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Biomedical subjects

John Crown

Publications and source records attributed to John Crown.

At least 19 recordsLinked to original sources
PubMed2006

Lapatinib plus capecitabine for HER2-positive advanced breast cancer.

BACKGROUND: Lapatinib, a tyrosine kinase inhibitor of human epidermal growth factor receptor type 2 (HER2, also referred to as HER2/neu) and epidermal growth factor receptor (EGFR), is active in combination with capecitabine in women with HER2-positive metastatic breast cancer that has progressed after trastuzumab-based therapy. In this trial, we compared lapatinib plus capecitabine with capecitabine alone in such patients. METHODS: Women with HER2-positive, locally advanced or metastatic breast cancer that had progressed after treatment with regimens that included an anthracycline, a taxane, and trastuzumab were randomly assigned to receive either combination therapy (lapatinib at a dose of 1250 mg per day continuously plus capecitabine at a dose of 2000 mg per square meter of body-surface area on days 1 through 14 of a 21-day cycle) or monotherapy (capecitabine alone at a dose of 2500 mg per square meter on days 1 through 14 of a 21-day cycle). The primary end point was time to progression, based on an evaluation by independent reviewers under blinded conditions. RESULTS: The interim analysis of time to progression met specified criteria for early reporting on the basis of superiority in the combination-therapy group. The hazard ratio for the independently assessed time to progression was 0.49 (95% confidence interval, 0.34 to 0.71; P<0.001), with 49 events in the combination-therapy group and 72 events in the monotherapy group. The median time to progression was 8.4 months in the combination-therapy group as compared with 4.4 months in the monotherapy group. This improvement was achieved without an increase in serious toxic effects or symptomatic cardiac events. CONCLUSIONS: Lapatinib plus capecitabine is superior to capecitabine alone in women with HER2-positive advanced breast cancer that has progressed after treatment with regimens that included an anthracycline, a taxane, and trastuzumab. (ClinicalTrials.gov number, NCT00078572 [ClinicalTrials.gov].).

Adult↗
PubMed2005

Phase III randomized trial of doxorubicin and docetaxel versus doxorubicin and cyclophosphamide as primary medical therapy in women with breast cancer: an anglo-celtic cooperative oncology group study.

PURPOSE To compare the clinical and pathologic response rates of doxorubicin and cyclophosphamide (AC) with doxorubicin and docetaxel (AD) as primary chemotherapy in women with primary or locally advanced breast cancer. PATIENTS AND METHODS Eligible patients with histologically proven breast cancer with primary tumors >/= 3 cm, inflammatory or locally advanced disease, and no evidence of metastases were randomly assigned to receive a maximum of six cycles of either doxorubicin (60 mg/m(2)) plus cyclophosphamide (600 mg/m(2)) administered intravenously (IV) every 3 weeks or doxorubicin (60 mg/m(2)) plus docetaxel (75 mg/m(2)) IV every 3 weeks, followed by surgery on completion of chemotherapy. Results A total of 363 patients were randomly assigned to AC (n = 180) or AD (n = 183). A complete clinical response was observed in 17% and 20% of patients treated with AC and AD, respectively (P = .42). Overall (complete and partial) clinical response rates for AC and AD were 61% and 70%, respectively (P = .06). There was no significant difference in either the pathologic complete response rates in the breast with AC (24%) and AD (21%; P = .61) or in the number of patients with positive axillary nodes at surgery with AC (61%) and AD (66%; P = .28). At a median follow-up of 32 months, there is no significant difference between the two groups for the number of relapses. CONCLUSION In contrast to the positive results reported for sequential docetaxel after AC as primary chemotherapy of breast cancer, our data do not suggest a benefit for simultaneous AD over AC.

Adult↗
PubMed2005

Pelvic recurrence in stage I seminoma: a new phenomenon that questions modern protocols for radiotherapy and follow-up.

