Search PubMed⌕ Search

Biomedical subjects

S Preston-Martin

Publications and source records attributed to S Preston-Martin.

At least 127 records · Page 7Linked to original sources
PubMed1986

Contribution of passive smoking to respiratory cancer.

This article reviews data from experimental and epidemiologic studies on passive smoking and makes 12 recommendations for further study. The physicochemical nature of passive smoke, the smoke inhaled by nonsmokers, differs significantly from the mainstream smoke inhaled by the active smoker. At present, measurement of urinary cotinine appears to be the best method of assessing exposures to passive smoking. Data indicate that the greater number of lung cancers in nonsmoking women is probably related to environmental tobacco smoke. Exposures in utero and very early in life to passive smoking may be important in relationship to the subsequent development of cancer and need further consideration. The short-term effects of environmental tobacco smoke on the cardiovascular system, especially among high-risk individuals, may be of greater concern than that of cancer and requires further study. Further study of increased risks of lung cancers in relation to environmental tobacco smoke exposure requires larger collaborative studies to identify lung cancer cases among nonsmokers, better delineation of pathology, and more careful selection of controls. In addition, studies of epithelial cells or specific cytology should be undertaken to determine evidence of cellular changes in relation to environmental tobacco smoke exposure. Animal inhalation studies with passive smoke should be initiated with respect to transplacental carcinogenesis, the relationship of sidestream smoke exposure with lung cancer, the induction of tumors in the respiratory tract and other organs, and the differences in the physicochemical natures of sidestream and mainstream smoke.

Air Pollutants↗
PubMed1985

Parity and cancer risk in Slovakia.

Mortality data from women aged 45-74 who died between 1968 and 1977 in Slovakia, Czechoslovakia, were used to examine the effect of parity (number of live-born children) on risk of dying from each of 20 common cancers. After controlling for the effects of age and year of death, the effect of parity on risk was statistically significant at the p less than 0.001 level, for cancers of the stomach, liver, gall-bladder, breast, cervix, and ovary; and at the p less than 0.01 level for uterine corpus and brain. No effect of parity was seen for cancer of the colon or rectum. Among parous women the trend relating risk to level of parity was significant at the p less than 0.001 level for cancers of the breast, uterine corpus, ovary and brain; and at the p less than 0.01 level for stomach cancer. The findings relating parity to cancers of the breast and reproductive organs are consistent with previous reports. The associations of parity with cancers of the digestive tract deserve further study.

Age Factors↗
PubMed1985

The epidemiology of primary nervous system tumors in children.

A study of the descriptive epidemiology of primary tumors of the brain and nervous system in children aged 0-14 was undertaken using international incidence data. The median cumulative incidence rates for this age group were found to be 0.47 per thousand for boys and 0.39 per thousand for girls with a male: female sex ratio of 1.2. Variation in incidence rates by geographic area and race are discussed and are compared to descriptive findings for tumors of this site among adults. Data on suggested risk factors for childhood brain tumors are reviewed.

Adolescent↗
PubMed1985

A dental x-ray validation study. Comparison of information from patient interviews and dental charts.

Information was collected from dentists of a subset of participants in a case-control interview study conducted in Los Angeles County, California, in August 1980-August 1981 to evaluate the relationship of dental x-rays to tumors of the parotid gland. Complete dental charts were available from 142 dentists of 84 cases and from 130 dentists of 79 controls. Analysis of data from these interview-chart comparisons indicates that recall appears to be unbiased since the measures of agreement between interview and dental chart data are similar for cases and controls. The authors further conclude that interview data alone may be used for case-control comparisons of dental x-ray exposure and would, because of unbiased misclassification, tend to underestimate the relative risks.

Adult↗
PubMed1985

Medical and dental x rays as risk factors for recently diagnosed tumors of the head.

We used epidemiologic data on 2 tumor sites, the intracranial meninges and the parotid gland, to evaluate the importance of medical and dental x rays as risk factors for radiogenic tumors of the head diagnosed among residents of Los Angeles County in recent years. Exposures to x-ray treatment to the head and to full-mouth dental x-ray series before 1960 appear to be risk factors for both meningiomas and parotid tumors. Evidence from both descriptive and analytic studies suggests that the female over male excess of meningiomas, which is greatest from ages 25 to 54 years, may be partially explained by the excess exposure of young women to dental x rays. Study participants' ability to recall diagnostic x rays accurately is also evaluated by our comparisons of interview data to those available from dental charts. Recall of these events appears to be unbiased and accurate enough to justify the use of interview data in investigations of these risk factors.

