27

has occurred. There is a high incidence of lung can-

cer in females, the ratio of male: female

is 1.87:1 in Guangzhou. Lung cancer death rate in females closely connected with coal consumption not only in Guangzhou city but also in other Chinese metropo- lises and counties. Using other fuels for cooking instead of coal might be an impor- tant measure to prevent lung cancer.

The Use of Linear Regression to Model Lung Cancer. Mortality Map Patterns. Piantadosi, S., Byar, D., Mason, T. National Cancer Institute, NIH, Bethesda, MD, U.S.A.

The purpose of this work is to describe simple methods for the analysis of geo- graphic patterns of disease mortality or incidence with emphasis on lung cancer in the U.S.A. Geographically based data have been increasingly used to generate hypotheses about environmental causes of cancer, and present special problems of analysis. For example the "ecological fallacy" may limit the interpretability of results, and spatial nonrandomness may affect significance tests. Lung can- cer mortality presents additional problems because of the unavailability of geogra- phic data on cigarette consumption and the lag in time between exposure and death. This paper outlines methods to cope with these problems and constructs a simple predictor of the geographic pat- tern of lung cancer mortality. Age adju- sted lung cancer mortality in white males during the period 1950-1969 based on state economic areas was used. Plausible surrogates for cigarette consumption were thought to be standardized mortality ratios for chronic bronchitis and emphysema. 73% of t~e variation in mortality, as measured by R , was explainable by simple linear regression models containing such variab- les as a smoking surrogate, measures of urbanicity, median income, ethnic compo- sition, industrial employment and other. Performance of models was tested, in part, using color coded maps. The models are consistent with previously recognized sociodemographic associations with lung cancer and also generate new hypotheses which may deserve further investigation.

Lung Cancer Epidemiological Evidence in

Italy. 1 Zanetti , M2, Montaguti I, U., Fiacchi 2, M., Morrone , G. Medical Direction, S. Orsola Hospital, Bologna, Italy. Thoracic Surgery Institute, Bologna, Italy.

The frequency of tumors, and particu- larly of lung cancer, as causes of death is constantly increasing in Italy as in

most affluent Countries.

The analysis of lung cancer mortality trends shows in Italy some interesting and singular characteristics.

In this lecture a description is given of the present epidemiological situation (sex, age, and geographic distributions) of lung cancer. A brief discussion is made on a datum relevant to the Italian young male population: in Italy, starting from the end of the the se- venties, 35-44 years old males show the high- est lung cancer mortality rate, compared to the rates shown by all the other industrialized countries.

The possible relationships between this phe- nomenon and the history of tobacco consumption in Italy are discussed.

Lung Cancer in Newfoundland & Labrador. Ganguly, P., Guy, J., Moores, D., Norris, B. Newfoundland Lung Cancer Clinic, St. John's Newfoundland, Canada.

This study was carried out with two objecti- ves:

i. provide a detailed epidemiological survey, 2. investigate and correlate basic clinical

parameters. The population of 579,000 was studied using

parameters including age, sex, employment, in- come, smoking habit, ethnic groups, industry, and air pollution. During the study period 1974 - 1983, 1,466 cases of primary lung can- cer were registered.

In the ten provincial census divisions there was no association of incidents to study para- meters except in two mining areas where the rates were twice the mean rate.

The symptoms, investigative findings, patho- logical classification, operability and survival of a subset of 563 lung cancer cases from Janu- ary 1977 to December 1983 were studied.

Mechanism of Interactions between Asbestos Fibers and Proteins. Valerio, F., Balducci, D. Istituto Nazionale per la Ricerca sul Cancro, Genova, Italy.

Interaction between proteins and asbestos has an important role in many biological ef- fects (emolysis, citotoxicity).

A first attempt to define mechanism was car- ried out.

Single proteins and total serum proteins ad- sorption isotherms were obtained using chryso- tile and crocidolite, and protein composition was evaluated before and after incubation. Two different and concurrent adsorption mechanisms were observed, the first aspecific and rever- sible, the second selective and involving strong bonds. Molecular weight of proteins selectively adsorbed was evaluated.

Experiments carried out with single proteins demonstrated that adsorp£ion capability of as- bestos fibers was not correlated with protein charge or with molecular weight, while amount of adsorbed proteins, in particular on chryso-

tile, was a linear function of proteins charge

28

density (number of charges per gram of

protein).

Double Refractile Crystals(DRC) in the Lung Tissue of Lung Cancer Patients Ex-

posed to Asbestos. 1 1 2

Miura , ~., Kimula , Y'I Tachi , H., 1 Nakayama-, M., Takayama , S. Makiguchi , K. i. Yokosuka Kyosai Hospital, Kanagawa, Japan. 2. Institute of Basic Medical Sci- ences, University of Tsukuba, Ibaraki, Japan.

