Assessing Predictors of Tamoxifen Nonadherence in Patients with Early Breast Cancer

Predictors of self-care in patients with cancer treated with oral anticancer agents: A systematic review

BACKGROUND

In the last two decades, the use of oral anticancer agents (OAAs) has increased in cancer patients. Despite this, patients and their caregivers face some challenging issues (side effects, drug-to-drug interactions, etc.) related to OAA administration. The three dimensions of self-care by Riegel et al., self-care maintenance (i.e., stability of patient condition), self-care monitoring (i.e., detection of side effects), and self-care management (i.e., management of side effects), may be implemented to avoid negative outcomes. However, knowledge of self-care determinants is necessary to recognise people at risk of poor self-care behaviours.

AIMS

Determine which are the predictors of self-care maintenance, self-care monitoring and self-care management in patients with cancer taking OAA.

METHODS

A systematic review with narrative synthesis was conducted. We included studies on adult patients with cancer using any kind of oral anticancer agent and describing a predictor of self-care. The search was performed on PubMed, CINAHL/PsycINFO, and Web of Science.

RESULTS

Of 3,061 records, 45 studies were included in this review. Forty-six predictors organised into 14 categories were identified. In general, all studies focused only on adherence, considered as a self-care maintenance component, and none of them focused on other dimensions of self-care. The predictors of OAA adherence most reported were age, side effects, and socioeconomic factors (e.g., insurance status, and annual income).

CONCLUSIONS

This systematic review highlighted the literature gap on the analysis of determinants of self-care behaviours in patients taking OAAs. This element could be a starting point for future research that can provide elements to support the oncology nursing research agenda, aimed at recognising patients at risk of poor self-care.

The impact of symptom clusters on endocrine therapy adherence in patients with breast cancer

BACKGROUND

When taken as prescribed, endocrine therapy is effective in reducing risk of recurrence and mortality in the treatment of patients with breast cancer. However, treatment side effects can act as a barrier to medication adherence. Existing research has not identified any specific side effects as consistent predictors of nonadherence. Our aim was to explore the influence of symptom clusters on self-reported adherence in patients with breast cancer.

METHODS

A cross-sectional online survey was conducted, including patients with breast cancer currently or previously prescribed endocrine therapy (N = 1051). This included measures of self-reported endocrine therapy adherence and common symptoms among this population (insomnia, depression, anxiety, fatigue, musculoskeletal, and vasomotor symptoms).

RESULTS

Unintentional nonadherence was higher than intentional nonadherence (50.8 % vs 31.01 %). The most troublesome symptom was insomnia (73.83 % displayed probable insomnia disorder). K-means cluster analysis identified 2 symptom clusters: overall High symptoms, and overall Low symptoms. Participants in the Low symptoms cluster were significantly more likely to be classed as adherent based on unintentional and intentional items.

CONCLUSIONS

Nonadherence was high in the current sample, and significantly more likely in participants reporting overall severe symptoms. Clinicians should be aware of the scale of common side effects and facilitate open conversation about potential barriers to adherence. Follow-up care should include assessment of common symptoms and signpost patients to appropriate support or treatment when required. Future research should explore potential for a central symptom to act as a target for intervention, to relieve overall side effect burden and facilitate better medication adherence.

Identifying determinants of adherence to adjuvant endocrine therapy following breast cancer: A systematic review of reviews

BACKGROUND

In oestrogen-receptor positive breast cancer, daily oral adjuvant endocrine therapy (ET) for at least 5 years significantly reduces risks of recurrence and breast cancer-specific mortality. However, many women are poorly adherent to ET. Development of effective adherence support requires comprehensive understanding of influences on adherence. We undertook an umbrella review to identify determinants of ET adherence.

METHODS

We searched PubMed, Embase, CINAHL, PsycINFO, Cochrane and PROSPERO (inception to 08/2022) to identify systematic reviews on factors influencing ET adherence. Abstracted determinants were mapped to the World Health Organization's dimensions of adherence. Reviews were quality appraised and overlap assessed.

