Biomedical subjects

M Dictor

Publications and source records attributed to M Dictor.

At least 19 recordsLinked to original sources

PubMed2004

Assessment of biological prognostic factors provides clinically relevant information in patients with diffuse large B-cell lymphoma--a Nordic Lymphoma Group study.

The purpose of this study was to investigate the prognostic effects of four biological markers, BCL2, TP53, Ki-67, and P-glycoprotein, and their possible clinical relevance in addition to the international prognostic index (IPI) in diffuse large B-cell lymphoma (DLBCL). A total of 405 patients with aggressive lymphoma, stage II-IV, between 18 and 67 years, were randomized in a trial comparing CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone) with MACOP-B (methotrexate, doxorubicin, cyclophosphamide, vincristine, prednisone, and bleomycin). Of these, 267 cases were classified as DLBCL, with adequate paraffin blocks available in 207 cases, enabling immunohistochemical assessment of the expression of BCL2, TP53, P-glycoprotein, and Ki-67. In a multivariate analysis, stratified for IPI, high BCL2 expression (>10%) low (<60%) expression of Ki-67, and high TP53 protein expression (>75%) were shown to provide additional prognostic information with regard to overall or failure-free survival. We found no association between expression of P-glycoprotein and outcome. Assessment of BCL2 positivity might be introduced as part of the routine investigation in patients with DLBCL, but further studies are necessary to confirm the clinical relevance of Ki-67 and TP53 expression.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed2001

HIV-1 in placentas of untreated HIV-1-infected women in relation to viral transmission, infectious HIV-1 and RNA load in plasma.

The presence of HIV in the placenta was analysed in relation to virological and immunological factors and vertical transmission of HIV in 39 pregnancies between 1989 and 1993 among 37 HIV-1-infected women without zidovudine prophylaxis. HIV-1 was detected in 12 of 37 (31%) placentas by immunohistochemistry and in 3 of 18 by PCR. Altogether 14/39 (36%) placentas bore evidence of HIV-1 infection, although there was no relation with the outcome of HIV infection in the child. Neither was there a relation between placental infection and either CD4 cell counts or HIV-1 RNA levels. However, HIV-1 was isolated from plasma in 20 of 39 (50%) pregnancies, which was inversely related to the presence of HIV in the placenta. When HIV-1 was identified in the placenta, HIV-1 was isolated from plasma in 3/14 (21%) pregnancies, vs 17/25 (68%) when it was not (p = 0.01), with a relative risk of having a placenta positive for HIV of 3.9 in pregnancies with a negative plasma HIV isolation. This inverse relation may point to differences in tropism between HIV-1 in placenta and plasma. The results show that the placental barrier prevents HIV transmission, irrespective of whether HIV enters the placenta or not.

CD4 Lymphocyte Count↗

PubMed2001

Cyclin D1 overexpression versus response to induction chemotherapy in squamous cell carcinoma of the head and neck--preliminary report.

The aim of this study was to investigate whether there is an association between overexpression of cyclin D1 and response to therapy. Immunohistochemical overexpression of cyclin D1 was determined in paraffin-embedded specimens from diagnostic biopsies of 89 primary cases of squamous cell carcinoma of the head and neck (SCCHN), using a polyclonal antiserum. The tumor response rates were estimated after curative treatment (i.e. surgery and/or radiotherapy and/or chemotherapy). Patients whose tumors were overexpressing cyclin D1 showed complete or partial response to neoadjuvant chemotherapy with cisplatin/5-FU. In addition, a majority of cyclin D1 negative tumors did not respond at all to this treatment (p = 0.02, Fisher's exact test). This study indicates that immunohistochemical assessment of cyclin D1 expression in SCCHN could be a new predictive marker to select a subgroup of patients that will benefit from neoadjuvant chemotherapy.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed2001

Characterization of chromosome aberrations in salivary gland tumors by FISH, including multicolor COBRA-FISH.

