Prognostic Value of Tumour Size in Colon Cancer – Smaller is Better?

Abstract Background: The prognostic value of tumour size in colon cancer remains controversial. This study aimed to reveal the correlation between tumour size and prognosis of colon cancer.Methods: A total of 498 patients with colon cancer were included in this study. The correlation of tumour size with prognosis, mismatch repair status and other clinicopathological characteristics as well as tumour microenvironment was analysed.Results: For stage IIA microsatellite stable (MSS) colon cancer, tumours sized <3.5 cm and ≥5 cm were associated with a poorer disease free survival (DFS) compared with tumours sized between 3.5 and 5 cm (p=0.002). Small tumour size (HR=5.098, p=0.001) and large tumour size (HR=2.749, p=0.029) were found to be independent prognostic factors for stage IIA MSS colon cancer. Moreover, high expression of transgelin (TAGLN), a marker of cancer-associated fibroblasts (CAFs), was found to be an independent prognostic factor for poorer DFS (HR=9.651, p=0.009), which was also associated with smaller tumour size (p=0.027).Conclusion: Small (<3.5 cm) and large (≥5 cm) tumour sizes are associated with decreased DFS in stage IIA MSS colon cancer. Enrichment of TAGLN+ CAFs is associated with decreased DFS and small tumour size.