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Biomedical subjects

S Preston-Martin

Publications and source records attributed to S Preston-Martin.

At least 109 records · Page 6Linked to original sources
PubMed1989

Diagnostic radiography as a risk factor for chronic myeloid and monocytic leukaemia (CML).

This interview study included 136 Los Angeles County residents aged 20-69 with CML diagnosed from 1979 to 1985 (cases) and 136 neighbourhood controls. During the 3-20 years before diagnosis of the case, more cases than controls had radiographic examinations of the back, gastrointestinal (GI) tract and kidneys, and cases more often had GI and back radiography on multiple occasions (odds ratio (OR) for back X-rays on five or more occasions = 12.0; P less than 0.01). Published estimates were used to assign a minimum dose to the active bone marrow for various radiographic procedures. ORs were estimated for cumulative marrow doses for each of four time periods (3-5 years, 6-10 years, 11-20 years and 3-20 years before the diagnosis of the case). The ORs for exposure to 0.99, 100-999, 1000-1999 and greater than or equal to 2000 mrad in the 3-20 years before diagnosis were 1.0, 1.4, 1.6 and 2.4 (P for highest exposure category and P for trend both less than 0.05). The association was strongest for the period 6-10 years before diagnosis, and the effects of radiation exposure during this period remained significant after consideration of other risk factors in a logistic regression analysis.

Adult↗
PubMed1989

Noise trauma in the aetiology of acoustic neuromas in men in Los Angeles County, 1978-1985.

The aim of this study was to investigate whether occupational and other suggested brain tumour risk factors relate to the development of acoustic neuromas (AN) in men. Responses to interviews were compared for 86 AN patients and 86 neighbourhood controls. During the period 10 or more years before the year of diagnosis of the case, more cases than controls had a job involving exposure to extremely loud noise; noise exposure was determined by a blinded review of job histories and linkage to the National Occupational Hazards Survey data base (odds ratio (OR) = 2.2, 95% confidence interval (CI) = 1.12, 4.67). A dose-response analysis showed an increase in risk related to number of years of job exposure to extremely loud noise (P for trend = 0.02) with an OR of 13.2 (CI = 2.01, 86.98) for exposure for 20 or more years during the period up to 10 years before diagnosis. We propose that the findings in this study which identify noise as a risk factor support the hypothesis that mechanical trauma may contribute to tumorigenesis.

Adult↗
PubMed1989

Risk factors for tumors of the brain and cranial meninges in Seventh-Day Adventists.

We studied the occurrence of tumors of the brain and cranial meninges in a cohort of 34,000 California Seventh-Day Adventists who completed a detailed life-style questionnaire in 1976 and who were followed for cancer incidence until the end of 1982. During the period of follow-up, 31 tumors were diagnosed in the cohort (21 gliomas, 10 meningiomas). Increased risk for glioma was associated with rural residence, history of a positive tuberculosis skin test and consumption of pork products; increased meningioma risk was associated with a positive reaction to a tuberculosis skin test, previous stroke, use of tranquillizers and a vegetarian life-style in childhood.

Adult↗
PubMed1989

Descriptive epidemiology of primary tumors of the brain, cranial nerves and cranial meninges in Los Angeles County.

This report presents data on the distribution of 8,612 cases of primary tumors of the brain, cranial nerves and cranial meninges (both benign and malignant) diagnosed among residents of Los Angeles County from 1972 to 1985. Incidence rates of gliomas, meningiomas, nerve sheath tumors and all histologic types combined are presented for specific age, sex and ethnic groups. At all ages, the highest incidence is seen for gliomas among men. Meningioma rates are higher among women than men in every ethnic group. In both sexes, glioma rates are highest among whites, and meningioma rates are highest among blacks. Asians have the lowest rates of both types of tumors. Proportional incidence ratios are elevated among those born in Eastern Europe, Southern Europe and the Middle East and among Jewish residents of Los Angeles County. A clear trend of increasing glioma incidence with increasing social class is seen among males. An analysis among white men aged 25-64 by occupation and industry at the time of diagnosis supports several previously published findings. A glioma excess is evident among workers in the aircraft industry. Workers in the petroleum industry and the rubber and plastics industry have an excess of meningiomas. Occupational groups at excess risk include dentists who have an increased risk of all types of brain tumors and electricians whose excess risk is limited to gliomas.

Adolescent↗
PubMed1989

Prior x-ray therapy for acne related to tumors of the parotid gland.