Fluorescence in situ hybridization (FISH), including COBRA-FISH, was used to characterize 11 salivary gland tumors that had been investigated by banding analysis. Five cases were pleomorphic adenoma (PA), three were adenoid cystic carcinoma, and one case each was mucoepidermoid carcinoma, carcinoma ex-pleomorphic adenoma (CaPA), and adenocarcinoma. All 11 cases were selected on the basis that they had shown rearrangement of 6q or 9p or had unresolved aberrations after karyotyping. The COBRA-FISH and FISH analyses led to a revised karyotype in all informative cases and made it possible to clarify almost all chromosomal rearrangements occurring in the tumors. Of particular note were the confirmation of the existence of 6q deletions, a common change in salivary gland carcinomas, and the demonstration that a seemingly balanced t(6;9) resulted in del(6q). Other rearrangements that were revealed by FISH included amplification of 12q sequences (MDM2 and CDK4) in one PA. We also investigated the status of the PLAG1 gene in four cases (one PA, one CaPA, one adenoid cystic carcinoma, and one mucoepidermoid carcinoma) with 8q12 rearrangements. Only in the former two cases were the FISH results compatible with intragenic rearrangements. Overall, the results of the study show that, even with good banding quality and in karyotypes of modest complexity, much new information will be gained by supplementing the banding analysis with a multicolor FISH approach, such as COBRA-FISH.

Adult↗

PubMed2000

Association of inverted sinonasal papilloma with non-sinonasal head-and-neck carcinoma.

The nature and pathogenesis of inverted papilloma of the nose and paranasal sinuses are debated. Evidence suggesting a viral association is controversial, and epidemiological evidence has pointed to tobacco smoking as a potential etiologic factor. A retrospective regional cohort of 197 patients with sinonasal papilloma was compared with a cohort of 1583 patients with nasal polyps showing a similar distribution by age and sex. All instances of head-and-neck carcinoma diagnosed in both cohorts during a 38-year calendar period were culled from the regional cancer registry, the incidence rate ratio was computed (papilloma:polyp, on tumors detected at the time of or prior to the index diagnosis), and the clinical details were obtained. Nine instances of oral or laryngeal squamous-cell carcinoma, all in men, were identified in the papilloma cohort, and 7 labial, oral or laryngeal carcinomas (2 in women) in patients with polyps. In addition, 5% of the papillomas progressed to sinonasal carcinoma, including 2 cases among those with other primary head-and-neck carcinomas. The incidence-rate ratio for non-sinonasal head-and-neck carcinoma was 12.8 (95% CI, 3. 7 to 50; p < 0.0001). Among the papilloma patients with oral/laryngeal carcinoma, 8 smoked tobacco. Inverted sinonasal papilloma is associated with an increase in non-sinonasal head-and-neck carcinoma, and tobacco may be a causative link.

Aged↗

PubMed2000

Cyclin D1 overexpression correlates with poor prognosis in patients with tongue squamous cell carcinoma.

Tongue squamous cell carcinoma makes up a large percentage of head and neck cancers, and the incidence among young patients is increasing. The aim of this study was to reveal the correlation between cyclin D1 (CCND1) expression and clinical and histologic features. We performed an immunohistochemical study on the level of CCND1 expression in tumor specimens obtained from 94 patients with tongue squamous cell carcinoma. The relationship between the expression and the following features such as age, sex, smoking and alcohol intake history, T, N, histologic grade, and multiple primary cancer was analyzed. Eighteen patients (19%) showed CCND1 overexpression (tumor cell nuclei positivity >/=50%). The 5-year survival rate of high CCND1 expressors was 39%, which was significantly poor (p=0.04). N classification correlated with CCND1 expression. CCND1 overexpression is associated with poor survival associated with progression of lymph node spread in patients with tongue squamous cell carcinomas. CCND1 expression may be a useful biologic marker for prognosis.

Adolescent↗

PubMed2000

Prognostic value of vascular endothelial growth factor (VEGF) in head and neck squamous cell carcinomas.

