Olanzapine Use and Vomiting Incidence in Chemotherapy-receiving Patients With Cervical Cancer: Multicenter Post Hoc...

Cisplatin administered at a dose of 40 mg/m² in concurrent chemoradiotherapy (CCRT) for cervical cancer is classified as highly emetogenic chemotherapy (HEC), in which the concomitant use of olanzapine is recommended. However, in Japan, the clinical use of olanzapine remains limited owing to pharmacokinetic concerns and contraindications. We aimed to clarify the real-world patterns of olanzapine use and its association with vomiting incidence in patients with cervical cancer undergoing CCRT.

This post hoc analysis used data from a multicenter collaborative study of 961 patients with cervical cancer who received CCRT between January 2016 and March 2024. Patient characteristics and antiemetic use, including olanzapine and its dosage, were recorded. Vomiting within six days after the first cisplatin administration was evaluated. Time to vomiting onset was analyzed using Kaplan-Meier methods and multivariate Cox proportional hazards models.

Olanzapine was used in 6.6% overall and 10.6% after guideline revision, indicating limited adoption. Users were younger (median age 52 vs. 56 years) and more frequently received aprepitant and palonosetron. Vomiting incidence was 6.3% vs. 7.6% in users and non-users, with no significant difference, and time to vomiting onset did not differ. Multivariate analysis adjusted for age, neurokinin 1 receptor antagonist use, type of 5-hydroxytryptamine type 3 receptor antagonist, smoking history, and alcohol consumption history showed no significant difference. Among stage IV patients, olanzapine <5 mg/day was more common.

Olanzapine use in patients with cervical cancer undergoing CCRT remained limited and was selectively prescribed to younger high-risk patients. No significant difference in vomiting control was observed, suggesting patient selection bias may have influenced characteristics.