Concurrent overexpression of p53 and c-erbB-2 correlates with accelerated cycling and concomitant poor prognosis in node-negative breast cancer

Simultaneous overexpression of c-erbB-2 and p53 has been reported to be prognostically unfavorable in breast cancer. Herein, we show that concurrent overexpression of these 2 proteins is associated with a marked reduction in the relative fraction of cells in G(1) phase of the cell cycle, indicating an accelerated cell cycle progression. Using an immunohistochemical approach, we examined 261 cases of node-negative infiltrating ductal carcinomas of the breast with respect to c-erbB-2 and p53 expression and to the proliferative activity measured by the Ki-67 index. By means of a novel monoclonal antibody, Ki-S2, which exclusively recognizes proliferating cells in the S, G(2), and M phases of the reproductive cycle, we were further able to calculate the relative fraction of the cells having passed the restriction point at the G(1)/S boundary, thus defining a cycling ratio (CR). The results were correlated with clinical outcome; median follow-up time was 96 months. Tumors that simultaneously overexpressed c-erbB-2 and p53 had a high median CR and followed an unfavorable course. However, increased CRs were also observed independently of c-erbB-2 and p53 overexpression, suggesting that other molecular mechanisms may contribute to acceleration of cell cycle progression. In a multivariate analysis that included patient age, tumor size, hormone receptor status, c-erbB-2 and p53 expression, and the Ki-67 index, CR emerged as the most significant independent predictor of overall and disease-free survival (P <.0001). It is concluded that the CR is a gauge of cell cycle deregulation and therefore may be a powerful indicator of the biologic behavior of cancers. HUM PATHOL 32:311-319.

Gene-expression profiles in hereditary breast cancer

BACKGROUND

Many cases of hereditary breast cancer are due to mutations in either the BRCA1 or the BRCA2 gene. The histopathological changes in these cancers are often characteristic of the mutant gene. We hypothesized that the genes expressed by these two types of tumors are also distinctive, perhaps allowing us to identify cases of hereditary breast cancer on the basis of gene-expression profiles.

METHODS

RNA from samples of primary tumor from seven carriers of the BRCA1 mutation, seven carriers of the BRCA2 mutation, and seven patients with sporadic cases of breast cancer was compared with a microarray of 6512 complementary DNA clones of 5361 genes. Statistical analyses were used to identify a set of genes that could distinguish the BRCA1 genotype from the BRCA2 genotype.

RESULTS

Permutation analysis of multivariate classification functions established that the gene-expression profiles of tumors with BRCA1 mutations, tumors with BRCA2 mutations, and sporadic tumors differed significantly from each other. An analysis of variance between the levels of gene expression and the genotype of the samples identified 176 genes that were differentially expressed in tumors with BRCA1 mutations and tumors with BRCA2 mutations. Given the known properties of some of the genes in this panel, our findings indicate that there are functional differences between breast tumors with BRCA1 mutations and those with BRCA2 mutations.

CONCLUSIONS

Significantly different groups of genes are expressed by breast cancers with BRCA1 mutations and breast cancers with BRCA2 mutations. Our results suggest that a heritable mutation influences the gene-expression profile of the cancer.

Assessing tablet bond types from structural features that affect tablet tensile strength

PURPOSE

The aim of this article was to study the possibility of assessing the structural features affecting tablet tensile strength to obtain information on the dominating bond types, i.e. interparticulate attractions, in tablets.

METHODS

The features of the internal tablet structure considered to be important for tablet tensile strength were assessed using a simple tablet model for tablets made from seven materials: potassium chloride, sodium chloride, sodium bicarbonate, lactose, sucrose, microcrystalline cellulose, and ascorbic acid.

RESULTS

Tablet porosity and particle size (measured as external specific surface area by permeametry) were the structural features that best correlated with tablet tensile strength. These features were described by a "structural factor," which was combined with tablet tensile strength, as an "interaction factor," to reflect the dominating bond types in tablets.

