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Biomedical subjects

L Norton

Publications and source records attributed to L Norton.

At least 73 records · Page 4Linked to original sources
PubMed1998

Dose and dose intensity as determinants of outcome in the adjuvant treatment of breast cancer. The Cancer and Leukemia Group B.

BACKGROUND: Both total dose and dose intensity of adjuvant chemotherapy are postulated to be important variables in the outcome for patients with operable breast cancer. The Cancer and Leukemia Group B study 8541 examined the effects of adjuvant treatment using conventional-range dose and dose intensity in female patients with stage II (axillary lymph node-positive) breast cancer. METHODS: Within 6 weeks of surgery (radical mastectomy, modified radical mastectomy, or lumpectomy), 1550 patients with unilateral breast cancer were randomly assigned to one of three treatment arms: high-, moderate-, or low-dose intensity. The patients received cyclophosphamide, doxorubicin, and 5-fluorouracil on day 1 of each chemotherapy cycle, with 5-fluorouracil administration repeated on day 8. The high-dose arm had twice the dose intensity and twice the drug dose as the low-dose arm. The moderate-dose arm had two thirds the dose intensity as the high-dose arm but the same total drug dose. Disease-free survival and overall survival were primary end points of the study. RESULTS: At a median follow-up of 9 years, disease-free survival and overall survival for patients on the moderate- and high-dose arms are superior to the corresponding survival measures for patients on the low-dose arm (two-sided P<.0001 and two-sided P = .004, respectively), with no difference in disease-free or overall survival between the moderate- and the high-dose arms. At 5 years, overall survival (average +/- standard error) is 79% +/- 2% for patients on the high-dose arm, 77% +/- 2% for the patients on the moderate-dose arm, and 72% +/- 2% for patients on the low-dose arm; disease-free survival is 66% +/- 2%, 61% +/- 2%, and 56% +/- 2%, respectively. CONCLUSION: Within the conventional dose range for this chemotherapy regimen, a higher dose is associated with better disease-free survival and overall survival.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1998

Survival of premenopausal women with breast carcinoma: effects of menstrual timing of surgery.

BACKGROUND: It is controversial whether the timing of tumor excision relative to the menstrual cycle influences the survival of patients with breast carcinoma. METHODS: Premenopausal patients (n=614) who had surgery for invasive, nonmetastatic breast carcinoma during the period 1978-1988 participated in an epidemiologic survey, reporting their menstrual cycle length and the date of their last menses. We ascertained deaths from any cause before 1993. RESULTS: Using Cox modeling, we found a nonlinear variation in the relative risk (RR) of death according to the timing of surgery during the menstrual cycle. The curve was best described by a cosine transformation of a 28-day cycle. For patients who had breast carcinoma surgery on the estimated day of ovulation, the risk of death was 0.59 (95% confidence limits [CLI=0.39-0.89, P=0.013) compared with patients who had surgery at the approximate time of menses. We observed this for patients treated in 1978-1981 (RR=0.43, 95% CL=0.23-0.83, P=0.011) and 1982-1983 (0.25, 95% CL=0.10-0.63, P=0.003), but not in 1984-1988 (1.48, 95% CL=0.64-3.4). The difference observed for 1984-1988 was explained by a significant improvement in the mortality rate (P=0.0004) for women whose surgery took place during menses or near to the date predicted for the next menses. No such improvement for women who underwent breast carcinoma surgery around the time of ovulation was observed during the period 1984-1988. These changes were not explained by the performance of lumpectomy or the increasing interval between biopsy and tumor excision. CONCLUSIONS: The shape of the survival curve contradicted the idea that it could be explained by levels of circulating estradiol or progesterone. Because observations that surgery was affected by menstrual timing seem not to have persisted beyond the mid-1980s, this study should not be used to support recommendations that surgeons perform breast carcinoma surgery on any particular day of the menstrual cycle.

Adult↗
PubMed1998

Recombinant humanized anti-HER2 antibody (Herceptin) enhances the antitumor activity of paclitaxel and doxorubicin against HER2/neu overexpressing human breast cancer xenografts.

