L7: Gastric Cancer Flashcards
Incidence of Gastric Cancer
what is decrease in the incidence of Gastric Cancer attributed to?
- advances in food preservation
- public awareness about healthy diet.
Highest Incidence of Gastric Cancer is in β¦β¦
In Eastern Asia, Eastern Europe, and South America.
Lowest Incidence of Gastric Cancer is in β¦β¦
In North America and parts of Africa
what are types of Gastric Cancer?
Two biological entities (classified by Lauren) which are different regarding epidemiology, etiology, pathogenesis, and behavior. Which are:
1) The Intestinal type.
2) The Diffuse type.
Compare between Intestinal & Diffuse (Infiltrative) Gastric Cancer
Precursor lesions of Intestinal type Gastric Cancer
Chronic superficial gastritis
Gastric atrophy with loss of parietal cell mass
Atrophic gastritis
Intestinal metaplasia and dysplasia
Incidence of Familial Gastric Cancer
- Most gastric cancers are sporadic but familial pattern is noted in 10% of cases.
- Hereditary (familial) gastric cancer accounts for 1-3% of gastric cancer and comprises at least three major syndromes
Types of Hereditary (familial) gastric cancer
1) Hereditary diffuse gastric cancer (HDGC).
2) Gastric adenocarcinoma and proximal polyposis of the stomach (GAPPS).
3) Familial intestinal gastric cancer (FIGC).
Mode of inheritance of Hereditary diffuse gastric cancer (HDGC)
Autosomal dominant (AD) inherited form of diffuse type gastric cancer.
Mutant Gene in Hereditary diffuse gastric cancer (HDGC)
It is due to germline truncating mutations in the cadherin 1 (CDH1) gene.
CP of Hereditary diffuse gastric cancer (HDGC)
- Characterized by late presentation.
- Affected patients generally are diagnosed at an early age.
Prognosis of Hereditary diffuse gastric cancer (HDGC)
Poor prognosis.
when to suspect Hereditary diffuse gastric cancer (HDGC)?
Prophylactic Therapy in Hereditary diffuse gastric cancer (HDGC)
- The risk of gastric cancer in asymptomatic carriers of a pathogenetic CDH1 mutation is sufficiently high to do prophylactic gastrectomy.
- Surgery is usually recommended between the age of 20 and 30.
Risk Factors for Gastric Cancer
- Helicobacter pylori
- Diet
- Obesity
- Smoking
- Occupational Exposure
- EBV
- Abdominal Irradiation
- Gastric Surgery
- Blood Group A
- Gastric Ulcer
- Gastric Diseases
Risk of H. Pylori in Gastric Cancer
- The WHO classified H. pylori as a group 1 or definite carcinogen.
- H. pylori is potentially modifiable risk factor for gastric cancer.
How does H. Pylori Predispose to Gastric Cancer?
- It triggers inflammation at the mucosa β results in atrophy and metaplasia.
- It is associated with the risk of intestinal and diffuse types of adenocarcinomas.
CP of H.Pylori
The majority of patients with H. pylori infection have no significant clinical symptoms.
Diet as a risk factor for Gastric Cancer
Obesity
Risk Factors for Gastric Cancer
- High-level evidence supports of association () obesity and increase risk of gastric cancer.
- The strength of the association increased with increasing BMI.
Smoking
Risk Factors for Gastric Cancer
High-level evidence supports that:
- Smoking increases the risk of gastric cancer by 1.5-fold.
- The risk decreased after 10 years of smoking cessation.
Occupational Exposure
Risk Factors for Gastric Cancer
Weak evidence suggests that occupations as mining, metal processing (particularly steel and iron), and rubber manufacturing industries increase the risk of gastric cancer.
EBV
Risk Factors for Gastric Cancer
It is that about 5-10% of gastric cancers worldwide are associated with EBV.
Abdominal Irradiation
Risk Factors for Gastric Cancer
β¦
Gastric Surgery
Risk Factors for Gastric Cancer
Gastric Ulcer
Risk Factors for Gastric Cancer
- An association between benign gastric ulcers and gastric cancers probably reflects common risk factors (ie, mainly H. pylori infection).
- The risk of gastric cancer was increased among patients with benign gastric ulcers (incidence ratio 1.8).
Blood Group A
Risk Factors for Gastric Cancer
It is possible that the observed associations are not due to the blood group antigens themselves but to the effects of genes closely associated with them.
Gastric Diseases
Risk Factors for Gastric Cancer
Hypertrophic gastropathy (including MΓ©nΓ©trierβs disease) and immunodeficiency syndromes β weak evidence suggests the link to gastric cancer.
Does Iatrogenic Achlohydria predispose to Gastric Cancer?
- Iatrogenic achlorhydria induced by long-term use of histamine 2 receptor antagonists or proton pump inhibitors has not been associated with an increased risk of either gastric adenocarcinomas or neuroendocrine tumors.
- An association between maintenance therapy with omeprazole and the development of atrophic gastritis in individuals with H. pylori infection has been suggested, but the data are inconclusive.
what are possible protetictive factors from Gastric Cancer?
- Fruits, vegetables, and fiber
- NSAIDs
- Reproductive hormones
- Helicobacter pylori eradication
Fruits, veges & Fibers
possible protetictive factors from Gastric Cancer
It is most likely due to vitamin C content β β the formation of carcinogenic N- nitroso compounds inside the stomach.
NSAIDs
possible protetictive factors from Gastric Cancer
Regular use has been inversely associated with the risk of distal gastric adenocarcinoma
H.Pylori Eradication
possible protetictive factors from Gastric Cancer
Reproductive Hormones
possible protetictive factors from Gastric Cancer
- Gastric cancer incidence rates are consistently lower in women.
- This supports that reproductive hormones may have a protective role in gastric cancer risk in women.
Intro to screening of Gastric Cancer
Screening for gastric cancer is controversial, and recommendations for screening differ based on the incidence of gastric cancer.
Screening for Gastric Cancer in High Incidence Countries
what are individuals at high risk for Gastric Cancer?
Screening for Gastric Cancer in low incidence Countries
Selective screening of high-risk subgroups is recommended.
Screening in High-risk patients from families with hereditary diffuse gastric cancer
Presentation of Gastric Cancer
- Most patients with gastric cancer are symptomatic.
- Weight loss and persistent abdominal pain are the most common symptoms at initial diagnosis.
- Approximately 25% of patients with gastric cancer have a history of gastric ulcer.
CP of Gastric Cancer
- Weight loss
- Abdominal pain
- Nausea or early satiety
- Dysphagia
- Gastric outlet obstruction
- Bleeding
- Palpable abdominal mass
- Distant Metastasis
- Local Infiltration