Risk Model-Guided Antiemetic Prophylaxis vs Physician's Choice in Patients Receiving Chemotherapy for Early-Stage Breast Cancer: A Randomized Clinical Trial.

Importance: Despite multiple patient-centered factors being associated with the risk of chemotherapy-induced nausea and vomiting (CINV), these factors are rarely considered when making antiemetic recommendations.

Objective: To compare risk model-guided (RMG) antiemetic prophylaxis with physician's choice (PC) in patients receiving chemotherapy for early-stage breast cancer.

Design, Setting, And Participants: A randomized clinical trial of 324 patients with early-stage breast cancer undergoing chemotherapy (cyclophosphamide and an anthracycline) for the first time at 2 specialty cancer care centers in Ottawa from April 10, 2012, to September 2, 2014. Patients were randomized to either the RMG arm (n = 154) or the PC control arm (n = 170). Prior to each cycle of chemotherapy patients in the RMG group were categorized as low or high risk for CINV, and their antiemetic treatments were adjusted accordingly.

Interventions: Patients considered to be at low risk received standard dexamethasone and a 5-HT3 antagonist, while those at high risk also received aprepitant with or without olanzapine, based on their risk level. The PC control group received antiemetic agents according to the treating physician's discretion.

Main Outcomes And Measures: The primary end points were control of both nausea and vomiting in the acute posttreatment period (first 24 hours after therapy) and in the delayed posttreatment period (days 2-5 after therapy).

Results: The total numbers of chemotherapy cycles delivered in the RMG and PC control groups were 497 and 551 respectively. In the acute period, significantly more patients in the RMG group reported no nausea (53.7% [95% CI, 49.2%-58.1%] vs 41.6% [95% CI, 37.4%-45.3%]; P < .001) and no vomiting (91.8% [95% CI, 89.0%-94.0%] vs 82.2% [95% CI, 78.8%-85.3%]; P < .001) compared with the PC control group. Similarly, significantly more patients in the RMG group reported no nausea (39.6% [95% CI, 35.3%-44.1%] vs 30.7% [95% CI, 26.8%-34.7%]; P = .01) and no vomiting (87.1% [95% CI, 83.8%-90.0%) vs 78.0% [95% CI, 74.3%-81.4%]; P < .001) in the delayed period respectively.

Conclusions And Relevance: In this trial, the RMG antiemetic prophylaxis led to improved control of acute and delayed CINV compared with physician's choice of therapy.

Trial Registration: clinicaltrials.gov Identifier: NCT01913990.