Abstract
The purpose of this study was to determine the course of the activity level, seen as a dimension of fatigue, as a function of chemotherapy within a breast cancer population receiving adjuvant chemotherapy. The second purpose of this study was to determine the course of the interference of fatigue, in general, with daily activities within a breast cancer population receiving adjuvant chemotherapy. In a prospective cohort study, a sample of 157 patients with breast cancer was interviewed, at the first, third, and fifth cycle of adjuvant chemotherapy as well as 4 and 12 weeks after the last cycle of adjuvant chemotherapy. The chemotherapy was administered with either a doxorubicin-containing schedule or cyclophosphamide, methotrexate, and 5-fluorouracil. These 2 groups were compared. The activity level was measured by the Multidimensional Fatigue Inventory. A linear multilevel model was used to analyze the course. The revised Piper Fatigue Scale was used to examine the behavioral changes in the interference of fatigue with activities of daily living. A logistic multilevel model was used to analyze the course of this interference over time. The activity level seems to be rather stable during the treatment with chemotherapy. After the completion of chemotherapy, an improvement is observed. The activity levels reported at the first and the last measurement do not significantly differ. The course of the activity level is not affected by the type of chemotherapy regimen. Age, having children, and the stage of breast cancer turn out to be important determinants of the course of activity level. At all measurement occasions, women with a mastectomy were significantly more hampered in their activity level than women that had undergone a lumpectomy. The longer the duration of radiotherapy, the less active, and the longer the time interval between the last radiotherapy session and the measurement point, the more active patients were at that measurement point. A phenomenon not easy to explain is that the activity level in women who had received, in total, more chemotherapy treatments was significantly less diminished than those who had received fewer treatments. During the study period, in approximately 15% to 35% of the sample, fatigue interferes considerably with their daily living activities. Furthermore, the interference of fatigue with activities in daily life first increases after the start of chemotherapy and decreases after the completion of chemotherapy. Fatigue definitely affects the daily living activities of patients with breast cancer receiving adjuvant chemotherapy. With this knowledge, healthcare providers can inform patients on what they can expect. Further research should include the trajectory preceding chemotherapy and a healthy control group.