Breast cancer research and treatment
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Breast Cancer Res. Treat. · Jan 2007
Survival disadvantage among Medicaid-insured breast cancer patients treated with breast conserving surgery without radiation therapy.
Clinical studies indicate that breast cancer patients treated with breast conserving surgery (BCS) without radiotherapy (RT) have a greater risk of recurrence and mortality compared to those receiving BCS plus RT. However, this relationship has been underdeveloped among low-income women in the community who may face barriers in accessing adjuvant treatment and post-treatment surveillance. It is possible that the prognostic significance of omission of RT in clinical trials underestimates the significance of risk in the community. ⋯ Adjuvant radiation following BCS was underused in this sample of poor breast cancer patients. Lack of adjuvant RT may be a proxy for inadequate access to care and poor cancer surveillance after treatment.
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Breast Cancer Res. Treat. · Jan 2007
Randomized Controlled Trial Comparative StudyLetrozole in advanced breast cancer: the PO25 trial.
Tamoxifen has been a standard first-line endocrine therapy for post-menopausal women with hormone-responsive advanced breast cancer, but more than half of patients fail to respond and time to progression is less than 12 months in responders. The third-generation aromatase inhibitors were developed to provide more effective alternatives to tamoxifen. In the Femara Study PO25, post-menopausal women with advanced breast cancer were randomized to receive letrozole 2.5 mg (n=453) or tamoxifen 20 mg (n=454) given orally daily until progressive disease occurred. ⋯ Prospectively planned analyses of the intent-to-treat population showed that letrozole significantly improved overall survival (OS) compared with tamoxifen over the first 24 months of the trial. An exploratory analysis of patients, who did not cross over, indicated a median OS benefit of 14 months for letrozole compared with tamoxifen. Letrozole is the only third-generation aromatase inhibitor that has demonstrated significant improvements in ORR, TTP, and early OS.
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Breast Cancer Res. Treat. · Jan 2007
Randomized Controlled Trial Multicenter Study Comparative StudyLetrozole in the neoadjuvant setting: the P024 trial.
Neoadjuvant chemotherapy trials have consistently reported lower response rates in hormone receptor-positive (HR+) breast cancer when compared with HR- cases. Preoperative endocrine therapy has therefore become a logical alternative and has gained considerable momentum from the finding that aromatase inhibitors (AIs) are more effective than tamoxifen for HR+ breast cancer in both the neoadjuvant and adjuvant settings. The most convincing neoadjuvant trial to demonstrate the superiority of an AI versus tamoxifen was the P024 study, a large multinational double-blind trial in postmenopausal women with HR+ breast cancer ineligible for breast-conserving surgery. ⋯ Interestingly, letrozole was effective even in marginally ER+ tumors and, unlike tamoxifen, consistently reduced the expression from estrogen-regulated genes (progesterone receptor and trefoil factor 1). Furthermore, when analyzed by Ki67 immunohistochemistry, letrozole was significantly more effective than tamoxifen in reducing tumor proliferation (P=0.0009). Thus, neoadjuvant letrozole is safe and superior to tamoxifen in the treatment of postmenopausal women with HR+ locally advanced breast cancer.
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Breast Cancer Res. Treat. · Jan 2007
The neonatal splice variant of Nav1.5 potentiates in vitro invasive behaviour of MDA-MB-231 human breast cancer cells.
Upregulation of functional voltage-gated Na+ channels (VGSCs) occurs in metastatic human breast cancer (BCa) in vitro and in vivo. The present study aimed to ascertain the specific involvement of the "neonatal" splice variant of Nav1.5 (nNav1.5), thought to be predominant, in the VGSC-dependent invasive behaviour of MDA-MB-231 cells. Functional activity of nNav1.5 was suppressed by two different methods targeting nNav1.5: (i) small interfering RNA (siRNA), and (ii) a polyclonal antibody (NESO-pAb); effects upon migration and invasion were determined. nNav1.5 mRNA, protein and signalling were measured using real-time PCR, Western blotting, and patch clamp recording, respectively. ⋯ TTX had no effect on cells already treated with NESO-pAb. It was concluded that nNav1.5 is primarily responsible for the VGSC-dependent enhancement of invasive behaviour in MDA-MB-231 cells. Accordingly, targeting nNav1.5 expression/activity may be useful in clinical management of metastatic BCa.
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Breast Cancer Res. Treat. · Jan 2007
The impact of breast cancer awareness and socioeconomic status on willingness to receive breast cancer prevention drugs.
To find associations between knowledge about risk factors for breast cancer and the socioeconomic status of healthy women, as well as their attitude toward taking chemopreventive drugs. ⋯ These findings emphasize the role of estimations of the risk of breast cancer for patients considering whether to accept chemoprevention treatment. To date, only a few modern models of risk estimation have been evaluated in relation to chemoprevention. There is a need for better integration of professional risk estimations into clinical practice.