CONCLUSION

The qualitative results gave dominating bond types in the tablets studied that matched the results of earlier studies, thus supporting the applicability of the method.

SPET imaging of central muscarinic acetylcholine receptors with iodine-123 labelled E-IQNP and Z-IQNP

1-Azabicyclo[2.2.2]oct-3-yl alpha-hydroxy-alpha-(1-iodo-1-propen-3-yl)-alpha-phenylacetate (IQNP) is a muscarinic acetylcholine receptor (mAChR) antagonist and the racemic ligand contains eight stereoisomers. In a single-photon emission tomography (SPET) study in monkeys we recently confirmed that [123I]E-(R,R)-IQNP ([123I]E-IQNP) is a radioligand with modest selectivity for the M1 and M4 subtypes, whereas [123I]Z-(R,R)-IQNP ([123I]Z-IQNP) is non-subtype selective. In the present SPET study, E- and Z-IQNP were examined in human subjects. SPET examination was performed on three male subjects after i.v. injection of [123I]E-IQNP and in another three after i.v. injection of [123I]Z-IQNP. The binding potential (BP) for [123I]E-IQNP was calculated using several quantitative approaches with the cerebellum as a reference region. High-performance liquid chromatography was used to measure radioligand metabolism in plasma. Following [123I]E-IQNP, the radioactivity was high in the neocortex and striatum, intermediate in the thalamus and low in the pons and cerebellum, which is consistent with the rank order for the regional density of M1 and M4 subtypes in vitro. For all regions, peak equilibrium was identified within the 48-h data acquisition. The simplified reference tissue approach using SPET data from 0 to 48 h was the most reliable in this limited series of subjects. Following injection of [123I]Z-IQNP, radioactivity was high in the neocortex and striatum, intermediate in the thalamus and pons and low in the cerebellum, which is in agreement with the density of M1, M2 and M4 subtypes as measured in vitro. Quantitative analyses provided indirect support for specific M2 binding of Z-IQNP in the cerebellum. The high selectivity of [123I]E-IQNP for M1 and M4 receptors allowed the use of cerebellum as a reference region devoid of specific binding, and may be advantageous for applied clinical studies of M1 and M4 receptors binding in man. [123I]Z-IQNP has potential for exploration of M2 receptor binding in the cerebellum.

Familial breast and ovarian cancer: a Swedish population-based register study

A cohort of offspring of mothers with breast or ovarian cancer diagnosed in 1958-1993 was established using Swedish population-based registers. The children (n = 158,041) were born between 1941 and 1993, and their cancer incidence was followed between 1961 and 1993. A total of 3,257 tumors in 3,102 children were found. Observed numbers of cases were compared with expected numbers based on national calendar year-, age-, and sex-specific incidences. For daughters of women with breast cancer, the standardized morbidity ratios for being diagnosed with breast cancer and ovarian cancer before age 50 years were 1.99 (95% confidence interval (CI): 1.86, 2.14) and 1.28 (95% CI: 1.05, 1.54), respectively. The corresponding figures for daughters of women with ovarian cancer were 1.79 (95% CI: 1.55, 2.07) and 2.38 (95% CI: 1.77, 3.12). The risks were raised if the mother's cancer was diagnosed at a young age, the mother had multiple breast/ovarian diagnoses, or there was a sister with breast/ovarian cancer. Among all offspring, increased risks were found for thyroid cancer, testicular cancer, and malignant melanoma, while lung cancer risk was decreased if the mother had had breast cancer. The authors developed a variance estimator for the standardized morbidity ratio to cope with overdispersion due to dependency within families.

Tumour biology of a breast cancer at least partly reflects the biology of the tissue/epithelial cell of origin at the time of initiation - a hypothesis

A hypothesis is presented suggesting that initiation of breast epithelial cell freezes the cell at least partly according to the development/differention of cell at the time of initiation. Tumour biology will mimic the physiology of normal cell development at the time of initiation and this is preserved at least partly onwards. Also preferentially, tumours will develop from the cell type that is proliferating at the time of initiation. This may explain the overrepresentation of different types of histology in breast cancer in relation to age of the woman. The development of each tumour may follow at least partly a distinct pathway of evolution.

