Chemotherapy dose intensity determination as a quality of care measure for managed care organizations in the treatment of early-stage breast cancer

The objective of this study was to demonstrate how a clinical practice database can be used to illustrate the variations in adjunctive chemotherapy for breast cancer, to describe a measure of dose intensity (DI) to monitor that variation, and to design interventions to maximize a full-planned dose. An arbitrary sample of oncology practices across the United States was selected, each providing data on 10-20 patients treated with adjuvant chemotherapy for early-stage breast cancer. Data on 17,566 patients from 1438 sites were collected, consisting of patient characteristics including age, number of positive nodes, planned and delivered chemotherapy agents, and a sample of absolute neutrophil or white blood cell counts by cycle. Mean age of the patient cohort was 48.5 years, and 54% of patients were below the age of 49. Treatment for the disease has changed during the 2 periods studied, 1983-1994 and 1995-1999. Use of Adriamycin/Cytoxan (AC) increased, whereas use of Cytoxan/Adriamycin/Fluorouracil (CAF) and fall-dose Cytoxan/Methotrexate/Fluorouracil (CMF1) decreased. However, the less intense Cytoxan/Methotrexate/Fluorouracil combination (CMF2) has seen an actual increase in use during the 2 periods. Within the context of oncology care, including chemotherapy, full-dose intensive therapy and cure has always been the ultimate goal. In this study only 10% of the patients given AC received less than 85% of the full referenced dose, whereas about 200/c of those receiving the other combinations fell into this category. Also, the summation dose intensity (SDI), a measure tying level of dose to survival, was highest in the AC group and lowest in the CMF2 group. Dose delays and dose reductions appear to account for the decrease in DI in the CMF1, CMF2, and CAF groups. DI, particularly SDI of adjuvant chemotherapy, which ties level of dose to survival in breast cancer patients, appears to be a reliable measure with which to assess the quality of care in community oncology practices. The 2 measures presented in this paper may be useful to managed care organizations for monitoring quality outcomes in this serious disease. Because one of the major reasons for reduction in chemotherapy dose appears to be neutropenia and its complications, these organizations can establish programs using DI as a basis for developing guidelines to optimize the clinical benefits of growth factors.