OBJECTIVE: To highlight the increased risk for pelvic relapse in patients with stage 1 seminoma treated with adjuvant radiotherapy limited to para-aortic template alone. PATIENTS AND METHODS: Over a four-year period, three patients presented with early pelvic recurrence after radical orchidectomy and adjuvant irradiation for stage 1 seminoma. In each case, radiotherapy had been limited to the para-aortic region with omission of the ipsilateral hemi pelvis. RESULTS: Pelvic recurrences occurred on the ipsilateral tumor side. Durable complete remission was achieved in each case; however, treatment was complex and there was associated morbidity. CONCLUSION: This significant incidence of pelvic recurrence questions the validity of modern radiotherapy protocol which excludes the ipsilateral pelvis from the radiation field.

Adult↗
PubMed2004

Investigation of MRP-1 protein and MDR-1 P-glycoprotein expression in invasive breast cancer: a prognostic study.

The efficacy of breast cancer treatment is limited by the development of resistance to various chemotherapeutic agents. We conducted a retrospective study of the expression of 2 drug resistance efflux pumps, MRP-1 and MDR-1 Pgp, in 177 invasive breast carcinomas. Immunohistochemical expression of these proteins was correlated with clinicopathologic characteristics as well as relapse-free survival (RFS) and overall survival (OS) times. MDR-1 Pgp was associated strongly with higher histologic grade (grade III). A highly significant association was shown between MDR-1 Pgp and MRP-1 expression (p < 0.01), 47.4% of patients expressing both proteins; MRP-1 was expressed in approximately 61% of patients and MDR-1, in approximately 66% of patients. No association was shown in the overall group between either MDR-1 Pgp or MRP-1 and any of the other clinicopathologic features. Kaplan-Meier analysis revealed that in a subset of patients with either high-grade (grade III) stage 1 (node-negative) or stage 2 (node-positive) tumours who were treated with surgery followed by adjuvant chemotherapy, MRP-1 expression in <25% of tumour cells at diagnosis was significantly associated with improved RFS (p < 0.02) and OS (p < 0.02). Using multivariate analysis, MRP-1 expression in <25% of tumour cells at diagnosis was identified as an independent, significant prognostic factor for RFS (p < 0.01) and OS (p < 0.01) in this patient group but not in other groups. In this subgroup, no significant correlation was observed between expression of MDR-1 Pgp and MRP-1. While the number of patients with high-grade tumours treated with adjuvant chemotherapy was small and further confirmatory research is warranted, it appears that assessment of MRP-1 expression at diagnosis may offer useful prognostic information in subgroups of patients with stage 1 or stage 2 high-grade tumours who receive CMF-based adjuvant chemotherapy. Given the known substrate specificities of MRP-1, any mechanistic relationship between MRP-1 expression and CMF resistance remains unclear. No association was shown between MDR-1 Pgp expression and either RFS or OS time in any subgroup of patients.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2004

Conventional adjuvant chemotherapy versus single-cycle, autograft-supported, high-dose, late-intensification chemotherapy in high-risk breast cancer patients: a randomized trial.

