Patient expectation is a strong predictor of severe nausea after chemotherapy: a University of Rochester Community Clinical Oncology Program study of patients with breast carcinoma.

BACKGROUND: Patients may use their past experiences with nausea, as well as information about the incidence of nausea from chemotherapy that other patients have experienced, to form a prediction, or response expectancy, of nausea from their own upcoming chemotherapy. Mounting evidence suggests that these expectancies relating to nausea are significant predictors, and, likely, contributing factors to the development of treatment-related nausea.

METHODS: The patients in the current study were participants in the control arm of a multicenter clinical trial conducted between November 1999 and July 2001 by the University of Rochester Community Clinical Oncology Program. All patients in the current report were age >/= 18 years and were about to begin a first cancer treatment regimen containing doxorubicin.

RESULTS: Expectancy of nausea assessed before patients received their first doxorubicin-based chemotherapy treatment was found to be a strong predictor of subsequent nausea and in fact was stronger than previously reported predictive factors, including age, nausea during pregnancy, and susceptibility to motion sickness. Women who believed it was "very likely" that they would have severe nausea from chemotherapy were five times more likely to experience severe nausea than fellow patients who thought its occurrence would be "very unlikely."

CONCLUSIONS: Further studies confirming an expectancy of nausea as a risk factor are warranted as are studies examining the benefit to a patient's quality of life from modifying antiemetic treatment guidelines to take into account symptom expectancies. Finally, ethically acceptable interventions that are designed to reduce patients' nausea expectancies or increase their expectancies of nausea control should be developed and studied.