Vascular endothelial growth factor (VEGF) has been identified as the substance that increases the permeability and proliferation of vascular endothelial cells. We examined the clinical significance of VEGF expression in 60 head and neck squamous cell carcinomas using the methods of Western blot, immunohistochemistry, and reverse transcriptase-polymerase chain reaction (RT-PCR), comparatively, and analysed the relationship between VEGF status in Western blot and tumour size, lymph-node status, histologic grade and disease-free survival (DFS) rate. Western blot analysis revealed high VEGF expressors (tumour/normal tissue density >/= 3-fold) in 26 patients (43%) and low VEGF expressors (< 3-fold) in 34 patients (57%). The results of the Western blot analysis correlated significantly with those of the RT-PCR (P = 0.00007) or immunohistochemistry (P = 0. 00006). High VEGF expressors are associated with the progression of lymph-node spread (P = 0.0009), which are correlated with poor DFS. The 2-year DFS rate of high VEGF expressors (30%) was significantly lower than that of low VEGF expressors (78%) (P = 0.0008). Multivariate analysis showed VEGF expression and stage were independent predictors for the DFS (P = 0.045 and 0.041, respectively). VEGF expression may play an important role in progression of HNSCC.

Adult↗

PubMed2000

Abnormalities on brain MR images during the course of familial haemophagocytic lymphohistocytosis in a child. A case report.

PURPOSE: To describe and report the neuroradiological findings and clinical features in a patient with familial haemophagocytic lymphohistocytosis (FHL), a rare hereditary immune dysregulation in early childhood characterised by multisystem involvement, including in approximately 30% of cases also the central nervous system (CNS). MATERIAL AND METHODS: Serial brain MR examinations were carried out in a 4.5-year-old boy with FHL, finally complicated with Epstein-Barr virus (EBV)-driven posttransplantation lymphoma. RESULTS: Multiple brain MR examinations before and after contrast enhancement showed discrete perivascular non-enhancing areas of high signal intensity on T2 images, and later also an enhancing lesion in the right caudate nucleus. CONCLUSION: FHL should be included in the differential diagnosis of patchy white matter abnormalities in young patients. EBV-driven post-transplantation lymphoma, which may present as meningial and/or parenchymal CNS infiltration, is a differential diagnostic problem.

Brain↗

PubMed2000

Nonrandom pattern of cytogenetic abnormalities in squamous cell carcinoma of the larynx.

Cytogenetic analysis of short-term cultures from 105 squamous cell carcinomas of the larynx (LSCC) revealed clonal chromosome aberrations in 56 tumors. Simple karyotypic changes (less than four aberrations per clone) were found in 24 cases, and the remaining 32 tumors had complex karyotypes with multiple numerical as well as unbalanced structural rearrangements. Extensive intratumor heterogeneity, in the form of multiple related subclones or unrelated clones, was observed in a large fraction of the tumors. The structural changes most often affected chromosomes 3, 1, 11, 7, 2, 15, 5, 4, 8, and 12, with rearrangements in the centromeric regions, i.e., the centromeric bands p10 and q10 and the juxtacentromeric bands p11 and q11, accounting for 43% of the total breakpoints. The most common imbalances brought about by numerical and unbalanced structural rearrangements were loss of chromosomal region 3p21-pter, chromosome arms 4p, 6q, 8p, 10p, 13p, 14p, 15p, and 17p, and gain of chromosomal regions 3q21-qter, 7q31-pter, and 8q. Among 17 recurrent aberrations identified, the most common were i(8q), hsr(11)(q13), i(3q), i(5p), and del(3)(p11). No statistically significant association was found between major karyotypic features and histological differentiation or TNM stage. The karyotypic features of the LSCC were also compared with previously published oral SCC, a subgroup of SCC that has been more extensively characterized cytogenetically. No clear-cut karyotypic differences were found between LSCC and oral SCC, with the exception that i(8q) was significantly more frequent among the latter.

