Tamoxifen Prescription Research Articles

Presence of Breast Cancer Information Recorded in United Kingdom Primary Care Databases: Comparison of CPRD Aurum and CPRD GOLD (Companion Paper 1).

To evaluate the presence of data elements related to diagnosis and treatment of malignant breast cancer in CPRD Aurum compared to those in the previously validated CPRD GOLD. Females in CPRD Aurum or GOLD with a first-time code for malignant breast cancer, mastectomy, or ≥1 prescription for tamoxifen or aromatase inhibitors (2004-2019) were selected. We compared the presence of the codes for breast cancer diagnosis, surgeries (mastectomy, lumpectomy), tamoxifen and aromatase inhibitor prescriptions, radiation, chemotherapy, and supporting clinical codes (suspected breast cancer, lump symptoms, biopsy, lumpectomy, cancer care, referral/visit to specialist, palliative care). Age standardized incidence rates of breast cancer diagnosis in CPRD Aurum and GOLD were calculated. There were 131,936 eligible patients in CPRD Aurum and 69,102 patients in GOLD. A similar proportion of patients in CPRD Aurum and GOLD had codes for breast cancer diagnosis, mastectomy, drug prescriptions, lump, biopsy, lumpectomy, chemotherapy, and cancer and palliative care coded in their electronic record during follow-up. However, suspected breast cancer, radiation, and referral/visits to specialists were coded more frequently in patients in CPRD Aurum compared to GOLD. Age-standardized incidence rates were similar for CPRD Aurum and GOLD. Overall, there was consistency between data elements related to malignant breast cancer recorded in CPRD Aurum and GOLD, particularly for the most informative clinical details. These findings provide reassurance that breast cancer information recorded in CPRD Aurum is generally comparable to that recorded in the previously validated CPRD GOLD and support the use of CPRD Aurum for breast cancer research.

Initiation of Antiresorptive Drug Treatment during Endocrine Therapy for Breast Cancer—A Retrospective Cohort Study of 161,492 Patients in Germany

The aim of this retrospective cohort study was to measure the proportion of women with an initial prescription of an antiresorptive drug (bisphosphonates or denosumab) during five years of endocrine breast cancer therapy. The study included women with an initial prescription of tamoxifen (TAM) or aromatase inhibitors (AIs) between January 2016 and December 2020. Kaplan-Meier analyses were performed to show the cumulative incidence of antiresorptive drug prescription for TAM and AIs separately for four age groups. A univariable Cox proportional hazards regression model was also used to estimate the relationship between initial endocrine drug (AIs vs. TAM) and antiresorptive drug prescription. Within 5 years, 14.1% of patients on AI and 6.1% on TAM received their first prescription for an antiresorptive drug (p < 0.001). The difference between AI and TAM was greatest in women ≤50 years (12.9% of AI and 2.8% of patients on TAM), and smallest in women >80 years (14.5% of AI and 10.3% of patients on TAM). The proportion of denosumab was 46.2% among AI patients vs. 29.1% among patients on TAM (p < 0.001) as alendronate was prescribed to 36.9% of AI vs. 50.0% of patients on TAM. Across all age groups, the cumulative incidence of antiresorptive drug prescriptions was higher in patients with BC treated with AI than those receiving TAM. Denosumab was most frequently used as an antiresorptive drug in patients treated with AI, while alendronate was administered more often in patients treated with TAM.

Determinants and Effectiveness of Extending the Duration of Adjuvant Hormone Therapy beyond 5 Years in Patients with Breast Cancer.

The proportion of patients with breast cancer extending adjuvant hormone therapy beyond 5 years has increased dramatically in recent years, which is associated with improved patient outcomes.

