A scoping review investigating the influence of comorbidities on the use and outcomes of biological therapies in breast cancer.
[INTRODUCTION] Comorbidity impacts breast cancer treatment decisions, toxicity and overall survival.
APA
Trotter S, Crook K, et al. (2026). A scoping review investigating the influence of comorbidities on the use and outcomes of biological therapies in breast cancer.. Journal of geriatric oncology, 17(4), 102964. https://doi.org/10.1016/j.jgo.2026.102964
MLA
Trotter S, et al.. "A scoping review investigating the influence of comorbidities on the use and outcomes of biological therapies in breast cancer.." Journal of geriatric oncology, vol. 17, no. 4, 2026, pp. 102964.
PMID
41934719
Abstract
[INTRODUCTION] Comorbidity impacts breast cancer treatment decisions, toxicity and overall survival. Use of biological therapies has rapidly expanded, with multiple new agents adopted in the past 10 years, including a range of human epidermal growth factor receptor 2 (HER2) targeting agents, cyclin-dependent kinase (CDK)4/6 inhibitors, antibody-drug conjugates, and PARP inhibitors. There has been no review assessing the influence of comorbidity on rates of drug use, toxicity, or overall outcomes. This scoping review has evaluated how comorbidity affects the prescribing, toxicity, and outcomes of biologics in breast cancer.
[MATERIALS AND METHODS] Using the Joanna Briggs Institute methodology for scoping reviews, all original research articles published since 2000, assessing the influence of comorbidity on use, toxicity and outcomes with biologics in breast cancer, were included.
[RESULTS] A total of 58 studies were included. Comorbidity assessment was heterogeneous: formal comorbidity indices were used in 18/58 studies (predominantly the Charlson Comorbidity Index, used in some form in 15/58), specific conditions as a proxy for comorbidity in 30/58, symptom burden in 3/58 and other measures in 7/58. Over half of the studies (33/58) assessed trastuzumab; we excluded 29 of these as they focused on comorbidities in relation to trastuzumab-related cardiotoxicity, which has been reviewed in existing systematic reviews. A further 4 of the 33 trastuzumab studies were retained as they also discussed biologic prescribing patterns. The remaining 29 studies assessed other anti-HER2 agents (15/29), CDK4/6 inhibitors (9/29), bevacizumab (2/29), everolimus (1/29), or multiple agents (2/29). There were no studies focused on PARP inhibitors or immunotherapies. The influence of comorbidity varied depending on the comorbidity measure used, outcome assessed, and biologic agent. Increasing comorbidity showed trends towards monotherapy prescribing (4/13) and reduced biologic initiation (6/13). Findings regarding toxicity (13/58), treatment interruption/discontinuation (7/58), and survival (6/58) were mixed.
[DISCUSSION] Comorbidity significantly impacts biological agent use in breast cancer, with reduced prescribing observed in patients with comorbidities. Effects on survival, toxicity, and treatment discontinuation remain heterogeneous and inconclusive. Focused research examining biologic use in specific patient subgroups with comorbidities is needed. Older age and frailty should also be explored.
[MATERIALS AND METHODS] Using the Joanna Briggs Institute methodology for scoping reviews, all original research articles published since 2000, assessing the influence of comorbidity on use, toxicity and outcomes with biologics in breast cancer, were included.
[RESULTS] A total of 58 studies were included. Comorbidity assessment was heterogeneous: formal comorbidity indices were used in 18/58 studies (predominantly the Charlson Comorbidity Index, used in some form in 15/58), specific conditions as a proxy for comorbidity in 30/58, symptom burden in 3/58 and other measures in 7/58. Over half of the studies (33/58) assessed trastuzumab; we excluded 29 of these as they focused on comorbidities in relation to trastuzumab-related cardiotoxicity, which has been reviewed in existing systematic reviews. A further 4 of the 33 trastuzumab studies were retained as they also discussed biologic prescribing patterns. The remaining 29 studies assessed other anti-HER2 agents (15/29), CDK4/6 inhibitors (9/29), bevacizumab (2/29), everolimus (1/29), or multiple agents (2/29). There were no studies focused on PARP inhibitors or immunotherapies. The influence of comorbidity varied depending on the comorbidity measure used, outcome assessed, and biologic agent. Increasing comorbidity showed trends towards monotherapy prescribing (4/13) and reduced biologic initiation (6/13). Findings regarding toxicity (13/58), treatment interruption/discontinuation (7/58), and survival (6/58) were mixed.
[DISCUSSION] Comorbidity significantly impacts biological agent use in breast cancer, with reduced prescribing observed in patients with comorbidities. Effects on survival, toxicity, and treatment discontinuation remain heterogeneous and inconclusive. Focused research examining biologic use in specific patient subgroups with comorbidities is needed. Older age and frailty should also be explored.