Approximately half of the patients with breast cancer who failed anti-nausea or vomiting therapy for chemotherapy-induced nausea/vomiting during their first cycle of treatment failed to avoid the side effect at some point during the next three treatment cycles.
While chemotherapy-induced nausea/vomiting can be effectively treated in patients with breast cancer, there is potential for the common side effect to return, especially in those whom treatment for the condition did not work the first time it was administered, according to study results presented at the 2020 San Antonio Breast Cancer Symposium.
Although many previous studies have evaluated chemotherapy-induced nausea/vomiting prevention strategies, Dr. Rudolph Navari noted there is limited research when it comes to subsequent bouts of the side effect.
“We sought to evaluate individual patients’ risk for repeat (chemotherapy-induced nausea/vomiting),” Navari, of the World Health Organization Cancer Care Program, said, explaining that this study was assessing how chemotherapy-induced nausea/vomiting risk changes with each chemotherapy cycle for patients with breast cancer.
Navari and colleagues collected data from a prospective, four-cycle chemotherapy-induced nausea/vomiting prophylaxis trial involving Akynzeo (netupitant/palonosetron) plus the steroid dexamethasone for patients with breast cancer who were receiving anthracycline and cyclophosphamide chemotherapy. A post-hoc analysis was also performed on a 2006 trial evaluating ondansetron plus aprepitant.
When patients did not experience chemotherapy-induced nausea/vomiting — defined as vomiting or the use of rescue medication within five days after chemotherapy — they were deemed to have a complete response. Other patients were deemed to have failed chemotherapy-induced nausea/vomiting prophylaxis treatment.
Of 402 patients who received 1,299 cycles of anthracycline and cyclophosphamide chemotherapy, 75.4% had a complete response to nausea and vomiting prevention drugs. Over the course of four cycles of chemotherapy, there were 253 chemotherapy-induced nausea/vomiting prophylaxis treatment failures. However, of the 303 patients who had a complete response to nausea and vomiting prevention therapy in the first cycle of chemotherapy, most (between 93% and 98%) achieved a complete response in subsequent cycles.
Among those who failed nausea and vomiting prevention therapy during the first cycle of chemotherapy, subsequent failure rates were higher, at 49.8% failing at some point between cycles 2 through 4.
Of 433 patients who received 1,537 cycles of ondansetron plus aprepitant in the 2006 trial, nearly half (49.2%) of patients experienced anti-nausea and vomiting treatment failure during the first cycle of therapy, and 46.7% failed at any point between the first four cycles.
As also seen in the group who received Akynzeo plus dexamethasone, patients who had a complete response during the first cycle had an increased chance (between 80.5% and 92.7%) of complete response in later cycles. Similarly, patients who had failed anti-nausea or vomiting therapy in the first cycle also had an increased chance (between 72.2% and 74.8%) of failure in subsequent cycles as well.
“Patients with treatment failure in cycle one did face a higher repeat failure rate,” concluded Navari. “These findings strongly suggest an individual patient with chemotherapy-induced nausea/vomiting on cycle one predict (chemotherapy-induced nausea/vomiting) in subsequent cycles.”
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