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Biomedical subjects

G Y Locker

Publications and source records attributed to G Y Locker.

At least 19 recordsLinked to original sources
PubMed2006

Comprehensive side-effect profile of anastrozole and tamoxifen as adjuvant treatment for early-stage breast cancer: long-term safety analysis of the ATAC trial.

BACKGROUND: The Arimidex (anastrozole), Tamoxifen, Alone or in Combination (ATAC) trial was designed to compare the efficacy and safety of anastrozole with tamoxifen as adjuvant treatment for postmenopausal women with early-stage breast cancer. After an extended follow-up beyond the 5 years of treatment, we aimed to assess the safety, tolerability, and risk-benefit indices of these compounds. METHODS: We analysed postmenopausal women (mean age 64 years [SD 9]) with localised breast cancer randomly assigned to anastrozole (n=3125) or tamoxifen (n=3116). Efficacy measures, including death and risk-benefit indices, were analysed by intention to treat. Safety analyses were based on treatment first received (n=3092 for anastrozole and n=3094 tamoxifen). We calculated a risk-benefit analysis using the two global indices for the Women's Health Initiative and for Disease-Free Survival and Serious Adverse Events. This study is registered as an International Standard Randomised Controlled Trial, number ISRCTN18233230. FINDINGS: At median follow-up of 68 months (range 1-93), treatment-related adverse events occurred significantly less often with anastrozole than with tamoxifen (1884 [61%] vs 2117 [68%]; p<0.0001), as did treatment-related serious adverse events (146 [5%] vs 277 [9%]; p<0.0001) and adverse events leading to withdrawal (344 [11%] vs 442 [14%]; p=0.0002). Patients given anastrozole had significantly fewer overall events for the Global Index of the Women's Health Initiative (744 [24%] vs 851 [27%]; hazard ratio 0.85 [95% CI 0.77-0.94], p=0.001) and the Global Index of Disease-Free Survival and Serious Adverse Events (1453 [46%] vs 1594 [51%]; 0.88 [0.82-0.94]; p=0.0004). INTERPRETATION: Anastrozole is tolerated better than tamoxifen by postmenopausal women with early-stage breast cancer, and results in fewer serious adverse events. Furthermore, it has a more favourable overall risk-benefit profile and lower recurrence rate than tamoxifen.

Anastrozole↗
PubMed2001

2000 update of recommendations for the use of tumor markers in breast and colorectal cancer: clinical practice guidelines of the American Society of Clinical Oncology.

OBJECTIVE: To update the 1997 clinical practice guidelines for the use of tumor marker tests in the prevention, screening, treatment, and surveillance of breast and colorectal cancers. These guidelines are intended for use in the care of patients outside of clinical trials. OPTIONS: Six tumor markers for colorectal cancer and eight for breast cancer were considered. They could be recommended or not for routine use or for special circumstances. In addition to carcinoembryonic antigen (CEA) and CA 15-3, CA 27.29 was also considered among the serum tumor markers for breast cancer. OUTCOMES: In general, the significant health outcomes identified for use in making clinical practice guidelines (overall survival, disease-free survival, quality of life, lesser toxicity, and cost-effectiveness) were used. EVIDENCE: A computerized literature search from 1994 to March 1999 was performed. VALUES: The same values for use, utility, and levels of evidence were used by the committee. BENEFITS, HARMS, AND COSTS: The same benefit, harms, and costs were used. RECOMMENDATION: Changes were recommended (see Appendix). VALIDATION: The updated recommendations were validated by external review by the American Society of Clinical Oncology's (ASCO's) Health Services Research Committee and by ASCO's Board of Directors. SPONSOR: American Society of Clinical Oncology.

Adult↗
PubMed2001

The spectrum of vascular lesions in the mammary skin, including angiosarcoma, after breast conservation treatment for breast cancer.

