Role of the Microbiome in the Diagnosis and Management of Gastroesophageal Cancers

PURPOSE

Stomach and esophageal cancers are among the highest mortality from cancers worldwide. Microbiota has an interplaying role within the human gastrointestinal (GI) tract. Dysbiosis occurs when a disruption of the balance between the microbiota and the host happens. With this narrative review, we discuss the main alterations in the microbiome of gastroesophageal cancer, revealing its potential role in the pathogenesis, early detection, and treatment.

RESULTS

Helicobacter pylori plays a major role the development of a cascade of preneoplastic conditions ranging from atrophic gastritis to metaplasia and dysplasia, ultimately culminating in gastric cancer, while other pathogenic agents are Fusobacterium nucleatum, Bacteroides fragilis, Escherichia coli, and Lactobacillus. Campylobacter species (spp.)'s role in the progression of esophageal adenocarcinoma may parallel that of Helicobacter pylori in the context of gastric cancer, with other esophageal carcinogenic agents being Escherichia coli, Bacteroides fragilis, and Fusobacterium nucleatum. Moreover, gut microbiome could significantly alter the outcomes of chemotherapy and immunotherapy. The gut microbiome can be modulated through interventions such as antibiotics, probiotics, or prebiotics intake. Fecal microbiota transplantation has emerged as a therapeutic strategy as well.

CONCLUSIONS

Nowadays, it is widely accepted that changes in the normal gut microbiome causing dysbiosis and immune dysregulation play a role gastroesophageal cancer. Different interventions, including probiotics and prebiotics intake are being developed to improve therapeutic outcomes and mitigate toxicities associated with anticancer treatment. Further studies are required in order to introduce the microbiome among the available tools of precision medicine in the field of anticancer treatment.

High-Salt Diet Exacerbates H. pylori Infection and Increases Gastric Cancer Risks

Gastric cancer ranks as the fifth-leading contributor to global cancer incidence and the fourth-highest in terms of cancer-related mortality. Helicobacter pylori (H. pylori) infection leads to inflammation and ulceration, atrophic and chronic gastritis, and eventually, increases the risk of developing gastric adenocarcinoma. In this paper, we delve into the combined impact of a high-salt diet (HSD) and concurrent H. pylori infection, which act as predisposing factors for gastric malignancy. A multitude of mechanisms come into play, fostering the development of gastric adenocarcinoma due to the synergy between an HSD and H. pylori colonization. These encompass the disruption of mucosal barriers, cellular integrity, modulation of H. pylori gene expression, oxidative stress induction, and provocation of inflammatory responses. On the whole, gastric cancer patients were reported to have a higher median sodium intake with respect to healthy controls. H. pylori infection constitutes an additional risk factor, with a particular impact on the population with the highest daily sodium intake. Consequently, drawing from epidemiological discoveries, substantial evidence suggests that diminishing salt intake and employing antibacterial therapeutics could potentially lower the susceptibility to gastric cancer among individuals.

iNKT cell-neutrophil crosstalk promotes colorectal cancer pathogenesis

iNKT cells account for a relevant fraction of effector T-cells in the intestine and are considered an attractive platform for cancer immunotherapy. Although iNKT cells are cytotoxic lymphocytes, their functional role in colorectal cancer (CRC) is still controversial, limiting their therapeutic use. Thus, we examined the immune cell composition and iNKT cell phenotype of CRC lesions in patients (n = 118) and different murine models. High-dimensional single-cell flow-cytometry, metagenomics, and RNA sequencing experiments revealed that iNKT cells are enriched in tumor lesions. The tumor-associated pathobiont Fusobacterium nucleatum induces IL-17 and Granulocyte-macrophage colony-stimulating factor (GM-CSF) expression in iNKT cells without affecting their cytotoxic capability but promoting iNKT-mediated recruitment of neutrophils with polymorphonuclear myeloid-derived suppressor cells-like phenotype and functions. The lack of iNKT cells reduced the tumor burden and recruitment of immune suppressive neutrophils. iNKT cells in-vivo activation with α-galactosylceramide restored their anti-tumor function, suggesting that iNKT cells can be modulated to overcome CRC-associated immune evasion. Tumor co-infiltration by iNKT cells and neutrophils correlates with negative clinical outcomes, highlighting the importance of iNKT cells in the pathophysiology of CRC. Our results reveal a functional plasticity of iNKT cells in CRC, suggesting a pivotal role of iNKT cells in shaping the tumor microenvironment, with relevant implications for treatment.

