CORRELATION AMONG [H-3] THYMIDINE, FLOW-CYTOMETRY AND PROLIFERATING CELL NUCLEAR ANTIGEN INDEXES IN COLORECTAL TUMORS

In colorectal cancer and other tumors, proliferating cell nuclear anti gen (PCNA) has been found to be a useful marker in immunohistochemical studies of cell proliferation, The presence of a correlation among PC NA labeling index (PCNA LI) and values of cell proliferation expressed by [H-3]thymidine labeling index (TLI) and flow cytometry (FC), the m ost common techniques used in the evaluation of proliferative activity in colorectal cancer were studied. In 50 operable colorectal cancer p atients, TLI, PCNA LI and determination of S-phase fraction by FC were carried out in order to evaluate the correlation among these three in dices. A good correlation was obtained between PCNA LI and both TLI (r =0.667; P=0.0001) and percent of cells in S-phase as determined by FC (r=0.819; P=0.0001). It is concluded that PCNA immunohistochemistry ca n be a reliable marker of the proliferative activity in colorectal rum ours. Furthermore, because of its technical simplicity and lower cost it can be more advantageous than TLI or FC.