Clinical course of early onset prostate cancer with special reference to family history as a prognostic factor

OBJECTIVE

The aim of this study was to describe the clinical characteristics of early onset prostate cancer, with special reference to family history as a possible prognostic factor.

MATERIAL AND METHODS

We identified all cases of prostate cancer diagnosed before the age of 51 in the Southern health care region in Sweden between 1958 and 1994. Clinical data were collected retrospectively from medical records. Data about family history of prostate cancer were also collected from the parish authorities and the Regional Cancer Registry.

RESULTS

In all, 89 cases were included. The median time of follow-up was 17 years. During the time of follow-up, 65 patients died, 57 of whom died from prostate cancer. At diagnosis, 34% of the patients had localized, 22% had locally advanced, and 40% had metastatic tumours. The tumours were well differentiated in 30% of the cases, moderately differentiated in 38%, and poorly differentiated in 28%. Information on tumour grade and stage was missing in 3 cases. The cause-specific survival was 48% at 5 years and 29% at 10 years. The 18 patients with a family history of prostate cancer had a somewhat better prognosis than the patients with a negative family history, though the difference did not reach statistical significance (p = 0.08).

CONCLUSIONS

Early onset prostate cancer is a serious disease with high mortality. The proportions of patients with poorly differentiated and metastatic tumours appeared to be larger than for cases diagnosed later in life, but this could be explained by selection bias since younger men may have a lower probability of having asymptomatic localized tumours diagnosed. Family history of prostate cancer was not significantly associated with prognosis.

MYB oncogene amplification in hereditary BRCA1 breast cancer

Comparative genomic hybridization analysis has demonstrated that breast tumors from BRCA1 and BRCA2 germ-line mutation carriers contain a large number of chromosomal copy number gains and losses. A high regional copy number gain at 6q22-q24 was observed in one BRCA1 tumor, and fluorescence in situ hybridization analysis indicated a strong amplification of the MYB oncogene (15 copies of MYB compared with 1 copy of chromosome 6 centromere). Fluorescence in situ hybridization analysis revealed amplification of MYB in 5 (29%) of 17 BRCA1 breast tumors, whereas none of 8 BRCA2 tumors and 13 breast cancer cell lines, and only 2 of 100 sporadic breast tumors exhibited altered MYB copy numbers. Gene amplification resulted in mRNA overexpression as determined by Northern blot and cDNA microarray analysis, and protein overexpression by immunohistochemical staining. We conclude that MYB amplification is infrequent in sporadic breast cancer but common in breast tumors from BRCA1 mutation carriers, suggesting a role of this cell cycle regulator and transcription factor in the progression of some BRCA1 tumors. However, we cannot rule out the significance of other genes in the 6q22-q24 amplicon.

Age-related dopamine D2/D3 receptor loss in extrastriatal regions of the human brain

Loss of dopamine D2-like receptors in the striatum has been associated with both normal human aging and impairment of cognitive and motor functions in the elderly. To investigate whether there are age-associated changes in dopamine D2 and D3 receptor subtypes (D2/3Rs) outside the striatum, a D2/3R selective high-affinity radioligand [11C]FLB 457 was used in positron emission tomography (PET) examinations for 24 normal healthy male subjects (age range 19-74 years). Significant age-related declines of D2/3Rs were detected in all the brain regions studied: the anterior cingulate cortex (decline of 13% per increase of a decade in age, P < 0.001). the frontal cortex (11%, P < 0.001), the lateral temporal cortex (10%, P < 0.001), the hippocampus (10%, P < 0.01), the medial temporal cortex (9%, P < 0.001), the amygdala (7%, P < 0.01), the medial thalamus (6%, P < 0.001) and the lateral thalamus (5%, P < 0.01). The rate of D2/3R decline was significantly faster in the frontal cortex as compared to the medial temporal cortex (P < 0.05, Bonferroni corrected) and as compared to the medial thalamus (P < 0.05, Bonferroni corrected). These results indicate that the previously demonstrated age-related decline in striatal dopamine D2 receptors extends to several extrastriatal regions in normal human males. Further, the rate of D2/3R decline may be faster in the frontal cortex as compared to the temporal and thalamic regions.