Antibiotics, the microbiome and gastrointestinal cancers: A causal interference?

Our understanding of the gut microbiota has significantly evolved over the last two decades. Advances in the analysis of the gut microbiome continues to reveal complex microbial communities and discoveries about their role in health and diseases, including cancer development, are continuously growing. In addition, research has demonstrated that the use of antibiotics can modulate the gut microbiota composition negatively and influence cancer treatment outcomes, suggesting that antibiotics should be avoided if possible. In this article, we review the role of the gut microbiota in the formation of GI cancers. We show that specific bacterial populations can positively or negatively affect cancer formation with specific attention given to gastric and colorectal cancer. We also review the role of microbial-targeted therapies on cancer treatment outcomes.

Intratumor Microbiome in Neuroendocrine Neoplasms: A New Partner of Tumor Microenvironment? A Pilot Study

Neuroendocrine neoplasms (NENs) are rare neoplasms with heterogeneous clinical behavior. Alteration in human microbiota was reported in association with carcinogenesis in different solid tumors. However, few studies addressed the role of microbiota in NEN. We here aimed at evaluating the presence of bacterial infiltration in neuroendocrine tumoral tissue. To assess the presence of bacteria, 20 specimens from pancreatic NEN (pan-NEN) and 20 from intestinal NEN (I-NEN) were evaluated through Fluorescent In situ Hybridization and confocal microscopy. Demographic data, pre-operative investigations, operative findings, pathological diagnosis, follow-up, and survival data were evaluated. Among I-NEN, bacteria were detected in 15/20 (75%) specimens, with high variability in microbial distribution. In eight patients, a high infiltration of microorganisms was observed. Among pan-NEN, 18/20 (90%) showed microorganisms’ infiltration, with a homogeneous microbial distribution. Bacterial localization in pan-NEN was observed in the proximity of blood vessels. A higher bacterial infiltration in the tumoral specimen as compared with non-tumoral tissue was reported in 10/20 pan-NEN (50%). No significant differences were observed in mean bacterial count according to age, sex, ki67%, site, tumor stage. Mean bacterial count did not result to be a predictor of disease-specific survival. This preliminary study demonstrates the presence of a significant microbiota in the NEN microenvironment. Further research is needed to investigate the potential etiological or clinical role of microbiota in NEN.

Microbiota-targeted therapies in inflammation resolution

Gut microbiota has been shown to systemically shape the immunological landscape, modulate homeostasis and play a role in both health and disease. Dysbiosis of gut microbiota promotes inflammation and contributes to the pathogenesis of several major disorders in gastrointestinal tract, metabolic, neurological and respiratory diseases. Much effort is now focused on understanding host-microbes interactions and new microbiota-targeted therapies are deeply investigated as a means to restore health or prevent disease. This review details the immunoregulatory role of the gut microbiota in health and disease and discusses the most recent strategies in manipulating individual patient's microbiota for the management and prevention of inflammatory conditions.

The Role of Gut Microbiota Biomodulators on Mucosal Immunity and Intestinal Inflammation

Alterations of the gut microbiota may cause dysregulated mucosal immune responses leading to the onset of inflammatory bowel diseases (IBD) in genetically susceptible hosts. Restoring immune homeostasis through the normalization of the gut microbiota is now considered a valuable therapeutic approach to treat IBD patients. The customization of microbe-targeted therapies, including antibiotics, prebiotics, live biotherapeutics and faecal microbiota transplantation, is therefore considered to support current therapies in IBD management. In this review, we will discuss recent advancements in the understanding of host−microbe interactions in IBD and the basis to promote homeostatic immune responses through microbe-targeted therapies. By considering gut microbiota dysbiosis as a key feature for the establishment of chronic inflammatory events, in the near future it will be suitable to design new cost-effective, physiologic, and patient-oriented therapeutic strategies for the treatment of IBD that can be applied in a personalized manner.

Fostering interest in research: evaluation of an introductory research seminar at hospitals in rural Rwanda

SETTINGS

Partners In Health Rwanda, in collaboration with the Ministry of Health, leads a multipronged approach to develop research capacity among health workers, particularly in rural areas.

