Abstract 324P
Background
Although declines in colon cancer mortality were found worldwide, there is limited evidence to explain which improvements in treatment and management of colon cancer have been responsible for improved survival in the last 20 years. This study evaluated the treatment trajectories and aimed to explore the reasons for the improvement in colon cancer survival.
Methods
A total of 8,532 newly diagnosed colon cancer patients were analyzed in the Yonsei Cancer Registry Database between Jan 1, 1995, and Dec 31, 2014. Five-year overall survival (OS) and treatment trajectories were analyzed. We evaluated the relative effects of screening and treatment improvement via modeling.
Results
Overall, 5-year OS was improved from 57.7% in 2000-2004 to 71.4% in 2015-2019. The relative contribution of 5-year OS improvement was 62.6% by colonoscopy screening and 37.4% by treatment improvement, respectively. We observed an improvement in stage distribution: the number of patients with stages 0-I colon cancer increased from 5.2% in 2000-2004 to 31.1% in 2015-2019, while stage IV colon cancer decreased from 32.3% in 2000-2004 to 21.9% in 2015-2019. Stage-specifically, 5-year OS in stage III was improved from 60.4% in 2000-2004 to 78.1% in 2015-2019, and 5-year OS in stage IV was improved from 14.2% in 2000-2004 to 22.8% in 2015-2019, albeit no trajectory improvement in stage I-II patients. Stage III patients (n=2,114) with adjuvant chemotherapy improved 5-year OS compared to patients without chemotherapy (hazard ratio [HR], 0.47; P<0.001). Among stage IV patients (n=1,941), liver metastasectomy (HR, 0.38; P<0.001), lung metastasectomy (HR, 0.42; P<0.001), resection of primary tumor (HR, 0.71; P<0.001), and palliative chemotherapy (HR, 0.85; P=0.006) were associated with improved survival.
Conclusions
With advances in early detection via colonoscopy screening and treatment improvement in stage III-IV, there were substantial survival improvements in colon cancer from 2000 to 2019. Additional mortality reductions can be achieved through more frequent targeted screening and novel therapeutic approaches.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
This study was supported in part by the National Research Foundation of Korea (NRF) grant funded by the Korean government (MSIT) (2022R1A2C4001879).
Disclosure
All authors have declared no conflicts of interest.