Defining Parallels between the Salivary Glands and Pancreas to Better Understand Pancreatic Carcinogenesis

MicroRNAs: emerging biomarkers and therapeutic targets in pancreatic cancer

Pancreatic cancer (PC) is a highly malignant disease with high aggressiveness and a dismal prognosis, which is challenging to diagnose clinically early and gains low benefit from standard therapies. MicroRNAs (miRNAs) have become a hot topic in oncology research. Current evidence indicates that miRNAs are regulators involved in the entire process of PC, providing new diagnostic and therapeutic strategies for this fatal disease. Related research has been rapidly updated, making it necessary to review it to propose new directions and ideas and provide guidance for the development of precision medicine for PC. We reviewed the relevant literature through Pubmed, Embase, Web of Science and Medline, showing that abnormally expressed miRNAs in PC patients have the potential to be used as biomarkers for diagnosis and prognosis, highlighting the excellent prospect of combining miRNAs with traditional therapies, and the effective application of these factors for PC, especially miRNA mimics and inhibitors. MiRNAs participate in the entire process of PC and play important roles in diagnosis, treatment and prognosis. They are potential factors in conquering PC in the future.

Heterotopia of salivary gland tissue in the pancreas

Heterotopia of the salivary gland occurs mainly in the head and neck region of the human body, rarely in regions such as the rectum, but has never been demonstrated in the pancreas. Within a screening effort of pancreatic samples for detecting ΔNp63 expression, we discovered two pancreatic samples from a 35-year-old male showing salivary gland heterotopia. Immunohistochemical stainings were done for markers of healthy and neoplastic salivary glands and showed expression of calponin, CD142 and KRT14 but not of S100p, GFAP or CD117. A PAS-staining and Alcian Blue staining showed the presence of acid mucins. These staining patterns were consistent with non-neoplastic submandibular gland tissue comprised of abundant seromucous glands, basal cells and myoepithelial cells, all features typically absent in the pancreas. Also, no pancreatic islets of Langerhans were detected. We show for the first time that salivary gland heterotopia can occur at the location of the pancreas.

CELA3B immunostaining is a highly specific marker for acinar cell carcinoma of the pancreas

Chymotrypsin-like elastase family member 3B (CELA3B, elastase-3B) is a pancreatic enzyme with digestive function in the intestine. Since RNA analyses of normal tissues suggest that CELA3B expression is limited to the pancreas, the potential diagnostic utility of CELA3B immunohistochemistry for the distinction of pancreatic from extrapancreatic cancers and in the distinction of acinar cell carcinoma from ductal adenocarcinoma was assessed. CELA3B expression was successfully analyzed in 13,223 tumor samples from 132 different tumor types and subtypes as well as 8 samples each of 76 different normal tissue types by immunohistochemistry in a tissue microarray format (TMA). In normal tissues, CELA3B immunostaining was only seen in acinar cells and in a fraction of ductal cells of the pancreas as well as on some apical membranes of surface epithelial cells of the intestine. Among tumors, CELA3B immunostaining was seen in 12 of 16 (75%) acinar cell carcinoma of the pancreas including 6 cases with strong staining (37.5%) as well as in 5 of 13,207 other tumors (0.04%). These included 1.2% of 91 adenoid cystic carcinomas, 1.2% of 246 mucoepidermoid carcinomas and 0.8% of 127 acinic cell carcinomas of salivary glands. Our data show a good sensitivity (75%) and a high specificity (99.9%) of CELA3B immunohistochemistry for diagnosing acinar cell carcinoma of the pancreas.

Obesity, diabetes mellitus, and pancreatic carcinogenesis: Correlations, prevention, and diagnostic implications

The prevalence of obesity, diabetes mellitus (DM), and pancreatic cancer (PC) has been consistently increasing in the last two decades worldwide. Sharing various influential risk factors in genetics and environmental inducers in pathogenesis, the close correlations of these three diseases have been demonstrated in plenty of clinical studies using multiple parameters among different populations. On the contrary, most measures aimed to manage and treat obesity and DM effectively reduce the risk and prevent PC occurrence, yet certain drugs can inversely promote pancreatic carcinogenesis instead. Most importantly, an elevation of blood glucose with or without a reduction in body weight, along with other potential tools, may provide valuable clues for detecting PC at an early stage in patients with obesity and DM, favoring a timely intervention and prolonging survival. Herein, the epidemiological and etiological correlations among these three diseases and the supporting clinical evidence of their connections are first summarized to favor a better and more thorough understanding of obesity- and DM-related pancreatic carcinogenesis. After comparing the distinct impacts of different weight-lowering and anti-diabetic treatments on the risk of PC, the possible diagnostic implications of hyperglycemia and weight loss in PC screening are also addressed in detail.

