Dataset Information

Incidence of comorbidities in women with breast cancer treated with tamoxifen or an aromatase inhibitor: an Australian population-based cohort study.

ABSTRACT: Background:The development of comorbidities has become increasingly relevant with longer-term cancer survival. Objective:To assess the pattern of comorbidities among Australian women with breast cancer treated with tamoxifen or an aromatase inhibitor. Design:Retrospective cohort study using Pharmaceutical Benefits Scheme (PBS) data (10% sample) from January 2003 to December 2014. Dispensing claims data were used to identify comorbidities and classified with the Rx-Risk-V model. The breast cancer cohort had tamoxifen or an aromatase inhibitor dispensed between 2004 and 2011 with no switching between types of endocrine therapy. Comparisons were made between the breast cancer cohort and specific control groups (age- and sex-matched at 1:10 ratio without any dispensing of anti-neoplastic agents during the study period) for the development of five individual comorbidities over time using Cox regression models. Results:Women treated with tamoxifen had a higher incidence of cardiovascular conditions, diabetes, and pain or pain-inflammation, but a lower incidence of hyperlipidaemia compared with non-cancer control groups, as indicated by PBS data. Women treated with aromatase inhibitors were more likely to develop cardiovascular conditions, osteoporosis, and pain or pain-inflammation compared with non-cancer control groups. The risks of hyperlipidaemia and osteoporosis were significantly lower among tamoxifen users compared with aromatase inhibitor users. Conclusions:Women with hormone-dependent breast cancer treated with an endocrine therapy had a higher risk of developing specified comorbid conditions than women without cancer, with different comorbidity profiles for those on tamoxifen versus aromatase inhibitors. Further research into the causes and mechanism of development and management of comorbidities after cancer is needed.

SUBMITTER: Ng HS

PROVIDER: S-EPMC5885067 | biostudies-literature | 2018 Jan-Dec

REPOSITORIES: biostudies-literature

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Incidence of comorbidities in women with breast cancer treated with tamoxifen or an aromatase inhibitor: an Australian population-based cohort study.

Ng Huah Shin HS Koczwara Bogda B Roder David D Niyonsenga Theo T Vitry Agnes A

Journal of comorbidity 20180101 1

<h4>Background</h4>The development of comorbidities has become increasingly relevant with longer-term cancer survival.<h4>Objective</h4>To assess the pattern of comorbidities among Australian women with breast cancer treated with tamoxifen or an aromatase inhibitor.<h4>Design</h4>Retrospective cohort study using Pharmaceutical Benefits Scheme (PBS) data (10% sample) from January 2003 to December 2014. Dispensing claims data were used to identify comorbidities and classified with the Rx-Risk-V mo ...[more]

PMID: 29651409

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Project description:BackgroundEarly discontinuation of aromatase inhibitors (AIs) is common and leads to poor outcomes but is challenging to predict. In the Exemestane and Letrozole Pharmacogenetics trial, a high rate of early discontinuation due to intolerance was observed. We hypothesized that early changes in patient-reported outcomes (PROs) predict AI discontinuation and that biochemical factors are associated with changes in PROs.Patients and methodsPostmenopausal women with early-stage breast cancer enrolled in a prospective randomized trial of exemestane versus letrozole completed questionnaires at baseline and serially over 24 months to assess overall quality of life (EuroQOL Visual Analog Scale [VAS]); mood; and multiple symptoms, including a musculoskeletal symptom cluster. A joint mixed-effects/survival model was used to estimate the effect of the change in PROs on AI discontinuation. Associations between biochemical factors and change in PROs were examined.ResultsA total of 490 patients were analyzed. Worsening of EuroQOL VAS and the musculoskeletal cluster were associated with the highest risk for early discontinuation (hazard ratio [HR], 2.77 [95% confidence interval (CI), 2.72-2.81; p = .015]; HR, 4.39 [95% CI, 2.40-8.02; p < .0001], respectively). Pharmacokinetics and estrogen metabolism were not consistently associated with change in PRO measures. No clinically significant differences in any PRO between AIs were observed.ConclusionChanges in PROs early during AI therapy were associated with treatment discontinuation. Identification of these changes could be used to target interventions in patients at high risk for early discontinuation.Implications for practiceEarly changes in patient-reported outcomes (PROs) can predict nonpersistence to aromatase inhibitor therapy. If used in clinical practice, PROs might identify women at highest risk for early discontinuation and allow for interventions to improve tolerance before significant toxicities develop. Further research is needed to improve capturing PROs in routine clinical practice.