Somatic frameshift alterations in mononucleotide repeat-containing genes in different tumor types from an HNPCC family with germline MSH2 mutation

Hereditary nonpolyposis colorectal cancer (HNPCC) is caused by a germline mutation in one of several DNA repair genes, which in the tumors is reflected as microsatellite instability (MSI). MSI+ tumors have been found to carry somatic frameshift mutations in mononucleotide repeats within the coding regions of several genes involved in growth control, apoptosis, and DNA repair, e.g., TGFBRII, BAX, IGFIIR, TCF4, MSH3, and MSH6. We have studied the occurrence of somatic frameshift alterations in these mononucleotide repeat-containing genes in 24 tumors (15 colorectal cancers, 1 colon adenoma, 4 endometrial cancers, 1 ovarian cancer, 1 gastric cancer, 1 urothelial cancer, and 1 duodenal cancer) from 14 individuals in an HNPCC family with germline hMSH2 mutation. Such somatic frameshift mutations occurred at a variable frequency; the long mononucleotide repeats that characterize intronic MSI markers were mutated in the majority of tumors, 13 of the tumors displayed alterations in the (A)(10) tract of TGFBII, eight tumors (all of gastrointestinal origin) had alterations in the (A)(9) repeat of TCF4, and one to five tumors had somatic frameshift alterations in the shorter mononucleotide repeats of IGFIIR, BAX, MSH3, and MSH6. Thus, longer mononucleotide repeats were more frequently affected by somatic frameshift mutations. The pattern of alterations varied between the tumors from different family members as well as between different tumors from the same individual. To what extent this variable pattern depends on the widespread mismatch repair deficiency induced by the underlying MSH2 mutation, or represents alternative ways whereby the tumors can achieve a tumorigenic phenotype, is unknown. We suggest, however, that the accumulation of somatic frameshifts, rather than the specific loci in which these occur, drives the development of the tumorigenic phenotype in HNPCC.

Blood transfusion at delivery and risk of subsequent malignant lymphoma in the mother

BACKGROUND AND OBJECTIVES

Blood transfusion has been shown to be a risk factor for non-Hodgkin's lymphoma (NHL).

MATERIALS AND METHODS

In a cohort of 77,928 women with bleeding complications at delivery in the period of 1973-1986, subsequent NHL cases were identified and the number was compared with the number expected from national incidence rates. In a case-control study the proportion of transfused NHL cases was compared with the proportion of transfused controls.

RESULTS

The observed number of NHL in the cohort was 18 versus 22.0 expected. Information on transfusion was obtained for 15 of the NHL cases and none (0%) was transfused versus 32 out of 136 controls (23%).

CONCLUSIONS

Blood transfusion at delivery is not a risk factor for NHL. The immune tolerance induced by pregnancy may reduce the risk of NHL associated with the transfusion of allogeneic blood cells.

