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Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

SJL mice spontaneously develop B-cell lymphomas that can be propagated by transplantation into syngeneic mice. These tumors usually have an indolent phenotype and require at least several weeks to produce morbidity following transplantation. However an aggressive lymphoma (RCS5) has been found that produces morbidity within days of transplantation. RCS5 cells fail to express the H-2Ds class I major histocompatibility complex antigen, whereas indolent tumors express H-2Ds. To identify genetic factors that may contribute to the tumorigenicity of B-cell lymphomas in SJL mice, tumor genomes were analyzed for mutations in cellular oncogenes. No rearrangements were detected by Southern hybridization analysis in tumors at the abl, myc, mbcl-2, Ha-ras, Ki-ras and raf loci. Indolent tumors were not rearranged at the myb oncogene, however alterations were detected in both myb alleles in RCS5. Northern hybridization analysis on RNA from in vivo-derived tumor preparations failed to detect any myb transcripts in RCS5. The loss of normal myb expression could directly contribute to the aggressive phenotype of RCS5. Alternatively, expression of the RCS5 myb allele may have contributed to early stages of tumor development. The possibilities that the observed myb mutations affect tumor aggressiveness and H-2Ds expression are discussed.
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PMID:Loss of myb expression in an aggressive SJL/J B-cell lymphoma. 188 9

Smooth-muscle tumors are an interesting group of tumors that show considerable site specificity in their pathobiology. Recent work has also shown that some previously so-called smooth-muscle tumors were not, in fact, truly leiomyogenic, hence the origin of the more embracing term stromal tumors. The purpose of this retrospective study was to delineate the tumor subsets constituting colorectal stromal tumors, and to determine the histopathologic correlates for biologic aggressiveness for these tumors. The cohort was constituted of 12 patients; the mean follow-up was 6.6 years with a median of 5.0 years. Immunohistochemical evaluations showed tumoral positivity for muscle-specific actin (12 of 12), vimentin (11 of 12), desmin (two of 12), and S100 protein (zero of 12). Electron microscopic examinations corroborated this leiomyogenicity profile (five of five). Semiquantitative histomorphometric analysis showed that tumor size, cellularity, mitoses, and necrosis, in that order, correlated with biologic aggressiveness. The immunohistochemistry results for this cohort of colorectal stromal tumors vindicated the traditional histochemical evaluations in that all tumors showed features of leiomyogenicity. For colorectal smooth-muscle tumors, tumor size appears to be the best predictor for biologic aggressiveness. This study reinforces the concept of site-specificity for smooth-muscle tumors.
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PMID:Colorectal smooth-muscle tumors. A pathobiologic study with immunohistochemistry and histomorphometry. 189 28

A microfluorometric analysis was performed to analyse the DNA content of 42 medulloblastomas (MBs) and to seek correlations, if any existed, between the DNA distribution and ploidy values, neoplasm types (i.e. classic vs desmoplastic), histological features of aggressiveness, and immunocytochemical features indicating glial and/or neuronal differentiation. Thirty-one cases were classified as classic and 11 cases as desmoplastic MBs. Ten of 11 desmoplastic MBs had a near-diploid main mode and the remaining 1 case had a near-tetraploid main mode. Moreover, 10 of 11 (90%) cases showed a "monomodal" DNA distribution diagram. All these cases showed a uniform histology. In contrast, classic MBs represented a heterogeneous group of neoplasms. Twenty-two cases were near-diploid, 5 cases were near-tetraploid and 3 cases were near-triploid. The histogram type distribution showed a similar heterogeneity. Twelve of 31 (39%) cases had a monomodal histogram, 12 (39%) cases had a bimodal diagram and 7 (22%) cases a complex DNA distribution. There was a statistically significant difference (P less than 0.001) in terms of prevalence of DNA monomodal histograms between classic and desmoplastic MBs. Significant correlations were not observed among classic MBs between histological features of aggressiveness, type and degree of differentiation and DNA distribution. The present study indicates that desmoplastic MBs represent a homogeneous group of neoplasms in terms of histology and DNA distribution. In contrast, classic MBs are lesions with different degrees of histologically apparent aggressiveness and a complex DNA distribution.
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PMID:"Desmoplastic" versus "classic" medulloblastoma: comparison of DNA content, histopathology and differentiation. 190 Sep 66

