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G Hortobagyi

Publications and source records attributed to G Hortobagyi.

At least 37 records · Page 2Linked to original sources
PubMed1996

Results of MDR-1 vector modification trial indicate that granulocyte/macrophage colony-forming unit cells do not contribute to posttransplant hematopoietic recovery following intensive systemic therapy.

To formally test the hypothesis that the granulocyte/macrophage colony-forming unit (GM-CFU) cells can contribute to early hematopoietic reconstitution immediately after transplant, the frequency of genetically modified GM-CFU after retroviral vector transduction was measured by a quantitative in situ polymerase chain reaction (PCR), which is specific for the multidrug resistance-1 (MDR-1) vector, and by a quantitative GM-CFU methylcellulose plating assay. The results of this analysis showed no difference between the transduction frequency in the products of two different transduction protocols: "suspension transduction" and "stromal growth factor transduction." However, when an analysis of the frequency of cells positive for the retroviral MDR-1 vector posttransplantation was carried out, 0 of 10 patients transplanted with cells transduced by the suspension method were positive for the vector MDR-1 posttransplant, whereas 5 of 8 patients transplanted with the cells transduced by the stromal growth factor method were positive for the MDR-1 vector transcription unit by in situ or in solution PCR assay (a difference that is significant at the P = 0.0065 level by the Fisher exact test). These data suggest that only very small subsets of the GM-CFU fraction of myeloid cells, if any, contribute to the repopulation of the hematopoietic tissues that occurs following intensive systemic therapy and transplantation of autologous hematopoietic cells.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1996

Technical approach for the study of the genetic evolution of breast cancer from paraffin-embedded tissue sections.

We have optimized a technique that allows the study of numerous chromosomal loci (n = 20-50) from single paraffin-embedded tissue sections by microsatellite length polymorphism analysis. DNA samples from normal and breast cancerous tissue can be obtained from the same section by means of microdissection. This technique was further improved by subjecting DNA to several cycles of amplification with a degenerate (universal) primer and then with specific microsatellite primers. This amplified DNA was also used to screen for mutations in the p53 gene by means of PCR-SSCP. In addition adjacent tissue sections were used to assess specific chromosome copy number by interphase cytogenetic analyses (chromosome in situ hybridization) and to analyze expression of specific genes such as p53 and ERBB2. As an example of the use of our approach we performed a detailed chromosome 17 allelotypic analysis in 22 breast tumors (5 ductal carcinomas in situ, 13 invasive ductal carcinomas, and 4 invasive lobular carcinomas). We detected mutations in the p53 gene by PCR-SSCP in 36% of the samples. Samples with significant levels of p53 protein accumulation detected by immunohistochemistry were also positive for mobility shifts in the SSCP analysis. We observed that chromosome 17 allelic losses and imbalance occurred at as early a stage as ductal carcinoma in situ (DCIS). Although in some cases we observed allelic losses or imbalance affecting the 17p13 region, close to the p53 locus, several of the tumors showed dissociation between such loss or imbalance and p53 mutation. Lobular carcinomas were predominantly disomic for chromosome 17 in contrast with ductal tumors, which often showed polysomy for chromosome 17. This comprehensive approach correlating the tumor subtype, its allelotype, with specific chromosome copy number and specific gene mutations and expression in preinvasive or early invasive breast cancer lesions will potentially provide information of relevance for a better understanding of the multistep mechanisms of breast carcinogenesis.

Alleles↗
PubMed1995

Recent advances in the application of gene therapy to human disease.

PURPOSE: To review the recent advances in the application of genetic modification strategies to the therapy of human diseases for which a molecular defect is known. METHODS: A computerized data bank search, the minutes of the National Institutes of Health (NIH) Recombinant DNA Advisory Committee published in the Federal Record, and reports of human clinical trials were used as data sources for this review. Clinical trials included in this review were published in the literature or approved by the NIH Recombinant DNA Advisory Committee. STUDY SELECTION: Evaluations of the efficacy of genetic modification strategies in clinical trials in human and in animal models are summarized. The design and outcome of the genetic modification strategies employed are reviewed for 16 marking trials, 16 gene replacement trials for molecular deficiency diseases, 3 chemoprotection and 4 chemotherapy sensitization trials, 11 cancer vaccine trials, 2 antisense oligonucleotide trials, and 3 molecular immunotherapy trials. DATA SYNTHESIS: The marking trials have shown that residual leukemia cells in the infused autologous marrow can contribute to relapse following autologous bone marrow transplants. The use of genetic modification for the replacement of missing or deficient genes in severe combined immunodeficiency, familial hypercholesterolemia, and cystic fibrosis has been associated with encouraging results so far. Clinical genetic therapy trials involving cancer vaccines, antisense oligonucleotides, adoptive immunotherapy with genetically modified T cells, delivery vectors containing interleukin-1 receptor inhibitor for arthritis, replacement strategies for storage diseases, and genetic suppression of human immunodeficiency viral replication are just commencing. CONCLUSIONS: The clinical application of genetic modification techniques has thus far been successful in the beginning phases of this field. These early results suggest that continuation of gene therapy trials designed to correct the molecular changes that lead to disease states in humans is warranted. Evaluation of such clinical trials in the future may be based on the analysis of assays for short-term surrogate endpoints, as well as on the therapeutic outcomes of the trial, such as survival or remission.

