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Biomedical subjects

I Heuch

Publications and source records attributed to I Heuch.

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

Reproductive factors and risk of ovarian cancer: a prospective study.

Associations between reproductive factors and risk of ovarian cancer were examined in a prospective study of 60,565 women in Norway. A total of 445 women were diagnosed as having ovarian cancer during follow-up, from 1961 through 1980. The highest risk was observed among nulliparous women, and the risk decreased significantly with increasing parity. The estimated odds ratio for women with 5 or more births compared with one birth was 0.46, after adjustment for age, urban/rural place of residence and occupational class. Neither age at first or last birth, nor age at menarche or menopause, nor marital status, showed significant associations with ovarian cancer risk after adjustment for parity. The apparent protective effect of high parity was observed for epithelial as well as non-epithelial cancers, and for the separate histological types of epithelial cancer except mucinous cystadenocarcinomas.

Age Factors↗
PubMed1988

Reproductive factors and risk of cervical cancer by cell type. A prospective study.

Relationships between reproductive variables and risk of cervical cancer were examined in a follow-up of 62,079 women in Norway from 1961 through 1980. For the 342 cases classified as squamous cell carcinomas, a higher risk was observed in ever married than in never married women. The risk was especially high among women married more than once and women who were widowed or divorced before start of follow-up. High age at first birth was associated with low risk. The estimated odds ratio for women with first birth at age 35 years or later versus 19 years or earlier was 0.18 (P less than 0.001) in analyses with adjustment for age, urban-rural place of residence and parity. In analyses with adjustment for age at first birth, neither parity or age at first marriage, nor age at menarche or menopause showed significant associations with squamous cell carcinoma. For the 30 cases classified as adenocarcinomas, no significant associations emerged with reproductive factors. The effects of marital status as well as age at first birth differed significantly between adenocarcinomas and squamous cell carcinomas, suggesting dissimilar aetiologies. Although associations between reproductive factors and squamous cell carcinoma may largely be secondary to relationships with sexual habits, there are indications that the association with age at first birth cannot be entirely explained in this way.

Adenocarcinoma↗
PubMed1988

Lactation and cancer risk: is there a relation specific to breast cancer?

Relations between previous lactation experience and risks of cancer of the breast and other sites were investigated after follow-up of 50,274 parous women from 1961 through 1980. Among women with complete information on lactation, 5102 developed cancer and, of these, 1136 were diagnosed with breast cancer. Analyses of associations with mean duration of lactation per birth and duration for each of the three first births suggested a nonlinear relation to breast cancer. The highest risk was observed for those with intermediate duration of breast feeding, whereas lower risks were found among those with very short or very long duration. For all nongenital cancers combined, decreased risks were observed among those with the longest duration of breast feeding. However, among cancers of specific sites, a significant inverse association was found for pancreatic cancer only. The overall impression given by our data is that breast feeding is not strongly related to risks of breast cancer or any other common cancer.

Breast Feeding↗
PubMed1988

Metastatic patterns in autopsy cases of cutaneous melanoma.

Metastases from 62 skin melanomas occurred in specific organ combinations. CNS involvement was associated with lack of local cutaneous or lymphogenous spread and absence of metastases in lungs, liver and bones. Two predominant patient clusters were observed, one visceral with wide dissemination, and one CNS cluster with cerebral spread but few other metastases. Survival tended to be longer in the CNS cluster, and also depended on age, clinical stage, histologic type and final number of metastases per patient in the total material. It is concluded that dissemination occurs in certain specific patterns with different biological behavior.

Adult↗
PubMed1987

A prospective study of reproductive factors and breast cancer. I. Parity.