Adult↗

PubMed1999

Dominant human herpesvirus type 8 RNA transcripts in classical and AIDS-related Kaposi's sarcoma.

Skin biopsy sections of Kaposi's sarcoma (KS) from 25 patients (5 AIDS-related, 20 classical cases) were histologically staged and hybridized in situ with oligonucleotide probes for constitutively transcribed human herpesvirus 8 (HHV-8) mRNA T0.7 and T1.1 using a colourimetric technique. T1.1 increases during experimental induction of the viral lytic phase in the HHV-8-infected lymphocytes of primary effusion lymphoma and its colourimetric detection in KS cells presumably corresponds to virion production. Immunostaining with anti-CD20, CD45RO, MAC 387, and alpha-smooth muscle actin was performed following T1.1 in situ hybridization (ISH). When the amount of T0.7 was above the detection threshold, the signal was made up of multiple coarse intranuclear dots in most spindle cells. Of the six early-stage lesions, none produced a T1.1 hybridization signal. Two of four AIDS-related and two of eight classical lesions with incipient spindle cell growth produced rare but distinct dense intranuclear T1.1 signals in endothelial cells lining narrow tubes. In contrast, eight of ten (all classical KS) mature spindle cell lesions displayed a signal, scattered in up to 2 per cent of spindled endothelial cells. Cell types other than endothelium produced no T1.1 hybridization signal in double stains. The results are consistent with other published data indicating latent HHV-8 infection in endothelium and its tumour cell progeny, with simultaneous virion production in a small subset of cells. Immunodeficiency may not influence the number of cells lytically infected with HHV-8 in early KS, in contradistinction to other herpesviruses with latent-lytic cycles.

Acquired Immunodeficiency Syndrome↗

PubMed1999

CHOP versus MACOP-B in aggressive lymphoma--a Nordic Lymphoma Group randomised trial.

BACKGROUND: The long-term survival of patients with advanced stage aggressive lymphoma has not improved significantly during the last twenty years. In a randomised trial, the efficacy of MACOP-B, a six-drug weekly chemotherapy regimen, was compared to CHOP, the current standard regimen, in terms of overall and failure-free survival, toxicity and health related quality of life. PATIENTS AND METHODS: Four hundred five patients with aggressive lymphoma, stage II-IV, age 18-67, were randomised to receive either 12 weeks of MACOP-B or 8 courses of CHOP over 24 weeks. Special emphasis was put in the definition of Ann Arbor stage in extranodal disease. A subset of 95 patients also entered a quality of life study, based on the EORTC QLQ-C30. RESULTS: Thirty-one patients were ineligible. Among the remaining 374 patients, the median age was 52 years. According to the age-adjusted International Prognostic Index, 37% were 'high-intermediate' or 'high-risk' patients. No difference could be demonstrated, either in overall survival (60% at five years in the MACOP-B group and 59% in the CHOP group) or in failure-free survival (47% at five years with MACOP-B and 44% with CHOP). In terms of quality of life, physical function and global quality of life were more impaired in patients receiving MACOP-B, who also exhibited more non-haematological toxicity. CONCLUSION: No superiority of MACOP-B compared to CHOP could be demonstrated. CHOP remains the treatment of choice in low-risk patients. At present, intensified or experimental treatment should be reserved for high-risk disease.

Adolescent↗

PubMed1999

Tenascin-C modulates tumor stroma and monocyte/macrophage recruitment but not tumor growth or metastasis in a mouse strain with spontaneous mammary cancer.