Bone Marrow Transplantation↗
PubMed1994

Phase II study of deoxyspergualin in metastatic breast cancer.

We conducted a phase II trial of the novel immunomodulatory/cytotoxic agent 15-deoxyspergualin in patients with metastatic breast cancer who had failed treatment with front-line chemotherapy. Thirty-eight courses of treatment were administered to fourteen patients enrolled in this trial, 25 at a dose of 1800 mg/m2/d (dose level 0) and 13 at a dose of 2150 mg/m2/d (dose level +1) administered by continuous intravenous infusion for 5 days. Treatment was well tolerated with neuromuscular side-effects (myalgias, paresthesias) and granulocytopenia (nadir granulocyte count of 0.50-0.99 x 10(9)/l) in two and three courses, respectively, as the only grade III toxicities. The neuromuscular toxicity of deoxyspergualin is probably related to the occurrence of hypomagnesemia. No partial or complete responses were observed in this study. One patient achieved a minor response but had progressive disease 65 weeks after enrollment. The response was observed coincident with an increase in T4/T8 ratio in the peripheral blood. The median time to progression for the entire cohort was eight weeks (range, 4-65 weeks). There was no clinical evidence of immunosuppression and no decrease in total peripheral blood lymphocyte counts or helper T-cells was observed. At the doses and schedule employed in this trial, deoxyspergualin does not appear to have significant activity against metastatic breast cancer resistant to front-line chemotherapy. The correlation between hypomagnesemia and neuromuscular toxicity of deoxyspergualin is an intriguing, previously unknown observation and requires further investigation.

Adult↗
PubMed1994

Natural immunity in breast cancer patients during neoadjuvant chemotherapy and after surgery.

Breast cancer is the most common cancer in women. Surgery, and more recently neoadjuvant chemotherapy, are being utilized as the initial treatment for breast cancer; however little is known about their effects on the natural immune system. The natural immune system (natural killer [NK] cells) is thought to be important in immune surveillance, including protection from metastasis during the intravascular tumour seeding that occurs during surgery. To investigate the effects of surgery on the natural immune system, we studied the pre-operative and post-operative peripheral blood lymphocytes (PBL) of 10 patients with stage I or II breast cancer: there was a 71.6 +/- 25.3% post-operative reduction in NK cell function (P < 0.005, Student's paired t-test). To investigate the effects of neoadjuvant chemotherapy and surgery, we examined PBL from five patients with stage III breast cancer: NK cell function dropped 95.7 +/- 1.9% after neoadjuvant chemotherapy, and there was a further 51.0 +/- 23.4% decrease after surgery (P < 0.05, Student's paired t-test). Neither group of patients had decreased numbers of NK cells, changes in the percentage of T helper or suppressor cells, or alterations in the production of cytotoxic factor by NK cells. These findings suggest that the impairment in NK cell function reflects a defect in the ability of NK cells to recognize and/or bind to tumour target cells. We conclude that the initial treatment of breast cancer patients, whether it involves surgery alone or with neoadjuvant chemotherapy, profoundly impairs their natural immune system and could increase the risk of metastasis. Further studies are needed to delineate the mechanism of this derangement in natural immunity and possibly alter its course.

Adult↗
PubMed1993

Genetic therapy of human neoplastic disease.

Molecular biology has provided clinical investigators and basic scientists with the tools to identify those changes present within neoplastic hematopoietic and epithelial cells that lead to the evolution of unregulated patterns of cell growth. This information has made possible the development of therapy that involves genetic modification of either the normal hematopoietic cells (for chemoprotection), or the tumor cells themselves to suppress the growth of these cells. This article will summarize the clinical and laboratory data that is evolving in this area.

Animals↗
PubMed1992

Chromosome in situ hybridization on formalin-fixed mammary tissue using non-isotopic, non-fluorescent probes: technical considerations and biological implications.

