Gastric Cancer Risk Assessment Test(ABCD Classiﬁcation)

Suggestion of Flow for Gastric Cancer Risk Assessment Test (ABCD Classification)
Confirmation of the “status of eradication” by medical interview, etc.

Editorial supervision：Kazuhiko INOUE, M.D., Ph.D., Director of Health Maintenance Center. JUNPUKAI FOUNDATION

What is ABCD Classification?
Gastric Cancer Risk Assessment Test (ABCD classification) is a method for
determining the health status of the stomach of an individual by means of a
combination of a pepsinogen test (as a gastric mucosal atrophy marker) and a
Helicobacter pylori antibody test to detect H. pylori infections (considered tobe the main cause of gastric ulcers, duodenal ulcers, and gastric cancers).
However, the ABCD classification is not applied to individuals who havereceived treatment to eradicate H. pylori, regardless of the result of thetreatment.
These previously treated individuals should be assigned to Group E(eradication group), so it is important to confirm the “status of eradication”
during the medical interview, or at another appropriate time.

What is pepsinogen (PG) test?
A pepsinogen (PG) test is a blood test designed to objectively evaluate thehealth status (degree of mucosal atrophy) of the stomach by measuring theserum concentration of a substance called “pepsinogen”.
Many gastric cancer cases are shown to develop subsequent to gastric mucosal
atrophy, the extent of which can be estimated using the pepsinogen test, and thetest results can be utilized to screen individuals for increased risk of gastriccancer.

What is an H. Pylori Antibody Test?
An H. pylori test is a test to detect H. pylori infections of the gastric mucosa.
When infected with H. pylori, the body produces antibodies against H. pylori(H. pylori antibodies) which are released into the blood and urine. This
antibody test is a method for measuring the amounts of these H. pylori
antibodies in the blood and urine of the individual.

H.pylori test (antibody)

ABCDClassification

(－ )

(＋)

(－ )

Group AGroup B(＋)

Group DGroup CPG testConfirmation of the “status of eradication”
by medical interview, etc.

Without eradication therapyWith eradication therapy

Individual to determination of ABCD classification

Exclusion fromABCD Classification*1

Blood test (ABCD Classification)

Group AGroup BGroup CGroup D(Eradication group)*2

Individuals who have received treatment to eradicate
H. pylori are not evaluated using the ABCD classification,
regardless of the result of the treatment.

Endoscopy

Exclusion from Determinationof ABCD Classification

Other tests for H.
H. pylori
pylori infection(test for presence) should be performed.

They should be assigned to Group E.

Group E：Eradication group

Before starting eradication therapy, the presence of an
existing infection with H. pylori should be confirmed.

Caution in interpreting the PG test should be used forindividuals who:

● received eradication therapy for H.pylori● have obvious upper gastrointestinal symptoms● are under treatment for upper gastrointestinal disease● are taking proton pump inhibitors (PPI)● received gastrectomy● had renal failureGroup EEradication therapy
Determination of eradication

Individuals who have undergone
H. pylori eradication are assigned
to Group E (eradication group)
and are recommended to haveregular endoscopic examinations
regardless of the result of theeradication treatment.
The risk for developing gastriccancer is reduced by eradication
therapy, but never eliminate therisk completely. Therefore,
follow-up with endoscopic
examinations is still necessary
even after eradication treatment.

*3

Imaging tests might be recommended; it depends on individual risks

Helicobacter pylori Infection & Diseases*1. For determination of the ABCD classification, test methods and measured values for the H. pylori antibody test and the pepsinogen test (e.g. EIA,

Helicobacter pylori infection (in childhood)

No

Yes

Inflammaion of the gastric mucosa (－)
Atrophy of the gastric mucosa (－)

Group A

Inflammation of the gastric mucosa (＋)

Group B

Gastroesophageal reflux disease
Eradication therapy

Gastric ulcer and duodenal ulcer
Gastric cancer (diffuse type)
Gastric MALT lymphoma

Atrophy of the gastric mucosa (＋)
Reduced gastric mucosal inflammation
Mild improvement in degree of gastricmucosal atrophy

Group EGroup CGroup D

Gastric cancer (intestinal type)
Gastric adenoma
Gastric hyperplastic polyp(Kazuhiko Inoue (2015). Effects of Eradication Therapy on Risk Category of Gastric Cancer - ABC Classification is a Gateway for GastricCancer Screening - Nobuhiro Sakaki (Editor) The Perfect Guide to H. Pylori Eradication Therapy. Japan Medical Journal. pp. 181-183)

It has been shown that H. pylori infection occurs during infancy or childhood (until the age of 4-5 years) when gastric acid secretionand the immune capacity of the gastric mucosa are not fully developed. Chronic H. pylori infection in adults is believed to be rare,
when no H. pylori infection occurs in childhood.
Infection with H. pylori causes inflammation of the gastric mucosa, which may lead to development of peptic ulcer, gastric MALT
lymphoma, or undifferentiated-type gastric cancer. Gastric mucosal atrophy then develops and becomes the geneses of gastricadenoma, hyperplastic polyps, and gastric cancers. Not all individuals infected with H. pylori will have stomach diseases; thefrequency of gastric cancer development is approximately 0.5% per year.
Eradication of H. pylori suppresses the recurrence of ulcers and reduces the risk for gastric cancer, but not eliminate therisk completely.

LA, CLEIA) should be reported.
*2. It is recommended that individuals assigned to Group A also undergo an imaging test at least once to determine the status of infection with H. pylori,and to evaluate the risk for developing gastric cancer with more certainty.
*3. Individuals who have received eradication therapy are assigned to “Group E”. Only the measured values of the H. pylori antibody test and thepepsinogen test should be reported, with no determination of the ABCD classification.
The gastric mucosa is generally healthy and there is a low risk for gastric diseases. Caution should be exercised to distinguishpylori infections from diseases unrelated to H. pylori such as reflux esophagitis.
Group Ａ H.
It is likely that individuals in Group A are not infected with H. pylori but some may have existing or previous H. pylori infections.
It is preferable that such individuals undergo imaging tests including endoscopy at least once.

Group ＢThe gastric mucosa is somewhat damaged. Caution should be exercised to distinguish between gastric ulcers and duodenal ulcers.
These individuals also have an increased risk of developing gastric cancer. An endoscopic examination is recommended.
H. pylori eradication therapy is usually recommended.

Group ＣThe gastric mucosa is clearly damaged and exhibit advanced atrophy. The individuals have high risk for developing gastric cancer.
Regular endoscopic examinations are recommended. H. pylori eradication therapy is recommended.

Group ＤThe gastric mucosa is considered as highly advanced atrophy. The individuals have extremely high risk for affecting diseases
such as gastric cancer. Examination for the presence of H. pylori infection is recommended. Ensure that the individuals undergo
disease visualization examinations, such as endoscopy, and that the individuals consult a physician at a specialized medicalinstitution.

ABCD Classification is the primarily test to stratify the risk for gastric cancer and should be clearly distinguished fromgastric cancer screening that is performed to determine the exist or absence of gastric cancer.
It is essential to properly inform individuals about the necessity of undergoing appropriate imaging tests such as
endoscopy and stomach X-ray for diagnosis of organic diseases, such as gastric cancer.