The local growth of tumors and their ability to metastasize are crucially dependent on their interactions with the surrounding extracellular matrix. Tenascin-C (TNC) is an extracellular matrix protein which is highly expressed during development, tissue repair and cancer. Despite the high levels of TNC in the stroma of primary and metastatic tumors, the function of TNC is not known. In the present study we have crossed TNC-null mice with a mouse strain where both female and male mice spontaneously develop mammary tumors followed by metastatic disease in the lungs. We report that the absence of TNC had no effect on the temporal occurrence of mammary tumors and their metastatic dissemination in lungs. Furthermore, the number and size of tumors, the number and size of metastatic foci in the lungs, the proliferation rate and apoptosis of tumor cells and tumor angiogenesis were not altered in the absence of TNC. Histological examination revealed that the tumor organisation, however, was modulated by TNC. In the presence of TNC both primary as well as metastatic tumors were organised in large tumor cell nests surrounded by thick layers of extracellular matrix proteins. In the absence of TNC these tumor cell nests were smaller but still separated from each other by extracellular matrix proteins. In addition, the TNC-null stromal compartment contained significantly more monocytes/macrophages than tumor stroma from TNC wild-type mice. Using in vitro coculture experiments we show that TNC-null tumor cells were still able to activate the TNC gene in fibroblasts which express low basal levels of TNC. Altogether these data indicate that TNC has a very limited role during the spontaneous development and growth of mamary tumors and their metastasis to the lungs.

Animals↗

PubMed1999

Abnormal cell cycle regulation in malignancy.

The cell cycle consists of an initial growth phase (G1), DNA replication (S), a gap phase (G2), and mitosis (M), after which the cell may differentiate or enter the resting state (G0). The cycle is driven by a number of positive and negative regulatory phosphorylation and dephosphorylation events, involving protein kinases, protein phosphatases, cyclins, cyclin-dependent kinases, and cyclin-dependent kinase inhibitors, that ultimately impinge on the activity of transcription factors. Unreplicated or damaged DNA blocks the progression of the cell cycle at checkpoints, including a late G1 checkpoint regulated by the dephosphorylated retinoblastoma protein and a late G2 checkpoint regulated by the phosphorylation of cyclin-dependent kinase 1 complexed with cyclin B. Many cell cycle regulator genes may be considered proto-oncogenes or tumor suppressor genes, and point mutations, amplifications, deletions, or rearrangements involving their loci, particularly those in the "RB pathway," are associated with various tumors. A number of molecular techniques may be used to detect genomic alterations or posttranscriptional modifications, but immunohistochemistry remains the most common method to determine expression levels of a regulatory protein. Multivariate analysis of the usefulness in prognosis has been applied most often for the general proliferation antigen Ki-67.

Biomarkers, Tumor↗

PubMed1998

K-ras mutations in sinonasal adenocarcinomas in patients occupationally exposed to wood or leather dust.

Of 39 males diagnosed with sinonasal adenocarcinomas over 30 years in the Lund University Hospital catchment area (1.5 million inhabitants), archival tumor tissue was available from 29. Of these, 16 had been exposed to wood dust and three had been exposed to leather dust. The intestinal-type and papillary adenocarcinomas were more common in the exposed patients (P = 0.0002, Fisher's exact test). The tumors from all but one of the 29 sinonasal adenocarcinomas could be analyzed for point mutations at codons 12, 13 and 61 of the K-ras gene. Four mutations were detected in the 28 tumors. The three mutations in the patients exposed to wood and leather dust were all G:C --> A:T transitions, with two at position 2 of codon 12 and one at position 2 of codon 13. The high proportion of G:C --> A:T mutations in this rare tumor may reflect a genotoxic agent in wood and leather dust.

Adenocarcinoma↗

PubMed1998

Cytogenetic analysis of four angiosarcomas from deep and superficial soft tissue.

Angiosarcomas are rare malignant vascular tumors, most commonly found in the skin or superficial soft tissue. We found clonal chromosome aberrations in four short-term cultured angiosarcomas. Two cases were diagnosed as epithelioid angiosarcomas, and one as postmastectomy angiosarcoma. Two of the tumors were deep-seated and two were superficial. Angiosarcomas from deep, soft tissue are extremely rare and have never been cytogenetically investigated before. The chromosome number ranged from hypodiploid to hypertriploid. When the results from the present study were combined with data on the four previously reported cytogenetically aberrant angiosarcomas, the most frequently rearranged chromosomes were 5, 7, 8, 13, 15, 20, 22, and the Y chromosome. Recurrent changes, each found in three of these eight angiosarcomas, were gains of 5pter-p11, 8p12-qter, and 20pter-q12, losses of 7pter-p15 and 22q13-qter, and -Y in two of three men.