Fluorescent in situ hybridization techniques have provided an important tool for interphase cytogenetic studies of human neoplasms. However, these techniques are difficult to use on formalin-fixed archival tissue sections. We describe here a non-fluorescent, non-isotopic in situ hybridization (ISH) approach that is easily applicable to paraffin-embedded breast tissue sections. The technical steps that must be monitored and individualized to optimize signal generation and detection are discussed. This ISH technique has several advantages over fluorescent detection methods. The signal obtained can be viewed using an ordinary light microscope and does not fade with time. More importantly, the signal is observed and analyzed in the context of tissue morphology. The technique permits detection of numerical chromosomal abnormalities not only in malignant but also in apparently normal and potentially premalignant mammary tissue. This may allow identification of focal genetic abnormalities as well as field-defects and enable analysis of their evolution during the multistep transformation to mammary neoplasm. This technique is also suitable for analysis of tumor heterogeneity and the correlation of numerical chromosomal aberrations with histologic, immunocytochemical, and clinical features of breast tumors.

Breast↗
PubMed1992

Vertebral osteomyelitis mimicking bone metastasis in breast cancer patients.

Vertebral osteomyelitis can be a diagnostic pitfall for physicians, since it is protean and often subtle in its clinical presentation. It can coexist with metastatic lesions or mimic vertebral bone metastasis. When it occurs in patients with breast cancer, who are prone to have bone metastasis, it can present perplexing diagnostic problems. Misdiagnosing vertebral osteomyelitis as bone metastasis or vice versa results in delayed diagnosis and inappropriate treatment and may cause serious morbidity. We emphasize this problem by presenting the cases of two patients with breast cancer whose clinical course was complicated by vertebral osteomyelitis. When the clinical course of breast cancer is different from this usual presentation, a different process should be suspected, and histologic diagnosis should be promptly sought. Fine-needle aspiration biopsy and culture of suspicious-appearing bony lesions is recommended as a rapid and reliable method of establishing a definite diagnosis in this circumstance.

Breast Neoplasms↗
PubMed1992

Inflammatory breast cancer: a review.

PURPOSE: The natural history of inflammatory breast cancer and the recent advances in its management were reviewed. DESIGN: The English medical literature from 1924 to 1990 was reviewed using the Cancerline and Medline retrieval systems, and through a manual review of bibliographies of identified articles. RESULTS: The majority of patients with inflammatory breast cancer treated only with local therapies died 18 to 24 months after diagnosis. A combined modality approach with chemotherapy, surgery, and radiation therapy has improved disease-free and overall survival rates for inflammatory breast cancer. Approximately 35% to 55% of patients treated with combined modality regimens remain disease-free and alive at 5 years. CONCLUSION: Induction combination chemotherapy administered with radiation therapy, mastectomy, both, or with additional chemotherapy favorably alters the natural history of inflammatory breast cancer. New drug combinations and high-dose chemotherapy with autologous bone marrow support are being evaluated to improve further patient survival.

Breast Neoplasms↗
PubMed1991

Breast cancer and second primary ovarian cancer in dermatomyositis.

We report six female patients with breast cancer who developed dermatomyositis and compare our data with those from other reports. The development of dermatomyositis in two patients led to the discovery of a second primary ovarian carcinoma, whereas the development of dermatomyositis in another two patients led to the discovery of recurrent breast cancer. In three patients the diagnosis of dermatomyositis preceded the diagnosis of breast cancer, while the rest developed dermatomyositis after the diagnosis of breast cancer. A parallel clinical course of dermatomyositis and breast cancer was seen in only one patient. Coexisting dermatomyositis and breast cancer is a rare phenomenon, and dermatomyositis that develops during the course of breast cancer may indicate the occurrence of a second primary malignancy or recurrent breast cancer. The onset of dermatomyositis may precede, coincide with, or follow the diagnosis of breast cancer. The clinical course of dermatomyositis sometimes, but not always, parallels the course of breast cancer. There are no specific clinical or laboratory markers to distinguish patients with dermatomyositis who have malignancy from those without cancer.

Adult↗
PubMed1990

Adjuvant systemic therapy.

Explore the source record for details and available documents.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1990

Immunohistochemical analysis of P-glycoprotein expression correlated with chemotherapy resistance in locally advanced breast cancer.

