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ABSTRACT: Abstract
Background
Some studies have indicated that reproductive factors affect the risk of histological types of breast cancer differently. The long-term protective effect of a childbirth is preceded by a short-term adverse effect. Few studies have examined whether tumors diagnosed shortly after birth have specific histological characteristics.
Methods
In the present register-based study, comprising information for 22,867 Norwegian breast cancer cases (20-74 years), we examined whether histological type (9 categories) and grade of tumor (2 combined categories) differed by parity or age at first birth. Associations with time since birth were evaluated among 9709 women diagnosed before age 50 years. Chi-square tests were applied for comparing proportions, whereas odds ratios (each histological type vs. ductal, or grade 3-4 vs. grade 1-2) were estimated in polytomous and binary logistic regression analyses.
Results
Ductal tumors, the most common histological type, accounted for 81.4% of all cases, followed by lobular tumors (6.3%) and unspecified carcinomas (5.5%). Other subtypes accounted for 0.4%-1.5% of the cases each. For all histological types, the proportions differed significantly by age at diagnoses. The proportion of mucinous and tubular tumors decreased with increasing parity, whereas Paget disease and medullary tumors were most common in women of high parity. An increasing trend with increasing age at first birth was most pronounced for lobular tumors and unspecified carcinomas; an association in the opposite direction was seen in relation to medullary and tubular tumors. In age-adjusted analyses, only the proportions of unspecified carcinomas and lobular tumors decreased significantly with increasing time since first and last birth. However, ductal tumors, and malignant sarcomas, mainly phyllodes tumors, seemed to occur at higher frequency in women diagnosed <2 years after first childbirth. The proportions of medullary tumors and Paget disease were particularly high among women diagnosed 2-5 years after last birth. The high proportion of poorly differentiated tumors in women with a recent childbirth was partly explained by young age.
Conclusion
Our results support previous observations that reproductive factors affect the risk of histological types of breast cancer differently. Sarcomas, medullary tumors, and possible also Paget disease, may be particularly susceptible to pregnancy-related exposure.
BMC Cancer. 01/2010;
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ABSTRACT: Some studies have indicated that reproductive factors affect the risk of histological types of breast cancer differently. The long-term protective effect of a childbirth is preceded by a short-term adverse effect. Few studies have examined whether tumors diagnosed shortly after birth have specific histological characteristics.
In the present register-based study, comprising information for 22,867 Norwegian breast cancer cases (20-74 years), we examined whether histological type (9 categories) and grade of tumor (2 combined categories) differed by parity or age at first birth. Associations with time since birth were evaluated among 9709 women diagnosed before age 50 years. Chi-square tests were applied for comparing proportions, whereas odds ratios (each histological type vs. ductal, or grade 3-4 vs. grade 1-2) were estimated in polytomous and binary logistic regression analyses.
Ductal tumors, the most common histological type, accounted for 81.4% of all cases, followed by lobular tumors (6.3%) and unspecified carcinomas (5.5%). Other subtypes accounted for 0.4%-1.5% of the cases each. For all histological types, the proportions differed significantly by age at diagnoses. The proportion of mucinous and tubular tumors decreased with increasing parity, whereas Paget disease and medullary tumors were most common in women of high parity. An increasing trend with increasing age at first birth was most pronounced for lobular tumors and unspecified carcinomas; an association in the opposite direction was seen in relation to medullary and tubular tumors. In age-adjusted analyses, only the proportions of unspecified carcinomas and lobular tumors decreased significantly with increasing time since first and last birth. However, ductal tumors, and malignant sarcomas, mainly phyllodes tumors, seemed to occur at higher frequency in women diagnosed <2 years after first childbirth. The proportions of medullary tumors and Paget disease were particularly high among women diagnosed 2-5 years after last birth. The high proportion of poorly differentiated tumors in women with a recent childbirth was partly explained by young age.
Our results support previous observations that reproductive factors affect the risk of histological types of breast cancer differently. Sarcomas, medullary tumors, and possible also Paget disease, may be particularly susceptible to pregnancy-related exposure.
BMC Cancer 01/2010; 10:226. · 3.01 Impact Factor
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ABSTRACT: Nulliparity has been found to negatively affect prognosis among endometrial cancer patients. Few previous studies have examined the prognostic impact of parity in patients with uterine sarcomas.
