108 research outputs found

    Notch-1-PTEN-ERK1/2 signaling axis promotes HER2+ breast cancer cell proliferation and stem cell survival

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    Trastuzumab targets the HER2 receptor on breast cancer cells to attenuate HER2-driven tumor growth. However, resistance to trastuzumab-based therapy remains a major clinical problem for women with HER2+ breast cancer. Breast cancer stem cells (BCSCs) are suggested to be responsible for drug resistance and tumor recurrence. Notch signaling has been shown to promote BCSC survival and self-renewal. Trastuzumab-resistant cells have increased Notch-1 expression. Notch signaling drives cell proliferation in vitro and is required for tumor recurrence in vivo. We demonstrate herein a mechanism by which Notch-1 is required for trastuzumab resistance by repressing PTEN expression to contribute to activation of ERK1/2 signaling. Furthermore, Notch-1-mediated inhibition of PTEN is necessary for BCSC survival in vitro and in vivo. Inhibition of MEK1/2-ERK1/2 signaling in trastuzumab-resistant breast cancer cells mimics effects of Notch-1 knockdown on bulk cell proliferation and BCSC survival. These findings suggest that Notch-1 contributes to trastuzumab resistance by repressing PTEN and this may lead to hyperactivation of ERK1/2 signaling. Furthermore, high Notch-1 and low PTEN mRNA expression may predict poorer overall survival in women with breast cancer. Notch-1 protein expression predicts poorer survival in women with HER2+ breast cancer. These results support a potential future clinical trial combining anti-Notch-1 and anti-MEK/ERK therapy for trastuzumab-resistant breast cancer

    Gonadotropin-releasing hormone analogs during chemotherapy for preservation of ovarian function and fertility in premenopausal early breast cancer patients: a systematic review and meta-analysis of individual patient-level data

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    Purpose The role of temporary ovarian suppression with gonadotropin-releasing hormone agonists (GnRHa) during chemotherapy as a strategy to preserve ovarian function and fertility in premenopausal women remains controversial. This systematic review and meta-analysis using individual patient\u2013level data was conducted to better assess the efficacy and safety of this strategy in patients with early breast cancer. Methods The trials in which premenopausal women with early breast cancer were randomly assigned to receive (neo)adjuvant chemotherapy alone or with concurrent GnRHa were eligible for inclusion. Primary end points were premature ovarian insufficiency (POI) rate and post-treatment pregnancy rate. Disease-free survival and overall survival were secondary end points. Because each study represents a cluster, statistical analyses were performed using a random effects model. Results A total of 873 patients from five trials were included. POI rate was 14.1% in the GnRHa group and 30.9% in the control group (adjusted odds ratio, 0.38; 95% CI, 0.26 to 0.57; P, .001). A total of 37 (10.3%) patients had at least one post-treatment pregnancy in the GnRHa group and 20 (5.5%) in the control group (incidence rate ratio, 1.83; 95% CI, 1.06 to 3.15; P = .030). No significant differences in disease-free survival (adjusted hazard ratio, 1.01; 95% CI, 0.72 to 1.42; P = .999) and overall survival (adjusted hazard ratio, 0.67; 95% CI, 0.42 to 1.06; P = .083) were observed between groups. Conclusion Our findings provide evidence for the efficacy and safety of temporary ovarian suppression with GnRHa during chemotherapy as an available option to reduce the likelihood of chemotherapy-induced POI and potentially improve future fertility in premenopausal patients with early breast cancer