Oral Microbiota and Tumor-A New Perspective of Tumor Pathogenesis

Microorganisms have long been known to play key roles in the initiation and development of tumors. The oral microbiota and tumorigenesis have been linked in epidemiological research relating to molecular pathology. Notably, some bacteria can impact distal tumors by their gastrointestinal or blood-borne transmission under pathological circumstances. Certain bacteria drive tumorigenesis and progression through direct or indirect immune system actions. This review systemically discusses the recent advances in the field of oral microecology and tumor, including the oncogenic role of oral microbial abnormalities and various potential carcinogenesis mechanisms (excessive inflammatory response, host immunosuppression, anti-apoptotic activity, and carcinogen secretion) to introduce future directions for effective tumor prevention.

Pancreatic lymphoepithelial cyst with concurrent HIV infection: A case report and review of the literature

Pancreatic lymphoepithelial cysts are rare, benign, non-neoplastic unilocular or multilocular cystic lesions. These circumscribed pancreatic lesions are filled with keratinous material grossly and exhibit distinct microscopic features. Pancreatic lymphoepithelial cysts are like the more common lymphoepithelial cysts of the parotid glands, which have been associated with the diffuse infiltrative lymphocytosis syndrome often seen in patients with HIV infection. However, pancreatic lymphoepithelial cysts are rare and their association with HIV infection has not been established. The presence of secondary changes in non-neoplastic cysts such as goblet cell metaplasia that was present in our case is an important feature to be included in the differential diagnosis and not to be interpreted as a mucinous neoplasm, particularly on fine-needle aspiration specimen microscopic evaluation that would impact further management. Here we describe the diagnosis and treatment of lymphoepithelial cysts in a patient who was on highly active antiretroviral therapy for HIV infection and we provide a brief literature review. Defining the clinical characteristics of lymphoepithelial cysts in patients with HIV and determining accurate preoperative diagnostic procedures will be critical for establishing effective surgical and medical approaches to treating these cysts, which differ substantially from other more serious pancreatic cystic lesions.

The oral microbiome, pancreatic cancer and human diversity in the age of precision medicine

Pancreatic cancer is a deadly disease with limited diagnostic and treatment options. Not all populations are affected equally, as disparities exist in pancreatic cancer prevalence, treatment and outcomes. Recently, next-generation sequencing has facilitated a more comprehensive analysis of the human oral microbiome creating opportunity for its application in precision medicine. Oral microbial shifts occur in patients with pancreatic cancer, which may be appreciated years prior to their diagnosis. In addition, pathogenic bacteria common in the oral cavity have been found within pancreatic tumors. Despite these findings, much remains unknown about how or why the oral microbiome differs in patients with pancreatic cancer. As individuals develop, their oral microbiome reflects both their genotype and environmental influences. Genetics, race/ethnicity, smoking, socioeconomics and age affect the composition of the oral microbiota, which may ultimately play a role in pancreatic carcinogenesis. Multiple mechanisms have been proposed to explain the oral dysbiosis found in patients with pancreatic cancer though they have yet to be confirmed. With a better understanding of the interplay between the oral microbiome and pancreatic cancer, improved diagnostic and therapeutic approaches may be implemented to reduce healthcare disparities. Video Abstract.

Glandular metastases from renal cell carcinoma show poor clinical responses to immune checkpoint inhibition but durable responses to angiogenesis inhibitors

While half of the metastatic clear cell renal cell carcinomas (ccRCCs) involve the lungs, metastatic lesions have been described in various other organs, including glandular tissues such as the pancreas. Recent evidence suggests that ccRCC lesions affecting the pancreas are poorly responsive to immune checkpoint inhibition (ICI) but show superior responses to tyrosine kinase inhibitors (TKIs) targeting the vascular endothelial growth factor (VEGF) signalling pathway. However, this has yet to be explored in ccRCC spreading to other glandular tissues. Here we present two cases of ccRCC with glandular metastases, the first to the pancreas and the second to the parotid gland. In both patients, ICI-based immunotherapy offered minimal clinical benefit, but both had durable responses to angiogenesis inhibitors. Given the anatomic similarity between the pancreas and parotid glands, ccRCC with involvement of the parotid gland may also benefit from VEGF-targeting TKIs as opposed to ICIs.