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FILE NAME Kent KNT DATE 1956 DOC KNT149 DOCUMENT DESCRIPTION Book Excerpt - Bronchogenic Carcinoma - Diseases of the Chest Diseases of the Chest H. CORWIN HINSHAW M. D. PH D. Clinical Professor of Medicine Medicine Stanford University School of Medicine L. HENRY GARLAND M. B. B. CH Clinical Professor of Radiology Stanford University School of Medicine - 634 Illustrations on 288 Figures SAUNDERS COMPANY 1956 Philadelphia and London ched flood propor- s should bring to gives rise to many r cent of patients ^ orts being appar- ogy of the disease vill be all the more and will be all the among men seek- - tracheobronchial the larger bronchi light tendency for ard more frequent s hard and finely listinct In color it ers in diameter or crotic Frequently mass is benign or mass may project issue with limited y natural barriers arge and small or nodes metastases ichial carcinomas 1 or epidermoid carcinomas are the hat all three types 1 that each maligutionary develop- ed epithelial cells Cytoplasm may be gnition in smears copist may recog- , cell carcinomas : of cuboidal or in abundance the es of over 500 cases uggesting that the e of squamous cell Chapter 20. BRONCHOGENIC CARCINOMA 303 The undifferentiated bronchogenic carcinomas constitute a heterogenous group The small cell cancers are sometimes called oat cell round cell and spindle cell types The tumors may resemble sarcomas and in the past were sometimes erroneously considered to be sarcomatous in nature.4 Undifferentiated large cell bronchogenic carcinomas are somewhat less rapid in growth than are the small cell types The simplified classification chosen here has clinical significance for patients with these three different types of tumors may require different treatment The squamous cell type of tumor appears to offer the best chance of cure to the patient for surgical extirpation may be accomplished while the tumor is still localized Adenocarcinoma of the bronchus grows more rapidly as a rule than does the squamous cell variety but not so rapidly as the undifferentiated types The adenocarcinoma has the advantage of arising more frequently in smaller bronchi an attribute which makes surgical removal easier but also makes endoscopic diagnosis more perplexing because the growth may be beyond the range of bronchoscopic vision The undifferentiated types of bronchial cancer are likely to spread widely before producing significant signs or symptoms and the chance of cure is very unlikely by the time the diagnosis is achieved Metastatic Proclivities All bronchogenic cancers tend to metastasize early and this accounts for the high mortality rate and places a heavy responsibility upon the clinician when the possibility of cancer appears on clinical or radiographic grounds Some patients have lost their lives while under observation perhaps because the physician was too timid to even mention the possibility of cancer to an apprehensive patient By the time a possibility has become a probability the tumor may well have metastasized sometimes to far distant parts of the body There is little clinical meaning to tabulations of metastases as observed at autopsy for when death has arrived the disease may have invaded many organs including regional lymph nodes distant lymph nodes liver pleura other pulmonary segments bones adrenals kidneys brain spinal cord pericardium and myocardium.5 Bronchogenic cancer is spread by both lymph and blood streams but lymphatic spread probably is earliest in many cases although small primary tumors have rather frequently caused early death by cerebral metastasis The lymph nodes at the root of the lung often are involved early after which metastases may soon localize in such a manner as to yield distinct clinical syndromes which the physician can recognize readily These are described in later paragraphs indications of inoperability ETIOLOGY Many brilliant minds are concentrating on problems relating to the causes of malignant growths in general and of bronchial carcinoma in particular but no satisfying answers have yet There are however some intriguing possibilities which apply to broncho- appeared genic carcinoma and to the squamous cell variety especially the Of foremost interest is the information relating tobacco smoking to cancer of lung.6 Most studies of this problem have led to conclusions to the effect that thereis an association between prolonged heavy smoking and the development of bronchial cancer This relation- ship seems to hold for the squamous cell variety of bronchogenic carcinoma and not for the adenocarcinoma and perhaps not for the undifferentiated types There seems to be an asso- 4 True primary sarcomas of the lung do occur but are extremely rare Primary and secondary lymphosarcomas and reticulum cell sarcomas are reported see Chapter 21 R. A. Willis The Spread of Tumors in the Human Body Churchill London 1934 6 R. Doll Brit M. J. 521 and ibid 585 1953 summarizes the evidence favoring this theory 304 Chapter 20. BRONCHOGENIC CARCINOMA ciation with cigarette smoking and not with the smoking of cigars and pipes Authors frequently emphasize that association does not necessarily indicate a cause and effect relationship There are deficiencies in all of the data which have been reported because there are inadequate data as to the frequency with which tobacco is abused by those who do not develop bronchogenic carcinoma Until such statistically acceptable data are accumulated this relationship must remain a theory but the reported studies are certainly suggestive Carcinogenic materials in cigarette smoke may become condensed in the tracheobronchial tree It has even been suggested that the defect incident to calcified tuberculous lesions may serve to trap these irritants.7 Other respiratory irritants have been incriminated especially the atmospheric pollution incident to modern civilization Most interesting have been studies correlating the incidence