Adult↗
PubMed1984

Salivary gland tumors and previous radiotherapy to the head or neck. Report of a clinical series.

To estimate what proportion of patients with newly diagnosed salivary gland tumors may have radiation-related disease, we interviewed all 275 patients in a surgical practice who had salivary gland resections during an 8 year period. Patients were asked about previous radiation treatment to the head and neck. Thirty-one patients (11 percent) had both an incident salivary gland tumor and a history of significant exposure. Four of these patients (13 percent) had multiple primary tumors of the salivary glands. The implications and generalizability of these findings have been discussed herein.

Adult↗
PubMed1984

N-nitroso compounds and human intracranial tumours.

Experimentalists have shown that various N-nitroso compounds are potent nervous system carcinogens, particularly when animals are exposed transplacentally. Information has been obtained concerning exposure to N-nitroso compounds and their precursors in three case-control studies of intracranial tumour patients in Los Angeles County, California. A study of women (185 pairs) found that level of consumption of nitrite-cured meats was related to meningioma development (p = 0.01). In a similar study of meningiomas in men (105 pairs), the association with cured meats was not clear. The most striking results were obtained in a study of young brain tumour patients (209 matched pairs). Increased risk was associated with maternal contact, during pregnancy, with N-nitrosamine-containing substances, such as burning incense (odds ratio, 3.3; p less than 0.01), sidestream cigarette smoke (odds ratio, 1.5; p = 0.03) and face make-up (odds ratio, 1.6; p = 0.02). Increased risk was also associated with maternal use of diuretics (odds ratio, 2.0; p = 0.03) and antihistamines (odds ratio, 3.4; p less than 0.01) and with the level of maternal consumption of cured meats (p less than 0.01). Diuretics and antihistamines contain nitrosatable amines and amides, and cured meats contain nitrites - chemicals which are precursors of N-nitroso compounds. Additional epidemiological studies of nervous system tumours in young people would appear to offer considerable promise for testing the hypothesis that N-nitroso compounds are etiologically related to human neurogenic neoplasms.

Adolescent↗
PubMed1983

Risk factors for meningiomas in men in Los Angeles County.

A case-control study among men in Los Angeles County was conducted to investigate further the causes of intracranial meningiomas. Meningioma patients and a neighbor of each one were interviewed about past experiences that might be associated with tumor development. Analysis of information from the 105 matched pairs showed an association with meningioma occurrence for various factors relating to head trauma and head X-rays: 1) ever boxed as a sport [odds ratio (OR) = 2.0, P = 0.03], 2) had a serious head injury (OR = 1.9, P = 0.01), and 3) had X-ray treatment to the head before 20 years of age and/or had five or more full mouth dental X-ray series before 1945 (OR = 3.5, P = 0.02). Of the 105 subjects, 72 (69%) had a history of exposure to at least one of these factors.

Adult↗
PubMed1982

Descriptive epidemiology of cancers of the upper respiratory tract in Los Angeles.

The descriptive epidemiology of cancer of three upper respiratory tract sites (lip; mouth and pharynx, excluding nasopharynx; and nose, sinus and nasopharynx) was explored using data from 1972-1976 from the population-based cancer registry covering Los Angeles County, California. In addition, the proportion of Los Angeles cases at each site which are explained by tobacco use was estimated using attributable risks calculated from previously published case-control studies. Causes of nontobacco-related cases are considered. Lip cancer was found to be a disease predominantly of white males with a male/female ratio of 9.8 for the lower lip and of 1.0 for the upper lip. Tobacco use is responsible for 60% of male lip cancers, and incidence rates of lip cancer after subtraction of the proportion of the incidence due to tobacco use were more than three times greater in men than in women. A hypothesis is proposed that an important etiologic factor is exposure to sun, wind and cold which results in chapping; this exposure is most intense for the lower lip; and the use of lip coverings in women protects their lips both from the sun and from chapping. Cigarette smoking was responsible for 51% of mouth and pharynx cancer in men and women in Los Angeles County, and after subtraction of the proportion of the incidence due to smoking, rates in men and women were similar. Factors such as poor dentition and nutritional deficiencies may help explain demographic characteristics such as the higher rates of mouth and pharynx cancer among men and women in the lower social classes and the secular decline in incidence rates. Cancers of the nose, sinus and nasopharynx were found to occur among workers in a wide range of occupations and industries which involved inhalation of dust, fumes and vapors. High incidence rates of nasopharynx cancer were observed among Chinese in Los Angeles and high rates of sinus cancer among Spanish-surnamed residents. Cancers at these sites appear to be related to the action of carcinogens on tissue chronically irritated by repeated upper respiratory infections or allergic responses. In addition racial differences in the physical structure of the nasal passage may influence where inhaled particles are deposited.