Tamoxifen for the Treatment of Etonogestrel Implant-Associated Bleeding in an Adolescent Gynecology Practice

To describe clinical outcomes in a cohort of adolescent female patients using tamoxifen for the treatment of bothersome etonogestrel (ENG) implant-associated bleeding. Retrospective chart review SETTING: A tertiary children's hospital PARTICIPANTS: Adolescent female patients ages 12-21 seen between August 2016 and August 2019 with an ENG implant in place who received a tamoxifen prescription for the indication of implant-associated bleeding. None MAIN OUTCOME MEASURES: Main outcome measures were implant continuation rates, average time to implant discontinuation after tamoxifen prescription, reasons for implant removal, number of doses and timing of tamoxifen use, bleeding patterns, and adverse effects. A total of 67 patients met the inclusion criteria. The mean age of patients was 16.7 years old. Of the patients with available follow-up data, 49 out of 60 (81.7%) were still using the implant at 12 months, 29 out of 53 (54.7%) at 24 months, and 9 out of 40 (22.5%) at 36 months. The average time from tamoxifen prescription to implant removal was 12.1 months. Bothersome bleeding was the primary reason for ENG implant discontinuation (68.6%). No side effects from tamoxifen use were reported. Tamoxifen was well-tolerated among this cohort of patients and can be considered a treatment option to manage bothersome implant bleeding in adolescents.

A case of tamoxifen-induced hypertriglyceridemia monitoring the changes in lipoprotein fractions over time

BackgroundTamoxifen, which is one of the selective estrogen receptor modulators (SERMs), can bring out life-threatening complication, e.g. hypertriglyceridemia-induced acute pancreatitis, although it is rare. We precisely report changes in lipoprotein metabolism before and after tamoxifen discontinuation because there have been few reports of it.Case presentation47-year-old premenopausal woman with dyslipidemia, type 2 diabetes, nonalcoholic fatty liver disease and chronic kidney disease was prescribed tamoxifen as adjuvant therapy after operation of breast cancer. She experienced severe tamoxifen-induced hypertriglyceridemia several months after dosing tamoxifen. Before cessation of tamoxifen, lipoprotein fraction test revealed marked stagnation of VLDL and IDL metabolisms, resulting in severe hypertriglyceridemia (serum triglyceride level was 1881 mg/dL). Seven days after tamoxifen withdrawal, lipoprotein fraction test showed that the metabolisms of endogenous lipoproteins were changed drastically.ConclusionsFrom these results, we confirmed that tamoxifen certainly changes lipoprotein metabolism through suppression of post-heparin lipolytic activity. It is very important to evaluate the balance between benefit and risk before dosing tamoxifen and survey lipid profiles constantly during treatment to avoid life-threatening complication when prescription of tamoxifen is planned.

Which antidepressant agent can be used in patients receiving tamoxifen?

IntroductionDepression is frequently observed in carcinology. Many patients with breast cancer, receiving Tamoxifen, may need antidepressants to treat depression. Tamoxifen is a synthetic non-steroidal antioestrogen metabolized by the cytochrome P450 2D6(CYP2D6) to endoxifen which is the active metabolite of this drug. It was reported that the concomitant prescription of Tamoxifen and some antidepressant agents such as paroxetine and fluoxetine may decrease the anticancer effect of tamoxifen as they may inhibit the CYP2D6 pathway.ObjectivesThe objective of this case was to highlight the particularity of management of depression in patients under tamoxifen.MethodsCase report description of a patient treated with Tamoxifen for her breast cancer and who was admitted for major depression, followed by a literature review.ResultsA 36 –year- old woman, had breast cancer and she underwent a mastectomy followed by chemotherapy. Since September 2016, she received 20 mg per day of Tamoxifen as an antihormonal treatment. In November 2018, she was referred to our psychiatry department for depressive symptoms. The patient was sad, she reported social withdrawal, insomnia, anhedonia, and low self-esteem. She had no history of mania or hypomania. A major depressive episode was diagnosed. We prescribed Escitalopram 10 mg per day with clinical improvement. The psychiatric and oncologic status of the patient was stable after two years under tamoxifen and Escitalopram.ConclusionsThe choice of the adequate antidepressant agent in patients under Tamoxifen remains a challenge and requires a thorough knowledge of drug interactions.