MHC class I and II molecules play an important role in specific interactions with cells of the immune system. Endogenous or exogenous antigens are presented to the clonotypic receptor of T cells as small peptides associated to MHC molecules. Qualitative or quantitative variation in the expression of these molecules in the surface of tumor cells could have important implications in anti-tumor immune responses. We have analysed 344 human tumors for HLA class I and II expression and found that 10-30% of tumors present a total loss of HLA ABC molecules. In addition, HLA-A or -B locus-specific losses were also detected. These alterations have been correlated with tumor aggressiveness in breast and laryngeal carcinomas. We also have observed that the expression of HLA ABC molecules in autologous metastasis did not always correspond with the expression detected in the primary tumor. In laryngeal carcinomas HLA-DR expression was associated with an excellent prognosis. We have observed in most tumors that the absence of class I molecules usually corresponds with a simultaneous loss of heavy chain and beta 2 microglobulin expression and with a low level of the mRNA specific for class I genes. Nevertheless, a variety of mechanisms are involved since in colon tumors the absence of expression is caused by beta 2 microglobulin down regulation. Also post-transcriptional mechanisms may be involved in the differential expression of HLA-A and -B locus products. There is no doubt that a more exact knowledge of the mechanisms that produce alteration in the expression of these antigens will help to manipulate MHC gene expression in human tumors and to induce a more efficient immune response.
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PMID:MHC expression on human tumors--its relevance for local tumor growth and metastasis. 191 16

The basaloid salivary carcinoma is proposed as the malignant counterpart of the basal cell or basaloid monomorphic adenoma. The carcinoma can arise de novo or by evolution from a maternal monomorphic adenoma. Particularly at risk for the latter sequence is the dermal analogue monomorphic adenoma. Preponderantly a parotid gland neoplasm, the basaloid carcinoma appears to be a biologically low-grade carcinoma with a low mortality but with a respectable local aggressiveness and recurrence rate.
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PMID:Basaloid salivary carcinoma. 195 75

The authors, in reaffirming the high incidence of the mucin-producing type of colo-rectal adenocarcinoma in young patients, underline the considerable aggressiveness of this tumor. After a brief note on the etiopathogenetic hypothesis which could explain such behavior, the factors usually contributing to a worsening of the prognosis are reviewed. Thus, the Authors report their series and conclude affirming as indispensable to arrive to an early diagnosis.
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PMID:[Colorectal carcinoma in young patients: review of 10-year experience]. 196 13

c-erbB-2 Protein expression was investigated in a series of fifty primary breast cancers by means of a specific monoclonal antibody and immunocytochemistry. Specific staining was observed at the plasma membrane level of neoplastic cells, according to the reported localization of c-erbB-2 protein. Sixty-four percent of tumors scored positive, with a variable amount of stained cells. The rate of protein expression was found to exceed the reported gene amplification. No relationship was observed between c-erbB-2 protein staining and age, menopausal status or histologic subtypes. An inverse association was found between c'erbB-2 protein staining and estrogen receptor content of tumors, assayed by immunocytochemistry. A positive relationship was observed between c-erbB-2 protein expression and presence of axillary node metastasis. These findings suggest that c-erbB-2 protein expression is a marker of tumor aggressiveness and that its prognostic power deserves further investigation both in node-positive and node-negative patients.
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PMID:Immunohistochemical expression of c-erbB-2 in human breast cancer by monoclonal antibody: correlation with lymph node and ER status. 197 54