Somatic deletions in hereditary breast cancers implicate 13q21 as a putative novel breast cancer susceptibility locus

A significant proportion of familial breast cancers cannot be explained by mutations in the BRCA1 or BRCA2 genes. We applied a strategy to identify predisposition loci for breast cancer by using mathematical models to identify early somatic genetic deletions in tumor tissues followed by targeted linkage analysis. Comparative genomic hybridization was used to study 61 breast tumors from 37 breast cancer families with no identified BRCA1 or BRCA2 mutations. Branching and phylogenetic tree models predicted that loss of 13q was one of the earliest genetic events in hereditary cancers. In a Swedish family with five breast cancer cases, all analyzed tumors showed distinct 13q deletions, with the minimal region of loss at 13q21-q22. Genotyping revealed segregation of a shared 13q21 germ-line haplotype in the family. Targeted linkage analysis was carried out in a set of 77 Finnish, Icelandic, and Swedish breast cancer families with no detected BRCA1 and BRCA2 mutations. A maximum parametric two-point logarithm of odds score of 2.76 was obtained for a marker at 13q21 (D13S1308, theta = 0.10). The multipoint logarithm of odds score under heterogeneity was 3.46. The results were further evaluated by simulation to assess the probability of obtaining significant evidence in favor of linkage by chance as well as to take into account the possible influence of the BRCA2 locus, located at a recombination fraction of 0.25 from the new locus. The simulation substantiated the evidence of linkage at D13S1308 (P < 0.0017). The results warrant studies of this putative breast cancer predisposition locus in other populations.

Increased cancer risk in offspring of women with colorectal carcinoma: a Swedish register-based cohort study

BACKGROUND

Colorectal carcinoma is one of the most common malignancies in the Western population, and a considerable proportion of colorectal carcinomas are estimated to have a familial background.

METHODS

Individuals whose mothers were diagnosed with colon carcinoma or rectal carcinoma from 1958 to 1993, a total of 1. 48 million person-years, constituted the cohort of this Swedish population-based register study. The children were born during the period 1941-1993, and the cancer incidence was observed during the period 1961-1993, with the expected national Swedish incidence used as a reference.

RESULTS

A significantly increased risk of colon carcinoma, rectal carcinoma, and non-Hodgkin lymphoma was observed in the cohort. The cancer risk was more pronounced in children whose mothers were age < 50 years at the time of diagnosis or had developed metachronous colorectal carcinoma. Whereas colon carcinoma in the proband implied an increased risk for both colon tumors and rectal tumors, the offspring of women who were diagnosed with rectal carcinoma were at increased risk of developing rectal carcinoma, but no significantly altered risk of colon carcinoma was observed. In the cohort, the cumulative risk for colorectal carcinoma before age 50 years was increased about 3.0 times compared with the general population.

CONCLUSIONS

This report shows a significant familial aggregation of colorectal carcinoma, demonstrates possible differences in hereditary pattern between colon carcinoma and rectal carcinoma, and confirms that younger age at the time of diagnosis or the occurrence of metachronous tumors indicate familial carcinoma.

High frequency of multiple melanomas and breast and pancreas carcinomas in CDKN2A mutation-positive melanoma families

BACKGROUND

: Inherited mutations in the CDKN2A tumor suppressor gene, which encodes the p16(INK4a) protein, and in the cyclin-dependent kinase 4 (CDK4) gene confer susceptibility to cutaneous malignant melanoma. We analyzed families with two or more cases of melanoma for germline mutations in CDKN2A and CDK4 to elucidate the contribution of these gene defects to familial malignant melanoma and to the occurrence of other cancer types.

METHODS

: The entire CDKN2A coding region and exon 2 of the CDK4 gene of an affected member of each of 52 families from southern Sweden with at least two cases of melanoma in first- or second-degree relatives were screened for mutations by use of polymerase chain reaction-single-strand conformation polymorphism analysis. Statistical tests were two-sided.

RESULTS

: CDKN2A mutations were found in 10 (19%) of the 52 families. Nine families carried an identical alteration consisting of the insertion of arginine at position 113 of p16(INK4a), and one carried a missense mutation, in which the valine at position 115 was replaced with a glycine. The 113insArg mutant p16(INK4a) was unable to bind cdk4 and cdk6 in an in vitro binding assay. Six of the 113insArg families had at least one member with multiple primary melanomas; the 113insArg families also had a high frequency of other malignancies-in particular, breast cancer (a total of eight cases compared with the expected 2.1; P =.0014) and pancreatic cancer (a total of six cases compared with the expected 0.16; P<.0001). Families with breast cancer also had a propensity for multiple melanomas in females, suggesting that a sex-dependent factor may modify the phenotypic expression of CDKN2A alterations.