OBJECTIVES

To describe the characteristics of participants and to assess the impact of an introductory research seminar series in three district hospitals in rural Rwanda.

DESIGN

This was a retrospective cohort study of seminar participants. Data were sourced from personnel records, assessment sheets and feedback forms.

RESULTS

A total of 126 participants, including 70 (56%) clinical and 56 (44%) non-clinical staff, attended the research seminar series; 61 (48%) received certification. Among those certified, the median assessment score on assignments was 79%. Participants read significantly more articles at 6 and 12 months (median 2 and 4 respectively, compared to 1 at baseline, P < 0.01). There was also a significant increase (P ⩽ 0.05) in self-reported involvement in research studies (28%, baseline; 59%, 12 months) and attendance at other research training (36%, baseline; 65%, 12 months).

CONCLUSION

The introductory research seminar series provided an important opportunity for engagement in research among clinical and non-clinical staff. Such an activity is a key component of a comprehensive research capacity building programme at rural sites, and serves as an entry point for more advanced research training.

Preoperative sonographic features of borderline ovarian tumors

OBJECTIVE

To determine the sonographic findings that distinguish borderline ovarian tumors (BOT) from both benign and invasive malignant tumors, thus allowing conservative treatment and laparoscopic management of these tumors.

METHODS

We reviewed retrospectively transvaginal sonograms of 33 women who, when evaluated further by surgery and histology, were found to have BOT. Twenty-three were premenopausal and 10 were postmenopausal (mean age +/- SD, 45.8 +/- 15.7 years). For each mass, size and morphological features and power Doppler characteristics were evaluated. We compared these findings with those of 337 patients with benign ovarian tumors and those of 82 patients with invasive malignant ovarian tumors. Patients with dermoid cysts were not included in the study.

RESULTS

Of the 33 BOT, 15 were mucinous and 18 were serous cystadenomas. The presence of papillae, defined as a small number of solid tissue projections, 1-15 mm in height and 1-10 mm in width (base) and length (base), into the cyst cavity from the cyst wall, was significantly more frequent in BOT (48%) than it was in benign (4%) and invasive (4%) malignant tumors. Intracystic solid tissue (> 15 mm in height or > 10 mm in width or length) was observed in 48% of invasive malignant masses but in only 18% of BOT and in 7% of benign tumors (P < 0.001). No sonographically unilocular, hypoechoic, smooth-walled adnexal cysts were invasively malignant but three unilocular cysts with a diameter of > 6 cm were serous BOT. Although close attention was paid to the cyst wall at ultrasound examination we did not observe in these three cysts the very small papillae which were found at histological analysis.

CONCLUSIONS

The most frequent diagnostic feature on imaging BOT is the presence of papillae within the cyst. However, neither papillae nor other sonographic features constituted highly sensitive sonographic markers of BOT.

Eccrine spiradenoma of the ear: case report

A case of eccrine spiradenoma of the left pinna is described. To the best of our knowledge, this is the first report regarding this site. The treatment was a surgical excision in safe margins. This rare benign tumour should be considered for the differential diagnosis of solitary or multiple soft tissue lesions of the head and neck.

Hearing loss evaluation of Sjögren's syndrome using distortion product otoacoustic emissions

Sjögren's syndrome (SS) is a cell-mediated immune disorder primarily affecting the exocrine glands and hearing loss may be the first otological manifestation of this autoimmune disease. In order to assess the degree of sensorineural hearing loss in SS, 22 female patients were examined by means of standard audiometric tests (pure-tone audiometry, acoustic reflexes and impedance testing) and using distortion product otoacoustic emissions (DPOAEs). The results indicated that only 36.3% of the patients had mild sensorineural hearing loss. Hearing level and distortion product threshold estimates were found to be significantly correlated. No relationship was found between the duration of the disease and the DPOAE and hearing threshold variables. The data suggest that SS may not directly cause sensorineural hearing loss.

