Patient Risk Factors May Guide CINV Antiemesis Treatment

Risk modelling based on patient characteristics may help clinicians choose an antiemetic regimen before chemotherapy begins

medwireNews: Risk model-guided (RMG) antiemetic use may help tailor prophylactic treatment against chemotherapy-induced nausea and vomiting (CINV) for women with early stage breast cancer, Canadian researchers believe.

Mark Clemons, from The Ottawa Hospital Cancer Center in Ontario, and co-workers used previously validated models – based on factors such as age, history of motion and pregnancy-related sickness and the individual’s expectations of chemotherapy – to classify patients as low- or high-risk for nausea and vomiting.

“These models have good predictive accuracy, and patients classified as high risk are 3 to 4 times more likely to develop acute as well as delayed CINV compared with patients deemed to be at low risk”, they explain in JAMA Oncology.

In all, 154 patients were randomly assigned to receive RMG treatment over 490 cycles of treatment; low-risk patients were given dexamethasone plus a 5-HT3 antagonist, while high-risk patients also received the neurokinin (NK)1 receptor antagonist aprepitant and, where necessary, the antipsychotic olanzapine. The remaining 170 patients were given their physician’s choice treatment over 558 cycles.

Patients in the RMG group were significantly more likely than patients given their physician’s choice of treatment to be free from nausea (53.7 vs 41.6%) and vomiting (91.8 vs 82.2%) in the first 24 hours after each cycle. RMG therapy was also associated with a significantly higher rate of freedom from symptoms 2 to 5 days after treatment for both nausea (39.6 vs 30.7%) and vomiting (87.1 vs 78.0%).

“This study demonstrated that our CINV risk prediction models are easy to use in clinic and can lead to an improvement in CINV control and patient [quality of life]”, the authors conclude. “Future directions include the application of the CINV models to other disease types and their direct incorporation into chemotherapy ordering systems.”

However, the authors of an accompanying comment note that the results favouring RMG therapy were “not surprising” as 81.2% of this treatment group were classified as high risk and received aprepitant in cycle 1, whereas only 4.1% of those given physician’s choice therapy received aprepitant.

“For practical purposes, this study was a test of guideline vs nonguideline therapy”, explain David Warr, from the University of Toronto in Ontario, Canada, and co-authors.

Furthermore, they question whether the risk model accurately identified a true low-risk patient group, noting that supplementary data showed that around 95% of low-risk patients given only dexamethasone and a 5-HT3 antagonist in the first cycle were given a NK1 receptor antagonist in the subsequent cycle.

While the commentators say there is “room for research to refine guideline recommendations”, they add the caveat that any such RMG approach must be practical in the clinic.

“Even if one can identify an unusually high- or low-risk group for emesis based on patient factors, would clinicians spend the time to elicit this information, calculate the risk of emesis, and change the antiemetics that may be prespecified on paper or electronic orders?”, they query.

“Unless this is a single, easily ascertained risk factor such as sex, the answer is “probably not.””

David Warr et al. therefore conclude: “For the moment, choosing antiemetics for cycle 1 based on chemotherapy emetogenicity rather than patient risk factors is the gold standard.”

References

Clemons M, Bouganim N, Smith S, et al. Risk model-guided anti-emetic prophylaxis vs physician’s choice in patients receiving chemotherapy for early-stage breast cancer. JAMA Oncol 2015; Advance online publication 12 November.doi:10.1001/jamaoncol.2015.3730

Warr D, DeAngelis C, Chow E. Can patient risk factors outperform antiemetic guidelines? Choosing wisely.JAMA Oncol 2015; Advance online publication 12 November.doi:10.1001/jamaoncol.2015.3757.

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