A study was conducted to compare results of transrectal ultrasound with pathologic findings on 116 patients who underwent radical prostatectomy for treatment of prostate cancer. In 96% (111 of 116), transrectal ultrasound guided biopsies of a hypoechoic lesion proved cancer; seven patients had known Stage A cancer; one patient had cancer detected by palpation and not detected by ultrasound. Cancers in the outer gland (peripheral and central zones) were compared with cancers in the inner gland (transition zone) by both ultrasound and pathology. Forty-eight percent (52 of 108) of cancers originating in the outer gland showed extraprostatic extension (Stage C disease). The primary sites of tumor escape from the outer gland were the prostatic capsule (38%), anterior fibromuscular stroma (5%), seminal vesicle (18%), the base of the gland at the neurovascular bundle (21%), and the apex (31%). Twenty-two percent (17 of 54) of cancers originating in the inner gland (transition zone) showed extraprostatic extension (Stage C disease). The primary sites of tumor escape from the inner gland were the anterior fibromuscular stroma (6%) and apex (11%). Both histologic and biologic differences between outer and inner gland cancers were found when tumor size was controlled. Gleason scores were significantly different for inner and outer gland cancers, with mean scores of 6.2 +/- 1.6 and 7.4 +/- 0.9, respectively. An odds ratio of 8.6 confirmed the increased risk of extraprostatic extension for outer gland cancer. Outer gland cancers showed increased aggressive behavior of both histologic and biologic nature. The difference in biologic aggressiveness of outer and inner gland cancers has definite implications for treatment options. Use of other diagnostic parameters, such as DNA ploidy, may help to determine which cancers to treat and when to treat them; this may have more relevance for cancers originating in the inner gland. Strategic transrectal ultrasound guided biopsy affords accurate tumor mapping and staging when modes of internal spread and escape of cancer from both outer and inner gland are known. Thus, transrectal ultrasound may be our "window of observation" through which additional research may explain the histologic and biologic discrepancies between outer and inner gland cancers.
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PMID:Prostate cancer: transrectal ultrasound and pathology comparison. A preliminary study of outer gland (peripheral and central zones) and inner gland (transition zone) cancer. 199 Dec 71

The antitumor effect of alkyl-lysophospholipid (ALP) was studied on a continuous glioma cell line (GaMg) as well as on tumor spheroids obtained from three different primary brain tumor biopsies. GaMg monolayer growth was reduced by 50% after treatment with 30 microM ALP; cells accumulated in the G2M phase of the cell cycle as determined by flow-cytometric analyses. Tumor spheroid growth was reduced by 25 and 44% during treatment with 10 and 30 microM ALP, respectively. These drug concentrations also caused a severe destruction of spheroids. No effect on growth or morphology was seen in spheroids treated with 0.1 and 1.0 microM ALP. ALP caused a dose-dependent inhibition of invasion by GaMg tumor spheroids into brain aggregates. After 168 h of 1.0 microM ALP treatment, the volume of the intact brain aggregate was 90% larger than that in the untreated co-cultures. To further investigate the efficacy of ALP as an anti-invasive drug, co-cultures were performed with specimens obtained from three primary brain tumors: a highly invasive glioblastoma multiforme, an anaplastic astrocytoma, and an astrocytoma. Treatment of spheroids from the most invasive tumor with ALP caused a 7-fold preservation of normal brain tissue relative to control co-cultures. Moreover, the sensitivity of primary glioma spheroids to the anti-invasive effect of ALP seemed to be associated with the aggressiveness of the tumor; spheroids from the more malignant specimen (glioblastoma multiforme) were more sensitive than those from the less aggressive tumors. The anti-invasive effect seen with nontoxic concentrations of ALP may prove valuable in the treatment of malignant gliomas.
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PMID:Effect of alkyl-lysophospholipid on glioblastoma cell invasion into fetal rat brain tissue in vitro. 199 62

A microfluorometric DNA study was conducted on isolated cells from 64 fragments of ovarian epithelial tumors. Data analysis considered the DNA content of the main stemline and the prevalence of cells in the different compartments of the DNA ploidy histogram in relation to the mitotic activity index and the histologic architecture. Main stemlines were found remarkably stable in different parts of the same tumor. Peridiploid (1.8c to 2.2c) stemlines were found both in well-differentiated and in poorly differentiated tumors. However, low aneuploid (2.2c to 3.0c) stemlines were mostly found in nonsolid tumors and high ploidy (3.2 to 5.04 c) stemlines were prevalent in solid tumors. A comparative analysis between DNA ploidy parameters and mitotic activity was useful to evaluate the expanding modalities of neoplastic cell populations. This analysis revealed that several tumors accumulate an excessive amount of heteroploid cells and others an excessive amount of G2 cells. Yet, most neoplastic cell populations vary from slow to rapidly growing patterns without relevant abnormalities in their ploidy graphic profiles. No relationship was found between stemline ploidy and histologic architecture compared with expanding modalities. These findings indicate that multifaced criteria combining features such as main ploidy, graphic profile, mitotic rate, and histologic architecture measured on one or more microsamples of the same tumor may help to objectively estimate the aggressiveness reached by the neoplastic cells at the time of clinical presentation.
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PMID:A multifaced DNA ploidy analysis to determine ovarian carcinoma aggressiveness. 200 1


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