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S Hellman

Publications and source records attributed to S Hellman.

At least 37 records · Page 2Linked to original sources
PubMed1998

Aging, progression, and phenotype in breast cancer.

The malignant potential of cancer is dynamic, changing throughout the natural history of a tumor. For breast cancer, this is especially important because the clinical presentation has been altered by the increasing use of screening mammography. The varied outcomes of similarly staged patients is most consistent with breast cancer not being a homogeneous disease, but rather a spectrum of disease states that have varying capacities for growth and metastasis. Evolutionary pressures are at play in both tumor development and during the clinically apparent portion of the life of a tumor and are responsible for this spectrum of tumor heterogeneity. Required of tumors is the development of critical phenotypic attributes: growth, invasion, metastagenicity, and angiogenesis. The combination and permutation of genetic changes that result in the acquisition of these characteristics may vary, but they must result in some expression of each of these phenotypes. The expression of these attributes will differ as tumors evolve to become more adept at each of these characteristics. Recognizing tumor heterogeneity emphasizes the need to determine an individual tumor's place in the evolutionary spectrum. This may be accomplished using clinical features such as size, nuclear grade, and patient age, as well as by examining markers of angiogenesis, metastatic capacity, and proliferation. Identification of the extent of tumor progression with regard to these major tumor phenotypes should allow individual therapy to be fashioned for each patient.

Aging↗
PubMed1997

Race and clinical outcome in breast cancer in a series with long-term follow-up evaluation.

PURPOSE: To compare the outcome of African American (AA) and Caucasian (C) breast cancer patients who had equivalent disease extent and were similarly treated. PATIENTS AND METHODS: We compared prognostic characteristics, treatment, and outcome of 1,037 C and 481 AA breast cancer patients treated with mastectomy between 1946 and 1987. The median follow-up duration was 15.6 years. RESULTS: During the study period, there was a successive increase in the percent of patients who presented with early breast cancer. Between 1980 and 1987, 35.1% AA versus 47.6% C patients had < or = 2-cm tumors and 50.0% AA versus 61.9% C patients were node-negative, while between 1946 and 1959, 27.7% AA and 31.3% C had < or = 2-cm tumors and 41.5% AA versus 40.4% C patients were node-negative. The treatments were similar during the study period. The 20-year disease-free survival (DFS) rate of AA compared with C patients with node-negative < or = 2-cm, 2.1- to 4-cm, and greater than 4-cm tumors and of patients with one to three and > or = four positive nodes was not significantly different. Equal-size tumors had similar proportion of positive axillary nodes in AA compared with C patients. The DFS for AA patients compared with C patients was similar in the periods 1946 to 1959, 1960 to 1969, and 1970 to 1979, but was lower between 1980 and 1987 (P = .02). In multivariable analysis, race was not a significant variable. CONCLUSION: In this large group of uniformly treated breast cancer patients, race was not an independent factor that influenced outcome. The racial differences seen between 1980 and 1987 are likely because of a larger percent of greater than 2-cm and node-positive tumors in AA patients. Education and access to early diagnosis should reduce or eliminate the racial differences seen.

Actuarial Analysis↗
PubMed1997

Effect of ethnicity on adherence to diabetic regimen.

OBJECTIVE: Evaluating the effectiveness of treatment of diabetic patients in our institution led us to seek the relationship between adherence to diabetic regimens and several demographic variables. Of primary importance was ethnicity, which the practitioners believed affected adherence. Other variables researched were: marital status, gender, weight, age, type and duration of diabetes, socioeconomic status, occupation and education. PATIENTS: Adult diabetic patients (215) seen in the diabetic clinic of a large health maintenance organization who had their diabetes for at least 6 months. METHODS: Data were collected from interviews and medical records over a two-year period. RESULTS: Ethnicity, the major test variable, did not show a relationship to adherence. Two variables, gender and weight, showed a trend to significant relationship to adherence. Chi square and t tests were used, depending on the type of data. CONCLUSIONS: Since there is no difference in adherence between ethnic groups, standardized care protocols are warranted, since they are cost-efficient.

Adult↗
PubMed1996

Angiogenesis as a predictor of long-term survival for patients with node-negative breast cancer.