In the present nationwide, register-based study in Norway, we explore whether parity influences survival among 493 women diagnosed with malignant uterine sarcomas. Hazard ratios for total mortality were calculated in Cox proportional hazard regression analyses.
The 5-year Kaplan-Meier survival rates for the 126 endometrial stromal sarcoma (ESS) patients, 249 leiomyosarcoma (LS) patients, and 118 carcinosarcoma (CS) patients were 74%, 68%, and 55%, respectively, but varied considerably by age at diagnosis and clinical stage. In the univariate analyses, nulliparous women had poorer prognosis than parous women among CS patients (P = 0.071, log-rank test) and ESS patients (P = 0.15). In analyses adjusted for clinical stage and age at diagnosis, nulliparity was associated with a worse outcome in ESS patients only (hazard ratio, 0.50; 95% confidence interval, 0.22-1.12; parous vs nulliparous women); a trend with increasing number of births was also observed, of borderline significance (P = 0.058). No independent prognostic impact of parity was found in LS or CS patients. However, a considerably higher proportion of nulliparous than parous CS patients was diagnosed with advanced-stage disease (P = 0.003).
Nulliparity seems to be associated with poorer prognosis in ESS patients; no independent prognostic impact of parity was seen among LS or CS patients. Further knowledge on underlying biological mechanisms may be valuable for improved treatment.
International Journal of Gynecological Cancer 08/2009; 19(6):1062-7. · 1.65 Impact Factor
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Spine 08/2009; 34(15):1625-6; author reply 1626. · 2.08 Impact Factor
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ABSTRACT: Parity and time interval since last birth have been found to be associated with the risk of endometrial cancer, but few previous studies have examined whether these reproductive factors have prognostic impact. We examined this issue among 740 nulliparous and 3355 parous endometrial cancer patients diagnosed in Norway during the period 1961-1999. The mean age at diagnosis was 55.7 years (range, 25-74 years). Hazard ratios (HRs) with 95% confidence intervals were calculated in Cox proportional regression models. Parous women had significantly (P < 0.001) better prognosis than nulliparous women. In analyses adjusted for age at diagnosis, clinical stage, and histological type, the HR for parous versus nulliparous women was 0.68 (95% confidence interval, 0.57-0.82). The prognostic impact of parity was restricted to patients with endometrioid tumors (P = 0.014, test for interaction) and appeared to be most pronounced in women without metastases (P = 0.14, test for interaction). Moreover, the improved prognosis was strongest for women with the shortest time interval since last childbirth. The HRs (nulliparous women as reference) were 0.51, 0.60, and 0.80 for women less than 15, 15 to 24, and 25 years or more since birth (P < 0.001). The observed beneficial effect of pregnancies may be related to a strong exposure to progesterone during pregnancy. However, it is possible that tumors developing in nulliparous and parous women have different biological features. Further knowledge on this issue may provide valuable information that can be used for individualized treatment.
International Journal of Gynecological Cancer 05/2009; 19(4):665-9. · 1.65 Impact Factor
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ABSTRACT: To explore whether twin births and sex of children influenced maternal risk of endometrial cancer, possibly with effect modification by age.
Population-based prospective study.
A total of 1,094,017 parous Norwegian women aged 30-74 years, including 3,356 endometrial cancer cases. Among the 27,158 mothers of twins, 101 cases occurred.
Incidence rate ratios (IRR) with 95% confidence intervals (CI) were calculated in Poisson regression analyses of person-years at risk.
Women ever having experienced a twin birth had an overall higher risk of endometrial cancer than women with singleton births only (IRR=1.26, 95% CI=1.03-1.53). Women with twin boys appeared to be the main contributor to the overall elevated risk (IRR=1.57, 95% CI=1.15-2.14). The risk estimates for women with twin girls or sex-nonconcordant twins were close to unity (IRR of 1.09 and 1.12, respectively). However, age-specific analyses revealed an elevated risk also in women with twin girls, but only before age 55 years (IRR=1.92, 95% CI=1.27-2.89); a lower risk was seen at older ages (IRR=0.41, 95% CI=0.19-0.92). The risk estimates for twin boys and sex-nonconcordant twins were consistently observed across age groups. The effect modification by age was statistically significant (p=0.0024). No association was found with sex of children in singleton mothers.
