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Biomedical subjects

Edith A Perez

Publications and source records attributed to Edith A Perez.

At least 37 records · Page 2Linked to original sources
PubMed2006

Aromatase inhibitors and bone loss.

The aromatase inhibitors (AIs) anastrozole (Arimidex), letrozole (Femara), and exemestane (Aromasin) are significantly more effective than the selective estrogen-receptor modulator (SERM) tamoxifen in preventing recurrence in estrogen receptor-positive early breast cancer. Aromatase inhibitors are likely to replace SERMs as first-line adjuvant therapy for many patients. However, AIs are associated with significantly more osteoporotic fractures and greater bone mineral loss. As antiresorptive agents, oral and intravenous bisphosphonates such as alendronate (Fosamax), risedronate (Actonel), ibandronate (Boniva), pamidronate (Aredia), and zoledronic acid (Zometa) have efficacy in preventing postmenopausal osteoporosis, cancer treatment-related bone loss, or skeletal complications of metastatic disease. Clinical practice guidelines recommend baseline and annual follow-up bone density monitoring for all patients initiating AI therapy. Bisphosphonate therapy should be prescribed for patients with osteoporosis (T score < -2.5) and considered on an individual basis for those with osteopenia (T score < -1). Modifiable lifestyle behaviors including adequate calcium and vitamin D intake, weight-bearing exercise, and smoking cessation should be addressed. Adverse events associated with bisphosphonates include gastrointestinal toxicity, renal toxicity, and osteonecrosis of the jaw. These safety concerns should be balanced with the potential of bisphosphonates to minimize or prevent the debilitating effects of AI-associated bone loss in patients with early, hormone receptor-positive breast cancer.

Aromatase Inhibitors↗
PubMed2005

Pharmacogenetics of tamoxifen biotransformation is associated with clinical outcomes of efficacy and hot flashes.

PURPOSE: Polymorphisms in tamoxifen metabolizing genes affect the plasma concentration of tamoxifen metabolites, but their effect on clinical outcome is unknown. METHODS: We determined cytochrome P450 (CYP)2D6 (*4 and *6) and CYP3A5 (*3) genotype from paraffin-embedded tumor samples and buccal cells (living patients) in tamoxifen-treated women enrolled onto a North Central Cancer Treatment Group adjuvant breast cancer trial. The relationship between genotype and disease outcome was determined using the log-rank test and Cox proportional hazards modeling. RESULTS: Paraffin blocks were obtained from 223 of 256 eligible patients, and buccal cells were obtained from 17 living women. CYP2D6 (*4 and *6) and CYP3A5 (*3) genotypes were determined from 190, 194, and 205 patient samples and in 17 living women. The concordance rate between buccal and tumor genotype was 100%. Women with the CYP2D6 *4/*4 genotype had worse relapse-free time (RF-time; P = .023) and disease-free survival (DFS; P = .012), but not overall survival (P = .169) and did not experience moderate to severe hot flashes relative to women heterozygous or homozygous for the wild-type allele. In the multivariate analysis, women with the CYP2D6 *4/*4 genotype still tended to have worse RFS (hazard ratio [HR], 1.85; P = .176) and DFS (HR, 1.86; P = .089). The CYP3A5*3 variant was not associated with any of these clinical outcomes. CONCLUSION: In tamoxifen-treated patients, women with the CYP2D6 *4/*4 genotype tend to have a higher risk of disease relapse and a lower incidence of hot flashes, which is consistent with our previous observation that CYP2D6 is responsible for the metabolic activation of tamoxifen to endoxifen.

Adult↗
PubMed2005

Trastuzumab plus adjuvant chemotherapy for operable HER2-positive breast cancer.

