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6th ESACP Congress, Heidelberg, April 7-11, 1999 |
A038
Background: The grade of Ta,1 urinary bladder tumors has therapeutic
impact, but intra- and interobserver reproducibility is poor. Previous
studies have shown that morphometric analysis of mean nuclear area of value
for objective grading.
Objective: To analyse with single- and multivariate analysis whether
mitotic activity index (MAI), nuclear area features and Ki-67
immunoquantitation, have additional discriminative value to each other in
different grades of Ta,1 bladder tumors.
Material & Methods: 150 consecutive Ta,1 urinary bladder tumors have
been analysed. Duplicate blind assessment of grade was performed by three
independent observations in standard HE-paraffin sections, which were also
used for morphometric analysis. The QPRODIT 6.1 system (Leica, Cambridge, UK)
was used for morphometric analysis and immunoquantitation of Ki-67. Single
and multivariate analysis was applied to discriminate the different grades.
Results: In the learning set (n=17 grade 1, 30 grade 2, 28 grade 3) the
best discriminating features were MAI and Ki-67, and to a lesser degree
the mean of the area of the ten largest nuclei. With multivariate analysis,
all three features were included. The best discriminating features between
grade 1 and 2 were MNA-10 and MAI, and between grade 2 and 3 the MAI and
Ki-67. With these features, 93.6% of the original grade 1 and 2 cases were
correctly classified (3 of the grade 2 cases were classified as grade 1).
Of the grade 2 and 3 cases, 96.6 % was correctly classified (2 grade 3
cases were classified as grade 2). In the test set, the classification
results were similar (89.4% of the grade 1 versus 2 and 94.8% of the grade 2
versus 3 were correctly classified).
Conclusions:
1. Combination of MAI, Ki-67 and MNA-10 gives much better discrimination
between grade 1, 2 and 3 Ta,1 urinary bladder tumors than MNA-10 alone.
2. The similarity of the classification results of the test set and the
learning set encourage us to apply the classification model in a prospective
analysis.
IMPROVED OBJECTIVITY OF GRAD IN Ta,1 URINARY BLADDER TUMORS BY
MORPHOMERIC PROLOFERATION AND DIFFERENTIATION ASSOCIATED FEATURES
AND KI-67 IMMUNOQUANTITATION
Bol MGW, Schuurmans LS, Baak JPA
Departments of Pathology, Academic Hospital Free University, Amsterdam,
Medical Center Alkmaar, Netherlands
Literature:
Blomjous et al, 1989, Anal. Quant. Cytol. Histol. 11: 426-437