Project description:ImportanceWithin 10 years after breast cancer diagnosis, roughly 5% of patients develop contralateral breast cancer (CBC). Randomized trials have found that therapy including tamoxifen citrate and aromatase inhibitors (AIs) reduces CBC risk. But little is known about the magnitude and duration of protective associations within the context of real-world clinical management settings, where varying durations of and gaps in treatment are common.ObjectiveTo determine the association between adjuvant tamoxifen and AI therapy and CBC risk within a general community setting.Design, setting, and participantsA retrospective cohort study of CBC risk among 7541 patients diagnosed with a first primary unilateral invasive breast cancer at Kaiser Permanente Institute for Health Research (Colorado) or Kaiser Permanente Northwest Center for Health Research (Oregon) between January 1, 1990, and December 31, 2008. Data were analyzed from 1 year after diagnosis of the first breast cancer through the earliest of the following events: CBC diagnosis, other second cancer diagnosis, death, last tumor registry follow-up, exit from the Kaiser Permanente health care plan, or end of study follow-up (December 31, 2010, for Oregon and December 31, 2011, for Colorado).ExposuresAdjuvant tamoxifen use and AI therapy were treated as time-dependent exposures, assessed using electronic prescription records.Main outcomes and measuresIncident CBC based on long-term systematic follow-up.ResultsAmong 7541 women with invasive breast cancer, median age at initial breast cancer diagnosis was 60.6 years (age range, 24.9-84.9 years). Women were predominantly (92.9% [7009 of 7541]) of white race. During a median of 6.3 years (range, 1-20.9 years) of follow-up, 248 women developed CBC (45 in situ and 203 invasive). Contralateral breast cancer risk decreased significantly with increasing tamoxifen therapy duration. In current users, the relative risk (RR) per year of tamoxifen use was 0.76 (95% CI, 0.64-0.89), with an estimated 66% (RR, 0.34; 95% CI, 0.29-0.40) RR reduction for 4 years of use compared with nonusers. Risk reductions were slightly smaller for past users but were still significant at least 5 years after stopping tamoxifen therapy (RR per year of use, 0.85; 95% CI, 0.71-0.995). In addition, AI use without tamoxifen therapy was associated with reduced CBC risk (RR for AI users compared with nonusers, 0.48; 95% CI, 0.22-0.97). Risk reductions were most apparent among women whose primary and CBCs were estrogen receptor positive.Conclusions and relevanceTamoxifen therapy was associated with reduced CBC risk during treatment and after its cessation, with risk progressively decreasing as tamoxifen therapy duration increased. Among those surviving at least 5 years, tamoxifen use for at least 4 years was estimated to prevent 3 CBCs per 100 women by 10 years after an estrogen receptor-positive first breast cancer, an absolute risk reduction that is consistent with findings from clinical trials. If adjuvant endocrine therapy is indicated for breast cancer treatment, these findings in concert with trial data suggest that women should be encouraged to complete the full course.