BACKGROUND: We present the combined results of two trials that compared adjuvant chemotherapy with or without concurrent trastuzumab in women with surgically removed HER2-positive breast cancer. METHODS: The National Surgical Adjuvant Breast and Bowel Project trial B-31 compared doxorubicin and cyclophosphamide followed by paclitaxel every 3 weeks (group 1) with the same regimen plus 52 weeks of trastuzumab beginning with the first dose of paclitaxel (group 2). The North Central Cancer Treatment Group trial N9831 compared three regimens: doxorubicin and cyclophosphamide followed by weekly paclitaxel (group A), the same regimen followed by 52 weeks of trastuzumab after paclitaxel (group B), and the same regimen plus 52 weeks of trastuzumab initiated concomitantly with paclitaxel (group C). The studies were amended to include a joint analysis comparing groups 1 and A (the control group) with groups 2 and C (the trastuzumab group). Group B was excluded because trastuzumab was not given concurrently with paclitaxel. RESULTS: By March 15, 2005, 394 events (recurrent, second primary cancer, or death before recurrence) had been reported, triggering the first scheduled interim analysis. Of these, 133 were in the trastuzumab group and 261 in the control group (hazard ratio, 0.48; P<0.0001). This result crossed the early stopping boundary. The absolute difference in disease-free survival between the trastuzumab group and the control group was 12 percent at three years. Trastuzumab therapy was associated with a 33 percent reduction in the risk of death (P=0.015). The three-year cumulative incidence of class III or IV congestive heart failure or death from cardiac causes in the trastuzumab group was 4.1 percent in trial B-31 and 2.9 percent in trial N9831. CONCLUSIONS: Trastuzumab combined with paclitaxel after doxorubicin and cyclophosphamide improves outcomes among women with surgically removed HER2-positive breast cancer. (ClinicalTrials.gov numbers, NCT00004067 and NCT00005970.)

Adult↗
PubMed2005

Randomized trial of letrozole following tamoxifen as extended adjuvant therapy in receptor-positive breast cancer: updated findings from NCIC CTG MA.17.

BACKGROUND: Most recurrences in women with breast cancer receiving 5 years of adjuvant tamoxifen occur after 5 years. The MA.17 trial, which was designed to determine whether extended adjuvant therapy with the aromatase inhibitor letrozole after tamoxifen reduces the risk of such late recurrences, was stopped early after an interim analysis showed that letrozole improved disease-free survival. This report presents updated findings from the trial. METHODS: Postmenopausal women completing 5 years of tamoxifen treatment were randomly assigned to a planned 5 years of letrozole (n = 2593) or placebo (n = 2594). The primary endpoint was disease-free survival (DFS); secondary endpoints included distant disease-free survival, overall survival, incidence of contralateral tumors, and toxic effects. Survival was examined using Kaplan-Meier analysis and log-rank tests. Planned subgroup analyses included those by axillary lymph node status. All statistical tests were two-sided. RESULTS: After a median follow-up of 30 months (range = 1.5-61.4 months), women in the letrozole arm had statistically significantly better DFS and distant DFS than women in the placebo arm (DFS: hazard ratio [HR] for recurrence or contralateral breast cancer = 0.58, 95% confidence interval [CI] = 0.45 to 0.76; P < .001; distant DFS: HR = 0.60, 95% CI = 0.43 to 0.84; P = .002). Overall survival was the same in both arms (HR for death from any cause = 0.82, 95% CI = 0.57 to 1.19; P = .3). However, among lymph node-positive patients, overall survival was statistically significantly improved with letrozole (HR = 0.61, 95% CI = 0.38 to 0.98; P = .04). The incidence of contralateral breast cancer was lower in women receiving letrozole, but the difference was not statistically significant. Women receiving letrozole experienced more hormonally related side effects than those receiving placebo, but the incidences of bone fractures and cardiovascular events were the same. CONCLUSION: Letrozole after tamoxifen is well-tolerated and improves both disease-free and distant disease-free survival but not overall survival, except in node-positive patients.

Aged↗
PubMed2005

A phase II trial of docetaxel and carboplatin as first-line chemotherapy for metastatic breast cancer: NCCTG study N9932.

