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Lung cancer


									Lung cancer
Lung cancer accounts for almost 30% of all deaths and is the most malignant
neoplasm in industrialized countries. Estimates of the percentage of lung
cancers attributable to occupational factors range from 3% to 17%.

Cigarette smoking is the most important risk factor for lung cancer. The most
important lung carcinogen is asbestos. Occupations with high smoking
prevalence have an increased risk of cancer: wait stuff, cashiers, orderlies,
drivers, construction workers, watchmen. The effects of some occupational
carcinogens are greatly enhanced by smoking (asbestos, radon).

Workers may be exposed to a wide range of carcinogens. Multiple exposure
to carcinogens (cancer-causing agents) results in damage to DNA in the cells
of the body and cause cancer.

Known carcinogens and processes linked to human lung cancer:
       asbestos
       talc containing asbestiform fibres
       crystalline silica
       sulfuric acid mists
       chloromethyl ethers
       arsenic and arsenic compounds
       beryllium and beryllium compounds
       chromium ( VI )
       nickel compounds
       cadmium and cadmium compounds
       mustard gas
       polyaromatic hydrocarbons ( benzo(a)pyren)
       radon and radon daughters
       soot
       coal carbonization
       aluminium production
       chimney sweeps
       printing industry
       diesel exhaust fumes
       iron and steel founding
       paint manufacture and painting
       coke production

Suspected carcinogens:
       toluene

1                                                           Empimed_Doctor’s Notes
                                                                    9 August 2008
       trichloroethylene
       tetrachloroethylene
       benzene
       lead
       cobalt
       iron
       molybdenum
       epichlorohydrin
       art glass manufacture
       insecticide application

All histological types of lung cancer are linked to cigarette smoking.

There is no one cell type that is pathognomonic of an occupationally related
lung cancer, except some exposures.

Histologic types of lung cancer

1. Non-small cell lung cancer is more common than small cell lung cancer:

    o squamose cell carcinoma ( epidermoid carcinoma ). It often begins in
        the bronchi, more often located centrally, with associated hilar
        adenopathy. The most common lung cancer in men.

    o adenocarcinoma. It begins in the glandular cells, presents more
        commonly as a peripheral nodule with pleural and chest wall
        involvement. The most common lung cancer in women and in people
        who have never smoked.

    o large cell carcinoma. This tumor usually begins along the outer edges
        of the lungs and is seen a large peripheral mass with associated

    o Adenosquamose carcinoma. It begins in flatted cells that also have
        secretory characteristics.

    o Undifferentiated carcinoma. It consists of abnormal-looking cells that
        tend to multiply quickly.

2. Small cell lung cancer (oat cell carcinoma). It grows rapidly and quickly
    spreads to other organs. A central lesion with atelectasis and both hilar

2                                                             Empimed_Doctor’s Notes
                                                                      9 August 2008
    and mediastinal adenopathy are common features of small cell carcinoma.
    Oat cell carcinoma of the lung predominates in cases of radiation induced
    lung cancers, chloromethyl ethers ( CMME ) and bis( chloromethyl) ether
    (BCE) exposure. Mustard gas?

3                                                          Empimed_Doctor’s Notes
                                                                   9 August 2008

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