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Biomedical subjects

U Kristoffersson

Publications and source records attributed to U Kristoffersson.

At least 37 records · Page 2Linked to original sources

Incidence of malignant tumours in relatives of BRCA1 and BRCA2 germline mutation carriers.

We investigated cancer incidence between 1958 and 1995 in 1873 individuals belonging to 29 consecutively identified BRCA1 and 20 BRCA2 associated families from Southern Sweden using data from parish and local tax authorities, as well as the Swedish Cancer Registry, Cause of Death Registry and Census Registry. 150 malignant tumours were analysed from 1145 relatives in the BRCA1 families and 87 tumours were analysed from 728 relatives in the BRCA2 families. After excluding index cases which led to the mutation analysis, the incidence for all malignant tumours was significantly increased for both BRCA1- standardised morbidity rate, SMR, 1.98, 95% confidence interval (CI) 1.59-2.45; P < 0.0001 and BRCA2- (SMR 1.79, 95% CI 1.35-2.31; P < 0.0001) associated family members. For women in BRCA1-associated families, the incidence of breast cancer (SMR 3.76, 95% CI 2.29-5.80, P < 0.0001), ovarian cancer (SMR 15.49, 95% CI 9.46-23.92, P < 0.0001), stomach cancer (SMR 5.86, 95% CI 1.60-15.01, P = 0.005) were significantly increased. Amongst men only invasive squamous cell cancer of the skin was significantly increased (SMR 6.02, 95% CI 1.96-14.05, P = 0.002). In BRCA2 associated families, female breast cancer (SMR 3.03, 95% CI 1.61-5.18, P = 0.0005) was increased after exclusion of index cases. If these were included, ovarian cancer (SMR 5.16, 95% CI 1.89-11.24, P = 0.001), invasive cervical cancer (SMR 4.21, 95% CI 1.15-10.79, P = 0.016), male breast cancer (SMR 290.52, 95% CI 125.42-572.43, P < 0.0001), and prostate cancer (SMR 2.21, 95% CI 0.89-4.56, P = 0.042) were significantly increased. The increased risk for ovarian cancer in BRCA2 related families were limited to the cases leading to mutation analysis. Our data suggest that apart from breast and ovarian cancer, the incidence of other cancer types do not appear to be greatly increased in BRCA1- and BRCA2-associated families and does not warrant specific clinical follow-up in carriers.

Adult↗

CAG repeat length in the androgen receptor gene is related to age at diagnosis of prostate cancer and response to endocrine therapy, but not to prostate cancer risk.

The length of the polymorphic CAG repeat in the N-terminal of the androgen receptor (AR) gene is inversely correlated with the transactivation function of the AR. Some studies have indicated that short CAG repeats are related to higher risk of prostate cancer. We performed a case-control study to investigate relations between CAG repeat length and prostate cancer risk, tumour grade, tumour stage, age at diagnosis and response to endocrine therapy. The study included 190 AR alleles from prostate cancer patients and 186 AR alleles from female control subjects. All were whites from southern Sweden. The frequency distribution of CAG repeat length was strikingly similar for cases and controls, and no significant correlation between CAG repeat length and prostate cancer risk was detected. However, for men with non-hereditary prostate cancer (n = 160), shorter CAG repeats correlated with younger age at diagnosis (P = 0.03). There were also trends toward associations between short CAG repeats and high grade (P = 0.07) and high stage (P = 0.07) disease. Furthermore, we found that patients with long CAG repeats responded better to endocrine therapy, even after adjusting for pretreatment level of prostate-specific antigen and tumour grade and stage (P = 0.05). We conclude that short CAG repeats in the AR gene correlate with young age at diagnosis of prostate cancer, but not with higher risk of the disease. Selection of patients with early onset prostate cancer in case-control studies could therefore lead to an over-estimation of the risk of prostate cancer for men with short CAG repeats. An association between long CAG repeats and good response to endocrine therapy was also found, but the mechanism and clinical relevance are unclear.

Adult↗

Prognostic implications of cytogenetic aberrations in diffuse large B-cell lymphomas.

