Individual Abstract within a Delegate Designed Symposium Clinical Oncology Society of Australia Annual Scientific Meeting 2024

Do patient characteristics influence the first-line chemotherapy regimen for adenocarcinoma of the pancreas?  (#142)

Michael Allen 1 2 , Bryan Chan 3 4 , Euan Walpole 2 5 6 , Jon Clark 6 , Danny Youlden 6 , Pardeep Dhanda 6 , Nathan Dunn 6 , Danica Cossio 6
  1. Sunshine Coast University Hospital, Birtinya, Queensland, Australia
  2. Queensland Cancer Control Safety and Quality Partnership, Systemic Therapy subcommittee, Cancer Alliance Queensland, Brisbane, Queensland, Australia
  3. Sunshine Coast Hospital and Health Service, Birtinya, Queensland, Australia
  4. School of Medicine, University of Queensland, Brisbane, Queensland, Australia
  5. Princess Alexandra Hospital, Brisbane, Queensland, Australia
  6. Cancer Alliance Queensland, Brisbane, Queensland, Australia

Aims: Most people with pancreatic cancer are diagnosed at a late stage when surgery is not feasible. Three main chemotherapy regimens are in use for this group: FOLFIRINOX including Oxaliplatin, Irinotecan and Fluorouracil (OIF); Gemcitabine with nab-Paclitaxel (GP); and Gemcitabine (Gem) alone. These regimens offer different levels of complexity, effectiveness and tolerability. Our aim was to investigate whether any key demographic characteristics influence the first-line chemotherapy received. 

 

Methods: Data was obtained from the population-based Queensland Oncology Repository, which brings together clinical, treatment and demographic information from multiple sources. The study cohort comprised Queensland residents diagnosed with pancreatic adenocarcinoma between 2018-2022 and who did not have curative surgery and received OIF, GP or Gem. The likelihood of receiving a particular chemotherapy regimen was determined by fitting multivariable Poisson models, adjusted for patient, clinical and facility characteristics. Three-year unadjusted all-cause survival was assessed using Kaplan-Meier analysis. 

 

Results: Of the 792 people in the study cohort, GP was the most common type of first-line chemotherapy (58%), followed by OIF (27%) and Gem (15%). People aged 65 years and over (p<0.001), those from areas with middle or disadvantaged socio-economic status (p=0.009), and people diagnosed with stage IV disease (p=0.01) had a lower likelihood of receiving OIF. There was also possible evidence that First Nations’ people were less likely to be treated with OIF (p=0.06). Three-year survival for OIF was 10% (95% CI 6%-15%) compared to 8% (4%-14%) for Gem and 3% (1%-5%) for GP (p<0.001). 

 

Conclusion: Equity of treatment for pancreatic cancer patients is crucial for this aggressive disease, ensuring that all individuals achieve optimal outcomes. Although survival was very poor within the palliative care setting irrespective of the chemotherapy regimen received, our results show that people from lower socio-economic areas and First Nations people were less likely to receive more complex chemotherapy.