Findings from this population-based study in Los Angeles County, California, suggest that recently diagnosed tumors of the parotid gland are related to prior x-ray therapy for acne (relative risk = 2.6; 95% confidence interval = 1.07, 6.34). Responses to interviews with 408 patients with a parotid tumor were compared with responses of 408 neighborhood controls. Risk increased with an increase in the number of acne treatments, and the relative risk for 15 or more treatments was 8.0. Clinicians who are still using this form of therapy, as well as those clinicians who care for patients who received this treatment, should be aware of this additional risk associated with its use.

Acne Vulgaris↗
PubMed1989

Epidemiological studies of perinatal carcinogenesis.

Epidemiological evidence for prenatal carcinogenesis includes associations between cancer in young people and intrauterine exposure to X-rays, drugs and hormones and prezygotic events such as specific chromosomal aberrations associated with specific cancers. Recent findings suggest that the hormonal environment during early gestation can result not only in the development of clear-cell adenocarcinoma of the vagina but also in the development of germ cell tumours of the testes and ovary. Hormone-related risk factors for testicular germ cell neoplasms include maternal use of exogenous oestrogens during early gestation and, possibly, maternal nausea, maternal obesity and race as well. Ovarian germ cell tumours also appear to be related to maternal use of hormones and obesity. Several epidemiological studies of cancer in young people have been directed towards suggested associations with parental occupational exposures, parental cigarette smoking and household exposures to electric and magnetic fields (EMF). The findings of the many studies of parental occupational exposures are inconsistent and are often nonspecific with respect to the type of childhood cancer and the job exposure implicated. Parental cigarette smoking has been associated in some studies with an increased risk for cancer among children and young adults, and in other studies with an increased risk among mature adults, but the findings are not consistent across studies. Three studies of all types of childhood cancer found risk to be related to household exposures to EMF; in all three, the risk for central nervous system tumours was increased, and in two of the three leukaemia risk as well. A fourth study showed no association between childhood leukaemia and EMF. A hypothesis is proposed which suggests that prenatal and early childhood exposure to N-nitroso compounds (NOC) may be related to the development of primary tumours of the brain in children. Experimentalists have shown that various NOC are potent nervous system carcinogens, particularly when animals are exposed transplacentally. This experimental model and findings from a Los Angeles case-control study (209 pairs) of brain tumours in young people led to the proposed epidemiological hypothesis. Although this and other epidemiological studies of NOC have major limitations, findings from epidemiological studies of congenital defects and of other childhood cancers lend the hypothesis some support. A large international collaborative case-control study of childhood brain tumours was begun recently. This study has a major advantage over most case-control studies in adults because the exposure period of greatest interest (gestation) is clearly defined.

Animals↗
PubMed1989

Epidemiological evidence for the role of nitroso compounds in human cancer.

Human exposure to N-nitroso compounds (NOC) is not to single compounds but to highly complex mixtures such as food or tobacco products which may contain various NOC, NOC precursors and modulators of NOC metabolism in addition to other known carcinogens. Aetiological models also stress the importance of other cofactors. The interrelationship of these cofactors with relevant NOC exposures and the possible influence of confounding factors need to be considered in order to evaluate the risk related to NOC. This task is made more difficult because the levels of human NOC exposure are often low, and some of the relevant exposure is likely to be from endogenously formed NOC. Nonetheless, current hypotheses reviewed here propose a role for NOC in the aetiology of tobacco-related cancers and of cancers of the bladder, stomach, oesophagus and brain. Data implicating tobacco-specific nitrosamines in the aetiology of cancers of the oral cavity among snuff dippers is most convincing. Evidence from epidemiological studies in support of other NOC/cancer hypotheses is circumstantial and much work remains to be done to define the role of NOC and develop strategies for prevention of these tumours.

Animals↗
PubMed1988

Dietary factors in oral and pharyngeal cancer.

A population-based case-control study of oral and pharyngeal cancer conducted in four areas of the United States provided information on a number of risk factors, including diet. Interviews were obtained from 871 oral cancer patients and 979 controls among whites, frequency matched for age and sex. Consumption frequency of 61 food items was assessed in the questionnaire; attention was given to foods that are sources of vitamins A and C and carotene. The major finding was an inverse relationship between fruit intake and risk of oral and pharyngeal cancer; individuals in the highest quartile of intake had about half the risk of those in the lowest quartile. Vitamin C, carotene, or fiber in fruit did not appear to account completely for this relationship, since these nutrients in vegetables did not provide similar protection. This finding suggests the influence of other constituents in fruits, although it is possible that cooking vegetables may have a nutrient-diminishing effect. Dietary intake of other nutrients, such as the B vitamins, vitamin E, folate, and iron, showed no consistent relationship to risk of oral and pharyngeal cancer. Coffee or other hot beverage consumption did not increase risk; intake of nitrite-containing meats or cooking practices, such as smoking, pickling, or charcoal grilling, also did not increase risk. All analyses were adjusted for the effects of tobacco and alcohol, strong risk factors for oral and pharyngeal cancer. Dietary findings among the few subjects who did not use tobacco or alcohol were similar to those for all subjects.

