Little strokes fill big oaks: a simple in vivo stain of brain cells

High-resolution functional imaging of neural activity in vivo relies on appropriate labeling methods. In this issue of Neuron, Nagayama et al. introduce a simple procedure for staining subsets of neurons with organic calcium indicator dyes via local electroporation. Neuronal populations are sparsely labeled, preserving the ability to resolve calcium signals in dendrites and synaptic structures.

Cardiovascular adverse events during adjuvant endocrine therapy for early breast cancer using letrozole or tamoxifen: safety analysis of BIG 1-98 trial

PURPOSE: Previous analyses of adjuvant studies of aromatase inhibitors versus tamoxifen, including the Breast International Group (BIG) 1-98 study, have suggested a small numerical excess of cardiac adverse events (AEs) on aromatase inhibitors, a reduction in the incidence of hypercholesterolemia on tamoxifen, and significantly higher incidence of thromboembolic AEs on tamoxifen. The purpose of the present study is to provide detailed updated information on these AEs in BIG 1-98. PATIENTS AND METHODS: Eight thousand twenty-eight postmenopausal women with receptor-positive early breast cancer were randomly assigned (double-blind) between March 1998 and May 2003 to receive 5 years of adjuvant endocrine therapy with letrozole, tamoxifen, or a sequence of these agents. Seven thousand nine hundred sixty-three patients who actually received therapy are included in this safety analysis, which focuses on cardiovascular events. AE recording ceased 30 days after therapy completion (or after switch on the sequential arms). RESULTS: Baseline comorbidities were balanced. At a median follow-up time of 30.1 months, we observed similar overall incidence of cardiac AEs (letrozole, 4.8%; tamoxifen, 4.7%), more grade 3 to 5 cardiac AEs on letrozole (letrozole, 2.4%; tamoxifen, 1.4%; P = .001)--an excess only partially attributable to prior hypercholesterolemia--and more overall (tamoxifen, 3.9%; letrozole, 1.7%; P < .001) and grade 3 to 5 thromboembolic AEs on tamoxifen (tamoxifen, 2.3%; letrozole, 0.9%; P < .001). There was no significant difference between tamoxifen and letrozole in incidence of hypertension or cerebrovascular events. CONCLUSION: The present safety analysis, limited to cardiovascular AEs in BIG 1-98, documents a low overall incidence of cardiovascular AEs, which differed between treatment arms.

Predictors of early relapse in postmenopausal women with hormone receptor-positive breast cancer in the BIG 1-98 trial

BACKGROUND: Aromatase inhibitors are considered standard adjuvant endocrine treatment of postmenopausal women with hormone receptor-positive breast cancer, but it remains uncertain whether aromatase inhibitors should be given upfront or sequentially with tamoxifen. Awaiting results from ongoing randomized trials, we examined prognostic factors of an early relapse among patients in the BIG 1-98 trial to aid in treatment choices. PATIENTS AND METHODS: Analyses included all 7707 eligible patients treated on BIG 1-98. The median follow-up was 2 years, and the primary end point was breast cancer relapse. Cox proportional hazards regression was used to identify prognostic factors. RESULTS: Two hundred and eighty-five patients (3.7%) had an early relapse (3.1% on letrozole, 4.4% on tamoxifen). Predictive factors for early relapse were node positivity (P < 0.001), absence of both receptors being positive (P < 0.001), high tumor grade (P < 0.001), HER-2 overexpression/amplification (P < 0.001), large tumor size (P = 0.001), treatment with tamoxifen (P = 0.002), and vascular invasion (P = 0.02). There were no significant interactions between treatment and the covariates, though letrozole appeared to provide a greater than average reduction in the risk of early relapse in patients with many involved lymph nodes, large tumors, and vascular invasion present. CONCLUSION: Upfront letrozole resulted in significantly fewer early relapses than tamoxifen, even after adjusting for significant prognostic factors.

Progress on BIG 1-02/IBCSG 27-02/NSABP B-37, a prospective randomized trial evaluating chemotherapy after local therapy for isolated locoregional recurrences of breast cancer

BACKGROUND: The utility of chemotherapy for women who experience a locoregional recurrence after primary treatment of early breast cancer remains an open question. An international collaborative trial is being conducted by the Breast International Group (BIG), the International Breast Cancer Study Group (IBCSG), and the National Surgical Adjuvant Breast and Bowel Project (NSABP) to determine the effectiveness of cytotoxic therapy for these patients, either alone or in addition to selective use of hormonal therapy and trastuzumab. METHODS: The trial population includes women who have had a previous diagnosis of invasive breast cancer treated by mastectomy or breast-conserving surgery, but subsequently develop an isolated local and/or regional ipsilateral invasive recurrence. Excision of all macroscopic tumor without evidence of systemic disease is required for study entry. Patients are randomized to receive chemotherapy or no chemotherapy; type of chemotherapy is not protocol-specified. Radiation, hormonal therapy, and trastuzumab are given as appropriate. The primary endpoint is disease-free survival (DFS). Quality-of-life measurements are collected at baseline, and then at 9 and 12 months. The accrual goal is 977 patients. RESULTS: This report describes the characteristics of the first 99 patients. Sites of recurrence at study entry were: breast (56%), mastectomy scar/chest wall (35%), and regional lymph nodes (9%). Two-thirds of patients have estrogen-receptor-positive recurrences. CONCLUSION: This is the only trial actively investigating the question of "adjuvant" chemotherapy in locally recurrent breast cancer. The case mix of accrual to date indicates a broad representation of this patient population.