of the disease with the proximity of the victims residency to industrial plants which expel derivatives of chromic acid into the atmosphere In this connection it must be noted that those who dwell in such areas are likely to belong to lower income groups which may be more susceptible for other reasons and also that the atmosphere in such areas must contain vast assortments of gaseous and particulate debris other than chromates which possibly could be carcinogenic This problem is complicated further by evidence that excessive tobacco smoking is a more prevalent habit among city dwellers where lung cancer rates are higher than among those who breathe the less contaminated air of rural and suburban com- munities.8 Carcinogenic agents are said to be present in the tars which are used to pave modern highways and it has been postulated that they might also be contained in the complex exhaust gases of internal combustion motors especially motors of the Diesel type.9 This does not explain all the increased incidence of bronchogenic cancer for such is reported in regions where these atmospheric pollutions do not exist The high incidence of bronchogenic carcinoma among workmen in certain mines of central Europe has been attributed to the radioactive qualities of the atmosphere in these mines.10 If this be a fact it is conceivable that atmospheric pollution with materials derived from atomic power plants and instruments of war during coming decades may have a similar deleterious effect upon large numbers of people The sum total of the surface area lining the ramifications of the respiratory tract is so enormous and the amount of air respired during a lifetime is so great that those cells which line the respiratory tract come into greater contact with the external environment than almost any other part of the human body Whatever the carcinogenic materials may be in our environment it is not strange that the bronchial tree should respond by producing nalignant growth frequently if we accept the theory of exogenous origin of new growths Interesting thoughts are aroused as to the reasons for the sex incidence of this disease The possibility of hormonal influence seems to be remote since we know of no hormonal control over bronchial epithelium and sporadic attempts to use hormonal therapy have shown no beneficial influence But our knowledge of hormones and growth remains in a primitive state despite a voluminous literature and the vast effort expended There is reason to believe that men come in contact with carcinogenic substances more C. E. Woodruff and H. C. Nahas Am Rev. Tuberc 620 1951 suggest this possibility 8 W. C. Hueper Indust Med 463 1954 discusses environmental lung cancer C. A. Mills and J. Porter J. Nat Cancer Inst 1283 1953 discuss the relative smoking habits of those who live in different environments J. A. Campbell Brit J. Exp Path 215 1937 discusses this in relation to experimental tumors of mice E. G. Lorenz J. Nat Cancer Inst 5 1944 reviews the problem of the high incidence of lung cancer among miners in this area frequently wider rang States also even her s that the dis marked tha emphasize women wh a hope that Symptom Therea tion may t teristic of : important- ment can audible wh struction ( no quality been exper Cough rarely is s ' with this scanty or r realize that excluded b indicates t purulent sj carcinoma ments with lung cance concurrent Cough is a is an unsat Hemop ease is pre the expect office Inf culosis T presumpti Pneum many caus acute sym H. giving com C. L. cases of no cinoma f normal structures natous masses often naplasia with loss of or examination lacks n appearing lesions ge proportion of the on occurring disease perhaps of ic evidence of transnilar to a disease of healthy sheep which oma among persons have been reported of laboratory mice s been reviewed by son and Lawrence olar Carcinoma cough dyspnea and hs Frothy sputum i Clinical diagnosis on ray diagnosis e of undetermined iding sarcoid other d unusual occupa1 showed tumor cells xaminations At au- ive bronchiolar ala farmer's wife and neep esponding well to ay suggest bronhave expectorated o and death from ss often are men- streaking or light d surgical cures lar focus reported inoma Bronchosutum if present Chapter 20. BRONCHOGENIC CARCINOMA 333 Laboratory Findings The one laboratory examination which may be of diagnostic help is the study of sputum cytology Characteristic groups of exfoliated cells can be found in the sputum of more than half of all cases of bronchiolar carcinoma If these cells are still found in the sputum after pulmonary resection it proves that the tumor has not been removed completely Treatment Surgical removal of bronchiolar carcinoma has been but rarely accomplished chiefly because the growth has extended to involve the contralateral lung before a diagnosis was made When the lesion is a small one the operation of lobectomy is preferable to segmental resection If more than one lobe is involved it is almost certain that the opposite lung is in- vaded and pneumonectomy would be useless Roentgen therapy is of moderate value for palliation SUMMARY Bronchogenic carcinoma has increased in incidence during recent decades and has now become the second most frequent visceral malignant disease of men It is at least five times more frequently encountered in men than in women Squamous cell carcinomas tend to develop in larger bronchi and to metastasize more slowly than do other types Adenocarcinomas are more frequent in smaller bronchi and metastasize more rapidly than squamous cell carcinomas but not so rapidly as do carcinomas composed of undifferentiated anaplastic cell types The latter are most often incurable when detected Excessive cigarette smoking air pollution with industrial dusts especially chromates and inhalation of radioactive materials suspected of being among the causative agents in bronchogenic carcinomas Symptoms of bronchial cancer when present may resemble those of