Early hematologic dynamics and their association with patient-reported symptom burden in breast cancer pharmacotherapy: a prospective cohort study.

[BACKGROUND] Systemic pharmacotherapy for breast cancer frequently induces hematologic toxicity and inflammatory changes that may affect symptom burden and treatment tolerance. This study evaluated baseline hematologic profiles, early treatment-related changes, and their association with patient-reported outcomes during the first cycle of therapy.

[METHODS] In this prospective cohort study, 106 women receiving systemic pharmacotherapy at two secondary referral centers in Indonesia were enrolled. Hematologic parameters and inflammatory indices-including neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), monocyte-lymphocyte ratio (MLR), and pan-immune-inflammation value (PIV)-were measured. Patient-reported outcomes were assessed using the EORTC QLQ-C30.

[RESULTS] The mean age was 51.9 ± 9.7 years, with most patients presenting with locally advanced disease and invasive ductal carcinoma. Early pharmacotherapy caused marked hematologic suppression, with leukocyte and neutrophil nadirs at week 1 and partial recovery by week 3 ( < 0.001). PLR, MLR, and PIV changed significantly over time ( < 0.001). Anemia increased from 51.9% to 74.0%, while neutropenia rose to 41.7% at week 1 before declining to 1.1% by week 3. Selected hematologic biomarkers correlated with patient-reported symptom burden, and only baseline MLR differed between survival subgroups ( = 0.043).

[CONCLUSION] Early breast cancer pharmacotherapy induces dynamic hematologic and inflammatory changes associated with patient-reported symptoms, supporting integrated monitoring to improve toxicity management.