The relation between childbearing and breast cancer risk was investigated in a prospective study of 63,090 Norwegian women, among whom 1,565 breast cancer cases occurred in a follow-up from 1961 through 1980. The authors observed a strong and highly significant inverse association between the number of full-term pregnancies and the risk of breast cancer. The association was consistently found in all subgroups according to demographic variables and was obtained for all histologic subtypes except for cases classified as Paget's disease. The relation with parity could not be explained by confounding with age at first birth or other reproductive factors. The apparent protective effect of high parity was strongest in the groups with an early first birth, and no such effect could be established among women with their first birth at age 35 or later. The protective effect of multiparity was observed for cancers in all age groups. Uniparous women had, however, higher risk of developing breast cancer under age 60 than nulliparous women. Those who reported at least one abortion had somewhat lower risk than those who did not, but no trend according to the number of abortions was observed.

Abortion, Spontaneous↗
PubMed1987

A prospective study of reproductive factors and breast cancer. II. Age at first and last birth.

The relations between age at first and last full-term pregnancy and breast cancer risk were investigated after 20 years of follow-up of 63,090 Norwegian women, among whom 1,565 breast cancer cases occurred. An association seen in preliminary analyses between early age at first birth and low risk of breast cancer was removed after adjustment for parity and age at last birth. Age at last birth showed initially no association with breast cancer. After adjustment for parity, however, a significant positive association emerged. The authors' observations suggest that the relation between age when a pregnancy occurs and breast cancer risk may be more complex than previously believed. Despite the overall association between increasing parity and lower risk, the women with many late pregnancies and those with few, widely spaced pregnancies had higher risk than nulliparous women, indicating that both the age when pregnancy occurs and the length of intervals between successive births may modify the protective effect. The findings are consistent with a dual effect of a pregnancy, causing a transient increase followed by a subsequent strong and long-lasting decrease in risk of breast cancer.

Adult↗
PubMed1986

Occupational exposure and lung cancer risk.

The importance of occupation held longest as a risk factor for lung cancer was examined in a prospective study in Norway of 11,995 men, among whom 125 cases occurred in a follow-up from 1966 through 1978. Based on information about occupation held longest, the respondents were classified into 3 groups according to suspected exposure to respiratory carcinogens at the workplace. After stratification for age, place of residence and cigarette smoking, we found a highly significant relative risk of 2.6 for those judged to have experienced definite exposure versus the group with no workplace exposure. The apparent risk-enhancing effect of occupational exposure was observed for all histologic subtypes. Stratification including a socioeconomic factor score led to a moderate reduction in the relative risk estimate. High risk estimates still obtained, however, for a limited number of occupations, the highest for workers in the mining and quarrying industries. Although the interpretation of the observed effect associated with a crude index of occupational exposure may be difficult, our results suggest that between 13 and 27% of the lung cancer cases observed among Norwegian men in the relevant time period can be attributed to harmful work-place exposure.

Adult↗
PubMed1986

Glioblastoma multiforme in three family members, including a case of true multicentricity.

Three cases of glioblastoma multiforme are described, occurring in two brothers and the sister of their father. One of the cases was found at autopsy to represent true multicentric glioblastoma, with five widely separated lesions affecting both hemispheres. It is postulated that there may be an association between factors responsible for multiple foci of transformation and a familial tendency to develop glioma.

Aged↗
PubMed1986

Coffee drinking, mortality, and cancer incidence: results from a Norwegian prospective study.

Relationships between coffee consumption and occurrence of cancer as well as mortality were explored in a Norwegian study of 13,664 men and 2,891 women who in 1967-69 reported their coffee consumption. No statistically significant positive associations were found between coffee consumption and disease. A weak negative association was found with total cancer incidence even when the first 4 of the 11 1/2 years of follow-up were excluded, and strong negative associations with coffee drinking were noted for cancer of the kidney and nonmelanoma skin cancer. For cancer of the pancreas and bladder, no increase in incidence was found among those with a high coffee consumption. In subjects less than 65 years of age at start of follow-up, coffee drinking showed a significant inverse association with colon cancer.

