Lung cancer- a preventable disease

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					     Lung cancer: a preventable

                         addresses issues
                         related to 
                        Heredity,
                        Life-style, and
                        Environment.

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     Lung cancer: how did it

 First described in 1420 in Schneeberg-
  Austria after the opening of cobalt- and
  nickel mines.
 Incidence was very low in the 19th century.
 Is now worldwide the commonest form of
  cancer in men, and the fifth most frequent
  cancer in women.

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     Cause and effect: cigarette
     smoking  lung cancer
 Men started smoking cigarettes in 1920s 
  20 years later, incidence of lung cancer in
  men climbed sharply.
 In 1940s, women became cigarette smokers
   20 years later, a similar dramatic
  increase in lung cancer among women.

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                                        Yearly incidence rates of lung cancer


       Yearly Incidence per
              100.000         100
                                    Males          Females
                                                         Sex distribution

                                              Maoris in New Zealand
                                              American blacks in San Francisco Bay Area
                                              Inhabitants of West Scotland
                                              African populations

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     Risk factors
 1. Tobacco (and passive) smoking
 2. Air pollution in urban areas
 3. Chronic conditions: COPD
 4. Occupational exposure (man-made
             mineral fibre)

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     Genetic factors
 Aryl-hydrocarbon-hydroxlase system
    (AHH) converts weak carcinogens in
    cigarette smoke into active carcinogens

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     Prevention of lung cancer
 80% of lung cancer          10% of lung cancer
    cases are associated           cases are associated
    with many years of             with exposure to
    tobacco smoking,               occupational
    and can therefore              carcinogens, and
    be AVOIDED.                    can therefore be

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     Histological types of lung cancer
 2 major types:
 small-cell lung cancer, and
 nonsmall-cell lung cancer, which is further
  subdivided into:
   squamous cell carcinoma,
   adenocarcinoma, and
   large-cell carcinoma.
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     Origin and characteristics of
     various types of lung cancer
 Squamous cell lung cancer: commonest
  type in males, central origin, manifests early
 Adenocarcinoma: commonest type in
  females, peripheral origin, manifests late
 Large cell lung cancer: least common type,
  peripheral origin
 Small cell lung cancer: most aggressive
  type, central origin, spreads quickly

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     Snap: Lung Cancer:

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     Histological distribution of lung
     cancer depends on age and sex
 In males 35 – 75          In females 35 – 75
 years:                     years:
Squamous cell             Adenocarcinoma
 carcinoma                 Small cell cancer
Small cell cancer         Squamous cell
Adenocarcinoma             carcinoma
Large cell cancer         Large cell cancer

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     Biology of lung cancer
Oncogenic event  pluripotent cell
            small cell lung cancer
            large cell lung cancer
            squamous cell lung cancer
            adenocarcinoma
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     Histological diversity of lung
     cancer (SCLC)
Pluripotent cell or stem cell can differentiate
 Small cell lung cancer
     classical cell line (70%)
    variant cell line (30%)

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     Histological diversity of lung
     cancer (NSCLC)
Pluripotent cell or stem cell can differentiate
 Non-small cell lung cancer
 Squamous cell lung cancer
 Non-squamous cell lung cancer

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     Early detection of lung cancer
 High mortality rate is related to low cure rate
 Low cure rate is related to lack of early detection
 Past screening measures: annual chest x-rays,
  quarterly sputum cytology have not been
 Biologic and genetic features offer new

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     Prevention of lung cancer
 Primary prevention
85 – 87% of lung cancers are caused by
tobacco smoking
 Secondary prevention
Diet and vitamin consumtion may play a role.
 Prevention strategies based on genetic and
  biologic changes
Replacement of missing suppressor genes?
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 No currently established means for the
  screening or early detection of lung cancer
 85-88% of all lung cancers are caused by
  active or passive exposure to tobacco smoke
 Reduction of tobacco consumption still is
  the most important strategy

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     Recommended literature
 Doll, Peto et al. “Mortality in relation to
  smoking: 20 years observation on male
  British doctors”. Br. Med. J., 1976 (2) pp
 Law MR. “Genetic predisposition to lung
  cancer”. Br J Cancer 1990 (61); 195-206.
 Carney DN. “The biology of lung cancer”.
  Current topics in lung cancer 1991, pp 3-14.
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     More Information on the WWW

         CancerNet: Statistical Data Sources
         UICC GLOBALink
         Institute of Epidemiology
         Department of Epidemiology – Links
         SEER Cancer Statistics Review, 1973-1996
         Cancer Epidemiology, Biomarkers Prevention
          Table of Contents
         Lecture Link Application
         Today’s??-Smoking and Kreyberg Lung Tumors
         What if I smoke cigarettes?
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