Recombinant humanized anti-HER2 antibody, rhuMAb HER2, inhibits the growth of breast cancer cells overexpressing HER2 and has clinical activity. We explored in preclinical models its capacity to enhance the tumoricidal effects of paclitaxel and doxorubicin. In cultures of naturally HER2-overexpressing cancer cells, rhuMAb HER2 inhibited growth and enhanced the cytotoxic effects of paclitaxel. Treatment of well established BT-474 breast cancer xenografts overexpressing HER2 in athymic mice with rhuMAb HER2 resulted in a dose-dependent antitumor activity. In combination studies, treatment with paclitaxel and rhuMAb HER2 or doxorubicin and rhuMAb HER2 resulted in greater inhibition of growth than that observed with any agent alone. The combination of paclitaxel and rhuMAb HER2 resulted in the highest tumor growth inhibition and had a significantly superior complete tumor regression rate when compared with either paclitaxel or rhuMAb HER2 alone. Clinical trials that are built on these results are under way.

Animals↗
PubMed1998

BRCA-associated breast cancer: absence of a characteristic immunophenotype.

To characterize the biological features of breast cancer associated with germ-line mutations in BRCA1 and BRCA2, invasive tumors were studied from 58 Jewish women ascertained through studies of early-onset breast cancer. All women were tested for the BRCA1 founder mutations 187delAG (commonly known as 185delAG) and 5385insC (commonly known as 5382insC) and the BRCA2 founder mutation 6174delT. Mutations were detected in 17 of 58 (29.3%) women. Comparing BRCA-associated breast cancers (BABCs) to cases arising in women without founder mutations, no differences were noted in tumor size, tumor stage, or frequency of axillary nodal involvement. Infiltrating ductal carcinoma was the predominant histological type in both groups. BABCs were significantly more likely to be of histological grade III (100 versus 63%; P = 0.04), estrogen receptor negative (75 versus 35%; P = 0.004), and HER2/neu negative (87 versus 58%; P = 0.04). An associated intraductal component was present in 59% of BABCs and 76% of cancers not associated with mutations (P = not significant). A high Ki-67 labeling index was more commonly observed in BABCs than in cases without mutations (83 versus 48%; P = 0.09). There were no differences between the two groups in the frequency of expression of epidermal growth factor receptor, cathepsin D, bcl-2, p27, p53, or cyclin D. There were no significant differences in relapse-free or overall survival. These observations suggest that breast cancers arising in Jewish women with germ-line BRCA founder mutations have a greater proliferative potential than cancers in women without such mutations. Additional studies of BABC are required to determine the nature and implications of additional genetic abnormalities occurring in these tumors.

Adult↗
PubMed1998

The epidermal growth factor receptor modulates the interaction of E-cadherin with the actin cytoskeleton.

Alterations in the expression or function of molecules that affect cellular adhesion and proliferation are thought to be critical events for tumor progression. Loss of expression of the cell adhesion molecule E-cadherin and increased expression of the epidermal growth factor receptor are two prominent molecular events that are associated with tumorigenesis. The regulation of E-cadherin-dependent cell adhesion by epidermal growth factor (EGF) was therefore examined in the human breast cancer cell line, MDA-MB-468. In this study, changes were observed in the subcellular distribution of components that mediate the cytoplasmic connection between E-cadherin and the actin-based cytoskeleton in response to activation of the EGF receptor. Serum withdrawal activated E-cadherin-dependent cell-cell aggregation in MDA-MB-468 cells, and this treatment stimulated the interaction of actin, alpha-actinin, and vinculin with E-cadherin complexes, despite the absence of alpha-catenin in these cells. By contrast, the co-precipitation of actin with E-cadherin was not detected in several alpha-catenin positive epithelial cell lines. Treatment with EGF inhibited cellular aggregation but did not affect either the levels of E-cadherin or catenin expression nor the association of catenins (beta-catenin, plakoglobin/gamma-catenin, or p120(cas)) with E-cadherin. However, EGF treatment of the MDA-MB-468 cell line dissociated actin, alpha-actinin, and vinculin from the E-cadherin-catenin complex, and this coincided with a robust phosphorylation of beta-catenin, plakoglobin/gamma-catenin, and p120(cas) on tyrosine residues. Furthermore, inactivation of the EGF receptor in serum-treated MDA-MB-468 cells with either a function-blocking antibody or EGF receptor kinase inhibitors mimicked the effects of serum starvation by stimulating both cellular aggregation and assembly of E-cadherin complexes with vinculin and actin. These results demonstrate that the EGF receptor directly regulates cell-cell adhesion through modulation of the interaction of E-cadherin with the actin cytoskeleton and thus substantiates the coordinate role of both of these molecules in tumor progression and metastasis.