Mucoceles of the frontal sinus. Clinical and therapeutical considerations

BACKGROUND

Mucocele is an epithelial lined mucus-containing sac completely filling a paranasal sinus and capable of expansion by virtue of a dynamic process of bone resorption and new bone formation. It is the most common lesion causing expansion of the paranasal sinuses. Even though mucoceles of paranasal sinuses are increasingly treated by endoscopic surgery, the external approach with or without the obliteration of the sinus still remains a useful and sometimes the only tool in the treatment of this disease.

METHODS

The results obtained in seven patients observed at the ENT Department of the University of Ferrara (Italy) in the period ranging from 1989 to 1999 are presented; they were affected by massive fronto-ethmoidal mucoceles and treated with the external approach alone or combined with an endonasal approach and osteoplastic flap. They were five males and two females, with a mean age of 56.5 years. Locations were bilateral in one mucocele, while in six patients only one side was involved, with a prevalence of the left frontal sinus (4:2).

RESULTS

No patient showed any local or general complication in the postoperative period. The follow-up showed no recurrence of the disease.

CONCLUSIONS

Since the osteoplastic flap was introduced one hundred years ago, it still remains the optimal surgical treatment for fronto-ethmoidal mucoceles. Even though, today, endoscopic surgery represents the new horizon in the management of the sinonasal disease, mucoceles need a surgical treatment which allows the total vision of the cavity to obtain radical treatment and any recurrence of disease.

[A case of temporal arteritis presenting with sensorineural hearing loss]

The inflammatory lesions in giant cell arteritis involve the cranial branches of the arteries originating from the arch of the aorta most prominently. The vessels are thickened tender, and nodular with absent or reduced pulsation. In literature sensorineural hearing loss and Horton's arteritis are rarely associated. A case of temporal arteritis presenting with sensorineural hearing loss is described.

Clinical and radiological findings in subjects with unilateral Ménière's disorder

In order to contribute to the knowledge of the possible causes of Ménière's disorder, the authors have conducted systematic studies based on blood analysis and on petrous bone radiological examinations in patients suffering from unilateral Ménière's disorder and in two control groups, one of patients with unilateral sudden sensorineural deafness and the other one of normally hearing subjects suffering from neurological diseases. Blood tests have revealed systemic disorders (dyslipidosis, hypoglycaemia, hyperglycaemia, hypothyroidism lues) in 49%, 48% and in 50% of the subjects respectively with Ménière's disorder, with sudden deafness, and with normal hearing. As to the radiological study, changes of the temporal bone (absence or small cells pneumatization and/or absence or narrowing of the vestibular aqueduct) were found in 78% of ears with Ménière's disorder, in 34% of ears with sudden deafness and in 46% of normal ears.

Clinical experience with remote masking

Remote masking (RM) consists of a rise of the threshold for low-pitched tones when the ear is exposed to a high-frequency noise band delivered with high intensity. This phenomenon has been attributed to mechanical non-linear distortion of the cochlear partition, as an effect of the envelope of a non-uniform signal. The authors studied RM in patients suffering from unilateral Menière's disorder, acoustic neuromata, other sensorineural lesions and presbyacusis. The behaviour of RM in the different experimental groups shows that the RM value is normal in acoustic neuromata; it is variable and not related to the severity of the hearing loss in sensorineural losses, and it is reduced in the affected ear in patients suffering from Menière's disorder. Finally, RM is reduced as a function of ageing, progressively and symmetrically in both ears in presbyacusic subjects. The results of the research seem to confirm the hypothesis that RM may be due to mechanical effects in the inner ear and suggest the possibility of using RM as a test of cochlear partition rigidity.

Remote masking in presbycusis

Remote Masking (RM) (a rise in threshold for low-frequency tones when the ear is exposed to a high intensity noise band of high frequency) has been attributed to mechanical nonlinear distortion of the cochlear partition, as an effect of the envelope of a nonuniform signal. Clinical studies using RM have revealed RM is normal only when both the endolabyrinthine pressure and the cochlear hydrodynamics are normal. Increasing the stiffness of the cochlear partition affects adversely the mechanism of motion of the cochlear duct and reduces RM values. We studied RM in normal young Ss and in patients with presbycusis in order to determine whether aging of the inner ear also induces stiffness of the cochlear partition. In presbycusic Ss the RM values were indeed reduced symmetrically in both ears and progressively as a result of aging. Thus RM demonstrates the existence of cochlear conductive presbycusis and can be considered a useful test of stiffness of the cochlear partition.