RESULTS

Of 5732 citations screened, 17 reviews were eligible (9 quantitative primary studies; 4 qualitative primary studies; 4 qualitative or quantitative studies) including 215 primary papers. All five WHO dimensions influenced ET non-adherence: The most consistently identified non-adherence determinants were patient-related factors (e.g. lower perceived ET necessity, more treatment concerns, perceptions of ET 'cons' vs. 'pros'). Healthcare system/healthcare professional-related factors (e.g. perceived lower quality health professional interaction/relationship) were also important and, to a somewhat lesser extent, socio-economic factors (e.g. lower levels of social/economic/material support). Evidence was more mixed for medication-related and condition-related factors, but several may be relevant (e.g. experiencing side-effects, cost). Potentially modifiable factors are more influential than non-modifiable/fixed factors (e.g. patient characteristics).

CONCLUSIONS

The evidence-base on ET adherence determinants is extensive. Future empirical studies should focus on less well-researched areas and settings. The determinants themselves are numerous and complex in indicating that adherence support should be multifaceted, addressing multiple determinants.

A Machine Learning Model to Predict Patients' Adherence Behavior and a Decision Support System for Patients With Metastatic Breast Cancer: Protocol for a Randomized Controlled Trial

BACKGROUND

Adherence to oral anticancer treatments is critical in the disease trajectory of patients with breast cancer. Given the impact of nonadherence on clinical outcomes and the associated economic burden for the health care system, finding ways to increase treatment adherence is particularly relevant.

OBJECTIVE

The primary end point is to evaluate the effectiveness of a decision support system (DSS) and a machine learning web application in promoting adherence to oral anticancer treatments among patients with metastatic breast cancer. The secondary end point is to collect a set of new physical, psychological, social, behavioral, and quality of life predictive variables that could be used to refine the preliminary version of the machine learning model to predict patients' adherence behavior.

METHODS

This prospective, randomized controlled study is nested in a large-scale international project named "Enhancing therapy adherence among metastatic breast cancer patients" (Pfizer 65080791), aimed to develop a predictive model of nonadherence and associated DSS and guidelines to foster patients' engagement and therapy adherence. A web-based DSS named TREAT (treatment adherence support) was developed using a patient-driven approach, with 4 sections, that is, Section A: Metastatic Breast Cancer; Section B: Adherence to Cancer Therapies; Section C: Promoting Adherence; and Section D: My Adherence Diary. Moreover, a machine learning-based web application was developed to predict patients' risk factors of adherence to anticancer treatment, specifically pertaining to physical status and comorbid conditions, as well as short and long-term side effects. Overall, 100 patients consecutively admitted at the European Institute of Oncology (IEO) at the Division of Medical Senology will be enrolled; 50 patients with metastatic breast cancer will be exposed to the DSS and machine learning web application for 3 months (experimental group), and 50 patients will not be exposed to the intervention (control group). Each participant will fill a weekly medication diary and a set of standardized self-reports evaluating psychological and quality of life variables (Adherence Attitude Inventory, Beck Depression Inventory-II, Brief Pain Inventory, 13-item Sense of Coherence scale, Brief Italian version of Cancer Behavior Inventory, European Organization for Research and Treatment of Cancer Quality of Life 23-item Breast Cancer-specific Questionnaire, European Organization for Research and Treatment of Cancer Quality of Life Questionnaire, 8-item Morisky Medication Adherence Scale, State-Trait Anxiety Inventory forms I and II, Big Five Inventory, and visual analogue scales evaluating risk perception). The 3 assessment time points are T0 (baseline), T1 (1 month), T2 (2 months), and T3 (3 months). This study was approved by the IEO ethics committee (R1786/22-IEO 1907).

RESULTS

The recruitment process started in May 2023 and is expected to conclude on December 2023.

