Long-term outcomes of locally or radically resected T1 colorectal cancer

Aim Little is known about the long-term outcome of T1 colorectal cancer (CRC) following curative resection. The present study addressed determine the long-term outcome of locally or radically resected T1 CRCs. Method A total of 430 patients with T1 CRC who underwent local or radical resection. The unfavorable histologic factors were defined as positive resection margin, deep submucosal invasion, vascular invasion, grade 3 and budding. The patients were classified as low-risk (unfavorable histologic factor negative, n=65) or high-risk (unfavorable histologic factor positive, n=365). Results Over a median follow-up of 78.4 months, disease recurred in 16 (3.7%) patients in the high-risk group, and no recurrence in the low-risk group. Resection type and vascular invasion were significantly associated with recurrence. In the vascular invasion (+) high-risk group, both 5-year disease-free survival rate and 5-year overall survival rate were significantly associated with resection type (radical 94.6%, local 43.8%, P <0.001 and radical 99.1%, local 66.7%, P <0.001). In the vascular invasion (-) high-risk group, 5-year disease-free survival rate was also significantly associated with resection type (radical 98.9%, local 84.7%, P = 0.001). However, 5-year overall survival rate was not associated with resection type (radical 98.9%, local 95.2%, P =0.816). Conclusion Local resection may be effective and oncologically safe in the low-risk T1 CRC. Although additional surgery should be recommended for the locally resected high-risk T1 CRC cases, intensive surveillance without additional surgery and timely salvage operation may offer another treatment option, if vascular invasion is negative. This article is protected by copyright. All rights reserved.