Survival after Curative Resection for Stage I Colorectal Mucinous Adenocarcinoma
Background: The prognostic value of the mucinous adenocarcinoma histotype on the early stages especially for stage I colorectal cancer (CRC) is still unclear. This study determined the clinicopathologic characteristics and long-term outcome of stage I colorectal mucinous adenocarcinomas (MAC). Methods: Among the total of 503 patients with stage I CRC (56 having MAC and 447 having non-MAC) who underwent radical resection, the correlation between clinicopathological factors and MAC was analyzed.
... MAC was analyzed. Multivariate analysis was performed to determine whether mucinous histotype itself was an independent prognostic impact in stage I patients. Results: MACs were observed more frequently located in the colon than rectum (p=0.046), more frequently displayed the microsatellite instability (MSI) phenotype (p=0.023) and had a greater frequency of T2 stage (p=0.001). The rate of recurrence was 13.5% and the cancer-specific mortality was 4.3% among all stage I CRC patients. There was no difference in disease-free survival and overall survival between MACs and non-MACs. On multivariate analysis, older age (p=0.030,hazard ratio: 2.62), rectal cancer (p=0.025, hazard ratio: 5.42), lymphovascular invasion (LVI) (p<0.001, hazard ratio: 9.74), and microsatellite stability (MSS) phenotypes (p=0.023, hazard ratio: 4.21) were independently associated to poor survival of stage I CRC. A high carcinoembryonic antigen (CEA) level (p=0.031, hazard ratio: 1.95), rectal cancer (p=0.045, hazard ratio: 1.64), LVI (p=0.002, hazard ratio: 3.95) and MSS phenotypes (p=0.012, hazard ratio: 2.98) were independently related to short disease-free survival of stage I CRC.Conclusions: Compared with non-MAC, MAC patients had more T2 patients and more MSI phenotypes in stage I CRC at presentation, but the mucinous histology is not a significant predictor of recurrence and prognosis in stage I CRC.