Adult↗
PubMed1988

Prior exposure to medical and dental x-rays related to tumors of the parotid gland.

Findings from this population-based study in Los Angeles County suggest, for the first time, that tumors of the parotid gland are related to prior exposure to diagnostic medical and dental radiography. Responses to interviews with 408 patients with a parotid tumor (269 benign tumors and 139 malignant tumors) were compared to responses of 408 neighborhood controls. Cumulative exposure of the parotid gland from diagnostic radiography was associated with a dose-related increase in risk of malignant tumors (P for trend less than .05; relative risk for exposure to greater than or equal to 50 rad = 3.4; 95% confidence interval = 1.02-11.46). Benign tumors showed a weaker positive association, and exposure before age 20 to a major diagnostic examination (full-mouth or panoramic dental radiography or medical radiography to the head) increased risk (relative risk = 1.8; confidence interval = 1.13-2.91). This study also confirmed the association of malignant tumors with prior radiation treatment to the head or neck; 28% of these tumors are attributable to exposure of the parotid gland from diagnostic and therapeutic radiation.

Adult↗
PubMed1988

Smoking and drinking in relation to oral and pharyngeal cancer.

A case-control study of oral and pharyngeal cancer conducted in four areas of the United States provided information on the tobacco and alcohol use of 1114 patients and 1268 population-based controls. Because of the large study size, it could be shown that the risks of these cancers among nondrinkers increased with amount smoked, and conversely that the risks among nonsmokers increased with the level of alcohol intake. Among consumers of both products, risks of oropharyngeal cancer tended to combine more in a multiplicative than additive fashion and were increased more than 35-fold among those who consumed two or more packs of cigarettes and more than four alcoholic drinks/day. Cigarette, cigar, and pipe smoking were separately implicated, although it was shown for the first time that risk was not as high among male lifelong filter cigarette smokers. Cessation of smoking was associated with a sharply reduced risk of this cancer, with no excess detected among those having quit for 10 or more years, suggesting that smoking affects primarily a late stage in the process of oropharyngeal carcinogenesis. The risks varied by type of alcoholic beverage, being higher among those consuming hard liquor or beer than wine. The relative risk patterns were generally similar among whites and blacks, and among males and females, and showed little difference when oral and pharyngeal cancers were analyzed separately. From calculations of attributable risk, we estimate that tobacco smoking and alcohol drinking combine to account for approximately three-fourths of all oral and pharyngeal cancers in the United States.

Black or African American↗
PubMed1988

Myelogenous leukemia and electric blanket use.

In a case-control study of adult acute and chronic myelogenous leukemia in Los Angeles County, we tested the hypothesis that excess exposure to electromagnetic fields from electric blankets was associated with risk of leukemia. We did this by studying 116 cases of acute myelogenous leukemia (AML) and 108 cases of chronic myelogenous leukemia (CML) along with matched neighborhood controls. The cases and controls were queried as to electric blanket use and the risks computed. For AML the risk was 0.9 (95% CI 0.5-1.6) and for CML the risk was 0.8 (95% CI 0.4-1.6). Cases did not differ from controls by duration of use, year of first regular use, year since last use, or socioeconomic status. Our best estimates of exposure indicate that electric blanket use increases overall exposure to electric fields by less than 50% and magnetic fields by less than 100%. We conclude that there is no major leukemogenic risk associated with electric blanket use in Los Angeles County.

Adult↗
PubMed1987

Thyroid cancer among young women related to prior thyroid disease and pregnancy history.

