysis in our previous next-generation sequencing study; therefore, we examined the clinicopathological impacts of SMAD4 in 51 cases of GAEDs (early: 17, advanced: 34). We performed Sanger sequencing for SMAD4 mutations and loss of heterozygosity (LOH) analysis of the SMAD4 locus, in addition to immunohistochemistry for SMAD4, to determine its clinicopathological correlations and impacts on survival. The frequency of LOH at the SMAD4 locus was 45.1%, and it was significantly higher in GAED compared to in conventional gastric adenocarcinoma. SMAD4 mutations were not found in any case. Reduced SMAD4 expression was found in 60.8% of cases; it was significantly correlated with advanced stages and lymph node metastasis and showed trends of larger tumor size and lymphatic invasion. Reduced SMAD4 expression in metastatic lymph nodes was found in 21 of 36 cases. Survival analysis revealed that reduced SMAD4 expression significantly affected the patient's overall survival (OS) and recurrence-free survival (RFS), although multivariate analysis showed that only liver metastasis and lymphatic infiltration (Ly+) were independent prognostic factors for OS and RFS. The SMAD4 locus is one of the susceptibility genes in this tumor, although SMAD4 mutation was not detected. Furthermore, the inactivation of SMAD4 appeared to contribute to the aggressiveness of GAED.

TP53 inactivation and expression of methylation-associated proteins in gastric adenocarcinoma with enteroblastic differentiation

Gastric adenocarcinoma with enteroblastic differentiation (GAED) is a rare variant of aggressive adenocarcinoma. We demonstrated previously that GAED is genetically characterized by frequent TP53 mutation. In this study, we aimed to further clarify the mechanism of inactivation of TP53 in GAED in the light of promoter methylation of TP53, and expression of methylation-associated proteins such as Ten-eleven translocation (TET) 1 and 5-hydroxymethylcytosine (5-hmc) in addition to ATM mutations. We analyzed 51 cases of GAED. The ATM mutation was detected in only one case. Promoter methylation of TP53 was detected in 18% and frequency of loss of heterozygosity (LOH) at TP53 locus was 37.2%. Reduced TET1 expression was found in 29 cases (56.9%) and was significantly associated with advanced stage (p = 0.01), lymph node metastasis (p = 0.04), and macroscopic type (p = 0.01). Reduced 5-hmc expression was found in 28 cases (54.9%) and was significantly associated with advanced stage (p = 0.01), gender (p = 0.01), tumor location (p = 0.03), tumor size (p = 0.01), and lymph node metastasis (p = 0.01). Among 9 cases with TP53 promoter methylation, reduced expression of TET1 was observed in 6 cases, and reduced expression of 5-hmc was observed in 5 cases. Reduced expression of both TET1 and 5-hmc was significantly associated with adverse clinical outcomes. In summary, promoter methylation of TP53 is partly involved in loss of p53 expression. Aberrant methylation by reduced TET1 and 5-hmc may be involved in the development of aggressive GAED.

Early Gastric Cancer with Purely Enteroblastic Differentiation and No Conventional Adenocarcinoma Component

Gastric carcinoma with enteroblastic differentiation (GCED) is a rare variant of gastric carcinoma, and a part of GCED produces alpha-fetoprotein. GCED is characterized by cells with clear cytoplasm and a tubulopapillary and solid growth pattern resembling those in the primitive gut. GCED is typically overlaid by a conventional adenocarcinoma (CA) component, implying that CA in the mucosa differentiates into GCED during tumor invasion and proliferation. We present the case of a 73-year-old woman with a 10-mm superficial elevated lesion and a slight central depression at the anterior wall of the lower gastric body. Endoscopic submucosal dissection revealed tumor cells having clear cytoplasm and severely atypical nuclei characteristic of GCED. The growth pattern was predominantly solid and trabecular but included submucosal layer invasion and limited tubular growth. Atrophic pyloric mucosa without intestinal metaplasia surrounded the tumor. Immunohistochemically, the tumor cells were positive for AFP, GPC3, and SALL4. The present patient showed a purely enteroblastic differentiation without a CA component despite the presence of early cancer, indicating that few cases of GCED may arise de novo in the gastric mucosa. GCED is more aggressive compared with CA; therefore, pathologists should be aware that GCED without CA can appear in biopsy specimens of early cancer while making an accurate diagnosis.

Expression of RNA-binding protein LIN28 in classic gastric hepatoid carcinomas, gastric fetal type gastrointestinal adenocarcinomas, and hepatocellular carcinomas: An immunohistochemical study with comparison to SALL4, alpha-fetoprotein, glypican-3, and Hep Par1

INTRODUCTION

Gastric hepatoid carcinomas (GHCs) include type I (classic) and type II (fetal type gastrointestinal adenocarcinoma). The classic type shows overlapping morphologic features with those of hepatocellular carcinoma (HCC). The aim of this study is to investigate expression of LIN28 in GHCs and explore its utility to distinguish classic GHC from HCC.

METHODS

We investigated immunohistochemical expression of LIN28 in 93 primary GHCs (47 type I, 46 type II) and 60 HCCs with comparison to SALL4, AFP, glypican-3, Hep Par1, p-CEA and CK7. We also stained LIN28 and SALL4 in 52 conventional gastric adenocarcinomas to assess their specificity in gastric carcinomas.

RESULTS

Classic GHCs and fetal type gastrointestinal adenocarcinomas showed positive LIN28 in 21/47 (45%) and 10/46 (22%), SALL4 in 41/47 (87%) and 36/46 (78%), AFP in 30/46 (65%) and 33/46 (72%), glypican-3 in 31/41 (76%) and 24/38 (63%), Hep Par1 in 27/41 (66%) and 28/37 (76%), and CK7 in 15/40 (38%) and 25/38 (66%), respectively. p-CEA staining was seen in 19/44 (43%) classic GHCs. Among HCCs, LIN28, SALL4, AFP, glypican-3, Hep Par1, p-CEA and CK7 was seen in 1/60 (2%), 0/60 (0%), 6/30 (20%), 23/30 (77%), 29/30 (97%), 28/30 (93%) and 21/30 (70%) cases, respectively. LIN28 and SALL4 staining was seen in 2/52 (4%) and 14/52 (27%) gastric conventional adenocarcinomas, respectively. The sensitivity and specificity of distinguishing classic GHCs from HCCs was 45% and 98% for LIN28, 87% and 100% for SALL4, 65% and 80% for AFP, 76% and 30% for glypican-3, 66% and 3% for Hep Par1, 43% and 7% for p-CEA, and 38% and 30% for CK7, respectively. Combining LIN28 and SALL4 increased the sensitivity to 96% with 98% specificity to distinguish classic GHCs from HCCs.

CONCLUSIONS

LIN28 is a very specific marker (98% specificity) for distinguishing classic GHCs from HCCs though it is not as sensitive as SALL4. AFP, glypican-3, Hep Par1 and p-CEA are not useful in distinguishing classic GHCs from HCCs. Combining LIN28 and SALL4 increased the sensitivity to distinguish classic PHCs from HCCs.