CONCLUSIONS

: Our findings confirm that the majority of CDKN2A-associated melanoma families in Sweden are due to a single founder mutation. They also show that families with the CDKN2A 113insArg mutation have an increased risk not only of multiple melanomas and pancreatic carcinoma but also of breast cancer.

Visual perception of dynamic properties: cue heuristics versus direct-perceptual competence

Constructivist and Gibsonian approaches disagree over the possibility of direct perceptual use of advanced information. A trenchant instance concerns visual perception of underlying dynamic properties as specified by kinematic patterns of events. For the paradigmatic task of discrimination of relative mass in observed collisions, 2 mathematical models are developed, 1 model representing a direct, invariant-based approach, and 1 representing a cue-heuristic approach. The models enable a critical experimental design with distinct predictions concerning performance data and confidence ratings. Although pretraining results were mixed, the invariant-based model was empirically confirmed after a minimal amount of training: Competence entails the use of advanced kinematic information in a direct-perceptual ("sensory") mode of apprehension, in contrast to beginners' use of simpler cues in an inferential ("cognitive") mode.

BRCA1 and BRCA2 mutations in ovarian cancer: Covariation with specific cytogenetic features

We analyzed 37 primary invasive carcinomas for BRCA1 and BRCA2 mutations by screening the entire coding regions of both genes. Seven predicted truncating mutations (four in BRCA1 and three in BRCA2) and one novel BRCA1 missense variant (S1542C) were identified (8/37, 22%). Two of the BRCA1 mutations were somatic changes, whereas the remaining three BRCA1 changes and all mutations of BRCA2 were found to be of germline origin. All eight BRCA-positive tumors were serous or seropapillary carcinomas (8/27 serous tumors, 30%), and all but one were poorly differentiated. The correlation between tumor karyotype and BRCA status showed that clonal chromosomal aberrations were present in all BRCA-positive tumors (8/8) compared with 20 of 29 BRCA-negative ones. The most consistently affected region in BRCA-positive tumors was the long arm of chromosome 6; alterations within this arm with a breakpoint in band 6q21 were seen in four of five BRCA1-positive and in two of three BRCA2-positive tumors, but only in four of 20 karyotypically abnormal tumors without BRCA mutations, suggesting that the genetic pathways of tumor progression differ in the two groups. The high frequency of germline BRCA mutations detected in this pilot study (16% of 37 invasive carcinomas) points to the need for more extended analyses of population-based series of patients to determine the true contribution of these predisposing genes to the overall incidence of ovarian cancer in this population.

Sunscreen use and malignant melanoma

In a new population-based, matched, case-control study from southern Sweden of 571 patients with a first diagnosis of cutaneous malignant melanoma, between 1995 and 1997, and 913 healthy controls aged 16 to 80 years, the association between sunscreen use and malignant melanoma was evaluated. The median sun protection factor (SPF) used by both cases and controls was 6, range 2 to 25. Sunscreen users reported greater sun exposure than non-users. Persons who used sunscreens did not have a decreased risk of malignant melanoma. Instead, a significantly elevated odds ratio (OR) for developing malignant melanoma after regular sunscreen use was found, adjusted for history of sunburns, hair color, frequency of sunbathing during the summer, and duration of each sunbathing occasion ¿OR = 1.8, 95% confidence interval (CI) 1.1-2.9]. The OR was higher in subjects who reported that sunscreen use enabled them to spend more time sunbathing (adjusted OR = 8.7, 95% CI 1.0-75.8 for always vs. never use). The association appeared to hold for subjects who did not suffer from sunburns while using sunscreens, for subjects who used SPF of 10 or lower, and among men. The pattern of a significantly increased melanoma risk was seen only for lesions of the trunk. Our results are probably related mainly to earlier sunscreens of low SPF. They substantiate the hypothesis that sunscreen use, by permitting more time sunbathing, is associated with melanoma occurrence.

