Confocal microscopy in the esophagus and stomach

Transversal Perspectives of Integrative Oncology Care in Gastric and Lobular Breast Cancer

The occurrence of gastric cancer has been associated with an increased risk of lobular breast tumors in a subset of patients harboring selected germline mutations. Among all, the germline alteration of the gene coding for E-Cadherin (CDH1) was associated with an increased risk of gastric cancer diffuse-histotype and lobular breast cancer. However, the risk assessment of breast neoplasms and the role of multiple prophylactic procedures in these patients has never been systematically addressed. In addition, the performance of the common screening procedures for lobular breast cancer like mammography is suboptimal. Therefore, recalling the need for a better articulation of the patient-centered strategies of surveillance for individuals with germline CDH1 and other similar alterations, to offer comprehensive approaches for prevention, early diagnosis, and treatment. Accordingly, this chapter aims to discuss the value and the role of integrated oncological care in the era of oncology sub-specializations. Additionally, it sheds light on how the harmonization across the health providers can enhance patient care in this setting.

Overview on new progress of hereditary diffuse gastric cancer with CDH1 variants

Hereditary diffuse gastric cancer (HDGC), comprising 1%-3% of gastric malignances, has been associated with CDH1 variants. Accumulating evidence has demonstrated more than 100 germline CDH1 variant types. E-cadherin encoded by the CDH1 gene serves as a tumor suppressor protein. CDH1 promoter hypermethylation and other molecular mechanisms resulting in E-cadherin dysfunction are involved in the tumorigenesis of HDGC. Histopathology exhibits characteristic signet ring cells, and immunohistochemical staining may show negativity for E-cadherin and other signaling proteins. Early HDGC is difficult to detect by endoscopy due to the development of lesions beneath the mucosa. Prophylactic gastrectomy is the most recommended treatment for pathogenic CDH1 variant carriers. Recent studies have promoted the progression of promising molecular-targeted therapies and management strategies. This review summarizes recent advances in CDH1 variant types, tumorigenesis mechanisms, diagnosis, and therapy, as well as clinical implications for future gene therapies.

Diagnosis and Management of Gastric Intestinal Metaplasia: Current Status and Future Directions

Gastric intestinal metaplasia (GIM) is a known premalignant condition of the human stomach along the pathway to gastric cancer (GC). Histologically, GIM represents the replacement of normal gastric mucosa by mucin-secreting intestinal mucosa. Helicobacter pylori infection is the most common etiologic agent of GIM development worldwide. The prevalence of GIM is heterogeneous among different regions of the world and correlates with the population endemicity of H. pylori carriage, among other environmental factors. GC remains the third leading cause of cancer-related mortality globally. GIM is usually diagnosed by upper endoscopy with biopsy, and histologic scoring systems have been developed to risk-stratify patients at highest risk for progression to GC. Several recent endoscopic imaging modalities may improve the optical detection of GIM and early GC. Appropriate surveillance of GIM may be cost effective and represents an opportunity for the early diagnosis and therapy of GC. Certain East Asian nations have established population-level programs for the screening and surveillance of GIM; guidelines regarding GIM surveillance have also recently been published in Europe. By contrast, few data exist regarding the appropriateness of surveillance of GIM in the United States. In this review, we discuss the pathogenesis, epidemiology, diagnosis, and management of GIM with an emphasis on the role of appropriate endoscopic surveillance.

Probe-based confocal laser endomicroscopy versus biopsies in the diagnostics of oesophageal and gastric lesions: A prospective, pathologist-blinded study

BACKGROUND AND AIM

Probe-based confocal laser endomicroscopy (pCLE) provides real-time microscopic visualisation. Our aim was to compare the diagnostic accuracy of pCLE with standard biopsies in patients with visible oesophageal or gastric lesions.

METHODS

This was a single-centre, prospective, pathologist-blinded study. Patients underwent high-resolution endoscopy, and lesions were examined by pCLE followed by standard biopsies. A definitive diagnosis was determined from resection specimen. Main outcomes were overall diagnostic accuracy, sensitivity, specificity and positive and negative predictive values.

RESULTS

We examined 74 lesions in 67 patients. Definitive diagnoses revealed 34 malignant and 40 non-malignant lesions. pCLE diagnosis was correct in 89.2% (66/74), while diagnosis based on biopsy was correct in 85% (57/67; p = 0.6). The overall diagnostic accuracy of biopsies was 85% (76-94%) and that of pCLE was 89% (79-96%). pCLE correctly diagnosed malignant lesions, comprising oesophageal adenocarcinoma, oesophageal squamous-cell cancer or gastric adenocarcinoma, in 88.2% (30/34) of cases, while biopsy was correctly diagnosed in 75.9% (22/29; p = 0.3). Sensitivity and specificity to diagnose a malignant lesion were 75.9% (95% confidence interval (CI) 56-89%) and 100% (95% CI 90-100%) for biopsies and 88.2% (95% CI 72-97%) and 92% (95% CI 79-98%) for pCLE. No differences between biopsies and pCLE were found with regard to sensitivity, specificity to diagnose dysplastic and benign lesions (p > 0.2).