Actinin↗
PubMed1998

Health promotion and health education: what role should the nurse adopt in practice?

Health promotion is widely accepted as part of the role of the nurse, midwife and health visitor. Theoretical definitions of health promotion and health education are presented. The author suggests that a variety of different approaches to health promotion can be adopted by nurses in practice, including education, persuasion, manipulation and attempts to promote an environment where healthy decisions about lifestyle can be made. Each strategy is examined and the advantages and the ethical limitations are explored. It is suggested that nurses may theoretically accept the notion of being a health promoter, but that in the reality of practice, their role may be primarily that of the health educator. The importance of recognizing that there are a variety of determinants of health, including social and environmental factors, as well as individual lifestyle, is emphasized throughout the paper.

Health Education↗
PubMed1998

Dose-dense therapy with weekly 1-hour paclitaxel infusions in the treatment of metastatic breast cancer.

PURPOSE: To evaluate the efficacy and toxicity of paclitaxel administered as a 1-hour infusion on weekly basis, without interruption, to patients with metastatic breast cancer who had received prior therapy. PATIENTS AND METHODS: Thirty patients with metastatic breast cancer received sustained weekly paclitaxel therapy at an initial dose of 100 mg/m2 until disease progression. Prior therapy included adjuvant only (n=17), metastatic only (n=7), or both (n=6). Eighteen patients had received prior anthracycline therapy, 12 of whom had demonstrated progression of disease within 12 months of it. All patients were assessable for efficacy; 29 patients were assessable for toxicity. Pharmacokinetic studies of paclitaxel were also performed. RESULTS: A total of 469 weekly paclitaxel infusions were administered to 30 patients (median, 14 infusions/patient). The median delivered dose-intensity was 91 mg/m2/wk (range, 80 to 108). The overall response rate was 53% (95% confidence interval [CI], 34% to 72%), with 10% complete responses (CRs) and 43% partial responses (PRs). Median response duration was 7.5 months (range, 2 to 11+). Responses were observed in nine of 18 (50%) patients with prior anthracycline therapy, including six of 12 (50%) with disease progression on anthracycline within 1 year (three of four within 6 months). Therapy was well tolerated and remarkable for a lack of overall and cumulative myelosuppression. Grade 3/4 neutropenia occurred in four patients; febrile neutropenia was not observed. Peripheral neuropathy prohibited dose escalation above 100 mg/m2, and grade 3 neuropathy was observed in two of 21 patients at < or = 100 mg/m2. CONCLUSION: Weekly paclitaxel therapy is active and well tolerated in patients with metastatic breast cancer. Weekly therapy should be considered as a current clinical option for these patients and should be incorporated into future comparative clinical trials.

Adult↗
PubMed1998

BRCA-associated breast cancer in young women.