8. Tamoxifen for the treatment of etonogestrel implant associated bleeding in an adolescent gynecology practice

<h3>Background</h3> The majority of early etonogestrel (ENG) implant removals occur in the first 12 months after placement and the most common reason for discontinuation is unscheduled and bothersome bleeding. Approximately 65% of adolescent patients with bothersome bleeding receive medication management to address this side effect. Recent studies on adult ENG implant users suggest that a 7-day treatment course of tamoxifen reduces unscheduled bleeding over placebo. Because bothersome bleeding is a common complaint that results in discontinuation of the ENG contraceptive implant, it is important to find safe and effective therapies in the adolescent gynecology population. The goal of this study is to describe outcomes in a cohort of adolescents using tamoxifen to address bothersome implant bleeding. <h3>Methods</h3> A retrospective chart review was performed on adolescent patients ages 12-21 who were seen at Children's Hospital Colorado between 8/2016 – 8/2019 with an ENG implant in place and a prescription for tamoxifen 10 mg twice daily for 7 days given for the indication of implant-associated bleeding. De-identified demographic, clinical, and prescription data was abstracted and stored in a secure REDCAP database. REDCAP data was exported into Stata 16 for analysis, including descriptive statistics and survival analysis using Kaplan Meier curve. IRB approval was obtained from the University of Colorado Anschutz (#20-2349). <h3>Results</h3> A total of 67 patients met inclusion criteria. For those with follow-up data, the continuation rates for the ENG implant were 86% at 12 months, 65% at 24 months, and 44% at 36 months. The average time from implant insertion to initial tamoxifen prescription was 9.3months (± 7.9) with 69.1% (n=47) of patients presenting with symptoms of recurrent bleeding within one year. The average time from tamoxifen prescription to repeat patient visit/call was 3.9mo (± 4.9), while the average time from tamoxifen prescription to implant removal was 12.1mo (± 11.0). Among those who discontinued the implant (n=29), bleeding was the primary reason for discontinuation (66.7%; n=24). No side effects from tamoxifen use were reported. <h3>Conclusions</h3> In this retrospective chart review of 67 adolescents prescribed tamoxifen to manage to bothersome implant bleeding, continuation rates for the ENG implant were comparable or higher than continuation rates reported in the literature. Tamoxifen was well-tolerated among this cohort of patients without any adverse effects reported. Future studies are needed to determine efficacy of tamoxifen compared to other treatments for management of bleeding in adolescent ENG users.

Effect of Personalized Breast Cancer Risk Tool on Chemoprevention and Breast Imaging: ENGAGED-2 Trial.

BackgroundLimited evidence exists about how to communicate breast density-informed breast cancer risk to women at elevated risk to motivate cancer prevention.MethodsWe conducted a randomized controlled trial evaluating a web-based intervention incorporating personalized breast cancer risk, information on chemoprevention, and values clarification on chemoprevention uptake vs active control. Eligible women aged 40-69 years with normal mammograms and elevated 5-year breast cancer risk were recruited from Kaiser Permanente Washington from February 2017 to May 2018. Chemoprevention uptake was measured as any prescription for raloxifene or tamoxifen within 12 months from baseline in electronic health record pharmacy data. Secondary outcomes included breast magnetic resonance imaging (MRI), mammography use, self-reported distress, and communication with providers. We calculated unadjusted odds ratios (ORs) using logistic regression models and mean differences using analysis of covariance models with 95% confidence intervals (CIs) with generalized estimating equations.ResultsWe randomly assigned 995 women to the intervention arm (n = 492) or control arm (n = 503). The intervention (vs control) had no effect on chemoprevention uptake (OR = 1.04, 95% CI = 0.07 to 16.62). The intervention increased breast MRI use (OR = 5.65, 95% CI = 1.61 to 19.74) while maintaining annual mammography (OR = 0.98, 95% CI = 0.75 to 1.28). Women in the intervention (vs control) arm had 5.67-times higher odds of having discussed chemoprevention or breast MRI with provider by 6 weeks (OR = 5.67, 95% CI = 2.47 to 13.03) and 2.36-times higher odds by 12 months (OR = 2.36, 95% CI = 1.65 to 3.37). No measurable differences in distress were detected.ConclusionsA web-based, patient-level intervention activated women at elevated 5-year breast cancer risk to engage in clinical discussions about chemoprevention, but uptake remained low.

