The development of anticipatory nausea in patients: Receiving adjuvant chemotherapy for breast cancer

Previous research on anticipatory nausea in cancer patients has focused on its occurrence in the clinic before chemotherapy infusions. The present study is the first, to our knowledge, to examine the development of anticipatory nausea across eight chemotherapy infusions for three time periods (night before, morning of, and immediately prior to each infusion). Based on classical conditioning experiments conducted with animal subjects, we hypothesized that the severity of anticipatory nausea would increase as the time for scheduled infusions approached. Eighty-two women diagnosed with Stage I or II breast cancer were assessed for the intensity of anticipatory nausea at three time periods prior to eight scheduled infusions of outpatient adjuvant chemotherapy. Analyses indicated a significant interaction between number of infusions experienced and temporal proximity to the infusion, supporting the hypothesis. Changes in the severity of anticipatory nausea across infusions were consistent with conditioned learning predictions. These results contribute to a growing recognition of the importance of conditioning principles for understanding side effects of chemotherapy for cancer and may have implications for the management of side effects secondary to a variety of pharmacotherapies in clinical practice.