BACKGROUND: Breast cancer patients with four or more positive axillary lymph nodes who are treated with conventional adjuvant therapy have a poor prognosis. In uncontrolled studies, high-dose chemotherapy produced much better results than conventional therapy. We compared the benefits of a single cycle of high-dose chemotherapy and the benefits of conventional chemotherapy in patients with high-risk breast cancer in a prospective, unblinded, randomized trial. METHODS: Between February 23, 1995, and June 29, 1999, 605 patients with breast cancer who had four or more positive lymph nodes were randomly assigned to treatment (307 to high-dose therapy and 298 to conventional therapy). The conventional chemotherapy regimen was four cycles of doxorubicin (75 mg/m2) followed by eight cycles of CMF (cyclophosphamide [600 mg/m2], methotrexate [50 mg/m2], and 5-fluorouracil [600 mg/m2]), all given intravenously on day 1 of a 21-day cycle. The high-dose regimen was four cycles of doxorubicin (75 mg/m2), followed by a single cycle of intermediate-dose cyclophosphamide (4000 mg/m2) supported by filgrastim (300 microg/day) for up to 10 days followed by high-dose cyclophosphamide (6000 mg/m2) and thiotepa (800 mg/m2). Peripheral blood progenitor cells were harvested by leukapheresis after treatment with cyclophosphamide and filgrastim and then re-infused after the high-dose cycle. Log-rank tests were used to compare survival rates. All statistical analyses were two-sided. RESULTS: At a median follow-up of 6 years, no statistically significant differences were detected between the arms in 5-year relapse-free survival (high-dose arm = 57%, 95% confidence interval [CI] = 51% to 63%; conventional-dose arm = 54%, 95% CI = 48% to 61% (P =.73) or in 5-year overall survival (high-dose arm = 62%, 95% CI = 56% to 68%; conventional-dose arm = 64%, 95% CI = 57% to 70%) (P =.38). CONCLUSION: Autograft-supported, high-dose therapy is not superior to conventional chemotherapy in patients with breast cancer who have multiple involved lymph nodes. This conclusion should be viewed in the context of improving the success of conventional chemotherapy.

Adult↗
PubMed2004

Results of two open-label, multicenter phase II studies of docetaxel, platinum salts, and trastuzumab in HER2-positive advanced breast cancer.

BACKGROUND: Preclinical data indicate that docetaxel, platinum salts, and the combination of both drugs are highly synergistic with the anti-HER2 antibody trastuzumab. The University of California at Los Angeles-Oncology Research Network (UCLA-ORN) and the Breast Cancer International Research Group (BCIRG) have conducted two phase II studies to evaluate docetaxel and trastuzumab in combination with either cisplatin or carboplatin for the treatment of women with advanced breast cancer that overexpresses HER2. METHODS: Each study enrolled 62 patients with HER2-overexpressing tumors. Patients received a median of six cycles of docetaxel at 75 mg/m2 of body surface area and cisplatin (BCIRG 101 study) at 75 mg/m2 or carboplatin (UCLA-ORN study) at AUC = 6 mg/mL. min given on day 1 and then every 21 days. Trastuzumab was given on day 1, cycle 1 (4 mg/kg) and then continued weekly at 2 mg/kg for 1 year or until disease progression. Tumor measurements were obtained at baseline, after three cycles of chemotherapy, and then every 3 months. HER2 gene amplification was determined by fluorescence in situ hybridization. RESULTS: Patient characteristics were comparable between trials with the exception that 15% of the patients in the UCLA-ORN study had received previous adjuvant taxane therapy. Both regimens were well tolerated, with manageable toxicities. Hematologic toxicities were more frequent in patients in the UCLA-ORN study than in patients in the BCIRG 101 study, whereas the reverse pattern was observed for non-hematologic toxicities. One patient in each study developed reversible congestive heart failure. Responses were observed in 49 of 62 patients in the BCIRG 101 study (overall response rate = 79%, 95% confidence interval [CI] = 66% to 89%) and in 34 of 59 evaluable patients in the UCLA-ORN study (overall response rate = 58%, 95% CI = 44% to 70%). Median times to progression were 9.9 months (95% CI = 8.3 to 13.1 months) and 12.7 months (95% CI = 8.6 to 15.5 months) for patients in the BCIRG 101 and UCLA-ORN studies, respectively. Overall response rates were higher and median time to progression was longer in the subset of patients whose tumors harbored HER2 gene amplification. CONCLUSION: Combinations of docetaxel, a platinum salt, and trastuzumab are feasible and active in patients with advanced breast cancers that overexpress HER2. The BCIRG is conducting ongoing randomized studies of the three-drug combination in both the metastatic and adjuvant settings.