Tamoxifen exposure induces cleft palate in mice

Cleft palate is a common birth defect in mammals, which can be caused by genetic or environmental factors, or both. Decades have witnessed that many environmental exposures during gestation extremely increase the incidence of cleft palate. Tamoxifen (TAM), a widely-used drug in treating breast cancer, has been reported to be associated with craniofacial defects including micrognathia and cleft palate in humans. However, its exact effects on the developing palate remain unclear. Here we took advantage of a mouse model to explore how TAM affects palatal development at the molecular level. We showed that excess exposure of TAM in the early embryonic stages indeed leads to cleft palate in mice. RNA-sequencing results strongly suggest the involvement of mitogen-activated protein kinase (MAPK) signalling in TAM-induced cleft palate. Interestingly, in the anterior portion of the TAM-treated palatal shelf, phosphorylated (p)-AKT and p-ERK1/2 were activated but p-p38 was inhibited, while in the posterior palate, the p-AKT increased but the levels of p-p38 and p-JNK decreased. We conclude that excess TAM exposure causes cleft palate defects in mice by regulating MAPK pathways, which implicates the importance of tightly-regulated MAPK signalling in palatal development. This study provides a basis for further exploration of the molecular aetiology of cleft palate defects caused by environmental factors and, based on our results, we would give a serious warning regarding prescription of TAM and potential cleft palate defects in animal models involving the inducible Cre-LoxP system.

Serum Detection of Nonadherence to Adjuvant Tamoxifen and Breast Cancer Recurrence Risk.

PURPOSENonadherence to long-term treatments is often under-recognized by physicians and there is no gold standard for its assessment. In breast cancer, nonadherence to tamoxifen therapy after surgery constitutes a major obstacle to optimal outcomes. We sought to evaluate the rate of biochemical nonadherence to adjuvant tamoxifen using serum assessment and to examine its effects on short-term, distant disease-free survival (DDFS).PATIENTS AND METHODSWe studied 1,177 premenopausal women enrolled in a large prospective study (CANTO/NCT01993498). Definition of biochemical nonadherence was based on a tamoxifen serum level < 60 ng/mL, assessed 1 year after prescription. Self-reported nonadherence to tamoxifen therapy was collected at the same time through semistructured interviews. Survival analyses were conducted using an inverse probability weighted Cox proportional hazards model, using a propensity score based on age, staging, surgery, chemotherapy, and center size.RESULTSSerum assessment of tamoxifen identified 16.0% of patients (n = 188) below the set adherence threshold. Patient-reported rate of nonadherence was lower (12.3%). Of 188 patients who did not adhere to the tamoxifen prescription, 55% self-reported adherence to tamoxifen. After a median follow-up of 24.2 months since tamoxifen serum assessment, patients who were biochemically nonadherent had significantly shorter DDFS (for distant recurrence or death, adjusted hazard ratio, 2.31; 95% CI, 1.05 to 5.06; P = .036), with 89.5% of patients alive without distant recurrence at 3 years in the nonadherent cohort versus 95.4% in the adherent cohort.CONCLUSIONTherapeutic drug monitoring may be a useful method to promptly identify patients who do not take adjuvant tamoxifen as prescribed and are at risk for poorer outcomes. Targeted interventions facilitating patient adherence are needed and have the potential to improve short-term breast cancer outcomes.