Adult↗
PubMed1985

The Collaborative Lipid Research Clinics Family Study: biological and cultural determinants of familial resemblance for plasma lipids and lipoproteins.

This paper reports on the biological and cultural determinants of total, LDL, and HDL cholesterol, and triglyceride (TC, LDL-C, HDL-C, TG) levels using a general linear model on randomly selected family data collected during 1975-1978 at nine North American Lipid Research Clinics. Initially, the analyses were clinic-specific to assess the importance of genetic and cultural transmission, marital resemblance, and other determinants of these traits and then were made jointly to identify the nature and sources of any heterogeneity between clinics. There was evidence of significant genetic and cultural factors for all traits in most clinics. Clinic heterogeneity was also significant, but excluding one clinic reduced the heterogeneity considerably. The genetic (h2) and cultural (c2) heritabilities for the remaining eight clinics were homogeneous with pooled estimates of h2 of .556 +/- .028, .539 +/- .028, .485 +/- .029, and .358 +/- .028, and of c2 of .029 +/- .006, .033 +/- .006, .075 +/- .008, and .089 +/- .009 for TC, LDL-C, HDL-C, and TG, respectively. Among the traits, HDL-C exhibited the most difference among clinics, and both HDL-C and TG showed the largest cultural heritability. The relevance of these and similar studies in a broader understanding of the determinants of plasma lipids and lipoproteins is discussed.

Cholesterol↗
PubMed1985

A multivariate analysis of familial associations of lipoprotein levels in the Lipid Research Clinics Collaborative Family Study: I. Familial correlation and regression analyses.

In view of the complex, intraindividual relationships among different lipoprotein levels (LDL-C, HDL-C, and VLDL-C), multivariate methods aimed at assessing joint familial associations and their possible determinants were performed in the white, random sample component of the Collaborative Lipid Research Clinics Family Study data (1,336 families with 5,097 subjects). After appropriate transformations and covariate adjustments of the data, several kinds of correlation and regression analyses were performed, taking into consideration variable family size and possible age and clinic differences. The association patterns across clinics and age strata were found to be homogeneous for the vast majority of comparisons. The results of multivariate analyses (especially the significant association of each lipoprotein among biological relatives), the persistence of parental levels as the best predictors for the same lipoprotein levels among the offspring, and the essentially unchanged partial correlation estimates as compared to ordinary correlations suggest strong influence of factors specific to each lipoprotein in the familial associations. But the highly significant intraindividual correlations and the nonnegligible cross-correlations among relatives also suggest the additional presence of common underlying factors for the familial associations, especially between HDL-C and VLDL-C and to a lesser extent between LDL-C and VLDL-C. The issues stemming from these analyses and the directions for further analyses are discussed.

Cholesterol↗
PubMed1983

Use of alcohol, tobacco and coffee, and risk of pancreatic cancer.

Associations between pancreatic cancer and use of alcohol, tobacco and coffee were examined in a Norwegian prospective study of 16,713 individuals in which 63 cases occurred. The associations were assessed using techniques for stratified logistic regression. Of the potential risk factors considered, use of alcohol showed the strongest positive association, with an estimated relative risk of 5.4 for those with a frequent use as compared with non-drinkers (P less than 0.001). A clear positive association was also obtained with chewing of tobacco or use of snuff. For cigarette smoking a somewhat weaker association was observed. No association could be established for pipe smoking or coffee drinking. In general, more clear-cut results were found when analysis was restricted to histologically-verified cases.

Aged↗
PubMed1977

An explicit formula for frequency changes in genetic algebras.

A general situation in population genetics is considered with any hereditary system described by a genetic algebra. It is assumed that there is random mating, no selection, and infinite population size. A formula is derived for the distribution of genetic types in the general jth generation given the distribution in the initial generation. Special attention is paid to the case of one locus with polyploidy and chromosome segregation. The calculations are carried out as far as possible in the situation with triploid gametes.

Gene Frequency↗