A randomized clinical trial of adjuvant chemotherapy for radically resected locoregional relapse of breast cancer: IBCSG 27-02, BIG 1-02, and NSABP B-37

In this phase III, multinational, randomized trial, the International Breast Cancer Study Group, Breast International Group, and the National Surgical Adjuvant Breast and Bowel Project will attempt to define the effectiveness of cytotoxic therapy for patients with locoregional recurrence of breast cancer. We will evaluate whether chemotherapy prolongs disease-free survival and, secondarily, whether its use improves overall survival and systemic disease-free survival. Quality of life measurements will be monitored during the first 12 months of the study. Women who have had a previous diagnosis of invasive breast cancer treated by mastectomy or breast-conserving surgery and who have undergone complete surgical excision of all macroscopic disease but who subsequently develop isolated local and/or regional ipsilateral invasive recurrence are eligible. Patients are randomized to observation/no adjuvant chemotherapy or to adjuvant chemotherapy; all suitable patients receive radiation, hormonal, and trastuzumab therapy. Radiation therapy is recommended for patients who have not received previous adjuvant radiation therapy but is required for those with microscopically positive margins. The radiation field must encompass the tumor bed plus a surrounding margin to a dose of >or= 40 Gy. Radiation therapy will be administered before, during, or after chemotherapy. All women with estrogen receptor-positive and/or progesterone receptor-positive recurrence must receive hormonal therapy, with the agent and duration to be determined by the patient's investigator. Adjuvant trastuzumab therapy is permitted for those with HER2- positive tumors, provided that intent to treat is declared before randomization. Although multidrug regimens are preferred, the agents, doses, and use of supportive therapy are at the discretion of the investigator.

Letrozole compared with tamoxifen for elderly patients with endocrine-responsive early breast cancer: the BIG 1-98 trial

PURPOSE: To explore potential differences in efficacy, treatment completion, and adverse events (AEs) in elderly women receiving adjuvant tamoxifen or letrozole for five years in the Breast International Group (BIG) 1-98 trial. METHODS: This report includes the 4,922 patients allocated to 5 years of letrozole or tamoxifen in the BIG 1-98 trial. The median follow-up was 40.4 months. Subpopulation Treatment Effect Pattern Plot (STEPP) analysis was used to examine the patterns of differences in disease-free survival and incidences of AEs according to age. In addition, three categoric age groups were defined: "younger postmenopausal" patients were younger than 65 years (n = 3,127), "older" patients were 65 to 74 years old (n = 1,500), and "elderly" patients were 75 years of age or older (n = 295). RESULTS: Efficacy results for subpopulations defined by age were similar to the overall trial results: Letrozole significantly improved disease-free survival (DFS), the primary end point, compared with tamoxifen. Elderly patients were less likely to complete trial treatment, but at rates that were similar in the two treatment groups. The incidence of bone fractures, observed more often in the letrozole group, did not differ by age. In elderly patients, letrozole had a significantly higher incidence of any grade 3 to 5 protocol-specified non-fracture AE compared with tamoxifen (P = .002), but differences were not significant for thromboembolic or cardiac AEs. CONCLUSION: Adjuvant treatment with letrozole had superior efficacy (DFS) compared with tamoxifen in all age groups. On the basis of a small number of patients older than 75 years (6%), age per se should not unduly affect the choice of adjuvant endocrine therapy.

Bone fractures among postmenopausal patients with endocrine-responsive early breast cancer treated with 5 years of letrozole or tamoxifen in the BIG 1-98 trial

BACKGROUND: To compare the incidence and timing of bone fractures in postmenopausal women treated with 5 years of adjuvant tamoxifen or letrozole for endocrine-responsive early breast cancer in the Breast International Group (BIG) 1-98 trial. METHODS: We evaluated 4895 patients allocated to 5 years of letrozole or tamoxifen in the BIG 1-98 trial who received at least some study medication (median follow-up 60.3 months). Bone fracture information (grade, cause, site) was collected every 6 months during trial treatment. RESULTS: The incidence of bone fractures was higher among patients treated with letrozole [228 of 2448 women (9.3%)] versus tamoxifen [160 of 2447 women (6.5%)]. The wrist was the most common site of fracture in both treatment groups. Statistically significant risk factors for bone fractures during treatment included age, smoking history, osteoporosis at baseline, previous bone fracture, and previous hormone replacement therapy. CONCLUSIONS: Consistent with other trials comparing aromatase inhibitors to tamoxifen, letrozole was associated with an increase in bone fractures. Benefits of superior disease control associated with letrozole and lower incidence of fracture with tamoxifen should be considered with the risk profile for individual patients.