OBJECTIVE: A phase II multi-institutional clinical trial conducted to evaluate the efficacy and tolerability of docetaxel and carboplatin as first-line therapy for women with metastatic breast cancer. METHODS: Patients had histologically confirmed metastatic breast cancer with at least one measurable lesion. Prior adjuvant chemotherapy was permitted, provided that at least 12 months had elapsed between any prior taxane and platinum therapy. Patients received docetaxel 75 mg/m(2) with carboplatin AUC 6 mg/ml.min every 21 days until disease progression or prohibitive toxicity. RESULTS: All 53 patients enrolled were evaluable for response and toxicity. Median number of cycles delivered was 6. Overall response rate was 60%, with 3 complete responses (6%) and 29 partial responses (54%). Median time to disease progression was 9.6 months. Median survival time was 20.4 months. Myelosuppression was the predominant toxicity, with grade 3 or 4 neutropenia occurring in 94% of patients and 15% of patients experiencing febrile neutropenia. The overall incidence (grades 1-3) of neurosensory toxicity was 57% and neuromotor toxicity was 25%, respectively, with grade 3 toxicity occurring in 4% of patients each. CONCLUSIONS: The combination of docetaxel and carboplatin is highly active in metastatic breast cancer. Prophylactic growth factor support is recommended in any further evaluation of this combination in the treatment of patients with breast cancer.

Adult↗
PubMed2005

Serum soluble epidermal growth factor receptor concentrations decrease in postmenopausal metastatic breast cancer patients treated with letrozole.

Previous studies have implicated estrogen as a regulator of epidermal growth factor receptor (EGFR) expression in breast tumors. We therefore speculated that estrogen might modulate serologic soluble EGFR (sEGFR) concentrations in breast cancer patients. Accordingly, we measured serum sEGFR concentrations in postmenopausal women with metastatic breast cancer (MBC) treated with letrozole, an aromatase inhibitor that blocks estrogen synthesis. Serum specimens were obtained prior to and following 1 and 3 months of letrozole therapy. We report that sEGFR concentrations do not differ between MBC patients prior to letrozole treatment and age- and postmenopause-matched healthy women (P = 0.468). In contrast, however, sEGFR concentrations decreased significantly in 76% of MBC patients after both 1 month (P = 0.006) and 3 months (P = 0.003) of letrozole therapy versus pretreatment concentrations. Within the limitations of this study, we found no evidence for an association between pretreatment sEGFR concentrations or decreased treatment sEGFR concentrations and either progression-free or overall survival. Nonetheless, we conclude that future prospective studies are warranted to determine if baseline and/or longitudinal serum sEGFR concentrations may be useful for predicting disease progression and survival, and/or for monitoring responsiveness to aromatase inhibitors or other endocrine therapies in breast cancer patients.

Antineoplastic Agents↗
PubMed2005

Phase II trial of dolastatin-10 in patients with advanced breast cancer.

PURPOSE: Phase II multicenter cooperative group study investigated the efficacy and toxicity of the novel anti-microtubule agent dolastatin-10 in patients with advanced breast cancer. PATIENT AND METHODS: Twenty-one patients with measurable metastatic breast cancer were treated with dolastatin-10 at a dose of 400 mcg/m2 by intravenous bolus once every 3 weeks. Patients must have received a total of 1 or 2 prior chemotherapy regimens and have an Eastern Cooperative Oncology Group performance status of 0-2. Patients received this treatment as either a first (n = 11) or second-line (n = 10) chemotherapy for metastatic disease. Eighteen patients (86%) had received a prior anthracycline. The National Cancer Institute provided the dolastatin-10. RESULTS: One out of 21 patients (5%; 95% CI: 0-24%) achieved a partial remission for a duration of 113 days. Four patients maintained stable disease for a median of 87 days. A total of 58 courses of dolastatin-10 were administered. Patients received a median of two cycles of dolastatin-10. Hematologic toxicity was moderate, with 8 patients developing grade 4 neutropenia, and 5 with grade 3 neutropenia; one grade 3 febrile neutropenia was observed. These episodes of grade 3 and 4 neutropenia were experienced on 36% of the treatment cycles. Non-hematologic toxicity was uncommon. CONCLUSION: While the toxicity profile of dolastatin-10 was acceptable, it had minimal activity in this advanced breast cancer study. We are not pursuing further clinical trials of this agent in the setting of advanced breast cancer.

Adult↗
PubMed2005

Phase II study of gemcitabine plus cisplatin in patients with metastatic breast cancer: a North Central Cancer Treatment Group Trial.