Adult↗
PubMed2004

High preoperative CA 15-3 concentrations predict adverse outcome in node-negative and node-positive breast cancer: study of 600 patients with histologically confirmed breast cancer.

BACKGROUND: CA 15-3 is the most widely used serum marker in breast cancer. Currently, its main uses are in the surveillance of patients with diagnosed disease and monitoring the treatment of patients with advanced disease. METHODS: Preoperative CA 15-3 concentrations were measured prospectively in 600 patients with histologically confirmed breast cancer. Marker concentrations were related to patient outcome by both univariate and multivariate analysis. RESULTS: After a median follow-up of 6.27 years, patients with high preoperative concentrations of CA 15-3 (>30 units/L) had a significantly shorter overall survival pattern than those with low concentrations. As a prognostic factor, CA 15-3 was independent of tumor size, axillary node status, and patient age. As well as being prognostic in the total population of patients, CA 15-3 also predicted outcome in different subgroups of patients, including those with both node-negative and node-positive disease, those who were both estrogen receptor (ER)-negative and ER-positive, and those younger and older that 50 years of age. CA 15-3 was also predictive of outcome irrespective of the type of adjuvant therapy administered, i.e., whether adjuvant hormone therapy, adjuvant chemotherapy, or radiotherapy was administered. CONCLUSION: Assay of CA 15-3 is a relatively inexpensive, convenient, and noninvasive method for evaluating prognosis in newly diagnosed breast cancer patients.

Adult↗
PubMed2004

Docetaxel and paclitaxel in the treatment of breast cancer: a review of clinical experience.

In the 10 years since their initial licensing in Europe, the taxanes, paclitaxel and docetaxel, have emerged as fundamental drugs in the treatment of breast cancer. Clinically meaningful benefits were first shown in the metastatic setting, and large-scale exploration of their roles in the adjuvant therapy of early-stage disease is ongoing. Benefits have been seen in the neoadjuvant setting as well, mainly with docetaxel. This paper reviews the current roles of the taxanes in the treatment of metastatic and early-stage breast cancer. Also addressed are outstanding issues involving optimal dosing and sequencing, as well as a discussion of the relative merits of each agent in this setting. Clinicians should choose a taxane-based regimen for their patients with breast cancer based on consideration of the pharmacokinetics, clinical activity, and dosing schedule that best meets the patients' needs. At the current time, the pharmacokinetic profile, consistent positive clinical results, and convenience of an intermittent, short-infusion schedule have made docetaxel the preferred taxane for many clinicians treating patients with breast cancer.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2004

Topoisomerase-II alpha expression as a predictive marker in a population of advanced breast cancer patients randomly treated either with single-agent doxorubicin or single-agent docetaxel.

PURPOSE: The predictive value of topoisomerase-II alpha (topo-II) has been evaluated in advanced breast cancer patients randomly treated with single-agent doxorubicin or docetaxel. EXPERIMENTAL DESIGN: Primary tumor samples from patients enrolled in a randomized, phase III clinical trial comparing single-agent doxorubicin (75 mg/m(2) q3wks) with docetaxel (100 mg/m(2) q3wks) were collected and topo-II status was evaluated by immunohistochemistry (clone KiS1). RESULTS: Topo-II status was evaluated in 108 samples, 55 (51%) in the doxorubicin arm and 53 (49%) in the docetaxel arm. An increment of 10% in cells expressing topo-II is associated with a statistically significant odds ratio (OR; 95% confidence interval) of 1.09 (1.03-1.15; P = 0.002) for overall response to doxorubicin versus 1.002 (0.94-1.07; P = 0.95) in the docetaxel arm. With increasing topo-II, the favorable OR for overall response to docetaxel compared with doxorubicin decreases to become not significant in patients with topo-II tumor content >10%. In a multivariate analysis, (a) HER-2 status seems positively correlated with overall response to chemotherapy (OR, 2.34; 95% confidence interval, 0.87-6.27; P = 0.09). (b) Overall response to doxorubicin is significantly lower than overall response to docetaxel (OR, 0.17; 95% confidence interval, 0.04-0.64; P = 0.009) but with a significant interaction term for doxorubicin-treated patients with topo-II tumor content >10% (OR, 8.31; 95% confidence interval, 1.86-37.03; P = 0.05). CONCLUSIONS: (a) Topo-II overexpression confers a higher probability of response in the doxorubicin arm only. (b) Despite being a small retrospective study, this study is in line with previously reported studies and the hypotheses raised are now being tested in a prospective neoadjuvant trial.

