As part of a search for predictive indicators of the prognosis of advanced
colon cancers, the significance of
PCNA and
AgNORs in terms of grading of
biological malignancy was investigated. In 47 selected cases, which had been sufficiently followed up for the present study,
PCNA labeling indices (
PCNA LI) were 20.96 +/- 8.87 and 54.78 +/- 11.35 in normal colonic mucosa and
colon cancer, respectively. With survival durations of more or less than 5 years, the
PCNA LI values were 57.27 +/- 9.56 and 48.27 +/- 13.37, thus, suggesting a decrease with poor prognosis.
PCNA LI decreased in proportion to the depth of
cancer invasion and the progression of stage. In all of these cases statistically significant differences were apparent, whereas other histopathologic factors did not demonstrate any correlation. Numbers of
AgNORs were 1.31 +/- 0.10 and 2.43 +/- 0.39 in normal tissues and
cancers, the differences being statistically significant. However, no correlation with prognosis or histopathologic factors was noted for this parameter. In conclusion, our data suggest that
PCNA LI might be an important predictive
indicator of prognosis in advanced
colon cancer. In contrast,
AgNORs are of no assistance with this problem, although use of both or combination might facilitate differentiation between benign and malignant lesions.