Mothers of twin boys had a significantly higher risk of endometrial cancer than women with singleton births only, whereas women with twin girls had an elevated risk before age 55 years. No significant association was seen with sex-noncordant twins, neither overall nor within age groups.
Acta Obstetricia Et Gynecologica Scandinavica 11/2008; 87(11):1123-8. · 1.77 Impact Factor
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ABSTRACT: In this study we examined whether results from a clinical test of passive mobility of soft tissue structures in the upper cervical spine, corresponded with signs of physical injuries, as judged by magnetic resonance imaging (MRI). Results were based on examinations of 122 study participants, 92 with and 30 without a diagnosis of whiplash-associated disorder, type 2. The structures considered were the alar and the transverse ligaments, and the tectorial and the posterior atlanto-occipital membranes. Ordinary and weighted kappa coefficients were used as a measure of agreement, whereas McNemar's test was used for evaluating differences in rating. The clinical classification and the MRI examination both comprised four response categories (grades 0-3), with 0 representing a normal structure, and 3 indicating a structure with pronounced abnormality. In our sample, an abnormal clinical test reflected a hyper- rather than hypo-mobility. Considering all four-response categories, the kappa coefficient indicated moderate agreement (range 0.45-0.60) between the clinical and the MRI classification. The results for the membranes appeared somewhat better than for the ligaments. When there was disagreement, the classifications obtained by the clinical test were significantly lower than the MRI grading, but mainly within one grade difference. When combining grade 0-1 (normal) and 2-3 (abnormal), the agreement improved considerably (range 0.70-0.90). Although results from the clinical test seem to be slightly more conservative than the MRI assessment, we believe that a clinical test can serve as valuable clinical tool in the assessment of WAD patients. However, further validity- and reliability studies are needed.
Manual therapy 11/2007; 13(5):397-403. · 2.32 Impact Factor
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ABSTRACT: In the present study, we examined whether active range of neck motion (AROM) differed between persons with and without a diagnosis of whiplash-associated disorder type 2 (WAD2) and explored whether magnetic resonance (MR)-verified lesions of specific ligaments or membranes at the craniovertebral junction was associated with increased or decreased motion in any particular direction among the WAD2 patients. A CROM goniometer was used for registration of flexion, extension, side bending (left and right) and rotation (left and right), respectively. The neck structures considered were the alar and the transverse ligaments, and the tectorial and the posterior atlanto-occipital membranes. Our study comprised 87 WAD2 patients and 29 control persons without any known neck injury. For comparing mean values of AROM between the groups, t-test and analysis of variance (ANOVA) were used. WAD patients had on average a shorter range of active motion for all movements compared with the control group. The difference was statistically significant for all measures considered, except side bending to the left. Among the WAD patients, increasing severity of lesions to the alar ligaments was associated with a decrease in maximal flexion and rotation. A similar pattern was seen for lesions to the transverse ligament, but the trend test was not significant. An abnormal posterior atlanto-occipital membrane was associated with shorter range of left rotation, with a significant trend test both in analyses with and without adjustment for lesions to other structures. No significant association was found in relation to lesions to the tectorial membrane, but very few persons had such lesions. These findings indicate that soft tissue lesions may affect neck motion as reflected by AROM. However, since lesions to different structures seem to affect the same movement, AROM alone is not a sufficient indicator for soft-tissue lesions to specific structure in the upper cervical spine.
Journal of Neurotrauma 05/2007; 24(4):713-21. · 3.65 Impact Factor
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ABSTRACT: The long-term protective effect of a pregnancy on breast cancer risk is preceded by a short-term adverse effect, possibly reflecting a promoting effect of pregnancy hormones. In the present study, we explore whether a family history of breast cancer modifies time-related effects of pregnancies, with special emphasis on the transient increase in risk of breast cancer shortly after birth. Our study cohort comprises 1,067,289 Norwegian women aged 20-74 years. The mean follow-up time was 18 years. Incidence rate ratios were estimated by Poisson regression analyses of person-years at risk. Of the 7,377 women diagnosed with breast cancer during follow-up, a total of 828 (11%) had a mother or a sister with breast cancer diagnosis. Women with a family history of breast cancer had a 2-3-fold higher risk of breast cancer than did women without any affected family member, highest for those with a relative diagnosed before they were 50 years. Similar to women without a familial excess risk, increasing parity was associated with an overall protective effect among women with a familial predisposition, regardless of age at diagnosis of the relative. Whereas women with no familial excess risk experienced a transient increase in risk mainly after late age births, women with a family history of breast cancer experienced an adverse effect of pregnancies also at younger ages. The present results give further support to the hypothesis that the adverse effect of a term birth can be explained by a promoting effect of pregnancy hormones.
