William Weiss

The histopathology of bronchogenic carcinoma and its relation to growth rate, metastasis, and prognosis

During the course of a prospective study in which 6,136 older men were examined by photofluorogram and questionnaire every 6 months, 179 developed proved bronchogenic carcinoma. Histologic sections were obtained in 161 cases and classified by a panel of 3 pathologists using a modified World Health Organization classification. The panel agreed with the diagnoses made by the hospital pathologists in most of those originally classified as squamous cell or adenocarcinoma but classified 30% of the undifferentiated carcinomas as squamous cell tumors. The panelists placed most of these in the anaplastic subgroup (lc). Unanimity was highest for squamous cell carcinoma and within this group the extent of agreement was best for the most highly differentiated subgroup (la). Five‐year survival rates were poor (10%), but equal for men with squamous cell and adenocarcinoma. These findings can be explained by the biologic character of the cancer types; squamous cell carcinomas have rapid growth rates and moderate metastatic potential, while adenocarcinomas have slow growth rates but high metastatic potential.

Coffee consumption and pancreatic cancer: temporal and spatial correlation.

An examination of available data on per caput consumption of coffee and pancreatic cancer mortality in the United States since 1950 shows a temporal association. A rise and fall in coffee consumption was followed by a rise and fall in the incidence of pancreatic cancer with roughly a 10-year lag. Nevertheless, there were inconsistencies in this relationship was also found between the consumption of coffee and pancreatic cancer mortality in 13 countries. While this relationship suggests an association, major inconsistencies case doubt on the possibility that it is one of cause and effect. This may be due to confounding, particularly by cigarette smoking and cancer of the pancreas is much more consistent with a causal relationship.

Asbestos and colorectal cancer

Reports in the literature on 21 cohorts of workers exposed to asbestos were reviewed and analyzed to determine whether there is a causal association between asbestos and colorectal cancer. The latest report up to 1988 was used for each cohort. The end point was the standardized morbidity or mortality ratio as the measure of relative risk. Two additional cohorts using mortality as the end point were excluded because the authors failed to use comparable diagnostic methods for the asbestos-exposed populations and controls. The summary standardized morbidity or mortality ratio for all 21 cohorts was 0.97 (P greater than 0.05), and there was no dose-response relationship in the two studies with such data. The evidence does not meet the established criteria for making a judgment that there is a causal relationship between asbestos and colorectal cancer.

The lack of causality between asbestos and colorectal cancer

To evaluate a potential causal relationship between asbestos exposure and the risk of colorectal cancer, 30 cohort studies published in English were reviewed and analyzed. The latest report of each cohort up through 1993 was used. The outcome measure was the standardized morbidity (incidence) or mortality ratio (SMR). Summary SMRs were examined by type of cohort registration, type of work, type of asbestos, latency from onset of exposure to period of risk, and incidence only. The overall relative risk was 0.99 for all 30 studies. The evidence does not meet the important criteria for a judgment of causality because the relative risk is not consistently elevated, weak in the two studies with a statistically significant elevation of SMR, and limited data do not support a dose-response relationship.

Asbestosis and lobar site of lung cancer

OBJECTIVE To assess the evidence for the hypothesis that lung cancer has a predilection for the lower lobes in workers with asbestosis. METHOD A review of the available literature with relevant information. RESULTS Six published reports were analysed. In four studies limited to series of cases with diagnoses of asbestosis, three showed lower lobe predominance of lung cancer whereas the fourth study included cases in which the radiographic readings did not meet the usual criterion of profusion for asbestosis. One cohort study showed lower lobe predominance; the other reported only 33% lower lobe cancers compared with 20% in unexposed controls. CONCLUSION There is some support for the hypothesis but more studies are needed.

A cohort analysis of pancreatic cancer, 1939--1969.

Pancreatic cancer mortality in the United States was examined by cohort analysis for the period 1939 to 1969. Birth cohorts at 5‐year intervals were studied. White males and non‐whites of both sexes showed a shift of the cohort mortality rate curves by age toward younger groups as birth cohorts went from 1870–1874 to 1900–1904. This shift disappeared in white males and diminished in non‐whites of both sexes between the cohorts of 1890–1894 and 1900–1904. The shift in non‐whites was larger than in white males so that although non‐whites had lower rates than whites in earlier birth cohorts, their rates exceeded those of whites in the most recent cohort. In the search for environmental cause(s) of pancreatic cancer, exposure characteristics should be compatible with these observations.

The growth rate of bronchogenic carcinoma: Is it constant?

Six patients with bronchogenic carcinomas presenting as solitary nodules had from seven to nine serial chest roentgenograms which permitted measurement of tumor diameters in the absence of definitive therapy. Growth curves were plotted simultaneously on semilogarithmic and arithmetic coordinates to determine whether growth rates were constant. The findings suggested exponential growth in three of the six cancers, but the curves for the other three cases did not provide evidence for constancy of growth rate. The sparse data in this series and in the literature are insufficient to permit generalization on the shape of growth curves for bronchogenic carcinoma.

Validation of a screening procedure for chronic nonspecific respiratory disease.

The Philadelphia Tuberculosis and Health Association surveyed 2,825 adults with a 70-mm photofluorogram, a questionnaire, and ventilatory tests. A selected sample of 71 individuals was carefully evaluated in one of four pulmonary physiology laboratories by history, physical examination, and a battery of pulmonary function tests to evaluate the sensitivity and specificity of the screen. In screening for chronic obstructive lung diseases, if this was defined as expectoration and/or a forced vital capacity below 62% of predicted by Baldwin standards and/or a one-second forced expiratory volume below 66% of observed vital capacity, the sensitivity was 79% and specificity was 72%, If the one-second forced expiratory volume below 66% was used alone, the sensitivity was only 42%, but the specificity was 96%.

Epidemiology of fibrous glass and lung cancer

In a recent commentary, Infante et al. [1994] summarized some of the epidemiologic literature on the relationship between glass wool and lung cancer. They concluded that this material is carcinogenic for the lung in humans. A review of the commentary in comparison with the original papers covered reveals that their analysis was incomplete and characterized by selection bias. A more careful examination of the literature cited and other relevant publications shows that the data cited by Infante et al. are subject to the errors of chance and confounding and that the association when present is inconsistent, weak, and lacks a dose-response relationship. Therefore, a conclusion of causality cannot be justified.

The migrating mycetoma.

A case of mycetoma is presented in which the fungus ball migrated from the apex to the base of the lung as a result of progressive parencyhmal destruction by tuberculosis. Histological and serological data suggested Aspergillus fumigatus as the cause of the mycetoma. Aspergillomas rarely coexist in cavities with active tuberculosis.