Complete histopathologic examination of risk reduction gastrectomy specimens for CDH1 germline mutation: Is it warranted in routine clinical practice?

A Systematic Review of Surgical and Pathological Outcomes in Patients With a CDH1 Mutation Undergoing Total Gastrectomy

BACKGROUND

CDH1 (E-cadherin) genetic mutations are associated with a 30%-70% increased lifetime risk of hereditary diffuse gastric cancer (HDGC). Although prophylactic total gastrectomy (PTG) reduces long-term risk of gastric cancer, the associated morbidity and mortality remain unclear. This systematic review aims to characterise postoperative surgical outcomes in patients undergoing total gastrectomy.

METHODS

A systematic literature search was performed for studies reporting endoscopic surveillance, surgical and pathological outcomes for patients with CDH1 mutation undergoing a total gastrectomy.

RESULTS

Thirty-nine studies included 1849 patients, of which 96% had a CDH1 (n = 1777) or CTNNA1 (n = 3) mutation. Endoscopy outcomes were reported for 1640 patients. Cancer foci were identified in 32% (n = 523/1640) and 71% of these patients went on to have a total gastrectomy (n = 369/523). The remaining 78% of patients did not have cancer foci detected on endoscopy (n = 1117/1640). Of these patients, 62% underwent a total gastrectomy (n = 688/1117) and 81% were found to have cancer on surgical histology (n = 556/688). Pathological staging was reported for 790 patients undergoing surgery, of which 68% had pT1 disease (n = 537). Postoperative complications were reported for 430 patients across 23 studies, with the most common complications being anastomotic strictures (25%), anastomotic leaks (13%), wound infections (12%) and pulmonary complications (11%). Only one postoperative death was reported within 30 days.

CONCLUSION

Rates of early cancers are high in CDH1 patients undergoing PTG, highlighting the need for improvement in reliable endoscopic surveillance. Although postoperative mortality in this surgical cohort remains low, high rates of postoperative complications warrant careful patient counselling.

Essentials of macroscopic evaluation of specimens from gastrointestinal tract

An astute macroscopic examination, coupled with correlating the gross findings with clinical indication and operative notes along with judicious, yet all pertinent sectioning for pathological examination is crucial for an accurate histopathological diagnosis, eventually leading to optimal patient care. This succinct review highlights the general concepts that lay the foundation of evaluating and grossing specimens from the luminal gastrointestinal (GI) tract. We also discuss the gross evaluation and sectioning of small therapeutic resections, along with a systematic approach and rationale when grossing and submitting histological sections from larger oncological resections from the luminal GI tract. Selected site-specific considerations, for example, grossing treated rectal and oesophageal cancers or taking sections from mucinous tumours of the appendix, among others, are also discussed.

Hereditary diffuse gastric cancer (HDGC). An overview

It is estimated that up to 10% of gastric carcinomas show familial aggregation. In contrast, around 1-3 % (approximately 33,000 yearly) are genuinely hereditary. Hereditary diffuse gastric cancer (HDGC) is a rare malignancy characterized by autosomal dominant inheritance of pathological variants of the CDH1 and CTNNA1 genes encoding the adhesion molecules E-cadherin and α-catenin, respectively. The multifocal nature of the disease and the difficulty of visualizing precursor lesions by endoscopy underscore the need to be aware of this malignancy as surgical prevention can be fully protective. Here, we provide an overview of the main epidemiological, clinical, genetic, and pathological features of HDGC, as well as updated guidelines for its diagnosis, genetic testing, counseling, surveillance, and management. We conclude that HDGC is a rare, highly penetrant disease that is difficult to diagnose and manage, so it is necessary to correctly identify it to offer patients and their families' adequate management following the recommendations of the IGCL. A critical point is identifying a mutation in HDGC families to determine whether unaffected relatives are at risk for cancer.