BACKGROUND: With the general acceptance of lumpectomy, axillary staging, and radiotherapy as local treatment for infiltrating breast cancer, an appreciation is evolving for the spectrum of vascular lesions that occur in the mammary skin after this treatment. Most of these lesions develop within the prior radiation field after breast conservation treatment. STUDY DESIGN: A retrospective chart and slide review was conducted, consisting of five patients with cutaneous vascular lesions after breast conservation treatment for infiltrating breast cancer. RESULTS: The latent time interval from definitive treatment of breast cancer to the clinical recognition of vascular lesions ranged from 5 to 11 years. Two patients did not have either arm or breast edema, two patients had breast edema, and the fifth patient had arm edema. Lesions arising in the irradiated mammary skin included extensive lymphangiectasia (one), atypical vascular lesions (two), and cutaneous angiosarcoma (four). CONCLUSIONS: Atypical vascular lesions at the skin margins of mastectomy may be predictive of recurrence after resection of angiosarcoma. Excision of skin from the entire radiation field may be necessary to secure local control of the chest wall in patients with cutaneous angiosarcoma after therapeutic breast radiotherapy.

Aged↗
PubMed1996

Tumor marker utility grading system: a framework to evaluate clinical utility of tumor markers.

Introduction of tumor markers into routine clinical practice has been poorly controlled, with few criteria or guidelines as to how such markers should be used. We propose a Tumor Marker Utility Grading System (TMUGS) to evaluate the clinical utility of tumor markers and to establish an investigational agenda for evaluation of new tumor markers. A Tumor Marker Utility Grading Worksheet has been designed. The initial portion of this worksheet is used to clarify the precise characteristics of the marker in question. These characteristics include the marker designation, the molecule and/or substance and the relevant alteration from normalcy, the assay format and reagents, the specimen type, and the neoplastic disease for which the marker is being evaluated. To determine the clinical utility of each marker, one of several potential uses must be designated, including risk assessment, screening, differential diagnosis, prognosis, and monitoring clinical course. For each of these uses, associations between marker assay results and expected biologic process and end points must be determined. However, knowledge of tumor marker data should contribute to a decision in practice that results in a more favorable clinical outcome for the patient, including increased overall survival, increased disease-free survival, improvement in quality of life, or reduction in cost of care. Semiquantitative utility scales have been developed for each end point. The only markers recommended for use in routine clinical practice are those that are assigned utility scores of "++" or " " on a 6-point scale (ranging from 0 to ) in the categories relative to more favorable clinical outcomes. Each utility score assignment should be supported by documentation of the level of evidence used to evaluate the marker. TMUGS will establish a standardized analytic technique to evaluate clinical utility of known and future tumor markers. It should result in improved patient outcomes and more cost-efficient investigation and application of tumor markers.

Biomarkers, Tumor↗
PubMed1994

High-dose aminothiadiazole in advanced colorectal cancer. An Illinois Cancer Center phase II trial.

Thirty-three patients with advanced colorectal carcinoma were entered on a phase II trial of weekly IV aminothiadiazole (175 mg/m2 escalated to 200 mg/m2) with concomitant allopurinol and non-steroidal anti-inflammatory agents (NSAID's). Toxicity was predominantly GI, cutaneous, and chest pain/dyspnea. Twenty-five percent of patients had grade 3 or 4 toxicity. There were no responses in 27 evaluable patients. Median survival was 12 months. Aminothiadiazole, at higher doses than used in previous reports, when given with NSAID's, had no significant activity against large bowel cancer.

Adenocarcinoma↗
PubMed1993

Elevated serum CA 125 secondary to tuberculous peritonitis.

A 33-year-old African-American woman presented with a 10-day history of abdominal pain, fever to 104 degrees F, and ascites. Her PPD converted to positive. A serum CA 125 level was 708 U/ml before therapy. Tuberculous peritonitis was diagnosed via peritoneal biopsy. The CA 125 level was used to follow response to treatment and was undetectable after 12 weeks of antituberculous treatment. This tumor marker may be used to follow disease activity in non-neoplastic ascitic states.

Adult↗
PubMed1987

Phase II trial of aminothiadiazole in previously treated and untreated patients with advanced colorectal carcinoma: an Illinois Cancer Council Trial.

Eighty-three patients with advanced colorectal carcinoma were entered on a phase II trial of weekly iv aminothiadiazole (125 mg/m2) plus daily oral allopurinol (300 mg). There were five partial responses. Median survival of all patients on study was 36 weeks from entry (48 weeks for those without prior therapy and 34 weeks for those with previous chemotherapy). Toxicity was generally mild and consisted predominantly of stomatitis. In the dose given, aminothiadiazole has limited activity against metastatic colorectal cancer.