CONCLUSIONS

The contribution of machine learning techniques through risk-predictive models integrated into DSS will enable medication adherence by patients with cancer.

TRIAL REGISTRATION

ClinicalTrials.gov NCT06161181; https://clinicaltrials.gov/study/NCT06161181.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/48852.

Resistance to Resilience: Understanding Post-surgical Hormone Therapy in Breast Cancer Care

Breast cancer is one of the most common types of cancer affecting women worldwide. Over the years, breast cancer has become a major public health concern, and its incidence is rising globally. The treatment of breast cancer does not stop with surgical intervention, but adjuvant therapies are administered to improve patient outcomes post-surgery based on the type of breast cancer diagnosed. This review focuses on the value of hormone therapy (HT) in improving the prognosis of breast cancer patients and why adhering to adjuvant treatment post-surgery is difficult for patients. HT aims to reduce the chances of breast cancer recurrence after surgical treatment. Even though HT is life-saving, patients tend to not adhere to the therapy due to various factors such as side effects, age-related issues, and socioeconomic status. Most patients stop adhering to the therapy as the duration can be as long as 5-10 years, and the quality of life is greatly impacted due to the side effects of the treatment. This review examines the possible factors leading to non-adherence to HT and tries to propose possible interventions that might improve patient compliance with the treatment. This article not only focuses on the impact of side effects of HT on patients' quality of life but also tries to understand the problems faced by breast cancer patients in adhering to HT.

The Late Effects of Cancer Treatment on Female Fertility and the Current Status of Fertility Preservation-A Narrative Review

Fertility counseling should be offered to all individuals of young reproductive age early in the patient's trajectory following a cancer diagnosis. Systemic cancer treatment and radiotherapy often have an inherent gonadotoxic effect with the potential to induce permanent infertility and premature ovarian failure. For the best chances to preserve a patient's fertility potential and to improve future quality of life, fertility preservation methods should be applied before cancer treatment initiation, thus multidisciplinary team-work and timely referral to reproductive medicine centers specialized in fertility preservation is recommended. We aim to review the current clinical possibilities for fertility preservation and summarize how infertility, as a late effect of gonadotoxic treatment, affects the growing population of young female cancer survivors.

Treatment-related side effects among Hispanic and non-Hispanic white long-term breast cancer survivors by tamoxifen use and duration

PURPOSE

To determine the associations between ethnicity, age at diagnosis, obesity, multimorbidity, and odds of experiencing breast cancer (BC) treatment-related side effects among long-term Hispanic and non-Hispanic white (NHW) survivors from New Mexico and explore differences by tamoxifen use.

METHODS

Lifestyle and clinical information including self-reported tamoxifen use and presence of treatment- related side effects were collected at follow-up interviews (12-15 years) for 194 BC survivors. Multivariable logistic regression models were used to examine associations between predictors and odds of experiencing side effects overall and by tamoxifen use.

RESULTS

Women ranged in age at diagnosis (30-74, M = 49.3, SD = 9.37), most were NHW (65.4%) and had in-situ or localized BC (63.4%). Less than half reportedly used tamoxifen (44.3%), of which 59.3% reported using > 5 years. Overall, survivors who were overweight/obese at follow-up were 5.42 times more likely to experience treatment-related pain (95% CI 1.40-21.0) compared to normal weight survivors. Survivors with multimorbidity, compared to survivors without, were more likely to report treatment-related sexual health issues (aOR 6.90, 95% CI 1.43-33.2) and poorer mental health (aOR 4.51, 95% CI 1.06-19.1). The statistical interactions between ethnicity and overweight/obese with tamoxifen use were significant (p-interaction < 0.05) for treatment-related sexual health issues.

