Liver metastases from colon and rectal cancer in terms of differences in their clinical parameters

Summary

Introduction:
From the clinical point of view, rectal cancer and colon cancer are clearly different nosological units in their progress and treatment. The aim of this study was to analyse and clarify the differences between the behaviour of liver metastases from colon and rectal cancer. The study of these factors is important for determining an accurate prognosis and indication of the most effective surgical therapy and oncologic treatment of colon and rectal cancer as a systemic disease.

Method:
223 patients with metastatic disease of colorectal carcinoma operated at the Department of Surgery, University Hospital in Pilsen between January 1, 2006 and January 31, 2012 were included in our study. The group of patients comprised 145 men (65%) and 117 women (35%). 275 operations were performed. Resection was done in 177 patients and radiofrequency ablation (RFA) in the total of 98 cases. Our sample was divided into 3 categories according to the location of the primary tumor to C (colon), comprising 58 patients, S (c. sigmoideum) in 61 patients, and R (rectum), comprising 101 patients. Significance analysis of the studied factors (age, gender, staging [TNM classification], grading, presence of mucinous carcinoma, type of operation) was performed using ANOVA test. Overall survival (OS), disease-free interval (DFI) or no evidence of disease (NED) were estimated using Kaplan-Meier curves, which were compared with the log-rank and Wilcoxon tests.

Results:
As regards the comparison of primary origin of colorectal metastases in liver regardless of their treatment (resection and RFA), our study indicated that rectal liver metastases showed a significantly earlier recurrence than colon liver metastases (shorter NED/DFI). Among other factors, a locally advanced finding, further R2 resection of liver metastases and positivity of lymph node metastases were statistically significant for the prognosis of an early recurrence of the primary colon and sigmoid tumor. Furthermore, we proved that in patients with primary rectal carcinoma, DFI (after the resection of liver metastases) was not influenced by the positivity of lymph node metastases of primary tumor or locally advanced primary tumor. The other factors studied (time from diagnosis of organ metastases to primary operation, grading, sex or age) were not shown to be statistically significant for the prognosis of OS and DFI (colorectal cancer in total).

Conclusion:
As proven by our study, rectal cancer and colon cancer are two different nosological units with specific prognostic factors with respect to their liver metastases. These differences have not been fully understood yet and require further exploration and classification based not only on histopathological, immunohistochemical and clinical factors, but also on molecular biological parameters.

Key words:
colon carcinoma metastases − rectal carcinoma metastases − prognostic factors − overall survival – liver metastases