A single institution series of 81 consecutive, cytogenetically analyzed, diffuse large B-cell lymphomas (DLBL), the majority of which treated with anthracycline-containing combination chemotherapy, were reviewed retrospectively to investigate whether the karyotypic pattern or certain abnormalities correlate with survival. Clonal chromosome changes were found in 79 of the 81 cases. The prognostic impact of the following aberrations, all suggested in previous studies to be associated with either shorter or longer survival, were tested: 1q21-23 breakpoints, +2/dup(2p), +3/dup(3p), +5, +6, 6q21-25 breakpoints, monosomy 7/der(7p)/i(7q), trisomy 7, 14q11-12 breakpoints, monosomy 17/der(17p)/i(17q), trisomy 18, > 4 marker chromosomes, > 4 breakpoints, and > or = 10 abnormalities. Univariate analysis showed that a breakpoint at 1q21-23 or trisomy 6 was associated with a shorter survival. However, when adjusted for age, stage, performance status and lactate dehydrogenase level, none of the cytogenetic aberrations had an independent prognostic value. Thus, the present investigation provides no support for any of the above-mentioned abnormalities being of prognostic importance in DLBL.

Adult↗

Genomic amplification of CCND2 is rare in non-Hodgkin lymphomas.

Cyclin D2, encoded by CCND2 at 12p13, takes part in the regulation of the cell cycle and has been suggested as a candidate for gene amplification in lymphoid malignancies. CCND2 is often overexpressed in chronic B-cell disorders, and we recently detected genomic amplification of the chromosomal region containing CCND2 in two of three investigated non-Hodgkin lymphomas (NHLs) with cytogenetic abnormalities involving 12p. In the present study, 58 NHLs without karyotypic evidence of 12p aberrations were analyzed by fluorescence in situ hybridization with probes for CCND2. No genomic amplification was found, strongly suggesting that this abnormality is rare in such NHLs.

Chromosome Aberrations↗

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.

Age of Onset↗

Frequency of RET mutations in long- and short-segment Hirschsprung disease.

Hirschsprung disease, or congenital aganglionic megacolon, is a genetic disorder of neural crest development affecting 1:5,000 newborns. Mutations in the RET proto-oncogene, repeatedly identified in the heterozygous state in both long- and short-segment Hirschsprung patients, lead to loss of both transforming and differentiating capacities of the activated RET through a dominant negative effect when expressed in appropriate cellular systems. The approach of single-strand conformational polymorphism analysis established for all the 20 exons of the RET proto-oncogene, and previously used to screen for point mutations in Hirschsprung patients allowed us to identify seven additional mutations among 39 sporadic and familial cases of Hirschsprung disease (detection rate 18%). This relatively low efficiency in detecting mutations of RET in Hirschsprung patients cannot be accounted by the hypothesis of genetic heterogeneity, which is not supported by the results of linkage analysis in the pedigrees analyzed so far. Almost 74% of the point mutations in our series, as well as in other patient series, were identified among long segment patients, who represented only 25% of our patient population. The finding of a C620R substitution in a patient affected with total colonic aganglionosis confirms the involvement of this mutation in the pathogenesis of different phenotypes (i.e., medullary thyroid carcinoma and Hirschsprung). Finally the R313Q mutation identified for the first time in homozygosity in a child born of consanguineous parents is associated with the most severe Hirschsprung phenotype (total colonic aganglionosis with small bowel involvement).

DNA Mutational Analysis↗

Sons of men with prostate cancer: their attitudes regarding possible inheritance of prostate cancer, screening, and genetic testing.

OBJECTIVES: To study attitudes regarding possible inheritance of prostate cancer among sons of men with prostate cancer. METHODS: A questionnaire was sent to 69 men with prostate cancer and their 101 unaffected sons. All participants were also interviewed by telephone. Sociodemographic data were collected, as were data about the fathers' disease. RESULTS: The response rate was high; 100 sons (99%) and 65 fathers (94%) answered all questions. Sixty of the sons claimed they had worries about having an increased risk of prostate cancer due to possible inheritance. About 90% of the sons wanted to know whether prostate cancer was inheritable (66 definitely and 24 probably), were positively inclined to undergo screening (65 definitely and 27 probably), and to undergo genetic testing (50 definitely and 41 probably), provided there had been multiple cases of prostate cancer in their family. An interest to know whether prostate cancer could be inherited was more frequent among sons with less than 12 years of education, worries about inheritance, younger age, a father treated with curative intent, and with children of their own, especially if sons. Interest in genetic testing was associated with less than 12 years of education and with worries about inheritance. CONCLUSIONS: A large majority of healthy men with a family history of prostate cancer were interested in knowing whether the disease could be inherited and were positively inclined to undergo screening and genetic testing. Our findings indicate that genetic counseling and a screening program could have beneficial psychological effects in families with multiple cases of prostate cancer.