BACKGROUND: This 2-stage, phase II cooperative group trial examined the efficacy and toxicity of 1000 mg/m2 gemcitabine plus 25 mg/m2 cisplatin weekly for 3 weeks and repeated every 28 days for patients with previously treated metastatic breast cancer. METHODS: Eligible patients had to have measurable metastatic disease. Progression on prior treatment with at least 1 chemotherapy program for metastatic disease and 1 prior anthracycline and/or taxane-containing regimen in either the metastatic or adjuvant setting was required. Patients who had received more than 2 chemotherapy treatments were not eligible for this study. RESULTS: Fifty-eight eligible patients were entered on this 2-stage study. A 38% incidence of grade 4 thrombocytopenia observed in the first stage of accrual required lowering the chemotherapy doses to 800 mg/m2 gemcitabine plus 20 mg/m2 cisplatin weekly for the first 3 weeks of a 4-week cycle during the second stage of the study. The overall response rate was 29% (95% confidence interval [CI], 11-52%) among patients receiving the original study dose and 32% (95% CI, 18-50%) for patients receiving the lower dose. In the original- and lower-dose groups, median time to progression was 30.7 weeks (95% CI, 12.7-43.4 weeks) and 26.0 weeks (95% CI, 19.0-32.1 week), respectively. Median survival of the original- and low-dose groups was 67.9 weeks (95% CI, 42.3-90.6 weeks) and 54.1 weeks (95% CI, 41.6-73.6 weeks), respectively. Hematologic toxicities were more manageable in the lower-dose group, whereas the nonhematologic toxicity profile was similar in the 2 dose groups. CONCLUSIONS: The response rate of this combination of gemcitabine and cisplatin is similar to that reported by other investigators but may not differ substantially from reports with single-agent gemcitabine in this patient population. The original dose level we used had unacceptable toxicity, which required lowering the doses of both gemcitabine and cisplatin by 20% to achieve acceptable toxicity and preserve clinical activity.

Adult↗
PubMed2005

Molecularly targeted therapies for breast cancer.

BACKGROUND: The management of patients with localized and advanced breast cancer continues to evolve. Chemotherapy, endocrine therapy, and trastuzumab are effective therapies but leave considerable room for improvement. As the cellular aberrations inherent to cancer cells in general and breast cancer cells specifically are better understood, therapies to target specific cellular pathways continue to be developed with the goal of expanding available effective therapy through better patient selection. METHODS: We conducted a computerized search of the medical literature as well as a manual search of selected meeting abstracts. RESULTS: Several targeted therapies are in phase III clinical trials testing their promise in the treatment of breast cancer. Many other agents are completing phase I and II testing. An overview of the most promising agents in clinical development is discussed herein. CONCLUSIONS: Targeted therapy for breast cancer is a reality at this time, and several new agents hold promise for expanding and refining the pool of patients likely to further benefit from this approach in the near future.

Antibodies, Monoclonal↗
PubMed2005

Weekly administration of docetaxel and paclitaxel in metastatic or advanced breast cancer.

The taxanes docetaxel (Taxotere; Aventis Pharmaceuticals Inc., Bridgewater, NJ, http://www.aventispharma-us.com) and paclitaxel (Taxol; Bristol-Myers Squibb, Princeton, NJ, http://www.bms.com) have significant clinical activity in metastatic breast cancer. A number of clinical trials have evaluated the tolerability and efficacy of weekly taxane administration to optimize the benefit-to-risk ratio in metastatic breast cancer. Single-agent studies with docetaxel and paclitaxel in metastatic breast cancer show clinically significant antitumor activity even in advanced, heavily pretreated, resistant, and/or refractory disease. This activity is also evident with taxane-based combination regimens. Severe hematologic and nonhematologic toxicities are infrequent, with other toxicities noted based on the dose and weekly regimen selected. Weekly docetaxel and paclitaxel regimens represent valuable therapeutic options for women with metastatic breast cancer and have entered evaluation as part of adjuvant therapy for this disease.

Antibodies, Monoclonal↗
PubMed2005

Nanoparticle albumin-bound paclitaxel (ABI-007): a newer taxane alternative in breast cancer.