Adult↗

PubMed1998

Cytogenetic and molecular genetic demonstration of polyclonality in an acinic cell carcinoma.

The paradigm that human malignancies are monoclonal has been questioned during recent years by the finding of unrelated, cytogenetically aberrant clones in short-term cultures from certain tumour types, notably carcinomas of the breast, skin and upper aerodigestive tract. In order to analyse whether cytogenetically unrelated clones are also unrelated at the molecular level, we analysed the X-chromosome inactivation status in cell cultures from a cytogenetically highly polyclonal acinic cell carcinoma of the parotid gland. By using cell cultures dominated by a single abnormal clone, obtained through in vitro culturing for 3-5 passages, we showed that the different clones must indeed have originated from different cells.

Aged↗

PubMed1998

p53 mutation, but not p53 overexpression, correlates with survival in head and neck squamous cell carcinoma.

Survival in squamous cell carcinoma of the head and neck (HNSCC) was compared with overexpression and mutation of the p53 gene. Archival tissue from 77 tumours was analysed for protein expression using immunohistochemistry (IHC) with the monoclonal antibody Do-7, and for the presence of mutation in exons 5-8 using single-stranded conformation polymorphism (SSCP), followed by DNA sequencing in SSCP-positive cases. p53 expression was scored as high (>70% nuclei stained) in 25 (32%) tumours, as intermediate (10-70% nuclei stained) in 19 (25%) tumours and as low (<10% nuclei stained) in 33 (43%) tumours. Twelve (18%) tumours exhibited gene mutation (ten missense and two nonsense mutations) and an additional five tumours contained changes that could not result in amino acid substitution or protein truncation. There was no correlation between gene expression and mutation, mutations being equally frequent in tumours with either high (4/25), intermediate (4/19) or low protein expression (4/33). Fifty-eight patients were eligible for survival analysis. There was a strong correlation between p53 mutation and cause-specific survival; median survival among mutated cases was 12.5 months compared with >160 months among non-mutated patients (P < 0.005). There was no correlation between p53 overexpression and survival. The results suggest that p53 mutation status is an important prognostic factor in HNSCC, and that IHC analysis of protein overexpression is an inadequate measure of gene mutation in these tumours.

Carcinoma, Squamous Cell↗

PubMed1997

Risk of second cancers in classical Kaposi's sarcoma.

An association between Kaposi's sarcoma (KS) and malignant lymphoma has been suspected for many years. Both cancers belong to the group of malignancies associated with immune suppression and have been known to occur in the same individual. Accordingly, a common etiology has been suspected. Through linkage within the Nordic cancer registries, we studied the occurrence of cancers in a population-based cohort of 741 patients with classical KS. The relative risk of subsequent malignancies was expressed as the ratio of the observed numbers of cancer to the numbers expected based on age-, sex-, period- and country-specific incidence rates, i.e., the standardized incidence ratio (SIR). A total of 104 cancers was observed during 5,802 person-years of follow-up, which was close to the expected 98.8 cases (SIR, 1.05). During the first year of follow-up, 3 lymphomas were observed, which is in significant excess of the 0.2 lymphomas expected (SIR, 13.0). In contrast, no lymphomas occurred in the period beyond the first year of follow-up vs. 2.3 expected. Cancers of the buccal cavity and pharynx (SIR, 10.6; n = 4) and of the colon (SIR, 2.7; n = 7) occurred in excess among women but not among men. Accordingly, our results indicate that patients with classical KS are not at increased risk of cancer in general. In particular, the overall risk of lymphomas was not significantly increased. The high relative risk of malignant lymphoma immediately after KS was based on a limited number of cases, and this observation is unlikely to indicate a common etiology.

Age Factors↗