Adult↗

The risk of malignant tumours in first-degree relatives of men with early onset prostate cancer: a population-based cohort study.

Previous studies have indicated that hereditary prostate cancer is common among men with early onset prostate cancer. The aim of this study was to investigate the incidence of malignant tumours in first-degree relatives of men with early onset prostate cancer. All prostate cancer cases diagnosed before the age of 51 years from 1958 to 1994 were identified in the population-based Swedish Cancer Register. The first-degree relatives of clinical cases were identified through parish data. Their vital status and cancer incidence were studied in the Swedish Cancer Register, the Cause of Death Register and the Census Register. The expected incidence of malignant tumours for the first-degree relatives were calculated using regional cancer register data. Cause-specific standardised incidence ratios (SIR) and 95% confidence intervals (CI) were calculated. The study included 423 first-degree relatives of 89 men with clinical prostate cancer. The first-degree relatives' SIR for malignant tumours was 0.99 (95% CI 0.78-1.23). The SIR for prostate cancer diagnosed at any age was 1.43 (95% CI 0.82-2.33), and 3.37 for first-degree relatives diagnosed before the age of 70 years (95% CI 1.36-6.94). There was no significantly increased risk of any non-prostatic malignant tumour. Only in five of the families did the pedigree show a pattern of hereditary prostate cancer. The first-degree relatives of men with early onset prostate cancer had more than a 3-fold increase in the risk of developing prostate cancer before the age of 70 years, but their total cancer risk was not increased. This study does not support the assumption that dominantly inherited susceptibility is a major cause of early onset prostate cancer.

Adult↗

Deletion of chromosome arm 3p in hematologic malignancies.

Cytogenetic aberrations resulting in deletion of 3p are common in solid tumors, indicating the presence of tumor suppressor genes (TSG) on this chromosome arm. The present study was undertaken to investigate 3p loss in hematologic disorders. Ten acute myeloid leukemias (AML), two myelodysplastic syndromes (MDS), one Philadelphia chromosome-positive chronic myeloid leukemia (CML), three acute lymphoblastic leukemias (ALL), one chronic lymphoproliferative disorder (CLD), and three non-Hodgkin's lymphomas (NHL) with abnormalities leading to 3p deletions were identified, constituting 2.9% of AML, 0.7% of MDS, 1.0% of CML with changes in addition to t(9;22), 1.5% of ALL, 4.2% of CLD, and 1.1% of NHL with cytogenetic abnormalities analyzed at our Department. Among 19042 karyotypically aberrant published cases, 1.2% of 6260 AML, 1.3% of 2285 MDS, 0.8% of 840 chronic myeloproliferative disorders (CMD), 0.7% of 1894 CML with additional aberrations to t(9;22), 0.6% of 3589 ALL 2.4% of 1602 CLD, 4.5% of 178 Hodgkin disease (HD), and 3.1% of 2394 NHL displayed partial loss of 3p (0.6-4.5%; P < 0.001); the majority occurring together with other abnormalities. The frequencies of 3p loss did not differ significantly among the MDS, ALL, and CLD morphologic subgroups, between B and T cell ALL, CLD, and NHL, among low-, intermediate-, and high-grade NHL, or between therapy-related MDS and de novo MDS, whereas the incidence of 3p deletions was higher in treatment-associated AML (P < 0.001) than in de novo AML and varied among the AML FAB groups (P < 0.001). The most frequently deleted chromosome bands were 3p25 in AML, 3p26 in MDS, 3p14 in CMD, 3p25, 3p23, and 3p21 in CML, 3p26 and 3p25 in ALL, 3p26 and 3p25 in CLD, 3p26 in HD, and 3p26 in NHL. These deletion hot spots are more distal than those reported in most solid tumor types, suggesting that different TSG are involved in hematologic malignancies and solid neoplasms.

Chromosome Aberrations↗

Hypereosinophilic syndrome in a child mosaic for a congenital triplication of the short arm of chromosome 8.

An 11-year-old boy with mental retardation, malformations, and the mosaic karyotype 47,XY,+i(8p)/46,XY presented with fever, headache and petechiae. Peripheral blood WBC was 190 x 10(9)/l; and contained > 90% mature eosinophils. Cytogenetic analysis of the eosinophils revealed no aberrations except the constitutional karyotype. The patient was diagnosed as having a hypereosinophilic syndrome. Shortly after initiation of therapy he died from extensive mural thrombi of the heart and thrombi of several other organs. This is the first case of congenital triplication of the short arm of chromosome 8 associated with hypereosinophilic syndrome, suggesting involvement of genes on chromosome 8p in the regulation of eosinopoiesis.