Adult↗
PubMed2003

Platinum-taxane combinations in metastatic breast cancer: an evolving role in the era of molecularly targeted therapy.

Metastatic breast cancer is a partially chemotherapy-sensitive neoplasm. Docetaxel appears to be the most active single agent for this condition. The platinum coordination complexes are also active, but are seldom used. An emerging literature suggests that taxane-platinum combinations have substantial activity. Trastuzumab, a molecularly targeted therapy for metastatic breast cancer is active as a single agent in HER2-overexpressing disease, and has been demonstrated to augment the activity of other agents in random assignment trials. Preclinical data suggest a powerful synergistic interaction between trastuzumab and both platinum and docetaxel. In early trials, platinum-taxane-trastuzumab combinations have exhibited promising clinical activity. The potential for cardiac toxicity when trastuzumab is combined with the anthracyclines suggests a further rationale for the development of non-anthracycline regimens, especially in the adjuvant setting. Randomized, multicenter, phase III trials in the metastatic and adjuvant setting are currently underway to test the hypothesis that synergistic combinations of docetaxel, platinums, and trastuzumab will result in superior safety as well as efficacy.

Antibodies, Monoclonal↗
PubMed2003

Caspase 3 in breast cancer.

PURPOSE: An inability to undergo apoptosis is widely thought to contribute to both tumorigenesis and tumor progression. One of the key mediators of apoptosis is the thiol protease caspase 3. In this investigation, caspase 3 mRNA and protein expression in breast cancer was examined. EXPERIMENTAL DESIGN: Caspase 3 was measured at the mRNA level using reverse transcription-PCR and at the protein level using both Western blotting and activity assays. Levels of apoptosis were determined using an ELISA, which detects nucleosomes released during DNA fragmentation. RESULTS: Relative levels of caspase 3 mRNA were similar in breast carcinomas (n = 103), fibroadenomas (n = 25), and normal breast tissues (n = 6). However, levels of both the precursor and active forms of caspase 3 were significantly higher in carcinomas compared with both fibroadenomas (P = 0.0188) and normal breast tissues (P = 0.0002). Levels of apoptosis were also highest in the carcinomas and correlated significantly with active caspase 3 levels (r = 0.481; P = 0.0003). In the carcinomas, expression of caspase 3 showed no significant relationship with either tumor size, tumor grade, nodal status, or steroid receptor status but was significantly higher in ductal carcinomas than in lobular carcinomas (P = 0.0188). CONCLUSIONS: We conclude that rates of apoptosis as measured by both caspase 3 activation and nucleosome release are higher in breast cancer than in nonmalignant breast tissue. This finding would appear to conflict with the widely held belief that apoptosis is reduced in malignancy. The proliferation:apoptosis ratio, however, may be higher in carcinomas than in the corresponding normal tissue.

Apoptosis↗
PubMed2002

High-dose chemotherapy for solid tumors: results of the EBMT.