The difference in tumorigenesis among various types of asbestos has been repor- ted in many papers. Lung Cancer and/or pleural mesothelioma occur frequently in workers exposed to crocidolite. We dis- closed that many DRC were found more among crocidolite than chrysotile. In this paper, intrapulmonary DRC of lung cancer patients were compared to that of non- cancer groups.

Lung tissues were examined under pola- rized microscopes and a score of DRC was calculated with the percentage of the field (200x view field) containing DRC.

Mean DRC score in age-matched follo-

wing groups; A: asbestos-exposed workers(37 pts)..79% B: male office clerks (37 pts)..38% C: house wives (37 pts)..32% (P<0.001:A and B, A and C)

DRC score in age- and se.~natched 84 pairs of lung cancer group and non-lung cancer group;

DRC score A: Lung caner I 7 9 18 25 15 B:Non-lung caner 9 17 16 17 14 9 C:Percentage of A 10 29 36 51 64 63

(positive correlation between DRC score and C, P<0.01)

An elemental analysis of DRC with an x-ray microanalyser revealed that DRC contained Si and A1.

These data showed that DRC were found more frequently in patients exposed to as- bestos and the deposition of DRC in lung tissue had a positive correlation with the occurrence of lung cancer. DRC have an important role on pulmonary carcinogenesis rather than asbestos fibers.

0-14 15-29 30-44 45-59 60-74 75-89 90-100% 9 2 82%

Benign Asbestos Pleurisy: Clinicnl Findinzs. Hillerdal, G., Ozesmi, M. Department of Lung Medicine, University Hospital, Upp- sala, Sweden.

Benign asbestos pleurisy is a fairly common occurrence which is often misdiag- nosed. We have reviewed our experience of 55 cases seen over the last 15 years. The criteria have been: exposure to asbestos and exclusion of other diseases, notably TB and malignancy. The patients were

seen among the more than 150G persons

with asbestos-related pleuraland parenchymal

changes who are regularly followed. There was only one woman. Mean age was 57 years, with extremes of 32 and 76 years. Smokers or ex- smokers were 52. Mean latency time from first exposure was 32 years (2-54). In 23 cases, aspi- ration of fluid and a blind pleural biopsy was made. Four were finally decorticated, one be- cause of false cytological diagnosis of malig- nancy (all others were negative). Erythrocyte sedimentation rate was more than 20 in 33 cases. In blood, slight eosinophilia was seen in 16 cases and marked eosinophilia was found in two exudates. The disease was usually devoid of symptoms, and it tended to linger on for months, and there were often recurrence on the same or the other side.

Sex Characteristics in Resected Lung Cancers. Bringel, C..Huddinge University Hospital, Stockholm, Sweden.

During 1981-84 surgery was performed in 35/ 151 women (23%) and 70/473 men (15%) with bron- chial malignancies. Age range for women was 34-76 years, for men 40-79 years, median age was 64 and 63 respectively. Six women were under 45 years, only one man. Women did smoke less, 76% were smokers/exsmokers, 98.5% of the men.

Histologically there was a slight predomi- nance of adenocarcinomas over squamous cell car- cinomas in women 14/11, while in men the op- posite condition was present 29/25. Among fe- male adenocarcinomas 4/14 consisted of broncho- alveolar cancer compared to 2/26 in men. Carci- noid tumours were diagnosed in six women and two men.

Tumour localisation was most frequent in the upper lobes in both sexes. Postsurgically 27/35 women (77%) were classified as stage I, 20 of these had a tumour size less than 30 mm - T In 12 female cases the tumour had been

i" roentgenologically observed between 1½ and six~ years prior to surgery. Delays longer than a few months were only occasionally seen in men. Male surgical stage I was only 70% but only 15 had T~ tumours. The greater number of tumours exceedin~ 30 mm could partly explain the great- er need for pulmectomy in men, 15, compared to 5 in women.

Prevalence of Sputum Cytological Abnormalities in Ahminium Potroom Workers.

Enarson, D.A., Embree, V., LeRiche, J., Nelems, B. Department of Medicine, UBC, Vancouver General Hospital, Vancouver, B.C.

As part of a lung cancer screening program in mining and related occupations in BC, 2467 individuals 40+ years of age have been studied (82% of the available workforce). This inclu- ded groups with and without known occupational exposure to substances causing lung cancer. Among the former were 245 individuals with 5+ years experience in aluminum potrooms. Study

procedures included a questionnaire, sputum