Prevalence of the co-prescription of tamoxifen and CYP2D6 inhibitors in Saudi population: A cross sectional study

Consumption of Cytochrome P450 2D6 (CYP2D6) inhibiting drugs along with tamoxifen treatment results in decrease in plasma concentration of endoxifen, the major active tamoxifen metabolite. Simultaneous use of CYP2D6 inhibitors, such as selective serotonin reuptake inhibitors (SSIs), as well as lesser tamoxifen adherence may negatively impact tamoxifen efficacy in patients with breast cancer. The objective of our study was to assess the co-prescription of CYP2D6 inhibitors and tamoxifen use and also to relate concomitant CYP2D6 inhibitor use and tamoxifen adherence to breast cancer in Riyadh, Saudi Arabia. All patients treated for breast cancer who had at least one tamoxifen prescription in their electronic medical records (EMRs) from June 2015 to June 2017 were included. Patients who had other adjuvant hormonal therapy were excluded from the study. In total, 499 patients (25 males and 474 females) with breast cancer using tamoxifen were included. Our study was purely observational study revealed that prescription of weak inhibitors with tamoxifen increased in the second year as opposed to decrease in the prescription of strong inhibitors. Also, a substantial percentage of patient population were found to be non-adherent to the tamoxifen therapy in this study.

Nonadherence to tamoxifen in breast cancer survivors: A 12 month longitudinal analysis.

Previous research has shown that up to 50% of breast cancer survivors prescribed tamoxifen do not take it as recommended, which is associated with increased risk of recurrence and mortality. Little research has attempted to identify modifiable psychosocial factors associated with tamoxifen nonadherence. This study aimed to examine how tamoxifen adherence rates change over a year and to identify modifiable predictors of nonadherence. Three hundred and forty-five breast cancer survivors who were in their first year of tamoxifen prescription were sent questionnaires at 4 points over a 12-month period. Questionnaires assessed demographic and clinical factors, side effects, beliefs about the illness and medication, social support, distress and tamoxifen adherence. Adherence was assessed using the Medication Adherence Rating Scale. Latent Growth Modeling was used to identify predictors of tamoxifen nonadherence. Reported rates of nonadherence increased over time (37-48%). Several demographic, clinical, and psychosocial variables were associated with nonadherence. Women who were nonadherent were more likely to be from a minority ethnic group, to have more negative medication beliefs and to have lower confidence in their ability to take tamoxifen. These demographic and clinical variables can be used to identify women at higher risk of nonadherence. The modifiable psychosocial variables can be used as the basis for psychological interventions to improve adherence in this population. Interventions should focus on both intentional and unintentional nonadherence. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Risk of dementia among postmenopausal breast cancer survivors treated with aromatase inhibitors versus tamoxifen: a cohort study using primary care data from the UK

PurposeAmong a cohort of postmenopausal breast cancer survivors, we aimed to compare the risk of dementia associated with aromatase inhibitor (AI) therapy versus tamoxifen.MethodsUsing UK primary care electronic health records, we identified 14,214 postmenopausal breast cancer survivors (aged ≥ 54 years) with a first AI or tamoxifen prescription between January 2002 and December 2015 and no previous dementia diagnosis. Women were followed-up to identify incident cases of dementia. Cox regression was used to calculate hazard ratios (HRs) with 95% confidence intervals (CIs) to quantify the association between AI exposure (vs. tamoxifen) and dementia, adjusted for confounders.ResultsA total of 368 incident dementia cases was identified over 57,102 person-years of follow-up. The crude incidence rate of dementia was 7.46 per 1000 person-years (95% CI 6.43–8.65) among women starting endocrine treatment on an AI, and 6.32 per 1000 person-years (95% CI 5.34–7.47) among women starting on tamoxifen. After accounting for age differences and assessing other potential confounders, there was no evidence of a difference in dementia risk between exposure groups (HR for AI vs tamoxifen 1.04, 95% CI 0.83–1.03). There was no evidence of effect modification by age.ConclusionThere was no evidence for a difference in dementia risk between AI and tamoxifen users among postmenopausal breast cancer survivors.Implications for Cancer SurvivorsOur findings suggest that there is no reason for concern about a difference in dementia risk with AI vs. tamoxifen, which is relevant to postmenopausal breast cancer patients recommended these treatments.