Estrogen receptor content in malignant breast tumors in men--a review

Male breast cancer is a rare disease and clinical or epidemiological data are available from only a relatively few cases. Nonetheless, both similarities and discrepancies are apparent between breast cancer in men and women. For example, lobular and mucinous carcinomas are seldom seen in men. Tumors in men more often display neuroendocrine differentiation, with an average age at diagnosis ten years later than in women. A high proportion of breast tumors in men are estrogen receptor-alpha positive (in this review 77%) and progesterone receptor positive (76%). Breast tumors in men often respond favorably to endocrine manipulation, including testicular ablation or antiestrogen therapy. Thus, the hormone receptors in these tumors can be functionally active and used for therapeutic intervention. This proposal has been questioned in some studies because estrogen dependent proteins are expressed to a lesser degree in men. Furthermore, men do not have a better overall breast cancer prognosis compared with women, after adjustments have been made for age and tumor stage. While the androgen receptor content has been assessed in a few studies, there are no studies on the estrogen receptor-beta content of breast tumors in men.

Prognosis and clinical presentation of BRCA2-associated breast cancer

54 female breast cancer patients from 22 families with BRCA2 germ line mutations from Sweden and Denmark were compared with 214 age- and date of diagnosis-matched controls identified among breast cancer patients from South Sweden. At diagnosis, BRCA2-associated cases were more often node-positive (N+). OR=1.9 (95% confidence interval (CI)=1.0-3.6; P=0.036), and were more often clinical stage IV: OR=4.6 (95% CI=1.3-17; P=0.021) than the controls. Bilateral disease was also more common among the BRCA2-associated cases: OR=2. 4 (95% CI=1.1-5.3; P=0.027). Breast cancer-specific survival (BCSS) was significantly worse among the BRCA2-associated cases: RR=2.0 (95% CI=1.2-3.4; P=0.010). When stage was corrected for in a multivariate analysis, BCSS was no longer significantly worse for the BRCA2-associated cases: RR=1.6 (95% CI=0.85-3.1). The corresponding effect after correction for bilateral disease was: RR=1.8 (95% CI=1.0-3.1; P=0.034). The unfavourable prognosis in BRCA2-associated breast cancer seems, to a great extent, to be a consequence of the higher clinical stage at diagnosis. The increased presence of bilateral cancers appears to have less impact on survival in this group of hereditary breast cancer. Data presented here needs to be taken into account when counselling healthy carriers of BRCA2 germ line mutations.

Analysis of Swedish male breast cancer family data: a simple way to incorporate a common sibling effect

Based on a population-based cohort study, Olsson et al. [1993] found significant evidence for elevated incidence of breast and ovarian cancers among female first-degree relatives of men with breast cancer. Using an extension of logistic regressive models we investigate whether, after allowing for multifactorial familial correlations, single locus segregation could be the cause of the elevated incidence in these families. The logit for a given sib in the class D logistic regressive model depends on the order in which affected sibs occur in a sibship. That makes the model less appropriate for the situation where a polygenic component or a common sibling environment may be present, as well as being computationally cumbersome. In this paper, we propose to use the proportion of siblings in a sibship who are affected to quantify a sibling correlation. That not only relaxes the interchangeability problem but also makes the model computationally efficient. We then use this modified class D logistic regressive model for our segregation analysis. Using the proportion of siblings in a sibship who are affected as a covariate resulted in a significantly higher likelihoods in all the models we investigated. We found evidence for a dominant Mendelian gene leading to early age of onset of breast and/or ovarian cancer. This could either be a germline mutation of BRCA2 or a mutation in a gene different from BRCA2.