Breast cancer remains the most common malignancy in women of developed countries. Taxanes are cornerstones in the treatment of breast cancer. Nanoparticle albumin-bound paclitaxel (ABI-007, Abraxane) is a novel taxane that obviates the need of using a toxic solvent such as Cremophor EL leading to a safer administration without standard premedication. Several factors such as the presence of albumin receptors in cell surface, the increased need of nutrients such as albumin by tumor cells and the lack of sequestering Cremophor micelles lead to increased intratumoral concentration of this new taxane. Recent trials have shown that ABI-007 is not only well tolerated but, compared with conventional paclitaxel, is associated with superior response rate, longer time to tumor progression and prolonged survival as second-line therapy in patients with metastatic breast cancer.

Albumin-Bound Paclitaxel↗
PubMed2005

Two concurrent phase II trials of paclitaxel/carboplatin/trastuzumab (weekly or every-3-week schedule) as first-line therapy in women with HER2-overexpressing metastatic breast cancer: NCCTG study 983252.

PURPOSE: The efficacy and tolerability of 2 different schedules of paclitaxel/carboplatin/trastuzumab for HER2-overexpressing metastatic breast cancer (MBC) were evaluated in this parallel multicenter phase II trial. PATIENTS AND METHODS: Patients received every-3-week therapy (n = 43) consisting of a 200 mg/m(2) dose of paclitaxel/carboplatin area under the curve (AUC) of 6 mg/mL per minute and trastuzumab (an initial 8 mg/kg dose and subsequent 6 mg/kg doses) administered every 21 days for 8 cycles or weekly therapy (n = 48) consisting of an 80-mg/m(2) dose of paclitaxel/carboplatin AUC of 2 mg/mL per minute for 3 of 4 weeks, with weekly trastuzumab (an initial 4-mg/kg dose and subsequent 2-mg/kg doses) administered every 4 weeks for 6 cycles. Trastuzumab was continued until disease progression or unacceptable toxicity. HER2 status was confirmed by a central laboratory review. RESULTS: The overall response rate (ORR) with every-3-week therapy was 65% (90% confidence interval [CI], 51%-77%), with a median time to disease progression of 9.9 months and median overall survival (OS) time of 2.3 years. The ORR with weekly therapy was 81% (90% CI, 70%-90%), with a median time to disease progression of 13.8 months and a median OS time of 3.2 years. Hematologic and nonhematologic toxicities occurred significantly less frequently with weekly therapy versus every-3-week therapy: grade 3/4 neutropenia (52% vs. 88%); grade 3 thrombocytopenia (4% vs. 30%); and grade 3 neurosensory toxicity (2% vs. 19%), respectively. CONCLUSIONS: Every-3-week and weekly regimens of paclitaxel/carboplatin/trastuzumab are highly active in women with HER2-overexpressing MBC. However, fewer patients developed severe neutropenia, leukopenia, or thrombocytopenia with the weekly schedule.

Adult↗
PubMed2004

Effect of doxorubicin plus cyclophosphamide on left ventricular ejection fraction in patients with breast cancer in the North Central Cancer Treatment Group N9831 Intergroup Adjuvant Trial.

PURPOSE: To evaluate changes in left ventricular ejection fraction (LVEF) after four cycles of adjuvant doxorubicin plus cyclophosphamide (AC) in women with human epidermal growth factor receptor 2-positive (node-positive or node-negative) breast cancer enrolled onto the North Central Cancer Treatment Group N9831 Intergroup Adjuvant Trial. PATIENTS AND METHODS: Patients were randomly assigned to receive standard doxorubicin (60 mg/m2) plus cyclophosphamide (600 mg/m2) every 3 weeks for four cycles followed by (1) weekly paclitaxel for 12 weeks; (2) weekly paclitaxel for 12 weeks, then weekly trastuzumab for 52 weeks; or (3) weekly paclitaxel plus trastuzumab for 12 weeks, then weekly trastuzumab for 40 weeks. LVEF was monitored before and after AC. RESULTS: Of the 1,576 eligible patients who completed AC, 1,458 had pre- and post-AC LVEF measurements taken using the same methodology (multiple-gated acquisition in 1,153 patients and echocardiogram in 305 patients). Among these 1,458 patients, 745 (51.1%) had < or = 15% decrease in LVEF and LVEF that remained at or above the radiologic lower limit of normal (LLN); 42 patients (2.9%) had < or = 15% decrease in LVEF and LVEF that decreased to or below the LLN; and 37 patients (2.5%) had an LVEF decrease of more than 15%. There was grade 2 LVEF toxicity in 96 (6.6%) of the 1,458 patients. CONCLUSION: Standard AC chemotherapy is associated with frequent decreases in LVEF, which are noted when measured 3 weeks after completion of the fourth cycle. Patients are being observed to determine the long-term significance of this and the potential impact on subsequent treatment options.