Association between tamoxifen use and acute myocardial infarction in women with breast cancer.

The relationship between tamoxifen use and acute myocardial infarction in women with breast cancer remains uncertain. The goal of the study was to assess whether tamoxifen use could be associated with acute myocardial infarction in women with breast cancer in Taiwan.A population-based case–control study was conducted to analyze the database of the Taiwan National Health Insurance Program. Totally, 489 women with breast cancer aged 20 to 84 years having the first episode of acute myocardial infarction from 2000 to 2011 were found as the cases. In addition, 1718 women with breast cancer aged 20 to 84 years without any type of ischemic heart disease were selected as the matched controls. Ever use of tamoxifen was classified as the studied women who had at least a prescription for tamoxifen before the index date. Never use of tamoxifen was classified as the studied women who never had a prescription for tamoxifen before the index date. We used the multivariable logistic regression model to estimate the odds ratio (OR) and 95% confidence interval (CI) for acute myocardial infarction associated with tamoxifen use.In a multivariable-adjusted analysis, women with acute myocardial infarction were 1.71 times more likely to be exposed to tamoxifen than those women without acute myocardial infarction (adjusted OR 1.71, 95% CI 1.38–2.13).The odds of tamoxifen use are 1.71 times higher in women with acute myocardial infarction versus those women without acute myocardial infarction in Taiwan.

Tamoxifen use correlates with increased risk of hip fractures in older women with breast cancer: A case-control study in Taiwan.

This study aimed to evaluate the association between tamoxifen use and hip fractures in older women with breast cancer in Taiwan. We carried out a retrospective nationwide case-control study using the database of the Taiwan National Health Insurance Program. A total of 762 female patients with breast cancer aged ≥65 years newly diagnosed with hip fractures from 2000 to 2011 were identified for inclusion in the study. Additionally, 7620 female patients with breast cancer aged ≥65 years without hip fractures were randomly selected as controls. Patients were defined as having used tamoxifen if they had an existing prescription for tamoxifen before the index date. Patients were defined as having never used tamoxifen if they had never been given a prescription for tamoxifen before the index date. We used an unconditional logistic regression model to calculate the odds ratio and 95% confidence interval for the association between tamoxifen use and risk of hip fractures. After adjustment for confounding variables, compared with patients who did not use tamoxifen, the adjusted odds ratio of hip fracture was 2.29 for those who had used tamoxifen (95% confidence interval 1.92, 2.72). Furthermore, adjusted odds ratios were 2.74 (95% confidence interval 2.19, 3.42) among patients with a cumulative duration of tamoxifen use of >3 years. Tamoxifen use is associated with increased risk of hip fractures among older women with breast cancer in Taiwan. Geriatr Gerontol Int 2019; 19: 56-60.

Correlation of the tamoxifen use with the increased risk of deep vein thrombosis and pulmonary embolism in elderly women with breast cancer: A case-control study.

The association between tamoxifen use and risk of deep vein thrombosis or pulmonary embolism in women with breast cancer has been reported in the Western population. The study aimed to evaluate the association between tamoxifen use and deep vein thrombosis or pulmonary embolism in older women with breast cancer in Taiwan.We conducted a retrospective case–control study using the database of the Taiwan National Health Insurance Program. A total of 281 women subjects with breast cancer aged ≥65 years with newly diagnosed deep vein thrombosis/or pulmonary embolism from 2000 to 2011 were identified as the cases. Additionally, 907 women subjects with breast cancer aged ≥65 years without deep vein thrombosis or pulmonary embolism were randomly selected as the controls. The cases and the controls were matched with age and comorbidities. Ever use of tamoxifen was defined as subjects who had at least a prescription for tamoxifen before index date. Never use of tamoxifen was defined as subjects who never had a prescription for tamoxifen before index date. We used the multivariable logistic regression model to calculate the odds ratio (OR) and the 95% confidence interval (CI) of deep vein thrombosis or pulmonary embolism associated with tamoxifen use.After adjustment for confounding variables, the adjusted OR of deep vein thrombosis or pulmonary embolism was 1.95 for subjects with ever use of tamoxifen (95% CI 1.45, 2.62), as compared with never use of tamoxifen. In addition, atrial fibrillation (adjusted OR 3.73, 95% CI 1.89, 7.35) and chronic kidney disease (adjusted OR 1.72, 95% CI 1.06, 2.80) were also associated with deep vein thrombosis or pulmonary embolism.Tamoxifen use is associated with 1.95-fold increased odds of deep vein thrombosis or pulmonary embolism among older women with breast cancer in Taiwan.

