The (Sialyl) Tn antigen: Contributions to immunosuppression in gastrointestinal cancers

Cellular signaling pathways are intricately regulated to maintain homeostasis. During cancer progression, these mechanisms are manipulated to become harmful. O-glycosylation, a crucial post-translational modification, is one such pathway that can lead to multiple isoforms of glycoproteins. The Tn (GalNAc-O-Ser/Thr) and Sialyl Tn (STn; Neu5Ac-GalNAc-O-Ser/Thr) antigens resulting from the incomplete synthesis of fully branched O-glycan chains on proteins contribute to disease progression in the pancreas and other gastrointestinal cancers. The tumor microenvironment (TME) is a major constituent of tumors and a key modulator of their behavior. Multiple cellular and secretory components of the TME dictate the development and metastasis of tumors. Immune cells like macrophages, natural killer (NK) cells, dendritic cells, B and T lymphocytes are a part of the tumor "immune" microenvironment (TIME). The expression of the Tn and STn antigens on tumors has been found to regulate the function of these immune cells and alter their normal antitumor cytotoxic role. This is possible through multiple cell intrinsic and extrinsic signaling pathways, elaborated in this review. Studying the interaction between Tn/STn antigens and the TIME of gastrointestinal cancers can help develop better and more robust therapies that can counteract immunosuppressive mechanisms to sensitize these tumors to anticancer therapies.

SDHC phaeochromocytoma and paraganglioma: A UK-wide case series

OBJECTIVE

Phaeochromocytomas and paragangliomas (PPGL) are rare, but strongly heritable tumours. Variants in succinate dehydrogenase (SDH) subunits are identified in approximately 25% of cases. However, clinical and genetic information of patients with SDHC variants are underreported.

DESIGN

This retrospective case series collated data from 18 UK Genetics and Endocrinology departments.

PATIENTS

Both asymptomatic and disease-affected patients with confirmed SDHC germline variants are included.

MEASUREMENTS

Clinical data including tumour type and location, surveillance outcomes and interventions, SDHC genetic variant assessment, interpretation, and tumour risk calculation.

RESULTS

We report 91 SDHC cases, 46 probands and 45 non-probands. Fifty-one cases were disease-affected. Median age at genetic diagnosis was 43 years (range: 11-79). Twenty-four SDHC germline variants were identified including six novel variants. Head and neck paraganglioma (HNPGL, n = 30, 65.2%), extra-adrenal paraganglioma (EAPGL, n = 13, 28.2%) and phaeochromocytomas (PCC) (n = 3, 6.5%) were present. One case had multiple PPGLs. Malignant disease was reported in 19.6% (9/46). Eight cases had non-PPGL SDHC-associated tumours, six gastrointestinal stromal tumours (GIST) and two renal cell cancers (RCC). Cumulative tumour risk (95% CI) at age 60 years was 0.94 (CI: 0.79-0.99) in probands, and 0.16 (CI: 0-0.31) in non-probands, respectively.

CONCLUSIONS

This study describes the largest cohort of 91 SDHC patients worldwide. We confirm disease-affected SDHC variant cases develop isolated HNPGL disease in nearly 2/3 of patients, EAPGL and PCC in 1/3, with an increased risk of GIST and RCC. One fifth developed malignant disease, requiring comprehensive lifelong tumour screening and surveillance.

Adenomatoid tumours of the gastrointestinal tract - a case-series and review of the literature

AIMS

Adenomatoid tumours are mesothelial-derived benign neoplasms with a predilection for the genital tract. Extragenital sites are rare and can cause significant diagnostic challenges. Herein, we describe the clinicopathological features of a cohort of adenomatoid tumours involving the gastrointestinal tract and liver in order to more clearly characterise their histological findings and aid in diagnosis.

METHODS AND RESULTS

The pathology databases at four institutions were searched for adenomatoid tumours involving the gastrointestinal tract or liver, yielding eight cases. Available clinicoradiological and follow-up data were collected from the medical records. Six tumours were incidentally discovered during imaging studies or at the time of surgical exploration for unrelated conditions; presenting symptoms were unknown in two patients. Histologically, the tumours were well-circumscribed, although focal ill-defined borders were present in four cases. No infiltration of adjacent structures was identified. Architectural heterogeneity was noted in five (63%) tumours; an adenoid pattern often predominated. The neoplastic cells were flattened to cuboidal with eosinophilic cytoplasm. Cytoplasmic vacuoles mimicking signet ring-like cells were present in five (63%) cases. Three (38%) cases showed involvement of the mesothelium with reactive mesothelial hyperplasia. Cytological atypia or increased mitotic activity was not identified. The surrounding stroma ranged from oedematous/myxoid to densely hyalinised. Immunohistochemistry confirmed mesothelial origin in all cases evaluated. No patients developed recurrence of disease.