We analyzed the expression of P-glycoprotein in samples from 48 patients with locally advanced breast cancer. Tumor samples from 40 patients were obtained at mastectomy, which was performed after three cycles of induction chemotherapy consisting of doxorubicin, cyclophosphamide, vincristine, and prednisone. P-glycoprotein expression distributed focally was observed in 20 tumors by the immunoperoxidase method using the anti-p170-monoclonal antibody C219. The percentage of the tumor cell population expressing P-glycoprotein varied from less than 5% to greater than 30%; expression was observed significantly more often in tumors that showed less than partial response to the preoperative chemotherapy. Furthermore, P-glycoprotein was not expressed in eight tumor specimens obtained at the time of diagnosis, prior to chemotherapy, from patients who subsequently had pathologic complete responses. A comparative study of P-glycoprotein expression before and after chemotherapy and upon recurrence of tumor was done on a limited number of samples. No significant differences in P-glycoprotein expression were found. Therefore, it is possible that an intrinsic, rather than acquired, drug resistance may play a role in the failure of induction chemotherapy for locally advanced breast cancer.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1990

A phase II study of mitoxantrone, etoposide, and thiotepa with autologous marrow support for patients with relapsed breast cancer.

To further improve the effect of high-dose chemotherapy in the treatment of locally advanced and metastatic breast cancer, we sought to develop a second active high-dose noncross-resistant regimen to use in tandem with our customary high-dose regimen of cyclophosphamide, etoposide, and cisplatin (CVP). We performed a phase II trial of high-dose mitoxantrone 30 mg/m2, etoposide 200 mg/m2 every 12 hours x 6, and thiotepa 250 mg/m2 x 3 days (MVT) in 31 patients with heavily pretreated metastatic breast cancer and one with locally advanced chemotherapy-refractory breast cancer. These patients were ineligible for high-dose CVP chemotherapy because of the amount of prior treatment and poor-response status. Of the 32 patients, 14 responded to cycle 1, did not experience any grade 4 toxicity, and received a second cycle of MVT. Overall, seven of 31 patients achieved a complete response (CR; 23%). Four of the 14, who were partial responders to the first cycle, achieved a CR after the second cycle. The overall response rate was 19 of 31 (61%) with an overall median freedom from progression of 4 to 5 months and an overall median survival of 9 months. Toxicity consisted primarily of mucositis (grade 3 or 4 in 69%). The results indicate that high-dose MVT produces significant activity, even in heavily pretreated patients. Administration of a second cycle of high-dose therapy with MVT increased the CR rate, and the morbidity and mortality from the second cycle were not greater than that for the first cycle. Because of the high incidence of grade 3 or 4 mucositis with this regimen, we are currently completing a follow-up study of high-dose mitoxantrone and thiotepa alone.

Adolescent↗
PubMed1989

c-erbB-2 amplification in node-negative human breast cancer.

c-erbB-2 gene analysis by Southern and DNA dot blot methods was done in 66 tumor samples from patients with histologically node-negative breast cancer. The c-erbB-2 gene was amplified 2- to greater than 8-fold in 13 tumors (20%). None of 59 tumors that were examined by the Southern method showed c-erbB-2 gene rearrangement. c-erbB-2 amplification was analyzed in relation to other prognostic factors. The c-erbB-2 gene was amplified in five of 36 (14%) diploid and eight of 30 (27%) aneuploid tumors. Thirteen of 54 (24%) tumors with nuclear Grade 1 or 2 displayed c-erbB-2 amplification, whereas none of 12 tumors with nuclear Grade 3 did. No correlation was observed with estrogen receptor content, tumor size, histological type, or age of patients. The median follow-up date for these patients was 85+ mo. Of 13 patients whose tumors showed c-erbB-2 amplification, six patients (46%) developed recurrence, and five patients (38%) died of metastatic disease. In contrast, of 53 patients whose tumors did not show c-erbB-2 amplification, 15 patients (28%) developed recurrence, and seven patients (13%) died of disease. In conclusion, our results show that c-erbB-2 gene amplification was more frequent in aneuploid tumors and tumors with poor nuclear grade. c-erbB-2 amplification may be considered a possible prognostic factor in node-negative breast cancer.

Adult↗
PubMed1989

5-Fluorouracil rechallenge by protracted infusion in refractory breast cancer.