Tamoxifen Use Correlates with Increased Risk of the First Episode of Ischemic Cerebrovascular Disease in Older Women with Breast Cancer: A Case-Control Study in Taiwan.

Background and Objectives: There are inconsistent results about the association between ischemic cerebrovascular disease and tamoxifen use in women with breast cancer. The study aimed to evaluate the association between the risk of ischemic cerebrovascular disease and tamoxifen use in older women with breast cancer in Taiwan.Methods: We designed a retrospective, nationwide, case-control study using the database of the Taiwan National Health Insurance Program. A total of 800 female subjects with breast cancer aged ≥65 years with the first episode of ischemic cerebrovascular disease from 2000 to 2011 were identified as the cases. Additionally, 2,876 female subjects with breast cancer aged ≥65 years without any type of cerebrovascular diseases were selected as the control subjects. The cases and the control subjects were matched with age and comorbidities. Ever use of tamoxifen was defined as a subject who had at least a prescription for tamoxifen before the index date. Never use of tamoxifen was defined as a subject who never had a prescription for tamoxifen before the index date. We used the multivariable logistic regression model to calculate the odds ratio (OR) and 95% confidence interval (CI) for ischemic cerebrovascular disease associated with tamoxifen use.Results: After adjusting for confounding variables, the adjusted OR of ischemic cerebrovascular disease was 2.5 for subjects with ever use of tamoxifen (95% CI 2.10, 2.97), compared with never use of tamoxifen. In addition, the adjusted OR of ischemic cerebrovascular disease was 1.15 (95% CI 1.10, 1.21) in subjects with ever use of tamoxifen as increase in use duration per 1 year. The adjusted OR of ischemic cerebrovascular disease was 2.54 (95% CI 2.03, 3.17) in subjects with ever use of tamoxifen as increase in dosage per 1 mg.Conclusions: Tamoxifen use is significantly associated with 2.5-fold increased odds of ischemic cerebrovascular disease among older women with breast cancer in Taiwan. There are duration-dependent and dose-dependent effects of tamoxifen use on the risk of ischemic cerebrovascular disease.

Tamoxifen usage correlates with increased risk of Parkinson’s disease in older women with breast cancer: a case–control study in Taiwan

Little is known about the association between tamoxifen usage and risk of Parkinson's disease in women with breast cancer. The present study aimed to evaluate the association between tamoxifen usage and Parkinson's disease in older women with breast cancer in Taiwan. We conducted a retrospective nationwide case-control study using the database of the Taiwan National Health Insurance Program. In total, 293 female subjects with breast cancer, aged 65years and above, who were newly diagnosed with Parkinson's disease between 2000 and 2011 were included. Additionally, 1053 female subjects with breast cancer aged 65years and above without Parkinson's disease were randomly selected as controls. Both cases and controls were matched for age and comorbidities. Ever use of tamoxifen was defined as subjects who had at least a prescription for tamoxifen before the index date, whereas never use of tamoxifen was defined as those who never had a prescription for tamoxifen before the index date. We used the unconditional logistic regression model to calculate the odds ratio (OR) and 95% confidence interval (CI) for the association between tamoxifen usage and risk of Parkinson's disease. After adjusting for confounding variables, the adjusted OR of Parkinson's disease was 3.32 for subjects with ever use of tamoxifen (95% CI, 2.50-4.43), compared with nonusers. Further analysis showed that the adjusted ORs of Parkinson's disease were 3.21 (95% CI, 2.29-4.49), 3.95 (95% CI, 2.77-5.64), and 11.4 (95% CI, 2.63-49.7) for subjects with <2, 2-6, and ≥6 years of cumulative tamoxifen usage, respectively, when compared with nonusers. Tamoxifen usage was associated with a 3.32-fold increase in the likelihood of having Parkinson's disease among older women with breast cancer in Taiwan.