California↗
PubMed1982

N-Nitroso compounds and childhood brain tumors: a case-control study.

We questioned mothers of 209 young brain tumor patients and mothers of 209 controls about experiences of possible etiological relevance which they had during pregnancy or which their children had while growing up. Long-suspected brain tumor risk factors such as head trauma and X-rays appeared to be factors for relatively few cases. Increased risk was associated with maternal contact with nitrosamine-containing substances such as burning incense (odds ratio, 3.3; p = 0.005), sidestream cigarette smoke (odds ratio, 1.5; p = 0.03), and face makeup (odds ratio, 1.6; p = 0.02); with maternal use of diuretics (odds ratio, 2.0; p = 0.03) and antihistamines (odds ratio, 3.4; p = 0.002); and with the level of maternal consumption of cured meats (p = 0.008). These drugs contain nitrosatable amines and amides, and the cured meats contain nitrites, chemicals which are precursors of N-nitroso compounds. We propose a hypothesis that brain tumors in these young people are related to in utero exposure to N-nitroso compounds and their precursors, the most potent nervous system carcinogens known in experimental animals.

Adolescent↗
PubMed1982

Epidemiological characteristics of adenocarcinoma of the lung in Los Angeles County.

The descriptive epidemiology of adenocarcinoma of the lung was compared with that of squamous cell carcinoma with the use of data for 1972-76 from the population-based cancer registry serving Los Angeles County. Several differences in the demographic characteristics between these two types of lung cancer were observed, including low male-to-female ratios and lack of social class gradients for adenocarcinoma. Cigarette smoking was responsible for 90% of squamous cell carcinoma in both men and women and for 79% of male and 46% of female adenocarcinoma. We also studied incidence rates of lung cancer after subtraction of the proportion of the incidence due to smoking by using data from a previously conducted case-control study in Los Angeles County. These residual rates for squamous cell carcinoma showed a fivefold excess in males compared with females, whereas those for adenocarcinoma were almost the same in men and women. These findings indicate that 1) smoking is etiologically less important for adenocarcinoma than for squamous cell carcinoma, and 2) other etiologic factors for adenocarcinoma affect women as much as men.

Adenocarcinoma↗
PubMed1981

Brain tumors in children and occupational exposure of parents.

Ninety-two cases of brain tumor in children less than 10 years old were compared with 92 matched controls for parental occupational history. Cases were more likely than controls to show material occupations involving chemical exposure, paternal occupations involving solvents, and employment of father in the aircraft industry. These three factors were not affected by adjustment for the potential confounding variables examined in this study.

Air Pollutants↗
PubMed1980

Case-control study of intracranial meningiomas in women in Los Angeles County, California.

A case-control study was conducted among women in Los Angeles County to investigate possible causes of intracranial meningiomas. Questionnaires sought information from patients and from a neighbor of each one on characteristics and past experiences that might be associated with the development of this disease. Information was obtained on 188 matched patient-neighbor pairs. Three primary factors appeared to be associated with meningioma occurrence: 1) a history of head trauma (odds ratio = 2.0, P = 0.01), 2) consumption of certain cured meats (odds ratio = 2.8, P less than 0.01), and 3) exposure to medical and dental diagnostic X-rays to the head. For diagnostic X-rays, the strongest association was with early exposure (less than 20 yr old) to full-mouth dental X-ray series (odds ratio = 4.0, P less than 0.01).

Age Factors↗