    Clinical and Genomic Risk to Guide the Use of Adjuvant Therapy for Breast Cancer

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    BACKGROUND The use of adjuvant chemotherapy in patients with breast cancer may be guided by clinicopathological factors and a score based on a 21-gene assay to determine the risk of recurrence. Whether the level of clinical risk of breast cancer recurrence adds prognostic information to the recurrence score is not known. METHODS We performed a prospective trial involving 9427 women with hormone-receptor–positive, human epidermal growth factor receptor 2–negative, axillary node–negative breast cancer, in whom an assay of 21 genes had been performed, and we classified the clinical risk of recurrence of breast cancer as low or high on the basis of the tumor size and histologic grade. The effect of clinical risk was evaluated by calculating hazard ratios for distant recurrence with the use of Cox proportional-hazards models. The initial endocrine therapy was tamoxifen alone in the majority of the premenopausal women who were 50 years of age or younger. RESULTS The level of clinical risk was prognostic of distant recurrence in women with an intermediate 21-gene recurrence score of 11 to 25 (on a scale of 0 to 100, with higher scores indicating a worse prognosis or a greater potential benefit from chemotherapy) who were randomly assigned to endocrine therapy (hazard ratio for the comparison of high vs. low clinical risk, 2.73; 95% confidence interval [CI], 1.93 to 3.87) or to chemotherapy plus endocrine (chemoendocrine) therapy (hazard ratio, 2.41; 95% CI, 1.66 to 3.48) and in women with a high recurrence score (a score of 26 to 100), all of whom were assigned to chemoendocrine therapy (hazard ratio, 3.17; 95% CI, 1.94 to 5.19). Among women who were 50 years of age or younger who had received endocrine therapy alone, the estimated (±SE) rate of distant recurrence at 9 years was less than 5% (≀1.8±0.9%) with a low recurrence score (a score of 0 to 10), irrespective of clinical risk, and 4.7±1.0% with an intermediate recurrence score and low clinical risk. In this age group, the estimated distant recurrence at 9 years exceeded 10% among women with a high clinical risk and an intermediate recurrence score who received endocrine therapy alone (12.3±2.4%) and among those with a high recurrence score who received chemoendocrine therapy (15.2±3.3%). CONCLUSIONS Clinical-risk stratification provided prognostic information that, when added to the 21-gene recurrence score, could be used to identify premenopausal women who could benefit from more effective therapy

    Adjuvant Paclitaxel and Trastuzumab for Node-Negative, HER2-Positive Breast Cancer

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    No single standard treatment exists for patients with small, node-negative, human epidermal growth factor receptor type 2 (HER2)–positive breast cancers, because most of these patients have been ineligible for the pivotal trials of adjuvant trastuzumab

    Chemotherapy-related amenorrhea after adjuvant paclitaxel–trastuzumab (APT trial)

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    Chemotherapy-related amenorrhea (CRA) is associated with infertility and menopausal symptoms. Learning how frequently paclitaxel and trastuzumab cause amenorrhea is important. Most other adjuvant breast cancer therapies induce CRA in approximately 50% of all premenopausal recipients [1]

    Goserelin for Ovarian Protection During Breast-Cancer Adjuvant Chemotherapy

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    Premature ovarian failure is a devastating long-term toxic effect of chemotherapy for premenopausal women. The survival benefit of adjuvant chemotherapy in young women with operable hormone receptor–negative breast cancer is well known, but concern over becoming infertile may influence the choice of treatment for many women. A number of trials have investigated the combined use of a gonadotropin-releasing hormone (GnRH) agonist and adjuvant chemotherapy in an attempt to protect ovarian function in premenopausal women. Results of such studies were mixed, and there were few data on pregnancy outcomes. The aim of this randomized trial was to determine whether administration of the GnRH agonist goserelin with chemotherapy would reduce the rate of ovarian failure after adjuvant or neoadjuvant treatment of hormone-receptor–negative early-stage breast cancer. A total of 257 premenopausal women with operable hormone receptor–negative breast cancer were randomized to receive standard chemotherapy with goserelin (goserelin group) or standard chemotherapy without goserelin (chemotherapy-alone group). The rate of ovarian failure at 2 years was the primary study end point. Ovarian failure was defined as the absence of menses for the preceding 6 months and follicle-stimulating hormone levels in the postmenopausal range at 2 years. Conditional logistic regression was used to compare rates. Secondary end points evaluated included pregnancy outcomes and disease-free and overall survival. Of the 257 patients, 218 were eligible and could be evaluated: 113 in the chemotherapy-alone group and 105 in the goserelin group. Complete primary end-point data were available for 135 of the 218 patients who could be evaluated. Among these, the ovarian failure rate was 8% in the goserelin group and 22% in the chemotherapy-alone group; the odds ratio was 0.30, with a 95% confidence interval of 0.09 to 0.97; 2-sided P = 0.04. To determine the effect of the missing primary end-point data on the main study findings, sensitivity analyses were performed. The results of these analyses showed that the missing data had no significant effect on the association between treatment and stratification variables (age and planned chemotherapy regimen). Among the 218 patients who could be evaluated, more women became pregnant in the goserelin group than in the chemotherapy-alone group (21% vs 11%, P = 0.03). Kaplan-Meier curves showed that more women in the goserelin group had improved disease-free survival (P = 0.04) and overall survival (P = 0.05). Consistent with the findings of previous randomized trials, these data suggest that administration of a GnRH agonist with chemotherapy protects ovarian function, reducing the risk of early menopause and improving prospects for fertility. Although missing primary-end-point data weaken interpretation of the findings, there is no evidence that the missing data influenced the relative comparison between randomized groups
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