COMMUNICATIONS TO THE EDITOR Editor's Note: This communication from a distinguished thoracic surgeon was received before completion of the report from the Mayo Clinic which is published in this issue (see page 511). The new data contained in the research described in the status report of the Mayo group provides a new and different perspective than the one presented in the communication by Bekher.

Adenocarcinoma and Smoking To the Editor:

Js it certain that adenocarcinoma of the bronchus is

not related to smoking? Kreyberg 1 said that it was not, and this statement has been widely accepted since that time. It seems to me, however, that there is increasing evidence that this affirmation should be re-examined. We2 observed some years ago, that the proportion of patients with adenocarcinoma in a s"urgical series had not altered with the passage of time. During a period of 15 years when the incidence of bronchial carcinoma in Britain had risen dramatically, the proportion of patients with adenocarcinoma had not changed. If the epidemic was due to smoking and adenocarcinoma was not, this proportion should have fallen, and it had not. Kennedyl' thinking along the same lines has recently reported this observation among British women. Secondly, the incidence of adenocarcinoma in both men and women in the Far East is very much higher than that in western countries, being about 40 percent' as against 20 percent in Europe and North America. But, there also, there has been a rise in the incidence of bronchial carcinoma of almost epidemic proportions during the last two decades, 5 it having gone up almost three times in ten years in Japan and Taiwan. Here again, if this rise is to be attributed to cigarette consumption, which in Japan at least, has been as high as that in many European countries for years, 8 and adenocarcinoma is not due to smoking, the proportion of tumors of this type should have fallen to an even greater extent than that which might have been expected in Europe. It has not done so. The figure still stands at 40 percent in both

622 COMMUNICATIONS TO THE EDITOR

men and women. Either the epidemic is due to smoking and so is adenocarcinoma or neither is. There are two reasons why it may prove difficult to pursue this problem. One is, that despite the classic work of Kreyberg in the precise description of the cell types of bronchial carcinoma, there is still considerable variation in reporting between different pathologists in different parts of the world and in different parts of the same country, of the proportion of cell types in series of bronchial carcinoma. The second is that despite the value that the information might be to the marketing departments of the tobacco companies, there is a remarkable paucity of reports about the relative smoking habits of men and women in different countries. Accurate information on both of these points from many parts of the world might go a long way toward solving the problem. Could it be that, as Kennedyl' suggests, the relationship of adenocarcinoma to smoking may be different in the two sexes? It so happens that in one of the few places where the different smoking habits of men and women are known, 7 the incidence of bronchial carcinoma in women is the highest in the world. This is in Hong Kong where the disease occurs twice as often in women as it does in the U.S.A. Here 10 percent of the female population smoke and 30 percent of those with carcinoma did, but here too, there is a very high proportion of adenocarcinoma. There is a carcinoma ~epidemic" there, with the incidence having risen ten times since 1950. This seems strong evidence that, at least in the Far East, there is a relationship between adenocarcinoma and smoking. In passing, the comment must be made that a cause must be sought for the high incidence of the disease among the nonsmoking women in this small colony, but that is another question. Kennedyl' also makes the point that the influence of smoking in adenocarcinoma in British women is different from that in their North American counterparts. Both Vincent et al 8 and Wynder et al9 have shown that adenocarcinoma in women in America is unrelated to smoking habits, whereas Kennedy3 could show no difference in the proportions of the cell types in female smokers and nonsmokers. It seems to me that there are several unanswered questions; the original one posed, namely, what is the relationship of adenocarcinoma to smoking? Secondly, is this relationship different in the two sexes? And thirdly, is it different in different ethnic groups or parts of the world? The importance of these questions when the etiology of this widespread disease is being considered, needs no emphasis. I think that it may well be that the best forum for the collection and reporting of the facts which could

CHEST, 67: 5, MAY, 1975

answer these questions is the American College of Chest Physicians. ]. R. Belcher, M.S., F.R.C.S., F.C.C.P. Consultant Surgeon London Chest Hospital London, England REFERENCES