PURPOSE: To delineate the clinical characteristics and outcomes of breast cancer that arises in the setting of a germline BRCA mutation and to compare BRCA-associated breast cancers (BABC) with those that arise in women without mutations. PATIENTS AND METHODS: We reviewed the clinical records of 91 Ashkenazi Jewish women ascertained during studies of the genetics of early-onset breast cancer. All women underwent testing for the BRCA1 mutations 185delAG and 5382insC. After the discovery of BRCA2, 79 women were also tested for the BRCA2 mutation 6174delT. RESULTS: Mutations were identified in 30 women (33%). BABC were less likely to present with stage I disease than cases in women without mutations (27% v 46%), more likely to have axillary nodal involvement (54% v46%), and more likely to have extensive axillary involvement (25% v 17%). These differences were not statistically significant. BABC were significantly more likely to be histologic grade III (100% v 59%, P=.04) and to be estrogen receptor-negative (70% v 34%, P=.04). In the entire cohort, there were no significant differences between BABC and non-BRCA-associated cancers in 5-year relapse-free survival (65% v 69%, P=not significant [NS]), 5-year event-free survival (57% v 68%, P=NS), or 5-year overall survival. However, among cases diagnosed within 2 years of study entry, there was a trend toward shorter event-free survival in BRCA heterozygotes, but not relapse-free survival. Women with germline BRCA mutations were significantly more likely to develop contralateral breast cancer at 5 years (31% v 4%, P=.0007). CONCLUSION: BABC present with adverse clinical and histopathologic features when compared with cases not associated with BRCA mutations. However, the prognosis of BABC appears to be similar to that of nonassociated cancer. Further studies of incident cases are necessary to define the independent prognostic significance of germline BRCA mutations.

Adult↗
PubMed1998

Phase II study of "dose-dense" high-dose chemotherapy treatment with peripheral-blood progenitor-cell support as primary treatment for patients with advanced ovarian cancer.

PURPOSE: We performed a pilot phase II study to evaluate the potential for delivery of rapidly sequenced high-dose chemotherapy treatments rescued with autologous peripheral-blood progenitor cells (PBP) in patients with previously untreated, advanced ovarian cancer. PATIENTS AND METHODS: A single cycle of mobilization was used, primed with cyclophosphamide (CPA)/paclitaxel (Txl) and filgrastim (granulocyte colony-stimulating factor [G-CSF]), followed by three cycles of high-dose carboplatin (CBDCA)/Txl and one cycle of high-dose melphalan (MEL), each rescued by PBP. We then analyzed the outcome for a total of 56 consecutive patients treated with high-dose chemotherapy as part of this program. RESULTS: In the phase II pilot, 21 patients were enrolled. There were no treatment-related deaths through 98 high-dose treatments, although 34 treatments were complicated by hospitalization, primarily for neutropenic fever. Seventy-six percent of patients experienced grade 3 to 4 gastrointestinal toxicity and 62% experienced grade 2 to 3 neuropathy. Five of 15 (33%) patients who underwent second-look surgery attained a pathologic complete response. In the overall analysis, 56 patients were reviewed. Forty-four patients were assessable for response by second-look surgery or clinical progression. Fifteen of 44 patients achieved a pathologic complete response (34%). The pathologic complete response rate in optimal-disease patients was 12 of 22 (55%), while only three of 22 (13%) suboptimal stage III and IV patients achieved a pathologic complete response. CONCLUSION: The Gynecologic Oncology Group has initiated a pilot phase II trial of this approach in patients with optimally debulked stage III ovarian cancer. There is no evidence to support the use of this or other aggressive regimens outside of a clinical trial.

Adult↗
PubMed1997

Phase II study of semisynthetic paclitaxel in metastatic breast cancer.

The aim of this phase II study was to characterise the efficacy and toxicity of semisynthetic paclitaxel in patients with metastatic breast cancer. Eligible patients had measurable disease and had been treated with one prior chemotherapy regimen either as adjuvant or for metastatic disease. Semisynthetic paclitaxel was given at a dose of 175 mg/m2 over 3 h every 21 days with dexamethasone, cimetidine and diphenhydramine premedications. 31 patients were entered. All were evaluable for toxicity. 30 patients were evaluable for response because 1 patient was lost to follow-up after receiving one cycle. One patient achieved a complete response and 10 patients achieved partial responses for an overall response rate (CR + PR) of 37% (95% confidence interval 20-56%). 17 patients (55%) experienced at least one episode of grade 3 or 4 neutropenia. There were two episodes of febrile neutropenia complicating 155 cycles of therapy. One of these resulted in a treatment-related death in a patient with pulmonary metastasis. 3 patients required dose reductions for grade 3 sensory neuropathy. Our study shows that the antitumour activity and toxic effects of semisynthetic paclitaxel appear to be identical to the naturally occurring product.

