3668 - Patient Demographics and Management Landscape of Metastatic Colorectal Cancer in the Third Line Setting: real-world data in an Australian Population

Background

Colorectal cancer is the third most common cancer and second leading cause of cancer mortality in Australia. In patients with metastatic disease who have progressed after two lines of therapies, survival is 4-6 months with best supportive care, and 6-8 months with newer agents. This retrospective analysis aims to explore real-world treatment landscape of metastatic colorectal cancer in the third-line setting.

Methods

We analysed the TRACC (Treatment of Recurrent and Advanced Colorectal Cancer) registry database from 2009 onwards. Patients treated with palliative intent who have progressed after two lines of therapies were included. One treatment line is defined as any combination of systemic therapy given until progression. Patient demographics, third line choices and survival outcomes were examined.

Results

A total of 2831 patients had metastatic colorectal cancer, and of these, 23% (642 patients) met study criteria. 48% (306 patients) of study population proceeded to receive third line therapy. A large proportion of patients had received doublet chemotherapy in both first and second lines. Median age was 62 years and ECOG at the start of third line was 1-2 (75%). A fluoropyrimidine-based doublet with oxaliplatin or irinotecan was the most common treatment choice in 42%. Other treatments included mono-chemotherapy +/- biological agent (23%), EGFR inhibitor alone (22%), EGFR inhibitor with doublet chemotherapy (6%), trifluridine/tipiracil (4%), regorafenib (2%), immunotherapy (<1%), clinical trials (1%), others (<1%). Median duration on third-line treatment was 2.4 months (0.07 – 40). Median overall survival (OS) was 8.7 months (0.4 – 58).

Conclusions

In a real-world Australian population, 11% of all patients diagnosed with metastatic disease received third line treatment, with commonest regimens being doublet chemotherapy. This treatment landscape may change with the approval of new drugs. Overall survival in these patients is comparable to third line trials on these agents. Analyses are underway to further characterise the breakdown of treatment regimens in all three lines in these patients, and assess survival with rechallenge regimens.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.