We conducted an epidemiologic case-control study of thyroid cancer in women aged 40 and under to test the hypothesis that endogenous hormones may relate to the development of this disease, since the only known cause of thyroid cancer, ionizing radiation, does not account for the striking female over male excess. When compared to neighbour controls women with thyroid cancer more often had a history of benign hyperplastic thyroid disease (Relative Risk (RR) = 14.5; P less than 0.01) and more often had ever been pregnant (RR = 2.1; P = 0.04). Both these findings were consistent with findings of previous studies. After eliminating women with a history of hyperplastic thyroid disease from the analysis we found a strong association with miscarriage as the outcome of the first pregnancy (RR = 11.5; P less than 0.01), and we suspect that this factor may be another indicator of thyroid abnormality. An independent and increasing risk was observed with an increase in the total number of pregnancies after excluding women with prior thyroid disease and those whose first pregnancy ended in a miscarriage. The RR for 4 or more pregnancies was 6.3 (P = 0.03). Prior exposure to radiation therapy was not an important factor in our study of young women; this suggests that the emphasis in future studies of thyroid cancer must shift to study other types of risk factors.

Abortion, Spontaneous↗
PubMed1987

A case-control study of osteosarcoma in young persons.

A study of 64 cases and 124 friend and neighbor controls was conducted to identify factors associated with the occurrence of osteosarcoma in young persons. Two types of information were collected: questionnaire data from telephone interviews with mothers, and data on height since birth from family, physician, and school records. Cases were not taller at the time of diagnosis than controls, nor were growth rates higher--either overall or during the 3-4 years prior to diagnosis. An excess risk, however, was observed among subjects whose birth length was at or below the 25th percentile, based on national standards. An excess risk was also found among subjects born more than one week early, but the positive association with short birth length remained when duration of pregnancy was taken into account. Positive associations were also found for prior trauma to the tumor site; congenital skeletal defects or other treated bone conditions; fetal x-ray; and maternal employment during pregnancy in manufacturing industries.

Adolescent↗
PubMed1987

Childhood leukemia and parents' occupational and home exposures.

A case-control study of children of ages 10 years and under in Los Angeles County was conducted to investigate the causes of leukemia. The mothers and fathers of acute leukemia cases and their individually matched controls were interviewed regarding specific occupational and home exposures as well as other potential risk factors associated with leukemia. Analysis of the information from the 123 matched pairs showed an increased risk of leukemia for children whose fathers had occupational exposure after the birth of the child to chlorinated solvents [odds ratio (OR) = 3.5, P = .01], spray paint (OR = 2.0, P = .02), dyes or pigments (OR = 4.5, P = .03), methyl ethyl ketone (CAS: 78-93-3; OR = 3.0, P = .05), and cutting oil (OR = 1.7, P = .05) or whose fathers were exposed during the mother's pregnancy with the child to spray paint (OR = 2.2, P = .03). For all of these, the risk associated with frequent use was greater than for infrequent use. There was an increased risk of leukemia for the child if the father worked in industries manufacturing transportation equipment (mostly aircraft) (OR = 2.5, P = .03) or machinery (OR = 3.0, P = .02). An increased risk was found for children whose parents used pesticides in the home (OR = 3.8, P = .004) or garden (OR = 6.5, P = .007) or who burned incense in the home (OR = 2.7, P = .007). The risk was greater for frequent use. Risk of leukemia was related to mothers' employment in personal service industries (OR = 2.7, P = .04) but not to specified occupational exposures. Risk related to fathers' exposure to chlorinated solvents, employment in the transportation equipment-manufacturing industry, and parents' exposure to household or garden pesticides and incense remains statistically significant after adjusting for the other significant findings.

Acute Disease↗
PubMed1987

N-nitroso compounds as a cause of human cancer.

Simultaneous consideration of epidemiological and experimental findings leads to the conclusion that the tobacco-specific nitrosamines (TSNA) 4-(N-nitrosomethylamino)-1-(3-pyridyl)-1-butanone (NNK) and N'-nitrosonornicotine (NNN) probably cause oral and respiratory cancers in humans. The role of other N-nitroso compounds (NOC) in the etiology of human cancer may best be defined by the study of known human carcinogens, such as certain foods eaten exclusively by populations with exceptionally high incidences and mortality rates for certain cancers. The evidence that NOC may be responsible for these elevated rates is reviewed in relation to two such high-risk populations: (i) residents of Lin-xian county in northern China, who have a striking excess of cancer of the oesophagus, and (ii) Cantonese people who have high rates of nasopharyngeal carcinoma (NPC). More studies are needed to define clearly the relationship between various types of cancers and prenatal or lifetime exposures to passive smoking. If passive smoking is found to increase the risk of developing various childhood and adult cancers, the NOC in tobacco are likely to be among the relevant carcinogens. Carcinogenesis models for studying the effects of prenatal exposure to NNK and NNN and other NOC seem particularly promising for the study of low-dose effects and modifying factors.

Adult↗