Mismatch repair protein MSH2, cytokeratin 18 and cytokeratin 20 expression: clinicopathological correlation and prognostic value in colorectal cancer patients

BACKGROUND/AIMS: The survival of patients with colorectal cancer has not varied appreciably in recent years. The knowledge that genetic factors and disruption in apoptosis could play a role in the etiology and prognosis of patients with sporadic colorectal cancer has opened up new lines of research. We have studied a group of patients with colorectal cancer and the possible influence on the prognosis of immunohistochemical MSH2, M30 cytodeath and cytokeratin 20 expression. METHODOLOGY: Forty-nine consecutive patients with unselected colorectal cancer treated by resection and with a minimum follow-up period of 5 years. Tumor specimens were evaluated by an inmunohistochemical method for MSH2, cytokeratin 18 (M30 cytodeath) and cytokeratin 20 expression and correlated with epidemiological, clinicopathological and survival data. RESULTS: Thirty-four patients were resected with curative intention. At the end of the follow-up period, 25 (51%) had died, the majority (21) in relation to tumor progression, the overall median survival period being 47.9 months (95% CI = 27-86.6). Only vascular invasion, (lower median values), (p = 0.04) was related to MSH2 expression and tumor stage (p = 0.02) with cytokeratin 20. Patients' survival was related to tumoral stage (p = 0.04) and vascular invasion (p = 0.002). MSH2 expression, apoptosis (M30 cytodeath) and cytokeratin 20 staining did not influence the prognosis of patients. CONCLUSIONS: A change in the percentage of tumoral staining cells for MSH2, M30 cytodeath and cytokeratin 20 is frequent in patients with colorectal cancer. Only vascular invasion was correlated with MSH2 expression and stage of disease with cytokeratyn 20. Survival was related to TNM stage and vascular invasion, but not to MSH2, M30 cytodeath or cytokeratin 20 expressions.