Adolescent↗
PubMed2004

Randomized phase II study of two irinotecan schedules for patients with metastatic breast cancer refractory to an anthracycline, a taxane, or both.

PURPOSE: A pressing need exists for agents active against anthracycline- or taxane-refractory metastatic breast cancer (MBC), or both. Previous clinical trials suggested that irinotecan might have such activity. We conducted this multicenter phase II study to assess efficacy and tolerability of two irinotecan schedules. PATIENTS AND METHODS: MBC patients who experienced disease progression after one to three chemotherapy regimens, including at least one anthracycline- or taxane-based regimen, were randomly assigned to irinotecan in 6-week cycles comprising 100 mg/m(2) weekly for 4 weeks, then a 2-week rest (weekly) or 240 mg/m(2) every 3 weeks. RESULTS: The weekly arm had 52 assessable patients; the every-3-weeks arm had 51 assessable patients. In the weekly arm, the objective response (complete regression [CR] + partial regression [PR]) rate was 23% (one CR, 11 PR; 95% CI, 13% to 37%). Median response duration was 4.9 months (range, 1.9 to 15.9 months), and median overall survival was 9.7 months (95% CI, 8.0 to 14.2 months). In the every-3-weeks arm, the objective response rate was 14% (nine PR; 95% CI, 6% to 26%), median response duration was 4.2 months (range, 3.1 to 13.9 months), and median overall survival was 8.6 months (95% CI, 7.0 to 12.3 months). Treatment generally was well tolerated, especially in the weekly arm. Grade 3 to 4 adverse events with > or = 10% incidence included neutropenia (29%) and diarrhea (17%) in the weekly arm and neutropenia (36%), vomiting (20%), dyspnea (18%), nausea (16%), and diarrhea (12%) in the every-3-weeks arm. CONCLUSION: Irinotecan is active with good tolerability in refractory MBC. Irinotecan (especially weekly) warrants additional study as monotherapy and in combination regimens in this setting.

Adult↗
PubMed2004

Clinical cardiac tolerability of trastuzumab.

PURPOSE: This review provides an update on the current understanding of the clinical cardiac tolerability of trastuzumab, a humanized monoclonal antibody effective in the treatment of patients with advanced breast cancer overexpressing or amplifying HER2. METHODS AND RESULTS: We produced a summary of currently available information regarding the incidence and natural history of trastuzumab-associated cardiac dysfunction. Data from new, prospective clinical studies that incorporate close cardiac monitoring and standardized follow-up in patients with either advanced or earlier stages of breast cancer are also presented, and hypotheses regarding potential mechanisms of trastuzumab-related cardiotoxicity are discussed. Patients treated with trastuzumab in the pivotal trials were found to have increased risk for cardiac dysfunction, mostly when used concurrent with anthracyclines. Recent trials have required more stringent and consistent cardiac monitoring criteria and excluded patients with abnormal cardiac function, pre-existing heart disease, and/or high cumulative doses of anthracyclines. Decreases of ejection fraction and a few cases of congestive heart failure (CHF) requiring medical therapy have been detected. Improvements in ejection fraction and the symptoms of CHF have been subsequently noted in a significant number of these patients. CONCLUSION: Trastuzumab is associated with an increased risk of asymptomatic decreases in ejection fraction, and, in a small number of patients, CHF that is almost always responsive to medical management. This risk is greatest in patients receiving concurrent anthracyclines. More data are needed to help elucidate the pathophysiology of this syndrome.

Anthracyclines↗