International Journal of Cancer 10/2006; 119(6):1468-74. · 5.44 Impact Factor
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ABSTRACT: Breast cancer diagnosed during pregnancy or 1 to 2 years after birth often occurs at a late stage. Little is known about tumor characteristics in the high-risk period shortly after a childbirth. We here explore whether stage of disease differs according to timing of births. Results are based on 22,351 Norwegian breast cancer patients of parity 0 to 5, ages 20 to 74 years. The proportion of stage II to IV tumors was considerably higher among parous than nulliparous women at age <30 years (52.7% versus 36.8%, P=0.009), but similar or lower in other age groups (P(interaction)=0.029). In general, the largest proportion of stage II to IV tumors was found among women diagnosed during pregnancy or <2 years after birth. However, among women with late-age births (first or second birth >or=30 years, third birth >or=35 years), as well as women with an early second birth (<25 years), the proportion with advanced disease was rather similar or even higher among those diagnosed 2 to 6 years after birth (49.3-56.0%). The association between clinical stage and time since birth reached statistical significance among women with a late first or second birth and among all triparous women (P <or= 0.032). The subgroups with a high proportion of advanced disease 2 to 6 years after birth corresponded quite well to those previously found to have the most pronounced transient increase in risk after birth. Thus, pregnancy hormones may have a progressive effect on breast cancer tumors in addition to a possible promoting effect. A potential effect of prolactin is discussed.
Cancer Epidemiology Biomarkers & Prevention 01/2006; 15(1):65-9. · 4.12 Impact Factor
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ABSTRACT: In the present study, we compared magnetic resonance imaging (MRI) findings of soft tissue structures in the upper cervical spine between whiplash-associated disorder (WAD) patients and population-based control persons, and examined whether MRI-verified abnormalities in WAD patients were related to accident-related factors hypothesized to be of importance for severity of injury. A total of 92 whiplash patients and 30 control persons, randomly drawn, were included. Information on the accident-related factors (i.e., head position and impact direction) was obtained by a questionnaire that was answered within 1 week after the accident. The MRI examination was performed 2-9 (mean 6) years after the accident. Focus was on MRI abnormalities of the alar and the transverse ligaments, and the tectorial and posterior atlanto-occipital membranes, graded 0-3. For all neck structures, the whiplash patients had more high-grade lesions (grade 2 or 3) than the control persons (Chi-square test, p < 0.055). An abnormal alar ligament was most common (66.3% graded 2 or 3). Whiplash patients who had been sitting with their head/neck turned to one side at the moment of collision more often had high-grade lesions of the alar and transverse ligaments (p < 0.001, p = 0.040, respectively). Severe injuries to the transverse ligament and the posterior atlanto-occipital membrane were more common in front than in rear end collisions (p < 0.001, p = 0.001, respectively). In conclusion, the difference in MRI-verified lesions between WAD patients and control persons, and in particular the association with head position and impact direction at time of accident, indicate that these lesions are caused by the whiplash trauma.
Journal of Neurotrauma 11/2005; 22(11):1294-302. · 3.65 Impact Factor
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ABSTRACT: The aim of this study was to explore whether reported pain and functional disability in whiplash-associated disorders (WAD) patients is associated with lesions to specific soft tissue structures in the upper cervical spine, as assessed by MRI. Pre-selected structures for MRI assessment included the alar ligaments, the transverse ligament, the tectorial and the posterior atlanto-occipital membranes. The questionnaire employed was a modification of the Oswestry Low Back Pain Index. It was comprised of ten single items related to pain and activity of daily living. Ninety-two whiplash patients and 30 control persons, randomly drawn, were included. WAD patients reported significantly more pain and functional disability than the controls, both for total score and each of the ten single items. In the WAD patients, MRI lesions to the alar ligaments showed the most consistent association to the reported pain and disability. Lesions to other structures often occurred in combination with lesions to the alar ligaments. Lesions to the transverse ligament and to the posterior atlanto-occipital membrane also appeared to be related to the NDI score, although the association was weaker than for the alar ligament. The disability score increased with increasing number of abnormal (grade 2-3) structures. These results indicate that symptoms and complaints among WAD patients can be linked with structural abnormalities in ligaments and membranes in the upper cervical spine, in particular the alar ligaments.