One-year safety study with bambuterol once daily and terbutaline three times daily in 2-12-year-old children with asthma. The Bambuterol Multicentre Study Group

The aim of this study was to compare bambuterol oral solution (10 mg) administered once daily in the evening with terbutaline oral solution (0.075 mg/kg body weight) administered three times daily in 2-5-year-old children and to compare bambuterol tablets (10 mg or 20 mg) administered once daily in the evening with terbutaline tablets (2.5 mg) administered three times daily in 6-12-year-old children with asthma. The study was of an open, randomized, parallel-group design, and lasted 1 year. The primary objective was to evaluate safety (pulse rate, blood pressure, adverse events, hematology, and clinical chemistry). Plasma terbutaline concentrations were also measured. Evaluation of efficacy (FEV(1)) was a secondary objective. A total of 141 patients (83 boys, 58 girls) were randomized and treated with the study drugs, i.e., 43 patients in the terbutaline group (30 on oral solution and 13 on tablets) and 98 patients in the bambuterol group (62 on oral solution and 36 on tablets). A total of 11 patients discontinued the study: 3 were on terbutaline, and 8 were on bambuterol. There were no clinically important differences between treatment groups regarding pulse rate, or systolic or diastolic blood pressure. There were no clinically important findings in the laboratory tests (hematology and clinical chemistry). Both terbutaline and bambuterol were well-tolerated, and the reported adverse events were mostly mild or moderate. Mean steady state plasma terbutaline concentrations at the visits ranged between 8.0-11.5 nmol/L in the bambuterol tablet group and between 10.6-15.2 nmol/L in the terbutaline tablet group. The corresponding values in children on oral solution were 10.3-11.3 nmol/L in the bambuterol group and 7.5-9.7 nmol/L in the terbutaline group. FEV(1) measured in the 6-12-year-old children increased by more than 0.2 L in both treatment groups during the year in the study. In conclusion, bambuterol tablets or oral solution once daily and terbutaline tablets or oral solution three times daily showed a comparable and favorable safety profile.

Risk of cutaneous malignant melanoma in relation to use of sunbeds: further evidence for UV-A carcinogenicity

In a population-based, matched, case-control study from southern Sweden of 571 patients with a first diagnosis of cutaneous malignant melanoma and 913 healthy controls aged 16-80 years, the association between sunbed use and malignant melanoma was evaluated. A total of 250 (44%) cases and 372 (41%) controls reported ever having used sunbeds. A significantly elevated odds ratio for developing malignant melanoma after regular exposure to sunbeds was found, adjusted for hair colour, raised naevi, skin type and number of sunburns (odds ratio (OR) 1.8, 95% confidence interval (CI) 1.2-2.7). A dose-response relationship between total number of sunbed uses and melanoma risk was only found up to the level of 250 times. The OR was higher in individuals younger than age 36 years (adjusted OR 8.1, 95% CI 1.3-49.5 for regular vs. never use). The association seemed to be true only for subjects with black/dark brown or light brown hair and among females. Lesions of the extremities showed the strongest association of increased risk with sunbed use. An increased risk was related to commercial exposure and to exposure during the winter. The results substantiate the hypothesis that exposure to sunbeds might increase the risk of developing malignant melanoma.

Naive empiricism and dogmatism in confidence research: a critical examination of the hard-easy effect

Two robust phenomena in research on confidence in one's general knowledge are the overconfidence phenomenon and the hard-easy effect. In this article, the authors propose that the hard-easy effect has been interpreted with insufficient attention to the scale-end effects, the linear dependency, and the regression effects in data and that the continued adherence to the idea of a "cognitive overconfidence bias" is mediated by selective attention to particular data sets. A quantitative review of studies with 2-alternative general knowledge items demonstrates that, contrary to widespread belief, there is (a) very little support for a cognitive-processing bias in these data; (b) a difference between representative and selected item samples that is not reducible to the difference in difficulty; and (c) near elimination of the hard-easy effect when there is control for scale-end effects and linear dependency.