CONCLUSION

Our results demonstrate that survivors with overweightness/obesity or multimorbidity may be more likely to experience BC treatment-related side effects. Tamoxifen use modifies associations between ethnicity, being overweight/obese, and sexual health issues following treatment. The likelihood of experiencing treatment-related side effects were more favorable for those on tamoxifen or those who had used tamoxifen for longer durations. These findings highlight the importance of fostering side effect awareness and applying appropriate interventions to assist with disease management throughout BC survivorship care.

First use of antineoplastic agents in women with breast cancer in the state of Rio de Janeiro, Brazil

Context: Breast cancer is the most common cancer, except for non-melanoma skin cancer, among women in Brazil and worldwide. Breast cancer treatment involves surgery, radiotherapy and chemotherapy, which is used in 70% of patients. This study analyzes the utilization of antineoplastic agents among women undergoing their first round of chemotherapy in Brazil's public health system (SUS) in the state of Rio de Janeiro. Methods: Data from the SUS Outpatient Information System's authorizations for high-complexity outpatient procedures (APACs) billed between January 2013 and December 2019 were extracted, and three datasets were created: all type 1 and type 2 APACs (including all chemotherapy procedures performed); all type 1 APACs; and first type 1 APACs (containing data only for the first round of breast cancer chemotherapy). Names of antineoplastic agents were standardized to enable the subsequent classification of therapy regimens, mitigating limitations related to data quality. Absolute and relative frequencies were used to describe sociodemographic, clinical and treatment characteristics, therapy regimen and supportive drugs. Results: We analyzed 23,232 records of women undergoing their first round of chemotherapy. There was a progressive increase in the number of procedures over time. Women were predominantly white, lived in the capital and close to the treatment center. Most had stage 3 cancer at diagnosis (50.51%) and a significant proportion had regional lymph node invasion (37.9%). The most commonly used chemotherapy regimens were TAC (docetaxel, doxorubicine, cyclophosphamide) (21.05%) and and cyclophosphamide (17.71%), followed by tamoxifen (15.65%) and anastrozole (12.94%). Supportive drugs were prescribed to 386 women and zoledronic acid was predominant (59.58%). Conclusion: The findings point to important bottlenecks and possible inequities in access to treatment and medicine utilization for breast cancer patients in Brazil. Efforts to improve breast cancer treatment and prevention should not only focus on interventions at the individual level but address the disease as a public health problem. The study focused on women undergoing their first round of treatment, providing valuable insight into patient and treatment characteristics to inform policy decisions.

New Concepts in Cardio-Oncology

Cancer and cardiovascular disease are the two major causes of morbidity and mortality in worldwide. Discovering new therapeutic agents for the management of breast cancer (BC) has increased the numbers of cancer survivors but with the risk of cardiovascular adverse events (CV-AEs). All drugs can potentially damage the cardiovascular system, with different types of clinical manifestations from ischemic myocardial disease to vasculitis, thrombosis or pericarditis. An early detection of CV-AEs guarantees an earlier treatment, which is associated with better outcomes. Cardio-oncology field enlarged its studies to improve prevention, monitoring and treatment of all cardiotoxic manifestations related to old or modern oncological agents. A multidisciplinary approach with a close partnership between oncologists and cardiologists is essential for an optimal management and therapeutic decision-making. The aim of this chapter is to review all types of cardiotoxic manifestations related to novel and old agents approved for treatment of BC patients including chemotherapy, anti-HER2 agents, cyclin-dependent kinase 4/6 inhibitors, PolyADP-ribose polymerase (PARP) inhibitors, antiangiogenic drugs and immunotherapy. We also focused our discussion on prevention, monitoring, treatment, and management of CV-AEs.

Impact of organic anion transporting polypeptide, P-glycoprotein, and breast cancer resistance protein transporters on observed tamoxifen and endoxifen concentration and adverse effects

OBJECTIVE

Drug transporters are important determinants of drug disposition and response. Tamoxifen is an antiestrogen for breast cancer therapy known for adverse drug reactions (ADRs). In this study, the involvement of OATP transporters in tamoxifen and endoxifen transport was studied in vitro while the impact of single nucleotide variation (SNV) in OATP and efflux transporters P-glycoprotein ( ABCB1 ) and Breast Cancer Resistance Protein ( ABCG2 ) on ADRs during tamoxifen therapy were assessed.