Nationwide Case-Control Study Examining the Association between Tamoxifen Use and Alzheimer's Disease in Aged Women with Breast Cancer in Taiwan.

Background and Objectives: Little is known about the association between tamoxifen use and Alzheimer’s disease in women with breast cancer. The study aimed to explore the association between tamoxifen use and Alzheimer’s disease in aged women with breast cancer in Taiwan.Methods: We conducted a retrospective nationwide case-control study using the database of the Taiwan National Health Insurance Program. Totally, 173 female subjects with breast cancer aged ≥ 65 years with newly diagnosed Alzheimer’s disease from 2000 to 2011 were identified as the cases. Additionally, 684 female subjects with breast cancer aged ≥ 65 years without any type of dementia were selected as the matched controls. The cases and the matched controls were matched with age and comorbidities. Ever use of tamoxifen was defined as subjects who had at least a prescription for tamoxifen before the index date. Never use of tamoxifen was defined as subjects who never had a prescription for tamoxifen before the index date. We used the logistic regression model to calculate the odds ratio (OR) and 95% confidence interval (CI) of Alzheimer’s disease associated with tamoxifen use.Results: The OR of Alzheimer’s disease was 3.09 for subjects with ever use of tamoxifen (95% CI 2.10, 4.55), compared with never use. The OR of Alzheimer’s disease was 1.23 for subjects with increasing cumulative duration of tamoxifen use for every 1 year (95% CI 1.13, 1.34), compared with never use.Conclusion: The increased odds of Alzheimer’s disease associated with tamoxifen use may be due to the survival effect, not the toxic effect. That is, the longer the tamoxifen use, the longer the patients survive, and the greater the likelihood that she may have a chance to develop Alzheimer’s disease.

Treatment Restarting After Discontinuation of Adjuvant Hormone Therapy in Breast Cancer Patients

Over half of breast cancer patients discontinue their adjuvant hormone therapy, permanently or temporarily. We aimed to identify predictors of treatment restarting after discontinuation of adjuvant hormone therapy and to test the hypothesis that treatment restarting is associated with better breast cancer outcomes. We conducted a population-based cohort study by linking data from the Stockholm-Gotland Breast Cancer Register, the Swedish Prescribed Drug Register, and a self-reported questionnaire. We followed women diagnosed with breast cancer (Stockholm, Sweden, 2005-2008) from their first prescription of tamoxifen or aromatase inhibitors through January 31, 2015, and categorized them as continuers (n = 1607), restarters (n = 953), and nonrestarters (n = 511) of adjuvant hormone therapy. All statistical tests were two-sided. Factors that decrease the likelihood of treatment restarting included younger age (<50 years), higher Charlson Comorbidity Score (≥2), smaller tumor size (<20 mm), human epidermal growth factor receptor 2 negative, lymph node negative, family history of breast cancer negative, using hormone therapy, using symptom relieving drugs, and switching therapy between tamoxifen and aromatase inhibitors. Restarting adjuvant hormone therapy was statistically significantly associated with prolonged disease-free survival, with an adjusted hazard ratio of 0.61 (95% confidence interval = 0.43 to 0.87, P = .006) for restarters vs nonrestarters. Our study provides-for the first time to our knowledge-evidence that restarting adjuvant hormone therapy is associated with better breast cancer outcomes. Clinicians now have further evidence to encourage patients to restart their treatment after discontinuation of adjuvant hormone therapy.