Time Toxicity of Endocrine-based Oral CDK4/6 Inhibitor Therapies

Abstract

Adjuvant endocrine therapy with CDK4/6 inhibitors necessitates regular visits, lab assessments and side effect management, currently conducted primarily at breast cancer centers in Germany. This retrospective analysis estimates the potential travel distances, times and CO₂ emissions associated with centralized therapy management of adjuvant CDK 4/6 inhibitor application.
Eligible patients for ribociclib or abemaciclib therapy were retrospectively identified from 5053 early breast cancer cases at the university hospitals of Ulm, Lübeck and Tübingen, using the monarchE and NATALEE criteria. Travel times were calculated assuming 24 visits over three years for ribociclib and 18 visits over two years for abemaciclib.
Of the HR+/HER2− cohort, 1432 (38%) were potentially eligible for adjuvant CDK4/6 inhibitors, with 1080 patients included, based on available postal codes. Median travel distances and times for Ribociclib (3 years) were 1200 km (24.0 hours driving; 176.0 kg CO₂ emissions; 50.4 hours by public transport; 72.0 kg CO₂ emissions) and 900 km (18.0 hours driving; 132.3 kg CO₂ emissions; 37.8 hours by public transport; 54.0 kg CO₂ emissions) for abemaciclib (2 years).
Despite its retrospective limitations, this analysis provides valuable insight into the impact of centralized care on travel time and CO₂ emissions for oral cancer therapies in Germany. As the use of oral therapies increases, clinicians, patients, policymakers and the pharmaceutical industry should jointly develop strategies to optimize the safety, feasibility, and efficacy of oral therapies.

Zusammenfassung

Die kombinierte adjuvante endokrine Therapie mit einem CDK4/6-Inhibitor erfordert regelmäßige Klinikbesuche und Laboruntersuchungen zur Therapiekontrolle und zum Nebenwirkungsmanagement. Derzeit wird das Therapiemonitoring in Deutschland überwiegend „zentralisiert“ an Brustkrebszentren durchgeführt. Diese Arbeit analysiert retrospektiv die potenziellen Fahrtstrecken, Fahrzeiten und CO₂-Emissionen, die mit einem zentralisierten Therapiemanagement der oralen adjuvanten CDK4/6-Inhibitor-Therapien verbunden sind.
Zu diesem Zweck wurden 5053 Fälle mit primärem frühem Mammakarzinom aus den Brustkrebszentren Ulm, Tübingen und Lübeck retrospektiv hinsichtlich einer potenziellen Indikation für Ribociclib oder Abemaciclib gemäß den Einschlusskriterien der monarchE- und NATALEE-Studien analysiert. Die mit der Therapie verbundenen Fahrtstrecken, Fahrzeiten und CO₂-Emissionen wurden anschließend kalkuliert.
Insgesamt erfüllten 1432 Patientinnen (37,9% der HR+/HER2− Kohorte) anhand klinisch-pathologischer Risikofaktoren die Kriterien für eine adjuvante CDK4/6-Inhibitor-Therapie. Für 1080 Patientinnen lagen Adressdaten vor, sodass sie in die Analyse eingeschlossen werden konnten. Die kumulative mediane Fahrtstrecke und -zeit betrug für die 3-jährige Ribociclib-Therapie 1200 km mit 24,0 Stunden Fahrzeit per Pkw (176,0 kg CO₂-Emissionen) beziehungsweise 50,4 Stunden mit öffentlichen Verkehrsmitteln (72,0 kg CO₂-Emissionen). Für die 2-jährige Abemaciclib-Therapie ergaben sich 900 km Fahrstrecke mit 18,0 Stunden Fahrzeit per Pkw (132,3 kg CO₂) beziehungsweise 37,8 Stunden mit öffentlichen Verkehrsmitteln (54,0 kg CO₂).
Trotz der Limitationen einer retrospektiven Auswertung liefert diese Analyse wertvolle Einblicke in die zeitliche Belastung und die ökologischen Auswirkungen einer zentralisierten Versorgung bei oralen Krebstherapien in Deutschland. Angesichts der zunehmenden Bedeutung oraler Therapien sollten Ärztinnen und Ärzte, Patientinnen und Patienten, politische Entscheidungsträger und die pharmazeutische Industrie gemeinsam Strategien entwickeln, um Machbarkeit und Praktikabilität dieser Behandlungsformen weiter zu optimieren.

Keywords

oncology - breast cancer - systemic therapy - CDK 4/6 inhibitors - oral cancer therapy - time toxicity

Schlüsselwörter

Onkologie - Brustkrebs - systemische Therapie - CDK4/6-Inhibitoren - orale Krebstherapie - zeitliche Belastungen

Publication History

Received: 12 July 2025

Accepted after revision: 05 October 2025

Article published online:
03 November 2025

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