Anastrozole

BackgroundTwo large clinical trials have shown a reduced rate of breast cancer development in high-risk women in the initial 5 years of follow-up after use of aromatase inhibitors (MAP.3 and International Breast Cancer Intervention Study II [IBIS-II]). Here, we report blinded long-term follow-up results for the IBIS-II trial, which compared anastrozole with placebo, with the objective of determining the efficacy of anastrozole for preventing breast cancer (both invasive and ductal carcinoma in situ) in the post-treatment period.MethodsIBIS-II is an international, randomised, double-blind, placebo-controlled trial. Postmenopausal women at increased risk of developing breast cancer were recruited and were randomly assigned (1:1) to either anastrozole (1 mg per day, oral) or matching placebo daily for 5 years. After treatment completion, women were followed on a yearly basis to collect data on breast cancer incidence, death, other cancers, and major adverse events (cardiovascular events and fractures). The primary outcome was all breast cancer.Findings3864 women were recruited between Feb 2, 2003, and Jan 31, 2012. 1920 women were randomly assigned to 5 years anastrozole and 1944 to placebo. After a median follow-up of 131 months (IQR 105-156), a 49% reduction in breast cancer was observed for anastrozole (85 vs 165 cases, hazard ratio [HR] 0·51, 95% CI 0·39-0·66, pInterpretationThis analysis has identified a significant continuing reduction in breast cancer with anastrozole in the post-treatment follow-up period, with no evidence of new late side-effects. Further follow-up is needed to assess the effect on breast cancer mortality.FundingCancer Research UK, the National Health and Medical Research Council Australia, Breast Cancer Research Foundation, Sanofi Aventis, and AstraZeneca.

Purpose Estimating risk of late distant recurrence (DR) is an important goal for managing women with hormone receptor-positive breast cancer after 5 years of endocrine treatment without recurrence. We developed and validated a simple clinicopathologic tool (Clinical Treatment Score post-5 years [CTS5]) to estimate residual risk of DR after 5 years of endocrine treatment. Patients and Methods The ATAC (Arimidex, Tamoxifen, Alone or in Combination) data set (N = 4,735) was used to create a prognostic score for post-5-year risk of DR. Validity of CTS5 (ATAC) was tested in the BIG 1-98 data set (N = 6,711). Time to late DR, 5 years after finishing scheduled endocrine therapy, was the primary end point. Cox regression models estimated the prognostic performance of CTS5 (ATAC). Results CTS5 (ATAC) was significantly prognostic for late DR in the ATAC cohort (hazard ratio, 2.47; 95% CI, 2.24 to 2.73; P 10%) identified 43% of the validation cohort as low risk, with an observed DR rate of 3.6% (95% CI, 2.7% to 4.9%) during years 5 to 10. From years 5 to 10, 63% of node-negative patients were low risk, with a DR rate of 3.9% (95% CI, 2.9% to 5.3%), and 24% with one to three positive nodes were low risk, with a DR rate of 1.5% (95% CI, 0.5% to 3.8%). A final CTS5 for future use was derived from pooled data from ATAC and BIG 1-98. Conclusion CTS5 is a simple tool based on information that is readily available to all clinicians. CTS5 was validated as highly prognostic for late DR in the independent BIG 1-98 study. The final CTS5 algorithm identified 42% of women with < 1% per-year risk of DR who could be advised of the limited potential value of extended endocrine therapy.

BackgroundResearch on the brain-gut-microbiota axis has led to accumulating interest in gut microbiota dysbiosis and intestinal barrier dysfunction in Alzheimer's disease (AD). Our previous studies have demonstrated neurotoxic effects of 27-hydroxycholesterol (27-OHC) in in vitro and in vivo models. Here, alterations in the gut microbiota and intestinal barrier functions were investigated as the possible causes of cognitive deficits induced by 27-OHC treatment.MethodsMale APP/PS1 transgenic and C57BL/6J mice were treated for 3 weeks with 27-OHC (5.5 mg/kg/day, subcutaneous injection) and either a 27-OHC synthetase inhibitor (anastrozole, ANS) or saline. The Morris water maze and passive avoidance test were used to assess cognitive impairment. Injuries of the intestine were evaluated by histopathological examination. Intestinal barrier function was assessed by plasma diamine oxidase (DAO) activity and D-lactate. Systemic and intestinal inflammation were evaluated by IL-1β, TNF-α, IL-10, and IL-17 concentrations as determined by ELISA. The fecal microbiome and short-chain fatty acids (SCFAs) were analyzed using 16S rDNA sequencing and ultra-performance liquid chromatography-mass spectrometry (UPLC-MS). Tight junction proteins were evaluated in the ileum and colon by qRT-PCR and Western blots. Tight junction ultrastructure was examined by transmission electron microscopy.ResultsTreatment with 27-OHC resulted in severe pathologies in the ileum and colon. There was impaired intestinal barrier integrity as indicated by dilated tight junctions and downregulation of tight junction proteins, including occludin, claudin 1, claudin 5, and ZO-1, and signs of inflammation (increased IL-1β, TNF-α, and IL-17). Fecal 16S rDNA sequencing and taxonomic analysis further revealed a decreased abundance of Roseburia and reduced fecal levels of several SCFAs in 27-OHC-treated mice. Meanwhile, co-treatment with ANS reduced intestinal inflammation and partially preserved intestinal barrier integrity in the presence of 27-OHC.ConclusionsThe current study demonstrates for the first time that 27-OHC treatment aggravates AD-associated pathophysiological alterations, specifically gut microbiota dysbiosis and intestinal barrier dysfunction, which suggests that the gut microbiome and intestinal barrier function warrant further investigation as potential targets to mitigate the neurotoxic impact of 27-OHC on cognitive function and the development of AD.

CDK4/6 inhibitors (CDK4/6i) improve outcomes for estrogen receptor (ER) positive/HER2-negative breast cancers (BCs), yet intrinsic and acquired resistance exist. Here, we evaluated anastrozole in combination with palbociclib (ANA/PAL) in the NeoPalAna Endocrine-Resistant cohort (NCT01723774). Thirty-four patients with clinical stage II/III ER + /HER2- BCs resistant to standard neoadjuvant endocrine therapy (on-treatment Ki67 > 10%) received neoadjuvant ANA/PAL, with serial biopsies analyzed. The primary endpoint, complete cell cycle arrest (CCCA; Ki67C1D15 ≤ 2.7% at cycle 1, day 15), was achieved in 57.6% of patients (95%CI: 39.2-74.5%). Resistance to ANA/PAL (Ki67C1D15 > 10%) was associated with higher pre-treatment tumor grade, Ki67, and specific PAM50 subtypes. Resistant tumors demonstrated reduced ER signaling and upregulation of cell cycle, mTOR, interferon, JAK/STAT, and immune checkpoints. Additionally, a 33-gene signature that predicted neoadjuvant Ki67 response to ANA/PAL was prognostic in a metastatic validation cohort. These findings underscore dysregulated oncogenic pathways as potential resistance mechanisms and biomarkers of response to CDK4/6i.