BACKGROUND: Angiogenesis (the formation of new blood vessels) is necessary for tumor growth and metastasis. PURPOSE: We investigated whether angiogenesis as measured by microvessel count (MVC) predicts clinical outcome in a series of patients with axillary lymph node-negative breast cancer who received no adjuvant therapy and who were followed for a long period of time. Our long-term goal is to identify those patients who may or may not need adjuvant chemotherapy. METHODS: Pathologic archival material and clinical information were analyzed for 167 patients treated with mastectomy from 1941 through 1987; none received adjuvant treatment. The median follow-up time among living patients was 15.4 years (range, 2.6-35.8 years). Ninety-six (58%) patients had a tumor size of 2 cm or less, 52 (31%) had tumors of 2.1-3 cm, and 19 (11%) had tumors of larger than 3 cm. Paraffin-embedded tissue sections were stained for expression of CD34 antigen on microvessel-associated endothelial cells by use of a monoclonal anti-CD34 antibody. Vascularity was defined as the number of microvessels (average of the three highest counts) per high-power microscopic field (400 x magnification) in the area of highest vascular density. A high vascular count was defined as 15 or more microvessels per field. Actuarial survival curves were calculated according to the Kaplan-Meier method and comparisons were made with the logrank test. The Cox proportional hazards model was used for multivariate analysis. All P values were based on two-sided testing. RESULTS: The 20-year disease-free survival (DFS) for the 167 node-negative patients treated with mastectomy and no adjuvant therapy was 74.8% (95% confidence interval [CI] = 64.7%-82.0%). The 20-year DFS was 93.1% (95% CI = 79.9%-97.7%) if the MVC was low versus 68.9% (95% CI = 56.8%-78.0%) if the MVC was high (P = .018). This difference was maintained irrespective of tumor size: for tumor size of 2 cm or less (93.3% [95% CI = 75.3%-98.3%] versus versus 67.8% [95% CI = 50.1%-80.3%]) and for tumor size of larger than 2 cm (92.3% [95% CI = 56.6%-98.9%] versus 70.9% [95% CI = 54.6%-81.6%]). However, the likelihood of a high MVC was greater with large tumors (P = .05). The proportions of tumors with low and high MVC were 33% and 67%, respectively, if the tumor size was 2 cm or less, and 20% and 80%, respectively, if tumor size was larger than 2 cm. There was no significant difference in the 20-year DFS as a function of tumor grade (P = .2). After combining patients with tumors of nuclear grades 2 and 3 compared with those of nuclear grade 1, the 20-year DFS was 93.9% (95% CI = 77.2%-98.4%) for low MVC versus 66.9% (95% CI = 52.2%-78.0%) for high MVC (P = .02). In a multivariate analysis that included the variables tumor size, age, nuclear grade, estrogen receptor status, and MVC, only MVC appeared to be an independent prognostic indicator (P = .04). CONCLUSIONS: Angiogenesis as measured by MVC is a reliable independent prognostic marker of long-term survival in patients with node-negative breast cancer. The prognostic usefulness of this marker is maintained after more than 15 years of follow-up. A low MVC identifies a subgroup of patients with DFS of 92% or more, independent of tumor size or grade.

Adult↗
PubMed1996

Tumor necrosis factor alpha (TNF-alpha) gene therapy targeted by ionizing radiation selectively damages tumor vasculature.

Intratumoral injection of an adenoviral vector containing radiation-inducible DNA sequences of the Egr-1 promoter linked to a cDNA encoding tumor necrosis factor (TNF) alpha (Ad.Egr-TNF) enhances the tumoricidal action of ionizing radiation in a human epidermoid carcinoma xenograft (SQ-20B). The dominant histopathological feature in tumor-bearing animals treated with Ad.Egr-TNF and irradiation is extensive intratumoral vascular thrombosis and tumor necrosis. Thrombosis and necrosis are not observed in animals treated with either the viral construct encoding TNF-alpha or radiation and did not occur in irradiated normal tissues adjacent to tumor in animals injected with Ad.Egr-TNF. To determine if the occlusive effects of Ad.Egr-TNF and X-irradiation were specific for tumor vessels, non-tumor-bearing mice were irradiated after receiving i.m. injection of Ad.Egr-TNF at viral titers 20-100 times greater than titers injected intratumorally. No vascular thrombosis was observed in the treated normal tissues. Combined Ad.Egr-TNF and radiation produced occlusion of tumor microvessels without significant normal tissue damage. Taken together, these data suggest that the interaction between radiation inducible TNF-alpha and X-irradiation occurs selectively within the tumor vessels.

