Individual Abstract within a Delegate Designed Symposium Clinical Oncology Society of Australia Annual Scientific Meeting 2023

Treatment Patterns in Victoria Across Three Cancers: An In-Depth Analysis (#129)

Fanny Franchini 1 , Jennifer Soon 1 2 , Karen Trapani 1 , Benjamin Daniels 3 , Marliese Alexander 2 , Yat Hang To 2 4 , Sophy Athan 1 , Grant McArthur 1 2 , Ben Solomon 2 , Peter Gibbs 2 4 , Sallie Pearson 3 , Maarten IJzerman 1 5
  1. University of Melbourne, Melbourne, VICTORIA, Australia
  2. Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia
  3. University of New South Wales, Sydney, New South Wales, Australia
  4. Walter and Eliza Hall Research Institute, Melbourne, Victoria, Australia
  5. Erasmus School of Health Policy and Management, Rotterdam, Netherlands

Aims
This study aims to conduct comprehensive analyses of initial and subsequent treatment lines (TL) among individuals diagnosed with melanoma (MEL), colorectal (CRC), and non-small cell lung (NSCLC) cancers in Victoria from 2010 to 2019. This scope of work has not been performed before in population-based cancer studies. For illustration, we primarily focus on CRC results.

Methods
We examined treatment data from Victorian CRC patients diagnosed between 2010-2019, linking the Victorian Cancer Registry to administrative hospital data, Medicare Benefits Scheme (MBS), and Pharmaceutical Benefits Scheme (PBS) records. Systemic therapies were categorised by their mechanisms of action, and treatment data were classified into corresponding TLs to map the entire care trajectory. Analyses included survival and treatment utilisation, unveiling current oncology practice in Victoria and associated patient outcomes.

Results
We incorporated data from 90,522 patients diagnosed with CRC (41.3%), MEL (30%), and NSCLC (28.7%). Among the 37,605 CRC patients, 21.7% were diagnosed at stage I, 22.7% at stage II, 22% at stage III, and 17.7% at stage IV. In patients with metastatic disease, median overall survival was 20 months. A Cox proportional hazard model, accounting for gender, diagnosis year, age, and birth region, found no significant survival difference between genders. However, patients diagnosed between 2016–2019 showed improved survival (HR 0.76, 95% CI: 0.71-0.82). Treatment patterns were visualised using Sankey and sunburst diagrams, underscoring chemotherapy's critical role in CRC management. Among stage IV patients, 66% received chemotherapy, and 42% a VEGF-inhibitor. Oxaliplatin, fluorouracil, and bevacizumab were the most prescribed drugs.

Conclusion
Leveraging PRIMCAT’s unique linked dataset, this study offers insights into treatment patterns of nominated cancers in Victoria. Our study examines the common treatment sequences and their relationship with patient outcomes, thereby filling a significant knowledge gap in contemporary cancer reporting. Our findings lay the groundwork for modelling work that forecasts the number of eligible patients. These results have substantial implications for health policy and clinical practices.