RESUMO
Background:Rectal cancer is a common malignant tumor of alimentary tract.It has been demonstrated that oxaliplatin-based neoadjuvant chemotherapy is effective for rectal cancer,however,its mechanism is not fully clarified.Aims:To explore the effect of neoadjuvant chemnotherapy with FOLFOX4 (folinic acid,fluorouracil,and oxaliplatin) on expressions of Ki-67,a proliferating cell-associated nuclear antigen,matrix metalloproteinase-2 (MMP-2),and Fas,a death receptor in cancerous tissue of patients with rectal cancer.Methods:A total of 104 cases of patients with histologically proven rectal cancer from Aug.2014 to Feb.2016 at Central Hospital of China National Petroleum Corporation were enrolled prospectively and randomly allocated into treatment group (n =58) and control group (n =46).Patients in treatment group finished 6 cycles of neoadjuvant chemotherapy with FOLFOX4 before surgery,and those in control group underwent surgery directly.Expressions of Ki-67,MMP-2 and Fas protein in cancerous tissue of surgical specimens were determined immunohistochemically.Results:Immunoreactivity of Ki-67 mainly located in the nucleus of rectal cancer cells,and those of MMP-2 and Fas mainly located in the cytoplasm.Expression rates of Ki-67 and MMP-2 were significantly lower in treatment group than in control group (41.4％ vs.80.4％,P ＜ 0.05;36.2％ vs.73.9％,P ＜ 0.05),while those of Fas was significantly higher in treatment group than in control group (62.1％ vs.32.6％,P ＜ 0.05).Conclusions:The therapeutic effect of neoadjuvant chemotherapy with FOLFOX4 on rectal cancer might be associated with the inhibition of proliferative,invasive and metastatic capacities and induction of apoptosis in cancer cells.