BackgroundThe role of tumor deposits (TDs) in TNM staging of colorectal cancer is controversial, especially the relationship with distant metastasis.PurposeThe aim of this study was to determine the effect of TDs on the survival of colorectal cancer and the occurrence of distant metastasis, and to determine whether TDs (+) patients behaved similarly to stage IV patients.MethodsRetrospective analysis of CRC patients from two large independent cohorts from the Surveillance Epidemiology and End

more »

... ults (SEER) database (n=58775) and the First Affiliated Hospital of Dalian Medical University (n=742).ResultsUnivariate logistic analyses revealed that TDs as an independent predictor of liver metastasis [p<0.001; odds ratio (OR): 5.738; 95% confidence interval (CI): 3.560-9.248] in the The First Affiliated Hospital of Dalian Medical University's patients. Meanwhile, TDs was also an independent predictor of isolated organ metastasis [p<0.001; odds ratio (OR): 3.028; 95% confidence interval (CI): 2.414 - 3.79; multiple organ metastases [p<0.001; odds ratio (OR): 4.778; 95% confidence interval (CI): 4.109 - 5.556]; isolated liver metastasis [p<0.001; odds ratio (OR): 4.395; 95% confidence interval (CI): 4.099 - 4.713] and isolated lung metastasis [p<0.001; odds ratio (OR): 5.738; 95% confidence interval (CI): 3.560-9.248] in the SEER database. Multivariate analyses suggested TDs were an independent poor prognostic factor for distant metastasis (p<0.001).ConclusionsOur results have shown that compared with patients with negative TDs, CRC patients with positive TDs are more likely to develop distant metastasis. Patients who categorized T4aN2bM0 TDs (+) and T4bN2M0 TDs (+) have similar prognosis as those with stage IV, and these patients should be classified as stage IV.