Animals↗
PubMed1996

Radiation oncology.

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Androgen Antagonists↗
PubMed1996

Natural history of node-positive breast cancer: the curability of small cancers with a limited number of positive nodes.

PURPOSE: The long-term outcome of node-positive breast cancer was analyzed to determine the risk of metastatic disease as a function of tumor size and number of positive nodes. METHODS: From 1927 to 1987, 501 women with node-positive breast cancer were treated at the University of Chicago Medical Center. Patients were treated with radical, extended radical, or modified radical mastectomy. Forty-eight patients received multiagent chemotherapy, and 118 were treated with hormonal therapy. The mean survival duration is 120 months, with a maximal follow-up time of 485 months (40 years). RESULTS: The number of nodes that contained metastatic disease and the pathologic size of the primary tumor were significant determinants of disease-free-survival (DFS) by multivariate analysis (P < .001). In patients with fewer than four positive nodes, tumor size was of prognostic importance, with small tumors more likely to be cured by local-regional therapy. The 20-year DFS rate for patients with one positive node was 69%; however, if the primary tumor was < or = 2 cm, the 20-year DFS rate was 81%, compared with 59% if the tumor was larger than 2 cm. Patients with two or three positive nodes had a 73% 20-year DFS rate if the tumor size was < or = 2 cm, compared with 53% 20-year DFS in patients with tumors larger than 2 cm. CONCLUSION: In patients with T1 lesions with less than four nodes positive, the long-term DFS rate is comparable to that for node-negative breast cancer of the same size. Four or more nodes positive is an indicator of likely systemic disease.

Adrenalectomy↗
PubMed1995

Genetic radiotherapy overcomes tumor resistance to cytotoxic agents.

We report that radiation enhances gene therapy of a radioresistant tumor by upregulating the induction of a chimeric gene encoding a radiosensitizing protein, tumor necrosis factor alpha (TNF-alpha). We ligated the radiation-inducible CArG elements of the radiation-inducible Egr-1 promoter/enhancer region upstream to the transcriptional start site of the human TNF cDNA (pE425-TNF). This construct was transfected using cationic liposomes into the variant murine fibrosarcoma cell line, P4L. The P4L cell line was both radioresistant (D0 = 188) and resistant to TNF. After a single intratumoral injection of 10 micrograms of pE425-TNF in cationic liposomes and two 20-Gy doses of irradiation, mean tumor volumes were significantly reduced in P4L tumors as compared to those receiving either pE425-TNF in liposomes or radiation alone (P = 0.01). TNf protein in P4L tumors was induced by radiation as high as 29 times control levels and remained detectable for 14 days. Our data indicate that combined gene therapy using liposomes, together with ionizing radiation to locally activate the induction of a radiosensitizing protein, is successful at overcoming resistance to both TNF and radiation.

Animals↗
PubMed1995

Spatial and temporal control of gene therapy using ionizing radiation.

Activation of transcription of the Egr-1 gene by X-rays is regulated by the promoter region of this gene. We linked the radiation-inducible promoter region of the Egr-1 gene to the gene encoding the radiosensitizing and tumoricidal cytokine, tumour necrosis factor-alpha (TNF-alpha) and used a replication-deficient adenovirus to deliver the Egr-TNF construct to human tumours growing in nude mice. Combined treatment with Ad5.Egr-TNF and 5,000 cGy (rad) resulted in increased intratumoral TNF-alpha production and increased tumour control compared with treatment with Ad5.Egr-TNF alone or with radiation alone. The increase in tumour control was achieved without an increase in normal tissue damage when compared to tissue injury from radiation alone. Control of gene transcription by ionizing radiation in vivo represents a novel method of spatial and temporal regulation of gene-based medical treatments.

Animals↗