OBJECTIVES: Chemotherapy induced myelosuppression (CIM), usually manifested as neutropenia, anemia and/or thrombocytopenia, is a common complication of chemotherapy. Although published literature exists on predicting neutropenia risk based on patients' characteristics among patients with breast, colorectal, lung, lymphoid, or ovarian cancer,^1,2 or predicting myelosuppression (neutropenia, anemia and/or thrombocytopenia) among NSCLC patients^3-4, there is a paucity of studies examining the risk of myelosuppression among patients with SCLC. The association between patient characteristics and myelosuppression in SCLC is examined in this study.

METHODS: Providence St. Joseph Health electronic medical record data was utilized to identify 338 SCLC patients who received chemotherapy between 2016-2019. Grade ≥ 3 CIM overall and by lineage was defined using laboratory values (hemoglobin <8.0 g/dL; absolute neutrophil count <1,000mm³; and platelet count <50,000mm³). Patient characteristics (age, sex, race, smoking history, stage, performance status, radiation treatment, and having second line of therapy) were examined for their association with CIM by logistic regression analysis.

RESULTS: Grade ≥ 3 CIM occurred in 61% of patients with CIM rates, being highest among patient ≤59 years (66%) and lowest among patients 74+ years (53%). This might be partially explained by the higher proportion of younger patients receiving 2^nd line chemotherapy. Overall, age-specific, and lineage specific multivariate regression analyses identified no significant associations between patient characteristics and myelosuppression. The area under the ROC curve was 0.65 for the model predicting myelosuppression among all patients and the area under the ROC curve was highest when the model was restricted to patients ≤59 years of age (0.79) and lowest for predicting thrombocytopenia (0.59).

CONCLUSIONS: Results from the models suggest there was no association between patient characteristics and risk of myelosuppressive events among SCLC patients receiving chemotherapy. Future studies are recommended to confirm this study’s findings and include a more comprehensive list of disease-related and treatment-related variables.¹