Relative Dose Intensity—Improving Treatment and Outcomes in Early-Stage Breast Cancer: A Retrospective Study

Purpose/Objectives: To determine the amount of chemotherapy delivered compared to amount of chemotherapy scheduled by calculating relative dose intensity (RDI) and to identify factors associated with nonadherence of scheduled treatment regimens for patients with early-stage breast cancer (ESBC).

Design: Retrospective, descriptive, correlational study.

Setting: Two community hospital cancer centers in northern Michigan.

Sample: 77 patients with ESBC receiving adjuvant chemotherapy.

Methods: The RDI Calculator™ was used for data collection. A worksheet was developed for each patient and included characteristics, treatment information, and RDI calculations. SAS®, version 19.2, was used for multivariate analyses based on logistical regression analyzing relationships among dependent and independent variables.

Main Research Variables: Dependent variables were RDI prescribed and RDI received. Independent variables included chemotherapy regimen, clinical characteristics, planned dose, and schedule.

Findings: The average RDI was 86.6%. The average RDI was 86.7% for patients younger than age 65, and 85.5% for those 65 and older. The most common reasons for dose reduction or dose delay were treatment toxicity, chronic disease risk factors, age, unplanned versus planned treatment dose, institution (different standards of care), patient preference, and weight.

Conclusions: Meeting treatment goals of RDI for patients with ESBC has been shown to increase the disease-free survival rate and positively affects overall survival.

Implications for Nursing: Nurses have the unique opportunity to case manage patients with ESBC throughout the spectrum of care. One of the key areas of focus is education of the patient and her family members from the time of diagnosis throughout treatment and rehabilitation.