Aims:
Hereditary diffuse gastric cancer (HDGC) can be caused by a germline mutation in CDH1
gene. Affected individuals generally present multiple foci of signet ring cell carcinoma
(SRCC) scattered throughout the gastric mucosa, which are difficult to detect by endoscopy,
and prophylactic total gastrectomy remains the first therapeutic option. We aim to
assess and compare the accuracy of random biopsies (according to Cambridge protocol)
with targeted biopsies, in patients with pathological CHD1 germline mutation.
Methods:
Prospective cohort study, between September 2016 and October 2017, including 16 patients
with CDH1 mutation submitted to a baseline high-resolution endoscopy (Olympus-GIF-HQ190)
with random biopsies according to Cambridge protocol and additional targeted biopsies
of any visible lesion. Three patients performed 2 endoscopies during the study period.
The total number of biopsies and the total number and localization of SRCC foci were
registered. For those patients submitted to prophylactic gastrectomy data was compared
with surgical specimen histology.
Results:
Nineteen endoscopies and a total of 614 biopsies were performed; 573 random biopsies
and 41 targeted biopsies; mean 32 biopsies per endoscopy. Three patients presented
only one SRCC focus in random biopsies and in one of those cancer was also noticeable
in 2 targeted biopsies. One hundred and ninety one random biopsies vs. 21 targeted
biopsies were necessary to identify SRCC. Eight patients were submitted to total gastrectomy
and all surgical specimens presented SRCC foci. Of these, only 2 patients presented
SRCC focus in biopsy samples from endoscopic evaluation.
Conclusions:
Despite the high number of random biopsies, endoscopy according to the Cambridge protocol
presents many limitations for the diagnosis of HDGC. Thus, we believe that the main
effort should be the recognition of subtle changes during endoscopy evaluation and
we argue if target biopsies wouldn't be enough.