The authors assessed the value of protracted low-dose 5-fluorouracil (5-FU) infusion (250 mg/m2/day) in refractory breast cancer. Thirty-six patients with prior 5-FU exposure who were not eligible for other investigational therapeutic measures mainly due to extensive prior chemotherapy (median, four regimens) and poor performance status (median of 3, Zubrod scale) were enrolled. Thirty-four patients were evaluable for toxicity and 32 for response. Concurrent radiotherapy was given to 17 patients. The median duration of 5-FU treatment was 65 days (range, 19-508+) delivering a median cumulative 5-FU dose of 13.75 g/m2 (4.75-144.5+). The median number of interruptions of infusion was 1 (0-16) for a median of 7 days (1-25). One patient achieved complete remission, and four a partial response, for a median of 129 days (101-412) and a response rate of 16%. Five additional patients had a minor objective response (16%), whereas 15 (48%) had no change, and seven progressed (22%). The main toxicities seen were oral mucositis in 13 patients, hand-foot syndrome in six, Coombs'-positive hemolytic anemia in two, and progressive liver dysfunction in two patients who also had cirrhotic changes on computed tomography. Myelosuppression was uncommon and transient. Elective temporary interruptions of the 5-FU infusion diminished the incidence of mucocutaneous toxicity. Hemoglobin indices consistently displayed macrocytic features which did not readily revert to baseline after discontinuation of 5-FU infusion. Despite the adverse characteristics of the treated population, 5-FU infusion demonstrated moderate activity in refractory breast cancer with clinical resistance to prior 5-FU-containing regimens. Intermittent scheduled interruptions of infusion rendered this method of 5-FU delivery nontoxic.

Adult↗
PubMed1989

Phase II evaluation of gallium nitrate by continuous infusion in breast cancer.

We evaluated the role of gallium nitrate infusion in the treatment of metastatic breast cancer. Gallium nitrate was administered at 300 mg/m2/day for 7 days every 3 weeks by continuous infusion concomitantly with oral calcium supplement of 500 mg twice daily and oral hydration. Fifteen patients with refractory metastatic breast cancer received such treatment for a total of 30 courses. Median age was 51, and median performance status (Zubrod scale) was 1. These patients had minimal prior chemotherapy (median 1 regimen). All patients were evaluable for toxicity and 14 for response. Nine patients had one to two metastatic sites, five patients had three to four sites. No major objective response was seen, but one patient had a minor response (10 weeks), and another showed no change in disease (16 weeks). Diverse low-grade toxicities were observed, including nausea and vomiting in 11 patients, anorexia in 11, diarrhea in eight, stomatitis in five, dysgeusia in six, musculoskeletal pain in five, skin rash in seven, partially reversible tinnitus and/or mild hearing loss in four and sensory neuropathy in two. A consistent drop in hemoglobin (median of 3.2 g/dL per patient) necessitated blood transfusion in seven patients. There was no granulocytopenia or thrombocytopenia; however, significant lymphopenia was noted. Reversible, moderate nephrotoxicity occurred in two patients. The hypocalcemic effect was consistent, with a median drop in serum calcium of 1.25 mg/dL per course. There was no hepatic toxicity. While no single toxicity was severe, overall toxicity adversely influenced treatment tolerance. Gallium nitrate by continuous infusion, as given in this study, has no activity in metastatic breast cancer.

Adult↗
PubMed1989

A monoclonal antibody cocktail for detection of micrometastatic tumor cells in the bone marrow of breast cancer patients.

We investigated whether monoclonal antibodies (MoAbs) reactive against both acidic and basic cytokeratins alone were sufficient to detect minimal numbers of contaminating epithelial tumor cells in the bone marrow of breast cancer patients. Monoclonal anti-cytokeratin antibodies (AE1 and AE3) were used to stain 14 breast carcinomas by the avidin-biotin-peroxidase technique. Nine tumors (64.3%) showed high reactivity and five (35.7%) showed low or moderate reactivity. Nine MoAbs that proved to be unreactive to light density bone marrow cells by immunoalkaline phosphatase histochemistry were screened for reactivity to breast carcinomas having only low or moderate positivity to cytokeratin antibodies. Three of nine MoAbs showed high percentages of positivity and were selected to supplement the anti-cytokeratin antibodies for immunohistochemical detection of minimal marrow disease in breast cancer patients. A MoAb cocktail was prepared, further tested for reactivity to another five breast carcinomas, and compared with cytokeratin staining alone. The cocktail labeled 100% of carcinoma cells in all the examined specimens. To determine the sensitivity of this panel for detecting minimal numbers of contaminating tumor cells in bone marrow, in vitro mixing experiments were performed. T47D breast carcinoma cells were mixed with bone marrow mononuclear cells at ratios from one tumor cell per 10 bone marrow cells up to one tumor cell per 1 x 10(6) marrow cells, and cytospin preparations were subsequently stained with the MoAb cocktail by the immunoalkaline phosphatase method. Our approach could detect one tumor cell in 1 x 10(5) hematopoietic cells.

Antibodies, Monoclonal↗