Clinical Trials as Topic↗
PubMed1985

Aziridinylbenzoquinone in recurrent, progressive glioma of the central nervous system. A Phase II study by the Illinois Cancer Council.

Aziridinylbenzoquinone (AZQ) was studied in a Phase II protocol for persons with glioma of the central nervous system (CNS) recurrent or progressive after surgery and radiotherapy. Patients received AZQ, 30 mg/m2 intravenously every 3 weeks if previously untreated or 27.5 mg/m2 if previously exposed to cytotoxic drugs. Partial response was defined as a reduction of at least 50% reduction in the product of the two longest perpendicular diameters of the indicator lesion persisting for a minimum of 28 days. Twenty-eight patients are evaluable for response at this time. Objective response (OR) occurred in four (14.3%): two complete and two partial. Stabilization of disease (SD) was seen in 7 (25.0%). Median survival, in weeks, was greater than 46.0 for responders, 41.7 for SD, and 19.3 for those with progressive disease. The survival experiences are significantly different (P = 0.030 [Breslow]). The OR rate was 21.1% in 19 without prior chemotherapy and 0% in 9 previously treated patients. There were two AZQ-related deaths in patients with prior exposure to nitrosoureas (1 CNS hemorrhage; 1 aspiration pneumonia). One patient had an anaphylactic reaction. Three patients whose tumor initially increased in size subsequently had marked tumor shrinkage. AZQ is an active agent that must be used with added caution in patients who have received nitrosoureas. Initial tumor enlargement may precede response. Although response appears to prolong survival, the correlation between stabilization of disease and survival is not well-defined.

Adolescent↗
PubMed1981

Ocular irritation from high-dose methotrexate therapy: pharmacokinetics of drug in the tear film.

Four of 13 patients receiving intermittent high-dose methotrexate therapy experienced recurrent symptoms of ocular irritation (burning, pruritus, "dry eyes") two to seven days after chemotherapy. Ophthalmic examination was unremarkable in symptomatic individuals except for decreased reflex production of tears in some patients. Pharmacokinetic studies of a group of these patients revealed concentrations of methotrexate in tears equivalent to those in plasma at 24 and 48 hours after treatment; these concentrations reached 1 X 10(-5) M during the infusion of methotrexate. The occurrence of acidic lacrimal secretions, pH 6.5 in one symptomatic patient, may have contributed to decreased solubility of methotrexate in the fluid of the conjunctival sac.

Adolescent↗
PubMed1981

Prevention of doxorubicin cardiac toxicity in the mouse by N-acetylcysteine.

This study was undertaken to investigate the effect of exogenous sulfhydryl compound administration on the toxicity of doxorubicin in mice. Pretreatment of CDF1 mice with a pharmacologic dose (2,000 mg/kg) of n-acetyl-l-cysteine 1 h before doxorubicin (20 mg/kg, i.p.) decreased lethality from 100% (n = 44) to 37.7% (n = 53), P less than 0.001. Variation in the timing and dose of n-acetylcysteine significantly diminished its protective activity. Pretreatment with n-acetylcysteine also significantly reduced long-term mortality in animals receiving multiple doses of doxorubicin; 10 wk after the third of three doxorubicin doses (5 mg/kg, i.p.) administered at 2-wk intervals, survival in the n-acetylcysteine pretreated group was 51.4% (n = 35) compared with 16.7% (n = 30) for animals receiving saline before doxorubicin, P less than 0.01. In this experiment, n-acetylcysteine pretreatment also diminished doxorubicin-related losses in total body weight and heart wet weight by 55.2% (P less than 0.05), and 60.9% (P less than 0.02), respectively, compared with animals pretreated with saline. N-acetylcysteine pretreatment also ablated electron microscopic evidence of doxorubicin cardiomyopathy without alleviating morphological features of its toxic effects on the liver or small intestinal mucosa. The cardioprotective action of n-acetylcysteine may be partially explained by the 429 +/- 60% increase in cardiac nonprotein sulfhydryl content (P less than 0.01) that was measured one hour after n-acetylcysteine administration; nonprotein sulfhydryl concentration in the liver at the same time was insignificantly different from control levels. Treatment with n-acetylcysteine also increased the nonprotein sulfhydryl content of P388 leukemia cells nearly threefold; however, it did not after the chemotherapeutic activity of doxorubicin against this murine tumor. Whereas n-acetylcysteine blocked doxorubicin cardiac toxicity, it did not affect the uptake or metabolism of doxorubicin in the heart or liver. These results suggest that the concentration of free sulfhydryl groups in the heart may play a role in the development of doxorubicin cardiac toxicity and that augmenting cardiac nonprotein sulfhydryl group content with n-acetylcysteine may provide a means to enhance the chemotherapeutic index of doxorubicin.

