Chemotherapy characteristics are important predictors of primary prophylactic CSF administration in older patients with breast cancer

Abstract

Chemotherapy is vital for breast cancer management, but early onset toxicities like neutropenia hinder its administration. Primary prophylactic (PP) use of colony- stimulating factors (CSF) helps prevent neutropenia and ensures successful chemotherapy completion. Nevertheless, lack of specific guidelines for CSF administration in older patients has lead to unexplained geographic and racial, and counter-intuitive clinical variations in CSF administration. This study examined the reasons for these variations and for the first time looked at variations in PP-CSF administration and duration of administration in breast cancer patients receiving chemotherapy. This retrospective observational study of newly diagnosed breast cancer patients receiving chemotherapy used SEER-Medicare data from 1994-2003. Regression analyses were used to explore the factors associated with PP-CSF administration and duration of administration. Clinical and therapeutic characteristics previously unexplored by other studies were included. Univariate analyses demonstrated geographic, racial and clinical disparities similar to previous studies. However, clinical correlations resolved to statistical insignificance after inclusion of chemotherapy characteristics. The analysis showed that significant geographic and racial disparities existed. History of recent antibiotic use was associated with shorter PP-CSF administration. Physicians' decision to administer PP-CSF is predominantly driven by neutropenia risk associated with pre-planned chemotherapy regimen. Older, sicker women at a higher risk of neutropenia receive less intense/toxic chemotherapy and thus do not require PP-CSF. Geographic variations are driven by proportion of physicians administering PP-CSF with no evidence for overuse among specific physicians. Association of recent antibiotic use with shorter PP-CSF administration suggests intended substitution of the expensive PP-CSF with prophylactic antibiotics.

Use of Hematopoietic Growth Factors in Elderly Lung Cancer Patients Receiving Chemotherapy

“…A previous study performed by one of the authors found that once chemotherapy characteristics like type of drug, number of drugs used per cycle, and duration between cycles are controlled for, age and comorbidity index were no longer correlated with CSF use. 34 The reduction in CSF use with increase in age and comorbidity index is similar to the results from other studies, which did not control for chemotherapy characteristics. 29,31,35 Despite controlling for clinical history, tumor, and treatment characteristics, sociodemographic variations persisted.…”

“…Both these differences have also been observed in older national studies examining the utilization of HGF in the United States, thereby raising concerns about the persistence of these variations and disparities over time. 29,[34][35] Regional variations are often an indication of cumulative differences in physician preferences and practice patterns between regions. Studies have documented that CSFs are frequently used in scenarios where their use is not recommended by evidencebased guidelines.…”

“…30,32 However, studies exploring the use of these drugs are not nationally representative, 32,33 do not control for the risk profile of patients on which the clinical guidelines are based, 25,29 or have not looked at more recent data. 25,29,[32][33][34][35] Moreover, there is very little evidence about the use of HGFs in lung cancer patients and a paucity of studies exploring the use of ESAs in general. Therefore, this study aimed to address these gaps and examined the factors associated with the use of HGFs in lung cancer patients.…”

Incidence of reduced chemotherapy relative dose intensity among women with early stage breast cancer in US clinical practice

“…A variety of different myelosuppressive chemotherapy regimens have proven to be efficacious and safe in clinical trials, and are commonly used today in US clinical practice [1,2]. Reductions from published trial-based or reference ''standard'' dose of chemotherapy among patients with ESBC may occur due to a variety of factors-especially advanced age and hematological adverse events, such as neutropenia and related infections-and are generally believed to result in an increased risk of disease progression and poorer overall survival [3][4][5][6][7][8][9][10].…”

Effect of primary prophylactic G-CSF use on systemic therapy administration for elderly breast cancer patients

“…Table 1 describes each characteristic and the corresponding variable. The association of these characteristics with primary prophylactic G-CSF administration has been explored by the authors previously [46]. Since administration of primary prophylactic G-CSF and risk of neutropenia are associated with the initiation of chemotherapy, all clinical history variables (e.g., modified Charlson comorbidity index, past history of any cancer, history of infections, antibiotic use, and hospitalizations) were measured with respect to initiation of chemotherapy.…”