Adult↗
PubMed1997

Pulmonary toxicity of high-dose chemotherapy for breast cancer: a non-invasive approach to diagnosis and treatment.

Drug-induced pulmonary toxicity is one of the most frequent non-hematologic toxicities in breast cancer patients receiving high-dose chemotherapy with cyclophosphamide, cisplatin and BCNU (CY/CDDP/BCNU). A non-invasive clinical scoring system was utilized in an attempt to diagnose and treat early lung toxicity in 64 consecutive breast cancer patients undergoing CY/CDDP/BCNU supported by peripheral blood progenitor cells. Following hospital discharge, patients who developed symptoms suggestive of lung toxicity were evaluated with physical examination, DLCO, 2-min walking oximetry and a chest radiograph. Clinically weighted scores were assigned as follows: crackles on lung exam, 2; decrease in corrected DLCO by > 10% from baseline, 3; decrease in O2 saturation by > or = 4% with a 2-min walk, 3; and interstitial infiltrates on chest radiograph, 3. Patients with scores > or = 6 were treated with prednisone (60 mg p.o. twice a day followed by a 2-month taper). Treatment was instituted in 37 patients (58%) a median of 56 days after high-dose chemotherapy. Steroid therapy was associated with rapid clinical improvement in most patients. No fatal complications or chronic pulmonary fibrosis was seen. This non-invasive clinical scoring system can be utilized as a model for the early diagnosis of lung toxicity. Further investigation is warranted for the development of preventative measures against this syndrome.

Adult↗
PubMed1997

Prevalence of recurring BRCA mutations among Ashkenazi Jewish women with breast cancer.

The BRCA1 mutations 185delAG and 5382insC and the BRCA2 mutation 6174delT have been detected in a significant proportion of Ashkenazi Jewish women with early-onset breast cancer. A group of 236 Jewish women with breast cancer was screened for the presence of these alterations. Mutations were detected in 25.0% (59/236). Among women with breast cancer diagnosed at or before the age of 45, the prevalence of these mutations was 29.1% (42/144). Among women diagnosed with breast cancer after age 45, mutations were noted in 18.5% (17/92). Among women with a family history of breast or ovarian cancer, the likelihood of detecting a mutation was 32.1% (53/165). BRCA1 185delAG was the most common mutation overall (40/236, 16.9%). The ratio of BRCA1 185delAG to BRCA2 6174delT was 4.0 in women with early-onset breast cancer and 1.3 in women with breast cancer diagnosed after age 45. Clinical features such as age at diagnosis, family history of breast or ovarian cancer, bilateral breast cancer, and personal history of breast and ovarian cancer increase the likelihood of detecting mutations among Ashkenazi women with breast cancer. The yield of testing is low in the absence of any of these features.

Adult↗
PubMed1997

Phase I and pharmacologic study of paclitaxel administered weekly in patients with relapsed ovarian cancer.

PURPOSE: Paclitaxel has shown significant activity in advanced ovarian cancer. In vitro studies with paclitaxel have suggested that fractionated brief infusion schedules may be more effective than the standard 24-hour infusion. We commenced a phase I evaluation of escalating-dose paclitaxel (40, 50, 60, 80, 100 mg/m2) administered weekly as a 1-hour infusion in patients with recurrent ovarian cancer. All patients had received prior paclitaxel and cisplatin therapy. All patients received standard premedication. PATIENTS AND METHODS: Eighteen patients are assessable on this phase I study. The mean age was 54 years (range, 48 to 74). The median number of prior chemotherapy regimens was three (range, two to five). The mean paclitaxel-free interval was 10.1 months (range, 1 to 24). RESULTS: A total of 194 cycles of therapy were administered, with a mean of 10 (range, one to 12) per patient. No mucositis or grade III neuropathy was seen. Alopecia occurred in one out of 18 assessable patients. The mean neutrophil nadir was 4.0 x 10(9)/L. At the top dose level (100 mg/m2) delivered, dose-intensity was 90.75% of that planned and greater than two fold the standard dose-intensity. Partial responses were seen in four of 13 assessable patients (30%). Two patients with progression of disease on standard three-week paclitaxel schedules switched to a weekly schedule with demonstrated response. Increasing paclitaxel dose correlated with measured area under the curve (AUC) (R2 = .614). Dose-limiting toxicity was reached at 100 mg/m2 with two of three patients experiencing a treatment delay, thus defining a maximum-tolerated dose of 80 mg/m2 in this group of heavily pretreated patients on this weekly schedule. CONCLUSION: (1) Paclitaxel administered as a 1-hour infusion is well tolerated; (2) this schedule of administration does not result in cumulative myelosuppression; and (3) this schedule of administration results in dose-intensive paclitaxel delivery with a favorable toxicity profile.