Acetylcysteine↗
PubMed1980

Enzymatic defenses of the mouse heart against reactive oxygen metabolites: alterations produced by doxorubicin.

The endogenous defenses of the mouse heart against reactive oxygen metabolites were investigated. The activities of three enzymes capable of detoxifying activated oxygen were determined in both the heart and liver; cardiac muscle contains 150 times less catalase and nearly four times less superoxide dismutase than liver. Glutathione peroxidase activities were, however, similar to the two tissues. Assay of glutathione peroxidase in the heart after 6 wk of selenium depletion with both hydrogen peroxide and cumene hydroperoxide as substrates revealed a >80% drop in enzyme activity and gave no indication that murine cardiac tissue contains nonselenium-dependent glutathione peroxidase. The selenium-deficient state, which was characterized by markedly decreased cardiac glutathione peroxidase levels, led to significantly enhanced doxorubicin toxicity at a dose of 15 mg/kg i.p. Doxorubicin administration in selenium-sufficient animals resulted in a dose-dependent decrease in cardiac glutathione peroxidase activity; the decrease in enzyme activity lasted 72 h after 15 mg/kg i.p. In contrast, cardiac superoxide dismutase and hepatic superoxide dismutase and glutathione peroxidase were unaffected by this dose of doxorubicin. These results suggest that the major pathway in cardiac tissue for detoxification of reactive oxygen metabolites is via the concerted action of superoxide dismutase and selenium-dependent glutathione peroxidase. The latter enzyme may be depleted by a selenium-deficient diet or doxorubicin treatment, leaving the heart with limited mechanisms for disposing of hydrogen peroxide or lipid peroxides.

Animals↗
PubMed1979

The clinical features of hepatic angiosarcoma: a report of four cases and a review of the English literature.

Four cases of hepatic angiosarcoma are reported with a review of 99 other cases in the English literature. Angiosarcoma of the liver is associated with chronic exposure to thorotrast, vinyl chloride, arsenicals, radium and possibly copper and with chronic idiopathic hemochromatosis. Although 40% of patients have hepatic fibrosis or cirrhosis at autopsy, the nature of the association between chronic liver disease and hepatic angiosarcoma is unknown. The clinical presentation of hepatic angiosarcoma is nonspecific with abdominal pain, weakness and weight loss common complaints and with hepatomegaly, ascites and jaundice common findings. Liver function tests are usually abnormal but there is no one liver function test or set of tests specific for the tumor. The occurrence of thrombocytopenia and disseminated intravascular coagulation is characteristic of hepatic angiosarcoma and may be related to local consumption of clotting factors and formed blood elements in the tumor. Catastrophic intraabdominal bleeding is also characteristic and occurs in one-fourth of all cases. This complication is likely related to the high incidence of clotting abnormalities and the vascular nature of the neoplasm. Selective hepatic arteriogram and open liver biopsy are the foundations of diagnostic evaluation. Percutaneous liver biopsy should be avoided. Failure to appreciate the possibility of hepatic angiosarcoma in the proper clinical setting, leading to blind percutaneous biopsy, may result in failure to make the diagnosis at the cost of significant morbidity and mortality. Survival of patients with hepatic angiosarcoma is brief; only 3% live longer than 2 years. Treatment of the tumor to date is empirical. There are probably a few patients who might benefit from radical surgery with curative intent. For all others chemotherapy is indicated. Adriamycin is active against hepatic angiosarcoma, but optimal dose and mode of administration require further investigation. Further study is also required to delineate the cause of hepatic angiosarcoma in the 60% of cases without definite epidemiologic association.

Adult↗