Poster Presentation Clinical Oncology Society of Australia Annual Scientific Meeting 2022

Pharmacogenetic testing for fluoropyrimidine (DPYD) and irinotecan (UGT1A1) based chemotherapies in routine clinical care: perspectives of medical oncologists and oncology pharmacists (#201)

Sarah Glewis 1 2 , Senthil Lingaratnam 1 2 , Mei Krishnasamy 2 3 4 , Jennifer Martin 5 , Jeanne Tie 2 6 7 , Marliese Alexander 1 2 , Michael Michael 2 6
  1. Department of Pharmacy, Peter MacCallum Cancer Centre, Melbourne, Vic, Australia
  2. Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville
  3. Academic Nursing Unit, Peter MacCallum Cancer Centre, Melbourne, Vic, Australia
  4. VCCC Alliance, Parkville, Vic, Australia
  5. School of Medicine and Public Health, University of Newcastle, Callaghan , NSW, Australia
  6. Department of Medical Oncology, Peter MacCallum Cancer Centre, Melbourne, Vic, Australia
  7. Personalised Oncology Division, Walter and Eliza Hall Institute of Medical Research, Parkville, Vic, Australia

Background and Aims: Despite international guidelines and robust evidence to support pharmacogenetic (PGx) testing prior to administration of fluoropyrimidine (FP) and irinotecan-based chemotherapy, integration into practice has been limited. This study aimed to explore clinicians’ views and experiences of pre-treatment DPYD and UGT1A1 gene testing and barriers to and enablers of routine clinical implementation.

Methods

A study-specific survey consisting of 17 questions was emailed (01 February-12 April 2022) to health care professionals (HCPs) from Clinical Oncology Society of Australia (COSA), Medical Oncology Group of Australia (MOGA), and the International Society of Oncology Pharmacy Practitioners (ISOPP). Data from survey responses were collated and descriptive statistics were utilised to analyse and report outcomes.

Results

One hundred and fifty-six HCPs responded (78% medical oncologists, 22% oncology pharmacists). Only 21% reported routinely test for pre-treatment DPYD and 1% for UGT1A1. For patients having treatments with curative or palliative intent, clinicians reported intent to implement genotype-guided dosing by reducing FP dose for people classified as DPYD intermediate metabolisers (79% curative intent versus 94% palliative intent), avoiding FP for DPYD poor metabolisers (68% curative intent versus 90% palliative intent), and reducing irinotecan dose for UGT1A1 poor metabolisers in palliative setting (84%). Barriers to implementation included: lack of financial reimbursements (82%) and perceived lengthy test turnaround time (76%). Enablers to implementation included: a dedicated program coordinator i.e., PGx pharmacist (74%), availability of resources for education/training (74%) and access to centralised testing services (74%).

Conclusion

PGx testing prior to the administration of FP and irinotecan is not routinely practiced despite robust evidence demonstrating its impact on clinical decision making in both the curative and palliative treatment settings. Research data, education, and implementation studies may overcome clinicians’ hesitancy to reduce dosing for curative intent treatments and barriers to routine clinical implementation.