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Biomedical subjects

T M Mack

Publications and source records attributed to T M Mack.

At least 55 records · Page 3Linked to original sources
PubMed1988

Tobacco, alcohol, diet, occupation, and carcinoma of the esophagus.

Information on occupation, smoking, food and beverage consumption, and medical history were compared between 275 incident cases of carcinoma of the esophagus and 275 neighborhood controls who were matched to the cases on age (within 5 years), race, and sex. Tobacco use, mainly cigarette smoking, was a significant risk factor for carcinoma of the esophagus. Ex-smokers of cigarettes showed a reduced risk relative to those who continued to smoke, and current smokers of two or more packs per day displayed a higher risk than those who smoked less. Alcohol consumption was another significant risk factor for carcinoma of the esophagus; there was a highly significant trend with average daily dose of ethanol. Relative to controls, cases also consumed significantly more fried bacon or ham, less fresh fruits and raw vegetables, and were more likely to prefer white than whole grain bread. Finally, there was a significant association between carcinoma of the esophagus and long-term occupational exposure to metal dust; this association was largely confined to the lower one-third section of the esophagus.

Alcohol Drinking↗
PubMed1988

Adenocarcinoma of the stomach and exposure to occupational dust.

The authors studied 1,342 cases of adenocarcinoma of the stomach identified by a population-based cancer registry in Los Angeles County, California. The cases were males aged 20-64 years first diagnosed between 1972 and 1982. To determine whether exposure to occupational dust increased the risk of developing stomach cancer, occupational titles were rated for the likelihood of exposure to various kinds of dust. Men who worked in dusty jobs had a risk for developing stomach cancer 1.3 times that of unexposed men (95% confidence interval = 1.2-1.4). The association of exposure to dust with stomach cancer was stronger at higher levels of exposure. The risk was not uniform throughout the stomach: the highest risk (1.8 times that of unexposed men) was found for the antrum/pylorus. At that site, exposure to mineral dust carried the greatest risk for cancer (3.7 times the risk for unexposed men). The highest risks from dust exposure were observed in blacks. Risk was related to race, socioeconomic status, and immigrant status, but these factors did not entirely explain the association with dust exposure. The observed relation between dust exposure and stomach cancer is consistent with results of previous mortality and case-control studies of cancer in men who worked in dusty occupations. Ingested dust may be one factor in the etiology of adenocarcinoma of the stomach.

Adenocarcinoma↗
PubMed1988

Re-evaluating the role of progestogen therapy after the menopause.

An estrogen-progestogen regimen of hormone replacement therapy has become widely used in recent years, primarily as a means to protect the endometrium from the carcinogenic effects of unopposed estrogen therapy (ERT). In this article, we evaluate the probable effects of this regimen on mortality from endometrial cancer as well as mortality from other chronic diseases. We conclude from this analysis that ERT is to be preferred to combination therapy for postmenopausal women without a uterus, primarily because it is predicted that ERT confers a significantly greater benefit on heart disease risk. In women with a uterus, if progestogens are to be prescribed, they should be given in the lowest possible dose needed to achieve the desired histologic changes in the endometrium, since the predicted loss in heart disease benefit from adding the progestogen is substantial.

Breast Neoplasms↗
PubMed1987

Cancer of the gastrointestinal tract among Japanese and white immigrants in Los Angeles County.

With the use of age-adjusted incidence rates and proportional incidence ratios, investigators studied the risk of cancer of the stomach and 3 subdivisions of the large bowel in three race-ethnic groups--Spanish surnamed whites, other whites, and Japanese--and compared Los Angeles County native residents, immigrants, and representative "homeland" populations. The risk pattern for each of the four anatomic sites was quite distinctive, suggesting at least four different etiologic complexes. For each site the observed gradients of risk are nearly identical for each sex, usually with risk for immigrants intermediary between that for homeland residents and that for local natives; the differences between race-ethnic groups are consistent with known international patterns. Particularly notable is the contrast between the low risks of cancer of both the sigmoid and the rectum in Japan and the high risks for Japanese immigrants to Los Angeles, which are nearly double those of their U.S. white neighbors. In all instances, and especially for both the upper and lower colon, the influence of the adult environment predominates over that of the early environment. The environmental determinants of stomach cancer do not always appear in inverse correlation with those of colon cancer, since Japanese immigrants to Los Angeles and their descendants are at high absolute and relative risk of both neoplasms. Our findings suggest that patterns of risk in relation to migration are complex and defy simple dietary or other interpretation. Without more information about the impact of migration to the United States on qualitative and quantitative aspects of lifestyle, it is not possible to put forward simple hypotheses that explain all available facts.