Child↗

Prenatal diagnosis in Sweden: organisation and current issues.

Invasive prenatal diagnosis was introduced in Sweden in the early 1970s and is an integral part of the public health care system. Funding is provided by taxation; the patient only pays a consultation fee. Genetic analyses on a broad range of cytogenetic and molecular disorders are performed at the 6 university-affiliated hospitals and in 1 county hospital. About 6% of all newborns have been cytogenetically screened during pregnancy, and about 90% of the analyses are performed after amniocentesis. The main indication is chromosome analysis because of advanced maternal age.

Chromosome Aberrations↗

Moderate frequency of BRCA1 and BRCA2 germ-line mutations in Scandinavian familial breast cancer.

Previous studies of high-risk breast cancer families have proposed that two major breast cancer-susceptibility genes, BRCA1 and BRCA2, may account for at least two-thirds of all hereditary breast cancer. We have screened index cases from 106 Scandinavian (mainly southern Swedish) breast cancer and breast-ovarian cancer families for germ-line mutations in all coding exons of the BRCA1 and BRCA2 genes, using the protein-truncation test, SSCP analysis, or direct sequencing. A total of 24 families exhibited 11 different BRCA1 mutations, whereas 11 different BRCA2 mutations were detected in 12 families, of which 3 contained cases of male breast cancer. One BRCA2 mutation, 4486delG, was found in two families of the present study and, in a separate study, also in breast tumors from three unrelated males with unknown family history, suggesting that at least one BRCA2 founder mutation exists in the Scandinavian population. We report 1 novel BRCA1 mutation, eight additional cases of 4 BRCA1 mutations described elsewhere, and 11 novel BRCA2 mutations (9 frameshift deletions and 2 nonsense mutations), of which all are predicted to cause premature truncation of the translated products. The relatively low frequency of BRCA1 and BRCA2 mutations in the present study could be explained by insufficient screening sensitivity to the location of mutations in uncharacterized regulatory regions, the analysis of phenocopies, or, most likely, within predisposed families, additional uncharacterized BRCA genes.

Adult↗

The FHIT and PTPRG genes are deleted in benign proliferative breast disease associated with familial breast cancer and cytogenetic rearrangements of chromosome band 3p14.

We have used nested reverse transcription-PCR (RT-PCR) and PCR on genomic DNA to search for aberrations in the FHIT and PTPRG genes, both located in chromosomal band 3p14.2, in specimens from cytogenetically analyzed benign breast lesions (three samples with atypical hyperplasia and one with fibroadenosis) from two women belonging to breast cancer families. The transcription analysis showed that the FHIT gene was either not expressed or that its expression was dramatically reduced to a level not detectable by nested RT-PCR in the samples with atypical hyperplasia. Genomic analysis of exons 3 and 5 of FHIT and exon 12 of PTPRG provided evidence that these DNA segments were homozygously deleted in the majority of the cells. These data are in line with the histopathological features and cytogenetic findings in the three samples; none contained normal parenchyma, and all had chromosomal aberrations involving band 3p14. RT-PCR analysis of the fibroadenosis specimen, which had a normal karyotype, detected the expected 856-bp fragment as well as an additional alternative transcript variant of FHIT with 1014 bp. The additional 158-bp sequence, which may add 38 amino acids to the NH2-terminal part of the previously described FHIT protein, was inserted between exons 4 and 5 and seems to be a new exon located in intron 4 of FHIT.

Acid Anhydride Hydrolases↗

Chromosome aberrations in prophylactic mastectomies from women belonging to breast cancer families.

Short-term cultures of samples from eight prophylactic mastectomies from five unrelated women who were genetically predisposed to breast cancer were analyzed cytogenetically. Clonal chromosome abnormalities were detected in five breasts. Three samples from two women had aberrations involving the short arm of chromosome 3, with a breakpoint in 3p14 in common. Three samples from three women had rearrangements of 1q. Two of them, one of which also displayed a 3p14 rearrangement, shared a breakpoint in 1q41. Both 1q41 and, in particular, 3p14 have been reported to be rearranged frequently in malignant breast proliferations. Whether alterations of genes in these bands are essential in mammary tumorigenesis and, if so, whether they are equally important in sporadic and in hereditary cases remains to be explored.

Adult↗