specific bronchial irritation pneumonia and asthma Hemoptysis should lead to suspicion of cancer Symptomless bronchial cancer may be revealed as an abnormal roentgen shadow Interpretation of such shadows requires good clinical judgment skillful reontgenography and careful investigation Physical examination may reveal signs of bronchial obstruction or evidence of palpable metastasis Bronchoscopy frequently demonstrates bronchogenic carcinoma and permits biopsy and aspiration of secretions for study Cytologic examination of bronchial secretions may reveal exfoliated malignant cells recognizable to the pathologist who is specially trained for such work Needle biopsy of the lung is but rarely indicated Exploratory thoracotomy frequently is recommended for diagnosis and possible treatment of pulmonary disease suspected of being malignant _ Exploration for nonpalpable cervical lymph nodes Daniels operation should be undertaken frequently Treatment of bronchogenic carcinoma consists of pulmonary resection lobectomy or pneumonectomy and in certain cases radical radiotherapy - Bronchogenic carcinoma is inoperable when extrathoracic lymph nodes or other structures are involved when physical signs of superior vena cava obstruction are present when a recurrent laryngeal nerve a phrenic nerve or the brachial plexus is involved or when the growth is so located as to be incapable of being resected 668 Chapter 40. OCCUPATIONAL PULMONARY DISEASES body is a fiber of the mineral surrounded by protein deposits The ordinary stains used in histology do not demonstrate asbestos bodies well but the Prussian blue staining procedure may be helpful When seen in tissue sections or in sputum these elongated fibers are recognized by their beaded appearance rounded bulbous ends which may resemble an elon- gated dumbbell The clinical manifestations of asbestosis include progressive shortness of breath on exertion cough weakness weight loss and clubbing of the fingers Emphysema bronchiectasis and occasionally pulmonary tuberculosis complete the clinical picture While it is generally believed that asbestosis predisposes to tuberculosis the tendency is not so striking as in the case of silicosis It has also been surmised that asbestosis may predispose to bronchogenic carcinoma hypothesis which has not been fully confirmed The earliest radiographic signs of asbestosis are those of a fine haziness in the lower lung fields due to a called reticular network of shadows creating a ground glass appearance Subsequently there is increasing evidence of more extensive and coarser fibrosis with variable degrees of pleural thickening A feature sometimes noted is a shaggy appearance of the cardiac silhouette resulting from the combination of parenchymal and pleural changes in later stages The diagnosis of asbestosis depends upon a radiographic appearance consistent with diffuse pulmonary fibrosis a history of prolonged exposure two years or more to asbestos dusts and the finding of asbestos bodies in the sputum In obscure cases diagnosis by lung biopsy may be advisable There is no treatment known to be of value Patients with early signs of asbestosis should be removed from such exposure and it is probable that the disease will not progress significantly after exposure is terminated Patients with asbestosis should avoid contact with tuberculosis and should be examined at frequent intervals to detect the earliest sign of tuberculous infection so that prompt and energetic specific antituberculosis treatment may be undertaken Pneumoconiosis due to Mica The micas are a group of complex aluminum silicate compounds of several types At least some of these are known to be capable of producing pulmonary fibrosis if inhaled in finely divided form in high concentration over a prolonged period An exposure of several years to ordinary industrial environments containing these substances is necessary to pro- duce disease The micas are used in the manufacture of paper products especially that type of wall paper which has a high gloss surface in the production of some paint products as lubricants in combination with oils and for insulating materials in electrical devices condensors motors and electrical heaters from A study by the United States Public Health Service revealed 10 cases of pneumo- coniosis in a group of 57 workmen who had been exposed to mica dust which was free silica.11 Policard found that the inhalation of mica dust can produce pathologic changes in the lungs which he believed to be identical to those produced by the inhalation of silica dust.12 Talc Pneumoconiosis Talc is a natural finely powdered hydrous magnesium silicate Commercial talc is of variable composition and is often mixed with other mineral substances Talc is widely used in industry in the manufacture of paint rubber paper insecticides and ceramics as well as 11 Pub Health Bull No. 250 Washington D. C. U. S. Public Health Service 1940 12 J. Indust Hyg 160,11934 ( in toilet preparations 1 considerably in their pathogenicity Pulmonary fibrosis dustry is reported to b quantities of silica it is actually cases of silicos Exposure for at leas clinical significance app exposed to talc dust in hand some persons ha without developing an was reported to be twer of Governmental Indu The clinical manife scribed for asbestosis w ness and weight loss P to acute lower respirato itation of chest expansi There is no charact appearances are similar The metal berylliur was it known that this that time the acute pn ports in European lite ported in the United S less many more have c Recognition of the the fact that but little industries as the manu S At least 100 cases lamp manufacturing in farae vage of fluorescent lar have been observed ar eat remarkable perhaps Aa have never engaged in cae containing dust possibility of pollution industry has had to Definition and Clas Berylliosis is a dis lungs It results from 1 There are two well . containing L. Greenberg Ya 14 J. Indust Hyg ar