Gastric Cancer Prevention - PowerPoint

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					      Gastric Cancer
       Prevention
Luis S. Mon, M.D., F.A.C.S.




              Carlos A. Perurena, M.D.
Gastric Cancer Prevention
• Drs. Mon and Perurena are proffesors
  or Surgery at the University of
  Panama´s Medical School. They can be
  contacted at monymon@cwpanama.net


• Gastric Cancer is the fifth most
  frequent cancer and the second most
  lethal in the Republic of Panama.
    Gastric Cancer Prevention
Learning Objectives:
1. State the basic biological characteristics of
  Adenocarcinoma of the Stomach.
2. Describe the principal epidemiological
  features of the disease.
3. Recognize the most probable risk factors for
  the disease.
Performance Objectives:
1. Propose specific strategies for Gastric
  Cancer primary prevention.
2. Propose strategies for Gastric Cancer
  secondary prevention.
Gastric Cancer Prevention

  •Biology
  •Epidemiology
  •Risk Factors
  •Primary Prevention
  •Secondary Prevention
 Gastric Cancer Prevention:
 Biology
• There are several Hystological
  types of Gastric Cancer of which
  adenocarcinoma is by far the
  most frequent.

• Sarcomas and Lymphomas can
  also occur.

• This presentation refers basically
  to adenocarcinoma.
 Gastric Cancer Prevention
 Biology: Hystopathology

Two types of adenocarcinoma
 are recognized:
1. Intestinal: resembles colon
  cancer, can be polypoid or
  ulcerated, occurs usually in the
  distal stomach and has a
  prolonged            pre-cancerous
  phase.
 Gastric Cancer Prevention
 Biology: Hystopathology

2. Difusse: Extends widely with no
  distinct margins and the glandular
  structure is rarely present.
 Patients tend to be younger and
  have a worst prognosis.
 Gastric Cancer Prevention
 Biology: Hystopathology

• Adenocarcinoma is considered
  early when it´s confined to the
  mucosa and sub-mucosa,
  irrespective of lymph node
  affection.
• Otherwise it’s called advanced.
 Gastric Cancer Prevention:
 Epidemiology

• Infrequent before 40 years of age.
• Twice as frequent in men than in
  women.
• Leading cause of death from
  cancer worldwide.
 Gastric Cancer Prevention:
 Epidemiology

• Highest incidence in Japan, South
  America and Eastern Europe.
• Adjusted rate worldwide is 15.62
  per 100 000
• Adjusted rate for Latin America is
  variable.
Gastric Cancer Prevention:
Epidemiology

• In Costa Rica the incidence rate
  for men is 51.5 and 28.7 for
  women.
• In Panama ( a country that
  borders Costa Rica) the global
  rate is 11.5
  Gastric Cancer Prevention:
  Epidemiology

• In the United States the incidence
  has been decreasing and
  unexplainedly the cancer has
  migrated proximally.
  Gastro-esophageal lesions are
  more frequent than antral lesions.
Gastric Cancer: Risk Factors
and Primary Prevention

• Gastric Cancer is a very
  common disease that carries
  a high mortality.
• The diagnosis in early phases,
  when better results should be
  expected, is difficult due to the
  unspecifity of early symptoms.
Gastric Cancer: Risk Factors and
Primary Prevention

• Recognition of risk factors and
  application of strategies directed
  towards their elimination are of
  paramount importance.
• We will discuss the most probable
  and convincing risk factors
  related to this disease.
Gastric Cancer Prevention:
Chronic Atrophic Gastritis

• Chronic Atrophic Gastritis is
  thought to be the initial step
  in the development of most
  Gastric Cancers.
Gastric Cancer Prevention:
Chronic Atrophic Gastritis

Chronic Atrophic Gastritis
  has been shown to appear
  in patients with:
1. Tobacco use.
2. H. pylori infection.
                          (cont.)
Gastric Cancer Prevention:
Chronic Atrophic Gastritis

3. Diets with high levels of
 nitrites, nitrates, salt and
 smoked foods.
4. Previous Gastric Surgery.
5. Pernicious Anemia.
 Gastric Cancer Prevention:
          Tobacco

• Smoking increases the risk of
  Gastric Cancer by 50% to 60%
• It is estimated that smoking
  tobacco is responsible for 11%
  of all Stomach Cancers
  worldwide.
Gastric Cancer Prevention:
         Tobacco

• Tobacco use decreases the
  levels of Carotenoids and
  Vitamin C which act as
  protective agents against
  this disease.
 Gastric Cancer Prevention:
          Tobacco

• Tobacco use is associated
  with Helycobacter pylori
  infection which in turn leads
  to Atrophic Gastritis.
 Gastric Cancer Prevention:
          Tobacco

• Smoking cessation returns
  the risk to that of the general
  population after 20 years.
 Gastric Cancer Prevention:
    Helycobacter pylori

• H. pylori is associated with a two
  to sixfold increase in the risk of
  developing Gastric Cancer.
• Many believe that genetic and
  environmental factors also need
  to be present for H. pylori to
  cause cancer.
 Gastric Cancer Prevention:
    Helycobacter pylori

• In 1994 the World Health
  Organization designated
  H. pylori a Group 1 carcinogen
 Gastric Cancer Prevention:
       Dietary Factors

• Consumption of fruit, vegetables
  and fiber has shown, in the
  majority of controled studies
  published, a protective effect
  against Gastric Cancer.
• This effect is probably due to
  Vitamin C or carotenes.
 Gastric Cancer Prevention:
       Dietary Factors


• Nitrates and nitrites found in
  salted, smoked and dried foods
  lead to atrophic Gastritis which
  in turn leads to Gastric Cancer.
Gastric Cancer Prevention:
     Genetic Factors

 All of the following genetic
factors have been shown to
increase the risk of Gastric
Cancer.
Gastric Cancer Prevention:
     Genetic Factors

• Blood type A.
• Hereditary non-polyposis
  colorectal cancer.
• e-cadherin gene mutations.
• A first degree relative with
  Gastric Cancer.
 Gastric Cancer Prevention:
      Genetic Factors

• Presently they are not subject
  to preventive measures except
  for prophylactic gastrectomy in
  e-cadherin mutations.
  Gastric Cancer Prevention:
    Secondry Prevention
• Secondary prevention is the
  “early” detection of cancer through
  screening.
• This is done in populations where
  the disease is a major health
  problem.
• Examples of this approach can be
  found in Japan and Costa Rica.
 Gastric Cancer Prevention:
   Secondary Prevention


• In Japan gas-contrast Stomach
  Fluorography is done in the
  mass population.
                         (cont.)
Gastric Cancer Prevention:
  Secondary Prevention


• Those considered abnormal
  (about 13%) will undergo further
  studies, including endoscopy
  and biopsy.
Gastric Cancer Prevention:
       Conclusions


 The best primary
 prevention strategies are:
Gastric Cancer Prevention:
       Conclusions
• Smoking avoidance or
  cessation.
• Diets rich in fruit, vegetables
  and fiber.
• Avoidance of salted, smoked
  and poorly preserved foods.
• Erradication of H. pylori.
Gastric Cancer Prevention:
       Conclusions


 • Mass screening is a
   viable strategy in high
   risk populations.

				
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