CONCLUSIONS

The current study evaluates the clinicopathological findings in a collective series of gastrointestinal and hepatic adenomatoid tumours, correlating with those described in individually reported cases. We highlight common histological features and emphasise variable findings that could mimic a malignant neoplasm.

The Hippo and Wnt signalling pathways: crosstalk during neoplastic progression in gastrointestinal tissue

The Hippo and Wnt signalling pathways play crucial roles in maintaining tissue homeostasis and organ size by orchestrating cell proliferation, differentiation and apoptosis. These pathways have been frequently found to be dysregulated in human cancers. While the canonical signal transduction of Hippo and Wnt has been well studied, emerging evidence shows that these two signalling pathways contribute to and exhibit overlapping functions in gastrointestinal (GI) tumorigenesis. In fact, the core effectors YAP/TAZ in Hippo signalling pathway cooperate with β-catenin in Wnt signalling pathway to promote GI neoplasia. Here, we provide a brief review to summarize the molecular mechanisms underlying the crosstalk between these two pathways and elucidate their involvement in GI tumorigenesis, particularly focusing on the intestine, stomach and liver.

Relationship between Helicobacter pylori infection and vomiting induced by gastrointestinal cancer chemotherapy

BACKGROUND

Nausea and vomiting are the most common adverse reactions to chemotherapy.

AIM

To discuss the relationship between Helicobacter pylori and chemotherapy-induced nausea and vomiting (CINV).

METHODS

A total of 112 patients with malignant tumours of the gastrointestinal tract was selected. Based on the 14C-urea breath test results, the patients were divided into H. pylori-positive (n = 59) and H. pylori-negative (n = 53) groups. Both groups received prophylactic antiemetic treatment during chemotherapy. The incidence of nausea and vomiting and their effects on the patients' life functions was recorded using the Multinational Association of Supportive Care in Cancer (MASCC) Antiemetic Tool (MAT) and the Functional Living Index Emesis (FLIE) from 0-120 h after chemotherapy. Records of the H. pylori-positive and H. pylori-negative groups were compared.

RESULTS

The rates of nausea and vomiting remission were higher in the H. pylori -negative group than in the H. pylori -positive group. The proportions of no effect in daily life (NIDL) patients in the nausea and vomiting section were 73.4 and 75.5% in the H. pylori -negative group respectively. There was a higher proportion of NIDL patients in the H. pylori -negative group than in the H. pylori -positive group (P < 0.001, P = 0.046). A multivariate unconditional logistic regression analysis was performed, and the results showed that H. pylori infection was a factor affecting the nausea scores on the FLIE (odds ratio = 0.757, 95% confidence interval 0.597-0.960, P = 0.021).

CONCLUSION

H. pylori infection in patients with cancer may be a factor that increases CINV.

Robot-assisted intersphincteric resection for rectal submucosal tumour

BACKGROUND

Rectal submucosal tumours are rare. The purpose of this study was to evaluate the safety and feasibility of robot-assisted rectal surgery.

METHODS

Patients who received robot-assisted intersphincteric resection (ISR) were included in the present study. Clinical outcomes, operating time, length of hospital stay and pathological status were analysed.

RESULTS

There were three patients with gastrointestinal tumours and three patients diagnosed with neuroendocrine tumours. The mean operating time was 369.2 min and the estimated blood loss was 66.7 ml. There were neither intraoperative complications nor conversions. On pathological examination, the mean number of lymph nodes harvested was 10.3 (range 3-16), the mean distal resection margin was 1.1 (range 0.1-3) cm and all six patients had the circumferential resection margins clear.

CONCLUSIONS

Our data show that robotic surgery is feasible and safe, with no morbidity or mortality, and that ISR provides bowel continuity and eliminates the need for colostomy. Copyright © 2015 John Wiley & Sons, Ltd.