California↗
PubMed1986

Estrogen use and cardiovascular disease.

In general, epidemiologic data from case-control and cohort studies have suggested that postmenopausal estrogen use confers a moderate degree of protection from coronary artery disease. The authors report reductions in all-cause mortality rates and in mortality rates for acute myocardial infarction among estrogen replacement users in comparison with never-users. It is calculated that even a small decline in the mortality rate for coronary artery disease among estrogen users would have a major impact on the overall risk/benefit ratio associated with estrogen use.

Aged↗
PubMed1986

Secular trends in histologic types of lung cancer.

The histology pattern of lung cancer in Los Angeles County was reviewed for a 10-year period, 1972-81. In men, the total lung cancer incidence has been fairly constant, but there has been a shift in the histology pattern with an increase in adenocarcinoma and a decrease in "other" cell type (i.e., carcinoma not otherwise specified, large-cell and undifferentiated tumors). This changing histology pattern may be partly due to changes in diagnostic standards and practices. With the assumption that these changes are comparable in men and women, the "true" annual rate of change was estimated for each lung cancer cell type in women. All lung cancer types have increased in women; of the cell types squamous cell carcinoma, small-cell carcinoma, and adenocarcinoma, small-cell carcinoma showed the largest rate of annual increase and adenocarcinoma, the smallest.

Adenocarcinoma↗
PubMed1986

Pancreas cancer and smoking, beverage consumption, and past medical history.

Four hundred and ninety pancreas cancer patients representative of confirmed cases in Los Angeles County residents of working age were compared to healthy controls individually matched by age, sex, race, and neighborhood. Home interviews were conducted on occupation, smoking, food and beverage consumption, and medical history. Cigarette smoking was a strong and consistent predictor of pancreas cancer occurrence; the effect disappeared after a decade of nonsmoking, and there was no increase in risk among current smokers as daily dose increased. There was no link between pancreas cancer and past consumption of tea, carbonated beverages, beer, or spirits; and an association with coffee consumption was inconsistent. A strong association between pancreas cancer and history of subtotal gastrectomy at any past time could not be explained by chance or any other factor. Pancreas cancer patients had experienced fewer allergies of any kind.

Alcohol Drinking↗
PubMed1986

Increased frequency of adenocarcinoma of the uterine cervix in young women in Los Angeles County.

By hypothesizing that oral contraceptives (OC's) might have a carcinogenic effect on glandular cells of the cervix if given during periods of active metaplasia (e.g., postmenarchal adolescence), an increasing rate of cervical adenocarcinoma was predicted in young women who had been teenagers when OC's were introduced roughly 20 years ago. Secular trends for cervical carcinomas in non-Hispanic whites were examined by age, histologic type, and social class by using data from the Los Angeles County population-based tumor registry. Between 1972 and 1982, the frequency of invasive cervical adenocarcinoma in women under 35 years of age increased from about 2 to about 5 annually, amounting to an average rate of change of 8% per year (P less than .01). There was essentially no trend for women over 35 years old; the frequency of other invasive carcinomas (and of squamous carcinoma in situ) decreased at average rates of about 3% per year in women under 35 years of age and decreased more rapidly in older women. The increase in adenocarcinoma, unlike risk from cervical cancer generally, was most striking among young women residing in middle-to-upper income neighborhoods, who were the first to use OC's; in this subgroup the average rate of increase was 16% per year (P less than .05). These findings are compatible with our hypothesis and merit further study.

Adenocarcinoma↗
PubMed1986

Cigarette smoking, obesity, diuretic use, and coffee consumption as risk factors for renal cell carcinoma.