Journal of Neurotrauma 05/2005; 22(4):466-75. · 3.65 Impact Factor
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ABSTRACT: The effects of highly active antiretroviral therapy (HAART) on immunoglobulin isotypes and immunoglobulin G (IgG) subclasses were studied in 12 patients in early stages of HIV-1 infection. Blood samples were obtained at enrollment and 2, 4, 8, 12, 24, 48, and 120 weeks after initiation of HAART. Immunoglobulin concentrations were determined by nephelometry, and anti-p24-specific IgG and IgG1 levels were determined by an enzyme immunoassay. Overall time changes were analyzed in analysis of variance models. IgG and IgG1 levels showed a marked overall decline, whereas other immunoglobulin isotypes and IgG subclasses did not change significantly. Anti-p24-specific IgG1 levels decreased considerably and significantly more in virus isolation-negative patients than in virus isolation-positive patients, as defined according to the ability to isolate HIV-1 from their CD4+ T cells after initiation of therapy. Anti-p24 IgG levels showed a similar but overall weaker decline in the two groups. However, the anti-p24 IgG1 level followed the biphasic decline in plasma viremia more closely than the anti-p24 IgG level, with an initial sharp decline that leveled off with time. These findings suggest that the main reduction in immunoglobulin levels is caused by reduced HIV-1-specific antigen stimulation rather than a general reduction in immune activation. Using anti-p24 IgG1 as a parameter of response to the effect of HAART merits further investigation.
JAIDS Journal of Acquired Immune Deficiency Syndromes 01/2004; 34(4):358-67. · 4.43 Impact Factor
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ABSTRACT: The concept of health contains aspects of social and mental well-being and not just the absence of disease. The concept of well-being is sometimes used interchangeably with the term happiness, although focus has been on other aspects as well. Here we explore associations between happiness and experience of stress at school, personal and social factors among 887 Norwegian school adolescents participating in a World Health Organization project on health-promoting schools. Happiness was measured by a one item question (ordered responses 1-4). The psychosocial factors were represented by an average score of 3-12 items. Odds ratios of feeling very/quite happy were calculated in multiple logistic regression analyses. An increasing degree of stress experience reduced the feeling of happiness significantly. Furthermore, increasing levels of general self-efficacy increased the odds of feeling happy, whereas the more specific measure of school self-efficacy showed no independent effect. Social support from teachers also enhanced happiness significantly. A less consistent pattern was found for support from peers, but the most happy pupils experienced significantly more support than pupils who reported being unhappy. No significant trend was found with decision control. We also explored associations between happiness and psychosomatic symptoms. Pupils feeling unhappy reported a particular symptom more often and they also had the highest mean number of reported symptoms. To evaluate whether these health indicators represent different dimensions of health, a comparison of strength of associations with common risk factors is made. Implications for health promotion practice are discussed.
International Journal of Nursing Practice 07/2003; 9(3):166-75. · 0.72 Impact Factor
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ABSTRACT: Associations between bullying behavior and school-related stress experience, self-efficacy, social support, and decision control were explored in a study of 885 Norwegian adolescents aged 13–15 years. Information was based on self-reports. The psychosocial factors were represented by an average of scores on 3–12 single items, each with 5 possible response categories. Bullying behavior was defined as bullying other pupils sometimes or more often during the term. The prevalence of bullying behavior was 9.2%, but significantly higher among boys than girls. Odds ratios of bullying behavior according to psychosocial factors were calculated in a multiple logistic regression analysis. Increasing school alienation was associated with an increased risk of bullying, whereas increasing support from teachers and peers decreased the risk. Increasing self-efficacy was associated with a significant increase in risk only among 14-year-old pupils, but a similar tendency was seen for 15-year-old pupils. No significant association was seen with decision control.
Journal of Youth and Adolescence 09/2001; 30(5):561-575. · 2.72 Impact Factor
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Epidemiology 06/1995; 6(4):465. · 5.57 Impact Factor