CONCLUSION

pCLE provides satisfactory diagnostic accuracy comparable with standard biopsies in patients with oesophageal or gastric lesions. ClinicalTrials.gov identifier: NCT0292049).

The role of endoscopy in the management of hereditary diffuse gastric cancer syndrome

Hereditary diffuse gastric cancer (HDGC) syndrome is an inherited cancer risk syndrome associated with pathogenic germline CDH1 variants. Given the high risk for developing diffuse gastric cancer, CDH1 carriers are recommended to undergo prophylactic total gastrectomy for cancer risk reduction. Current guidelines recommend upper endoscopy in CDH1 carriers prior to surgery and then annually for individuals deferring prophylactic total gastrectomy. Management of individuals from HDGC families without CDH1 pathogenic variants remains less clear, and management of families with CDH1 pathogenic variants in the absence of a family history of gastric cancer is particularly problematic at present. Despite adherence to surveillance protocols, endoscopic detection of cancer foci in HDGC is suboptimal and imperfect for facilitating decision-making. Alternative endoscopic modalities, such as chromoendoscopy, endoscopic ultrasound, and other non-white light methods have been utilized, but are of limited utility to further improve cancer detection and risk stratification in HDGC. Herein, we review what is known and what remains unclear about endoscopic surveillance for HDGC, among individuals with and without germline CDH1 pathogenic variants. Ultimately, the use of endoscopy in the management of HDGC remains a challenging arena, but one in which further research to improve surveillance is crucial.

Probe-based confocal laser endomicroscopy (pCLE): a preclinical investigation of the male genital tract

The aim of this study was to assess the potential of probe-based confocal laser endomicroscopy (pCLE) as a new diagnostic imaging technique for the male genital tract. For this purpose, testes, epididymides, and vasa deferentia were obtained during transsexual surgery of healthy patients (n = 10, 26-52 years). Prior to this, testes of rats (n = 10, Sprague-Dawley) and mice (n = 8, wild-type) were examined. Ex vivo tissues were investigated by pCLE after topical fluorescence staining. Images and pCLE real-time video sequences were compared to images acquired by confocal laser scanning microscopy (CLSM); this allowed the identifying of corresponding microstructures. Interestingly, the seminiferous tubules of transsexual humans contained mainly spermatogonia due to long-term estrogen treatment, whereas the seminiferous tubules of the murine and rat spermatogenesis-related cell types were differentiated. Mosaicking improved the inspection potential by wide-angle views. Similarly, the microarchitecture of the epididymis and the vas deferens was successfully visualized in situ and on a cellular level by pCLE. In summary, pCLE allows for real-time identification of relevant microstructures responsible for spermatogenesis under ex vivo conditions. Additionally, pCLE enabled to localize vital spermatozoa in the testis thus opening up new ways to improve sperm retrieval rates during assisted reproduction. Both clinically relevant experiences hold promise to introduce this diagnostic method into a clinical study, and to investigate its potential as a clinical diagnostic procedure to expedite and improve the medical situation.

State-of-the-art molecular imaging in esophageal cancer management: implications for diagnosis, prognosis, and treatment

Molecular imaging techniques are increasingly being used in addition to standard imaging methods such as endoscopic ultrasound (EUS) and computed tomography (CT) for many cancers including those of the esophagus. In this review, we will discuss the utility of the most widely used molecular imaging technique, (18)F-fluorodeoxyglucose ((18)F-FDG) positron emission tomography (PET). (18)F-FDG PET has a variety of potential applications ranging from improving staging accuracy at the time of initial diagnosis to assisting in radiation target volume delineation. Furthermore, (18)F-FDG PET can be used to evaluate treatment response after completion of neoadjuvant therapy or potentially during neoadjuvant therapy. Finally, we will also discuss other novel molecular imaging techniques that have potential to further improve cancer care.

Recent advances in molecular imaging of premalignant gastrointestinal lesions and future application for early detection of barrett esophagus

Recent advances in optical molecular imaging allow identification of morphologic and biochemical changes in tissues associated with gastrointestinal (GI) premalignant lesions earlier and in real-time. This focused review series introduces high-resolution imaging modalities that are being evaluated preclinically and clinically for the detection of early GI cancers, especially Barrett esophagus and esophageal adenocarcinoma. Although narrow band imaging, autofluorescence imaging, and chromoendoscopy are currently applied for this purpose in the clinic, further adoptions of probe-based confocal laser endomicroscopy, high-resolution microendoscopy, optical coherence tomography, and metabolomic imaging, as well as imaging mass spectrometry, will lead to detection at the earliest and will guide predictions of the clinical course in the near future in a manner that is beyond current advancements in optical imaging. In this review article, the readers will be introduced to sufficient information regarding this matter with which to enjoy this new era of high technology and to confront science in the field of molecular medical imaging.