One hundred sixty incident cases of renal cell carcinoma under the age of 55 years and an equal number of age-(within 5 yr), race-, and sex-matched neighborhood controls were interviewed. Cigarette smoking was a risk factor for renal cell carcinoma in males [relative risk (RR) = 2.1, one-sided P = .02] but not in females (RR = 1.1, P = .50). Obesity was a significant risk factor in both males and females: The RR for a 4th quartile compared to a 1st quartile Quetelet's Index 10 years ago was 2.5 for males and 3.3 for females. Additional risk factors in females were diuretic use (RR = 4.5, P = .002) and daily coffee consumption (RR = 2.3, P = .06).

Adult↗
PubMed1986

Risk factors for invasive cervical cancer among Latinas and non-Latinas in Los Angeles County.

A case-control study among white women in Los Angeles County was conducted to investigate etiologic factors that might explain the high rates of invasive cervical cancer among Latinas. Two hundred patients with invasive squamous cell carcinoma of the uterine cervix and matched (age, sex, preferred language, and neighborhood) controls were interviewed, 98 pairs in English and 102 pairs in Spanish. Seven factors were found to contribute independently and significantly (P less than .01) to risk, each after adjustment for the other six: years since last Pap smear, years of education (protective), frequency-years douching, pack-years of smoking, years of barrier contraceptive use (protective), number of sexual partners before age 20, and recognized episodes of genital warts. An eighth variable, interval in years between menarche and first intercourse, was the second variable to enter the stepwise logistic regression analysis but lost its statistical significance when sexual partners before age 20 entered the model. Together, these eight variables accounted for almost 99% of the risk. There were no significant interactions between any of these variables and age, language of interview, or birth in a Latin country. There was no increased risk associated with use of oral contraceptives, either before or after adjustment for the other significant factors. Compared to English-speaking controls, Spanish-speaking controls smoked less, douched less, had fewer sexual partners before 20, and had essentially the same average interval between menarche and first intercourse and the same average number of episodes of genital warts; however, they had had a longer interval since their last Pap smear, fewer years of barrier contraceptive use, and fewer years of education. Education, presumably a correlate of an inadequately measured etiologic risk factor (possibly papillomavirus infection), was responsible for the greatest difference in risk between the Spanish- and English-speaking cases.

Adolescent↗
PubMed1985

Pancreas cancer is unrelated to the workplace in Los Angeles.

From 1975 to 1981, 490 cases of exocrine adenocarcinoma of the pancreas, representative of those occurring in the working-age population of Los Angeles County, were compared to matched neighborhood controls. Among the items of information obtained from each subject was a lifetime job history and a history of specific workplace exposures; this came directly from both case and control in 124 pairs. Although the matched cases and controls were generally comparable, they were not matched with respect to job history. While other strong risk factors for pancreas cancer were found in the same study, no significant or suggestive differences in the jobs or perceived chemical or process exposures between cases and controls were found. Those minor differences which were found did not suggest credible mechanisms of carcinogenesis when examined in detail. Our study does not point to the workplace as an important determinant of pancreas cancer in the economically diversified urban area of Los Angeles.

Adenocarcinoma↗
PubMed1985

Uses of a cancer registry in the assessment of occupational cancer risks.

Five approaches for the evaluation of occupational factors in cancer etiology are described. These approaches, based on one's having access to cancer registry data, are for examining cancer profiles for industry and occupation, evaluating information on occupation and industry to infer exposure, observing time trends in incidence to evaluate tumors of occupational interest, using cases of interest to form the basis for case-control studies, and linking cohorts with known exposure to the tumor registry to ascertain cancer incidence in that cohort.

Adult↗
PubMed1985

Religion and cancer in Los Angeles County.

