Polymorphisms of T- cell leukemia 1A gene loci are not related to the development of adjuvant letrozole-induced adverse events in breast cancer

The Burden of Illness of Treatment-Induced Vasomotor Symptoms in Individuals with Breast Cancer: A Systematic Literature Review

Objective: This systematic literature review (SLR) evaluates the global burden of treatment-induced vasomotor symptoms (VMSs) in individuals with breast cancer receiving tamoxifen or aromatase inhibitors (AIs). Methods: Embase and PubMed were searched for observational and interventional studies published between January 2010 and January 2023 reporting on adults who experienced moderate to severe VMSs after tamoxifen or AI treatment for breast cancer. Epidemiological, clinical, humanistic, economic, and treatment pattern data were extracted where available. Results: Of 694 unique publications identified, 37 independent studies (22 observational and 15 interventional) were included. The prevalence or incidence of treatment-induced VMSs was reported in 17 studies. The prevalence of hot flashes ranged from 32.5% to 82.9% in observational studies, while their incidence ranged from 2% to 60.0% in interventional studies. In four studies that reported data, individuals experienced VMSs with a frequency of 2 to 20 episodes per day. There were limited data on VMS timing (within a 24 h period or in relation to treatment dosing), duration, and correlations with clinical outcomes. Age, weight gain, body mass index, ethnicity, employment intensity, and certain genetic haplotypes were identified as risk factors for VMSs; however, these factors were often reported in only one study each. Notable evidence gaps in the literature included treatment options or management strategies for treatment-induced VMSs and the economic burden associated with treatment-induced VMSs. Conclusions: This SLR highlights the burden of treatment-induced VMSs in individuals with breast cancer receiving tamoxifen or AI therapy. Moderate to severe symptoms were reported in a large proportion of individuals across several studies. Evidence gaps were identified for economic burden and treatment patterns; further research is needed to understand the unmet needs for this population.

Musculoskeletal symptoms associated with aromatase inhibitors in the treatment of early breast cancer: A scoping review of risk factors and outcomes

PURPOSE

Aromatase inhibitor-associated musculoskeletal symptoms (AIMSS) are the most common adverse effects experienced by breast cancer patients. This scoping review aimed to systematically synthesize the predictors/risk factors and outcomes of AIMSS in patients with early-stage breast cancer.

METHODS

A systematic search was conducted in PubMed, Web of Science, EMBASE, CINAHL, and the China National Knowledge Internet (CNKI) from inception to December 2024 following the scoping review framework proposed by Arksey and O'Malley (2005).

RESULTS

A total of 5,008 studies were identified, and 98 were included in this review. The risk factors for AIMSS included psychosocial and demographic factors (e.g., age, BMI, menstrual status, and anxiety), clinical factors (e.g., history of chemotherapy, preexisting pain, and musculoskeletal diseases) and gene polymorphisms (e.g., ESR1, OPG, RANKL, TCL1A, and CYP19A1). The outcomes of AIMSS encompassed physical, psychological, behavioral, and survival-related impacts.

CONCLUSION

This scoping review synthesized the available evidence on predictors, risk factors, and outcomes of AIMSS, providing a foundation for developing risk prediction models and enhancing symptom management strategies.

Pharmacogenetics of Toxicities Related to Endocrine Treatment in Breast Cancer: A Systematic Review and Meta-analysis

BACKGROUND/AIM

Endocrine therapy is the standard treatment for hormone receptor-positive (HR+) breast cancer (BC). Yet, it is accompanied by treatment-related toxicities, leading to poor treatment adherence, high relapse, and low rates of survival. While pharmacogenomic variants have the potential to guide personalized treatment, their predictive value is inconsistent across published studies.

MATERIALS AND METHODS

To systematically assess the literature's current landscape of pharmacogenomics of endocrine therapy-related adverse drug effects, systematic searches in MEDLINE, Embase, Cochrane CENTRAL, Google Scholar and PharmGKB databases were conducted.

