Histopathologic analysis of total gastrectomies from asymptomatic CDH1 carriers

Within gastric cancer predisposition syndromes, Hereditary Gastric Cancer (HDGC) is caused by CDH1 germline alterations and is characterised by multigenerational diffuse gastric cancer and lobular breast cancer. Gastroscopy has limited diagnostic accuracy for the identification of early neoplastic lesions, and total gastrectomy (TG) is currently the treatment of choice for asymptomatic CDH1 carriers. In order to better understand the natural history of HDGC syndrome and the impact of histopathological findings for the clinical management of these patients, we performed a comprehensive literature review, focused on total gastrectomies performed in asymptomatic HDGC patients.The series encompassed total gastrectomies from 174 CDH1 carriers. The results of this study showed that a thorough histopathological examination of gastric mucosa remains the gold standard for detection of cancer foci in HDGC gastrectomy specimens, requiring experienced pathologists for an accurate diagnosis. This approach will provide relevant information for better clinical management of HDGC patients, particularly regarding the optimal timing for the performance of TG.

Authors and affiliations:
Rocha JP 1, Gullo I 2,3,4,5, Wen X 4,5,6, Devezas V 7,8,9, Baptista M 7,8,9, Oliveira C 3,4,5, Carneiro F 2,3,4,5. 1 Local Health Unit of Matosinhos, Matosinhos, Portugal. 2 Department of Pathology, Centro Hospitalar de São João (CHSJ), Porto, Portugal. 3 Department of Pathology, FMUP, Porto, Portugal. 4 Institute of Molecular Pathology and Immunology at the University of Porto (Ipatimup), Porto, Portugal. 5 Institute for Research Innovation in Health (i3S), University of Porto, Porto, Portugal. 6 Department of Pathology, Centro Hospitalar Vila Nova de Gaia/Espinho, Vila Nova de Gaia, Portugal. 7 Department of General Surgery, CHSJ, Porto, Portugal. 8 Department of General Surgery, FMUP, Porto, Portugal. 9 General Surgery, High Risk Consultation of Digestive Tumours, CHSJ, Porto, Portugal.

Abstract:
Hereditary diffuse gastric cancer (HDGC) is an autosomal dominant syndrome characterised by multigenerational diffuse gastric cancer, and is mainly caused by germline alterations in the CDH1 gene. Currently, endoscopy has limited diagnostic accuracy, and total gastrectomy (TG) is the treatment of choice for asymptomatic CDH1 carriers. In this study, we aimed to obtain a better understanding of HDGC syndrome by exploring the histopathological findings of TG specimens from asymptomatic HDGC patients. A comprehensive literature review was carried out, searching for TGs performed in asymptomatic HDGC patients. Fourteen unpublished cases, analysed in our institution, were also included. The series encompassed 174 CDH1 carriers. Preoperative endoscopic biopsies were positive in 28.3%. A macroscopic lesion was apparent in 11.7% of TGs. Histopathological analysis revealed intraepithelial lesions and/or intramucosal signet ring cell carcinoma in 87.9% of TGs. When we explored the type of protocol used for handling the specimens, we found that microscopic cancer foci were detected in 95.3% of TGs when a total-embedding protocol (assessment of the totality of gastric mucosa) was applied, and only in 62.5% when no specific protocol was used (P < 0.001). Helicobacter pylori infection was found in 23.4% cases. In conclusion, a thorough histopathological examination of gastric mucosa remains the gold standard for detection of cancer foci in HDGC gastrectomy specimens, requiring experienced pathologists for an accurate diagnosis. A better understanding of the natural history of HDGC will enable better clinical management of HDGC patients, particularly regarding the optimal timing for the performance of TG.

Journal: Histopathology, Volume 73, Issue 6, December 2018, Pages 878-886

Link: https://onlinelibrary.wiley.com/doi/abs/10.1111/his.13715