The patterns of cancer risk by religion in the large multidenominational population of Los Angeles County were examined with the method of proportional incidence. Risk estimates for individual cancers by religion were screened and those extreme but stable estimates found were reexamined in light of relative socioeconomic class, nativity, and ethnicity. Within Protestant denominations, gradients which can still best be attributed to religious preference were observed for leukemia, stomach, and cervix cancer. Roman Catholics tend to have high risks of stomach and gallbladder and a low risk of prostate cancer, whereas Eastern Orthodox women trade high risk of stomach cancer for low risk of endometrial and lung cancer. The most extreme pattern of risk, that for Jews, is comprised of lowered risk for cervical cancer and for most sites usually associated with smoking, plus consistently higher risk for lymphomas, thyroid cancer, and bladder cancer among males. Like Jews, Seventh-Day Adventists experience high risk for lymphoma and low risk for cervical and respiratory cancers. Risk to Mormons in Los Angeles differs from that of the standard Protestant population in only minor and inconsistent ways. Neither Mormons nor Adventists showed the previously reported deficits of colorectal or breast cancer. Although the method of proportional incidence may be partly responsible for our failure to confirm previous findings, nonreligious cultural or methodologic factors in the original investigations also provide plausible explanations. More generally, associations of the modest magnitude observed between cancer risk and religion in American populations should probably not be attributed to religious life-style, unless extraordinary circumstances permit the exclusion of other determinants.

California↗
PubMed1985

Cancer in Hispanics in Los Angeles County.

Using ethnicity of surname, nativity, residential social class, and inferred age at migration to characterize and subdivide Hispanics in Los Angeles, we compared risk ratios and proportional incidence ratios to examine the patterns of occurrence of selected neoplasms within the Hispanic community. Common neoplasms for which Hispanics have high, low, and intermediary risk were examined in detail. Although the patterns expected on the basis of current concepts of etiology were generally found and served to reinforce presumptions about the biologic significance of the risk factors, a number of observations cannot be explained easily with current knowledge. The risks for stomach and bowel cancers do not conform to the mirror-image patterns to be expected on the basis of inverse patterns of dietary acculturation. Incidence of cancer of the breast, in contrast to that of cervix, does not appear to reflect early cultural practice. Consistent details in the patterns of cancers of the bladder, rectum, ovary, prostate, and possibly pancreas imply unrecognized determinants of disease. Gallbladder cancer in Hispanic women is the disease most closely tied to Hispanic origin or culture, or both, but the ethnic pattern in women differs greatly from that in men.

California↗
PubMed1984

Job activity and colon cancer risk.

The authors studied 2,950 population-based colon cancer cases in males in Los Angeles County, California, that were diagnosed between 1972 and 1981. To determine if colon cancer risk is reduced by physical activity on the job in males aged 20-64 years, the authors first rated each occupation by judging the activity level as high, moderate, or sedentary. Men with sedentary jobs had a colon cancer risk at least 1.6 times that of men whose jobs required a high level of activity. Risk increased in a stepwise manner as activity level decreased. This gradient was consistently seen within each socioeconomic stratum, among whites, blacks, immigrant and native Hispanics, and for each subsection of the colon from the hepatic flexure to the sigmoid. The protective effect of physical activity was very strong in the descending colon and diminished in a gradient both proximally and distally. There was no such relationship between physical activity and risk for rectal cancer. Physical activity may play a major, previously unrecognized role in colon cancer etiology. Such a role is consistent with the known pattern of colon cancer occurrence and with our understanding of colon physiology and colon cancer pathogenesis. In addition to the implications for prevention, understanding the effects of physical activity on colon cancer risk may allow future studies to evaluate more accurately the role played by diet.

Adult↗
PubMed1984

Parallels in the epidemiology of selected anogenital carcinomas.

Characteristics of Los Angeles, Calif., residents in whom carcinomas of the cervix, vulva, vagina, anus, and penis were diagnosed during the period 1972-81 were compared with those of all residents and with those in whom any cancer was diagnosed during the same period. At all five sites, risks for squamous and transitional cell carcinomas generally increased with decreasing social class, were low among Jews (not explained by social class), and were elevated among persons who were separated or divorced at diagnosis compared to married persons. Single men had a striking excess of anal but not penile carcinomas. The five sites represent contiguous and histologically similar tissues, and the clinical literature suggests common risk factors, e.g., sexually transmitted infections and other forms of chronic irritation. These observations are all consistent with the hypothesis that tumors at these sites have common or similar etiologic elements.

Adenocarcinoma↗