RESULTS

We identified 87 articles. Substantial heterogeneity and variability in pharmacogenomic effects were evident across studies, with many using data from the same cohorts and predominantly focusing on the Caucasian population and postmenopausal women. Meta-analyses revealed Factor V Leiden mutation as a predictor of thromboembolic events in tamoxifen-treated women (p<0.0001). Meta-analyses also found that rs7984870 and rs2234693 were associated with musculoskeletal toxicities in postmenopausal women receiving aromatase inhibitors (p<0.0001 and p<0.0001, respectively).

CONCLUSION

Overall, the current body of evidence regarding the potential role of pharmacogenomics in endocrine therapy-related toxicity in BC remains largely inconclusive. Key concerns include the heterogeneity in toxicity definitions, lack of consideration for genotype-treatment interactions, and the failure to account for multiple testing. The review underscores the necessity for larger and well-designed studies, particularly with the inclusion of premenopausal women and non-Caucasian populations.

Genome-wide association study of aromatase inhibitor discontinuation due to musculoskeletal symptoms

OBJECTIVE

Aromatase inhibitors (AIs) are commonly used to treat hormone receptor positive (HR +) breast cancer. AI-induced musculoskeletal syndrome (AIMSS) is a common toxicity that causes AI treatment discontinuation. The objective of this genome-wide association study (GWAS) was to identify genetic variants associated with discontinuation of AI therapy due to AIMSS and attempt to replicate previously reported associations.

METHODS

In the Exemestane and Letrozole Pharmacogenetics (ELPh) study, postmenopausal patients with HR + non-metastatic breast cancer were randomized to letrozole or exemestane. Genome-wide genotyping of germline DNA was conducted followed by imputation. Each imputed variant was tested for association with time-to-treatment discontinuation due to AIMSS using a Cox proportional hazards model assuming additive genetic effects and adjusting for age, baseline pain score, prior taxane treatment, and AI arm. Secondary analyses were conducted within each AI arm and analyses of candidate variants previously reported to be associated with AIMSS risk.

RESULTS

Four hundred ELPh participants were included in the combined analysis. Two variants surpassed the genome-wide significance level in the primary analysis (p value < 5 × 10-8), an intronic variant (rs79048288) within CCDC148 (HR = 4.42, 95% CI: 2.67-7.33) and an intergenic variant (rs912571) upstream of PPP1R14C (HR = 0.30, 95% CI: 0.20-0.47). In the secondary analysis, rs74418677, which is known to be associated with expression of SUPT20H, was significantly associated with discontinuation of letrozole therapy due to AIMSS (HR = 5.91, 95% CI: 3.16-11.06). We were able to replicate associations for candidate variants previously reported to be associated with AIMSS in this cohort, but were not able to replicate associations for any other variants previously reported in other patient cohorts.

CONCLUSIONS

Our GWAS findings identify several candidate variants that may be associated with AIMSS risk from AI generally or letrozole specifically. Validation of these associations in independent cohorts is needed before translating these findings into clinical practice to improve treatment outcomes in patients with HR + breast cancer.

Aromatase Inhibitor-Associated Musculoskeletal Syndrome: Understanding Mechanisms and Management

Aromatase inhibitors (AIs) are a key component in the chemoprevention and treatment of hormone receptor-positive (HR+) breast cancer. While the addition of AI therapy has improved cancer-related outcomes in the management of HR+ breast cancer, AIs are associated with musculoskeletal adverse effects known as the aromatase inhibitor-associated musculoskeletal syndrome (AIMSS) that limit its tolerability and use. AIMSS is mainly comprised of AI-associated bone loss and arthralgias that affect up to half of women on AI therapy and detrimentally impact patient quality of life and treatment adherence. The pathophysiology of AIMSS is not fully understood though has been proposed to be related to estrogen deprivation within the musculoskeletal and nervous systems. This review aims to characterize the prevalence, risk factors, and clinical features of AIMSS, and explore the syndrome's underlying mechanisms and management strategies.