METHODS

Patients receiving tamoxifen for breast cancer, who were CYP2D6 normal metabolizers were enrolled ( n  = 296). Patients completed a survey that captured ADRs and a blood sample was collected. Tamoxifen and endoxifen plasma concentration were measured, while DNA was genotyped for SNVs in ABCB1, ABCG2, SLCO1A2, SLCO1B1 , and SLCO2B1 . HEK293T cells were used to determine the extent of OATP-mediated transport of tamoxifen and endoxifen.

RESULTS

Common SNVs of ABCB1, ABCG2, SLCO1A2 , and SLCO1B1 were not associated with tamoxifen or endoxifen concentration. However, tamoxifen concentration was significantly higher in carriers of SLCO2B1 c.935G>A (129.8 ng/mL) compared to wildtype (114.9 ng/mL; P  = 0.036). Interestingly, subjects who carried SLCO1A2 c.38A>G reported significantly less dizziness ( P  = 0.016). In-vitro analysis demonstrated increased cellular accumulation of tamoxifen in cells overexpressing OATP1A2 and 1B1, but endoxifen uptake was not effected in OATP overexpressing cells.

CONCLUSIONS

We showed that OATP1A2 , a transporter known to be expressed at the blood-brain barrier, is capable of tamoxifen transport. Additionally, OATP1A2 c.38A>G was associated with reduced ADRs. Taken together, our findings suggest genetic variation in OATP transporters may be an important predictor of tamoxifen ADRs.

Orobanche crenata Forssk. Extract Affects Human Breast Cancer Cell MCF-7 Survival and Viral Replication

BACKGROUND

Breast cancer (BC) is the leading cause of death worldwide. The severity of BC strictly depends on the molecular subtype. The less aggressive hormone-positive subtype is treated with adjuvant endocrine therapy (AET), which causes both physical and psychological side effects. This condition strongly impacts the adherence and persistence of AET among oncologic patients. Moreover, viral infections also constitute a serious problem for public health. Despite their efficacy, antiviral agents present several therapeutic limits. Accordingly, in the present work, we investigated the antitumor and antiviral activities of Orobanche crenata Forssk. (O. crenata), a parasitic plant, endemic to the Mediterranean basin, traditionally known for its beneficial properties for human health.

METHODS

The MTT assay was carried out to evaluate the cytotoxic effect of O. crenata leaf extract (OCLE) on human breast cancer cells (MCF-7 and MDA-MB-231) and the primary HFF-1 cell line. The lactic dehydrogenase (LDH) assay was performed on MCF-7 cells to analyze necrotic cell death. The antioxidant effect of OCLE was evaluated by intracellular determination of the reactive oxygen species and thiol groups, by DPPH and ABTS assays. The antiviral activity of OCLE was determined against Poliovirus 1, Echovirus 9, Human respiratory syncytial virus, Adenovirus type 2 and type 5, Coxsackievirus B1 (CoxB1) and B3 (CoxB3), Herpes simplex type 1 (HSV-1) and type 2 (HSV-2), and β-Coronavirus by the plaque reduction assay.

RESULTS

The extract, after 24 h of incubation, did not affect MDA-MB-231 and HFF-1 cell viability. However, at the same time point, it showed a dose-dependent inhibitory effect on MCF-7 cells, with an increase in LDH release. OCLE exhibited free radical scavenging activity and significantly increased non-protein thiol levels in MCF-7 cells. OCLE effectively inhibited HSV-1, HSV-2, CoxB1, and CoxB3 replication.

CONCLUSIONS

The overall results showed an interesting inhibitory effect of OCLE on both MCF-7 cell survival and viral replication.