Project description:Five years of tamoxifen reduces breast cancer risk by nearly 50% but is associated with significant side-effects and toxicities. A better understanding of the direct and indirect effects of tamoxifen in benign breast tissue could elucidate new mechanisms of breast carcinogenesis, suggest novel chemoprevention targets, and provide relevant early response biomarkers for Phase II prevention trials. Seventy-three women at increased risk for breast cancer were randomized to tamoxifen (20 mg daily) or placebo for three months. Blood and breast tissue samples were collected at baseline and post-treatment. Sixty-nine women completed all study activities (37 tamoxifen and 32 placebo). The selected biomarkers focused on estradiol and IGFs in the blood, DNA methylation and cytology in random periareolar fine needle aspirates, and tissue morphometry, proliferation, apoptosis, and gene expression (microarray and RT-PCR) in the tissue core samples. Tamoxifen downregulated ets-oncogene family members ETV4 and ETV5 and reduced breast epithelial cell proliferation independent of CYP2D6 genotypes or effects on estradiol, ESR1 or IGFs. Reduction in proliferation was correlated with downregulation of ETV4 and DNAJC12. Tamoxifen also modulated expression of RAB GTPases, and several genes involved in epithelial-stromal interaction, and reduced tumor suppressor gene methylation. Three months of tamoxifen did not affect breast tissue composition, cytological atypia, preneoplasia or apoptosis. Tamoxifen may durably reduce breast cancer risk through downregulation of ETV4 and ETV5 which could deplete mammary progenitor populations. This pathway has the potential to provide novel targets and early response biomarkers for phase II prevention trials. Randomized prospective double blinded placebo-controlled trial of tamoxifen (20 mg daily) versus placeo in women at increased risk for breast cancer. Gene expression was assessed in whole breast tissue cores obtained at baseline and after three months of treatment for 35 women. Core biopsies were obtained in the late luteal phase (day 28 +/- 2) for premenopausal women (N = 19). Breast lobules from the baseline and post-treatment cores were microdissected for 5 tamoxifen subjects.

Project description:Resistance to endocrine therapy agents has presented a clinical obstacle in the treatment of hormone-dependent breast cancer. Our laboratory has initiated a study of microRNA regulation of signaling pathways that may result in breast cancer progression on aromatase inhibitors (AI). Microarray analysis of microRNA expression identified 115 significantly regulated microRNAs, of which 49 microRNAs were believed to be hormone-responsive. Within the AI-resistant cells, microRNAs were differentially expressed between the steroidal and non-steroidal AI-resistant lines. Also, a group of microRNAs were inversely expressed in the AI-resistant lines versus LTEDaro and tamoxifen-resistant. We focused our work on hsa-miR-128a which was hormone-responsive and up-regulated in the letrozole-resistant cell lines. Human miR-128a was shown to negatively target TGFBRI protein expression by binding to the 3’UTR region of the gene. Loss of TGFBRI resulted in compromised sensitivity to the growth inhibitory effects of TGFB in the letrozole-resistant lines. Inhibition of endogenous miR-128a resulted in re-sensitization of the letrozole-resistant lines to TGFB growth inhibitory effects. This data suggests that the hormone-responsive miR-128a can modulate TGFB signaling and survival of the letrozole-resistant cell lines. To our knowledge, this is the first study to address the role of microRNA regulation as well as TGFB signaling in AI-resistant breast cancer cell lines. We believe that in addition to estrogen-modulation of gene expression, hormone-regulated microRNAs may provide an additional level of post-transcriptional regulation of signaling pathways critically involved in breast cancer progression and AI-resistance. To look at microRNA expression profiles of breast cancer cell lines derived from MCF-7 cells that are resistant to endocrine therapy agents. MCF-7 cells that overexpress aromatase (MCF-7aro) were cultured long-term in the presence of endocrine therapy agents until cells acquired resistance. Three different aromatase inhibitors (letrozole, anastrozole or exemestane) were used, as well as the ER antagonist tamoxifen, or the hormone-free long-term estrogen deprived cells (LTED). Three replicates of the control cells (MCF-7aro) and all resistant cells were used for microarray experiments. Total of 23 samples were analyzed by microarray.

Dataset Information

Incidence of comorbidities in women with breast cancer treated with tamoxifen or an aromatase inhibitor: an Australian population-based cohort study.

Publications

Incidence of comorbidities in women with breast cancer treated with tamoxifen or an aromatase inhibitor: an Australian population-based cohort study.

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