Pharmacist-Led Services in Outpatient Oncology – the Evidence

Introduction

Oncology pharmacy is a burgeoning specialty area which has been evolving quickly over the last three decades. Oncology pharmacists support safe preparation and administration of oncolytic drugs, conduct patient assessments, educate patients on toxicities, and monitor therapy so that it can be optimized for individual patients. Increasingly, these activities are being done utilizing a more formal framework, where pharmacists run specific clinics and receive referrals from other healthcare providers. There is a wealth of data which has been published in this area, particularly in the past few years, looking at the impact of clinical pharmacy services on various outcomes in the oncology setting. This document is intended as a short summary of the available evidence supporting the efficacy of these services.

Methodology

A search of the literature was conducted looking at the evidence for oncology pharmacy services with the help of an academic librarian including abstracts published up to 2024. PubMed and EMBASE were searched utilizing a formal search strategy and the articles found were reviewed independently by two separate reviewers. A summary of the full list of final articles is available in Appendix 1. For convenience, we have chosen to highlight several strong articles that were found in both the Canadian and international settings.

Results

A literature search for evidence of oncology pharmacy services identified 138 published abstracts from 22 different countries (Figure 1). Abstracts were most commonly published in the USA (30%), Japan (17%) or Canada (10%). Abstracts were identified from 1999 to 2024 with 83% published from 2016 to 2024 (Figure 2). A summary of abstracts is provided in Appendix 1.

Figure 1. Published abstracts that describe oncology pharmacy services from 1999-2024, grouped by country (n = 138).

Figure 2. Published abstracts that describe oncology pharmacy services by publication year (n = 138).

Canadian Abstracts

Abstracts on services provided by Canadian pharmacists are summarized in Table 1.

As is evident from the Canadian data, there are multiple services that have been implemented across the country spanning a variety of settings. Pharmacist-led clinics encompassing patient review, assessment, and follow-up have been instituted for breast cancer, pediatric hematology/oncology, immunotherapy, and more generally in ambulatory oncology care and oral anticancer therapy areas. The published article by Hynes et al does not describe a clinic per se, however it is instructive that pharmacists in Alberta are taking the initiative to prescribe independently in ambulatory oncology clinics and in many cases are ordering new medications. A wide range of outcomes has been achieved through these initiatives, including improved time on therapy, relieving time pressure on medical oncologists, improved patient adherence to therapy, and an increase in the number of drug-related problems addressed.

International Abstracts

A summary of select international abstracts is presented below in Table 2.

From the international data, it is clear that many aspects of oncology care can be improved with pharmacist assessment, follow-up, and intervention. The selected trials were done in a wide range of cancer patients, including those with GU cancers, patients with head and neck cancers, oral anti-cancer agent users, patients with lung cancer, and general oncology patients. Trials showed multiple improved outcomes, including improving patient adherence, reducing toxicity, timely interventions, improved patient understanding of treatment, and reductions in treatment discontinuation, hospitalization, and death. This highlights the increasing importance of oncology pharmacists within multidisciplinary teams.

Summary and Conclusion

The role of oncology pharmacists in outpatient settings has expanded significantly over the past three decades, evolving from primarily supporting drug preparation and administration to providing direct patient care through pharmacist-led clinics and interventions. This review summarizes the growing body of evidence demonstrating the impact of these services on patient outcomes in both Canadian and international settings.

The Canadian data highlights the successful integration of pharmacists into ambulatory oncology care, with documented improvements in medication reconciliation, adherence monitoring, toxicity management, and prescribing practices. Pharmacist-led clinics have been implemented for specific cancer types, such as breast cancer and pediatric oncology, as well as for managing immunotherapy-related adverse events. These services have led to increased clinician efficiency, reduced physician workload, and improved medication safety. Furthermore, independent pharmacist prescribing in Alberta demonstrates an advanced scope of practice, allowing pharmacists to take on a more active role in optimizing therapy.

International studies further support the effectiveness of pharmacist interventions in oncology care. Randomized controlled trials and cohort studies from 22 countries provide compelling evidence that pharmacist-led programs improve adherence, reduce toxicity, enhance patient education, and contribute to better treatment outcomes. These studies demonstrate a reduction in drug-related problems, improved management of side effects, and lower rates of treatment discontinuation, hospitalization, and mortality.

Overall, the findings reinforce the critical role of oncology pharmacists within multidisciplinary teams, ensuring safe and effective cancer treatment. The growing body of literature supports continued expansion of pharmacist-led services, with potential benefits including cost savings, improved patient-centered care, and optimized therapy management. As oncology treatment becomes increasingly complex, formalizing and expanding pharmacist-led interventions will be essential in enhancing patient outcomes and healthcare efficiency. Future research should continue to explore innovative models of pharmacist involvement, including telepharmacy, precision oncology, and advanced prescribing roles, to further enhance the impact of oncology pharmacy services.