Adenocarcinoma, Clear Cell↗
PubMed1997

Systemic effect of intrathecal methotrexate during the initial phase of treatment of childhood acute lymphoblastic leukemia. The European Organization for Research and Treatment of Cancer Children's Leukemia Cooperative Group.

PURPOSE: The in vivo response to prephase corticosteroid therapy for 1 week has been described as a major prognostic factor in childhood acute lymphoblastic leukemia (ALL). Patients with less than 1,000 blasts/microL at day 8 are considered responders and have a better prognosis. This prephase therapy is usually considered as an evaluation of glucocorticoid sensitivity. In fact, it also includes one intrathecal (IT) injection of methotrexate (MTX). In this study, we try to clarify the influence of this injection of IT MTX on the response to the prephase therapy. PATIENTS AND METHODS: This retrospective study analyzed the response to prephase therapy in 1,044 children with ALL entered onto the European Organization for Research and Treatment of Cancer (EORTC) trial 58881 of the Children's Leukemia Cooperative Group (CLCG). Analysis was restricted to 732 cases with an initial blast count greater than 1,000/microL. The following variables were tested to analyze response to prephase therapy: age, sex, evaluated risk factor (RF), blast count on day 0, actual dose of prednisolone administered, immunophenotype (T v non-T), and day of IT MTX. For statistical analysis, the variable day of IT MTX (D) was stratified into three groups: group 1 if D less than 2, group 2 if D > or = 2 but < or = 6, and group 3 if D greater than 6. RESULTS: All variables tested had a significant influence on response to the prephase therapy. This was especially true for IT MTX: 90.4% responders in group 1, 76.9% in group 2, and 70% in group 3 (P < .001). Immunophenotype was also a major predictor of response to the prephase: 88% responders in B-lineage ALL versus 56.2% in T-lineage ALL. IT MTX had a significant influence in B-lineage ALL (96% responders in group 1, 90% in group 2, and 79% in group 3; P < .001), whereas the influence could not be detected in T-lineage ALL. CONCLUSION: These results clearly demonstrate a therapeutic systemic effect of low doses of IT MTX in childhood ALL, and response to prephase therapy should not be considered as an in vivo test for cortico-sensitivity only. Earlier use of IT MTX leads to a higher percentage of responders.

Antimetabolites, Antineoplastic↗
PubMed1997

Adjuvant Drug Treatment for Resectable Breast Cancer.

Breast cancer is the most common life-threatening malignancy in Western women and the second most common cause of cancer-related death. A paradox in the care of patients with breast cancer is the observation that the majority appear to be curable at the time of initial surgery, yet a large number later experience relapse followed by death from disease. To combat this problem, systemic drug therapy in conjunction with surgery and radiation therapy is now standard for many patient subgroups. Standard medical treatment options include up to five years of tamoxifen for receptor positive amenorrheic patients, approximately six months of combination chemotherapy for younger patients and those who are receptor negative, and both in some patient subgroups. These interventions have a profound public health impact even though the majority of patients destined to recur do so even following "optimal" treatment. Further improvements are hoped for as a result of ongoing research involving the use of high-dose chemotherapy, dose-dense chemotherapy, and newer agents. Clinical trials testing these approaches offer the best chance to continue our progress and help to better define appropriate and standard treatment strategies for the future.

Journal Article↗