Lung Cancer

1 The death rate dueto cancer of the lungs has increased more than 800 percent in males and hasmore than doubled in females during the last 25 years.It is considerably

higher in urban andindustrial areas than in rural districts.There are many possible causes,but itis still controversial which are most blamewor-thy.Those factors which have

been mentioned mostfrequently are the presence of foreign particles and other irritants in theair(smoke particles,smog,exhaust fumes),and the smoking of cigarettes and

cigars.

2 Numerous studieshave demonstrated a striking correlation between the death rate from lungcancer and smoking habits.Among heavy smokers-21 to 30 cigarettes per day-

the mortality ratefrom lung cancer is nearly 17 times the rate from nonsmokers.It is expectedthat the death rate among women will increase as the present high rate of

smoking among womenhas its effect.

3 Sometimes cases oflung cancer are discovered at the time when an X-ray is taken for the purposeof detecting tuberculosis.Too often,however,a current emphasis upon the

danger of exposureto radiation from X-ray machines can frighten people away from routine chestX-rays and thus prevent an early diagnosis of lung cancer.Early detection is

absolutely essentialif any possibility of cure is to be maintained.Modern X-ray machines incompetent hands pose such slight danger,at least to those over 40 years ofage,that

this would be muchmore than offset by the advantages of discovering a tumor while it is smallenough to be com-pletely removed.

4 A common form oflung cancer is bronchogenic carcinoma,so-called because the malignancyoriginates in a bronchus.The tumor may grow until the bronchus is

blocked,cutting offthe supply of air to that lung.The lung then collapses,and the secretionstrapped in the lung spaces become infected,with a re-sulting pneumonia or the

formation of a lungabscess.Such a lung cancer can also spread to cause secondary growths in thelymph nodes of the chest and neck as well as in the brain and other parts of

the body.The on-lytreatment that offers a possibility of cure,before secondary growths have timeto form,is to remove the lung completely.This operation is called

pneumonectomy.

5 Malignant tumorsof the stomach,the breast,the prostate gland and other organs may spread to thelungs,causing secondary growths.Paragraph2______

A.Common SecondaryLung Cancers

B.The AdwintagesBrought About by Routine Chest Checkup

C.RelationshipBetween Mortality Rate From Lung Cancer and Smoking Habits

D.Operable andInoperable Lung Cancers

E.The IncreasingDeath Rate From Lung Cancer and Possible Causes