The European Group for Blood and Marrow Transplantation (EBMT), formerly known as European Group for Bone Marrow Transplantation, was established in 1974 in the Netherlands to share experiences, to promote research and clinical studies and to set up registries in the field of hematopoietic tissue transplantation. At the present time more 400 European and non-European centers are members of the EBMT group. In 1984 a new Working Party was created (Solid Tumors) with the aim to investigate the role of high-dose chemotherapy and stem cell support in the fields of adult and pediatric solid tumors. By January 2000 more than 14000 patients were registered, and at the present time this Registry is the world largest database on this subject. Several phase III randomized clinical trials have recently started on behalf of the Group in different diseases (breast carcinoma, small cell lung cancer, ovarian carcinoma, germ cell tumors and Ewing's family sarcoma). Hundreds of randomized patients will finally produce clearer information on this still experimental therapeutic modality. This paper will describe the EBMT Solid Tumors Working Party Registry updated results as well as the main ongoing studies.

Antineoplastic Agents↗
PubMed2002

Chemotherapy for metastatic breast cancer-report of a European expert panel.

The anthracyclines doxorubicin and epirubicin, and the taxanes paclitaxel and docetaxel, are effective chemotherapeutic agents for the first-line and second-line treatment of metastatic breast cancer, and their clinical use is widespread. However, for women whose disease has progressed despite receiving these drugs, treatment options are limited. These women often have a good performance status, and may survive for many months or even years, so they should be given the opportunity to benefit from further chemotherapy. The goals of chemotherapy in these patients are to obtain maximum control of symptoms, prevent serious complications, and increase survival without diminishing quality of life. Several agents are used for this purpose, including fluorouracil, docetaxel (in patients who have already received paclitaxel), vinorelbine, and mitomycin c, but because data from controlled trials are limited, a standard regimen has not yet been established. Moreover, these agents may be inconvenient to administer and can be associated with adverse events requiring hospitalisation. Therefore, there is a clear need for additional therapeutic options for patients with metastatic breast cancer. Ideally, agents should have a convenient method of administration, eg, oral, and should be suitable for home-based rather than hospital-based therapy. Treatment should control disease in at least 20-30% of patients with an acceptable side-effect profile. Novel oral therapies have now been developed and are being used increasingly in patients whose disease has progressed following taxane therapy.

Antibiotics, Antineoplastic↗
PubMed1995

Rapidly cycled courses of high-dose alkylating agents supported by filgrastim and peripheral blood progenitor cells in patients with metastatic breast cancer.

Our purpose was to determine the feasibility of a regimen of multiple, rapidly cycled courses of high-dose alkylating agents, including paired courses of escalating doses of thiotepa, supported by peripheral blood progenitor cells and filgrastim, in patients with responding stage IV breast cancer. The regimen consisted of two courses of cyclophosphamide (3.0 g/m2/course) followed by two courses of thiotepa (500-700 mg/m2/course). All courses were supported by filgrastim. Leukaphereses were performed after each cyclophosphamide course to harvest peripheral blood progenitors (PBPs) for use as rescue following thiotepa administration. The planned interval for all courses was 14 days. Forty-two patients were enrolled. Thirty-eight received all four courses, and four did not receive the second thiotepa cycle due to poor PBP mobilization. The maximum dose of thiotepa that was administered was 700 mg/m2 x 2. At this dose, one patient developed encephalopathy, which resolved over several weeks. The median number of days to an absolute neutrophil count of 0.5 x 10(9)/liter after PBP reinfusion for cycles 1 and 2 of thiotepa were 9 (range, 7-16) and 9 (range, 8-13) days, respectively. The corresponding values for platelet recovery to >20 x 10(9)/liter were 11 (range, 8-39) and 12 (range, 10-28) days, respectively. There were no treatment-related deaths. Hospitalization was required following 28 of 84 cyclophosphamide courses and 76 of 80 thiotepa courses. Four patients developed grade III-IV mucositis. The median interval between courses of treatment was 15 (range, 13-29) days. Of 19 patients who entered the protocol with measurable disease in partial response from prior therapy, 8 (42%) achieved complete response following the high-dose therapy. Nine (21%) of 42 remain progression free at a median follow-up of 28 (range, 20-32) months. Therefore, we concluded that the administration of multiple, rapidly cycled courses of high-dose alkylating agents is feasible.

Adult↗