Management of chemotherapy-induced vomiting has improved with the use of antiemetics, but chemotherapy-induced nausea remains a major clinical problem, according to Alex Molassiotis, RN, PhD, Professor and Head of the School of Nursing at The Hong Kong Polytechnic University. And, he added, the scope of nausea may be broader than we think.
“We often connect it with vomiting, but perhaps there are other issues to consider, and maybe we got it wrong altogether,” admitted Dr. Molassiotis at the 2016 Multinational Association of Supportive Care in Cancer/International Society of Oral Oncology (MASCC/ISOO) International Symposium on Supportive Care in Cancer in Adelaide, Australia.1
Lawrence H. Einhorn, MD, Distinguished Professor of Medicine at Indiana University School of Medicine in Indianapolis, agreed. “I would not say we’ve conquered emesis, but we’ve greatly mitigated the threat of severe vomiting,” he said, adding that the mechanism of nausea is not necessarily similar to the mechanism of emesis in patients receiving chemotherapy. “No longer is the major unmet need for our patients complete remission with no emetic episodes and no use of rescue medication—It is clearly, unequivocally nausea,” declared Dr. Einhorn at the conference.2
Separating Vomiting From Nausea
“Vomiting is a useful reaction of the body; it protects the body from toxins. We can’t say the same thing about nausea,” said Dr. Molassiotis. “Patients say they feel better after vomiting, but having that constant feeling of nausea really impacts their lives.”
The percentage of patients receiving chemotherapy who experience acute or delayed vomiting is only 20% or less with appropriate use of antiemetics, revealed Dr. Molassiotis, but the percentage of those experiencing nausea is triple that. According to one study, 60% to 70% of patients experienced delayed nausea due to chemotherapy, and the rates of acute and delayed nausea varied according to different chemotherapy cycles.3
Furthermore, a different study showed almost identical results.4 Acute vomiting was observed in 9% to 14% of patients over 2 chemotherapy cycles, but acute nausea was observed in 6 times more patients, 64%. “So linking nausea and vomiting together is probably not the best way to do it,” acknowledged Dr. Molassiotis. “Traditionally, antiemetic trials actually looked at it as a single outcome—chemotherapy-induced nausea and vomiting management—but we need to start splitting these two and looking at them very differently.”
Key Messages From the Literature
According to Dr. Molassiotis, the results of many studies over the years have yielded some key principles regarding chemotherapy-induced nausea and vomiting.
- Vomiting is largely well controlled, with the exception of moderately emetogenic chemotherapy, where antiemetic management of nausea needs improvement.
- Nausea, both acute and delayed, is a significant problem in more than half of patients receiving highly or moderately emetogenic chemotherapy.
- Nausea can be present without vomiting; acute symptoms of chemotherapy-induced nausea and vomiting are better managed than delayed symptoms (of both nausea and vomiting).
- Some patients receiving highly emetogenic chemotherapy are undertreated, whereas patients in other protocols may be overtreated, especially with low and minimally emetogenic chemotherapy.
Anticipatory nausea is another big problem. A 2016 study showed that every 1-mm increase in anticipatory nausea on the visual analog scale was significantly associated with a 2% to 13% increase in the likelihood of chemotherapy-induced nausea and vomiting.5 “This is important because anticipatory symptoms make a very big difference in the development of [chemotherapy-induced nausea and vomiting] later on,” added Dr. Molassiotis.
Nausea as a Symptom Cluster
“Nausea is very complicated, and patients describe...