2 3 4 5 6 7 8 9

Kreyberg L: Lung tumors: Histology, aetiology and geographic pathology. Unio Internat Contra Cancrum 15:78, 1959 Belcher JR, Anderson R: Surgical treatment of carcinoma of the bronchus. Br Med J 1:948, 1965 Kennedy A: Relationship between cigarette smoking and the histological type of lung cancer in women. Thorax 28:204, 1973 Yang SP, Lin CC, Luh KT : Personal communication, 1969 Belcher JR: Worldwide differences in the sex ratio of bronchial carcinoma. Br J Dis Chest 65:205, 1971 Beese DH: Tobacco consumption in various countries (publication no. 6) . London, Tobacco Research Council. 1965 Lueng JS: Personal communication, 1971 Vincent TN, Satterfield JV, Ackermon LV: Carcinoma of the lung in women. Cancer 18:559, 1965 Wynder EL, Mabuchi K, Beattie EJ: The epidemiology o~ lung cancer. JAMA 213:2221, 1970

Quadricuspid Aortic Valve To the Editor:

Up to the present time, most cases with fourcusp aortic valve reported in the world literature were diagnosed at postmortem examination. The case here presented was diagnosed by aortography; there were three equal sized cusps and one smaller cusp. Moderate degree aortic insufficiency was an associated finding. CAsEREPORT

A 44-year-old white woman was admitted to our hospital with complaints of exertional dyspnea and palpitation. There was no previous history of acute rheumatic fever. Physical examination revealed a well developed, well nourished patient. Her blood pressure was 140/60 mm Hg and the heart rate was regular, 90 per minute. The lungs were clear. The heart was enlarged and maximal impulse was felt at the sixth intercostal space outside the midclavicular line. There was a grade 3/6 blowing diastolic murmur audible over the entire precordium, with maximum point of intensity in the third left interspace parasternally. The liver was not enlarged and there was no ankle edema. X-ray examination of the chest showed moderate cardiomegaly and electrocardiogram revealed left ventricular hypertrophy. Other laboratory findings were within normal limits. Right heart catheterization revealed normal right sided pressure. Left heart catheterization showed no systolic gradient across the aortic valve. An aortic root angiogram showed

CHEST, 67: 5, MAY, 1975

F1cURE 1. Close-up of aortic valve area from patient's aortogram. The four cusps are well observed.

moderate aortic insufficiency and four cusps of the aortic valve ( three equal-sized cusps and one smaller cusp) were well observed (Fig l). At surgery, four cusps were found, and an aortic valve replacement was inserted. DISCUSSION

Bicuspid aortic valve and unicuspid aortic valve are relatively common cardiac maHormations, but a supernumerary aortic cusp is a rare anomaly. To date 'lffl cases of aortic or pulmonary quadricuspid valves have been reported, 192 pulmonary and 15 aortic.1 The first case of quadricuspid aortic valve was reported in 1862 by Balington.2 According to Simonds,3 it occurs in less than 0.008 percent of the population. Of the 15 aortic cases mentioned in the world literature so far, most were diagnosed at postmortem examination. The first case to be diagnosed by aortography was reported by Peretz et al.4 It should be added that quadricuspid semilunar valve, almost always a single malformation, is rarely associated with other congenital anomalies, such as atrial septa! defect, ventricular septa! defect, or patent ductus arteriosus. Seven anatomic variations of quadricuspid valves have been described by Hurwitz and Roberts, 1 the piost common variation consisting of three equal sized cusps and one smaller one. Although the function of quadricuspid pulmonary valve is nearly always normal, quadricuspid aortic valves frequently function abnormally. Valvular insufficiency is the most common hemodynamic abnormality that is not observed in the early years of life.4 CoNCLUSION

Four-cusp aortic valve may be rarely demonstrated by aortography. Robicsek et al5 reported a case wherein aortic insufficiency was diagnosed by aortography; however, quadricuspid aortic valve

COMMUNICATIONS TO THE EDITOR

~

Letter: Adenocarcinoma and smoking.

Is bronchial adenocarcinoma related to smoking? Although the proportion of patients with adenocarcinoma in a surgical series did not rise over a 15 ye...
597KB Sizes 0 Downloads 0 Views