BACKGROUND: The prevalence of nausea/vomiting in patients with advanced cancer has a wide range. Due to a very low level of evidence regarding antiemetic treatment, current guidelines recommend an etiology-based approach. The evidence for this approach is also slim and research is urgently needed.

OBJECTIVES: (Part One) to elucidate the prevalence of nausea and the possible associations with sociodemographic and clinical variables and (Part Two) to investigate possible etiologies of nausea and antiemetic treatments initiated in patients with nausea.

METHODS: Patients with advanced cancer and no recent antineoplastic treatment were included in a prospective two-part study. In Part One, patients completed an extended version of the EORTC QLQ-C15-PAL. Nauseated patients could then be included in Part Two in which possible etiologies and antiemetic treatment were recorded and a follow-up questionnaire was completed.

RESULTS: Eight hundred twenty-one patients were included and 46% reported any degree of nausea. Younger age and female sex were associated with a higher degree of nausea. Common etiologies included constipation, opioid use, and "other," and treatments associated with a statistically significant decrease in nausea/vomiting were olanzapine, laxatives, corticosteroids, domperidone, and metoclopramide.

CONCLUSION: Nausea was a common symptom in this patient population and many different etiologies were suggested. Most patients reported a lower degree of nausea at follow-up. More research in treatment approaches and specific antiemetics is strongly needed.