The prognostic significance of DNA cytophotometry and proliferation index (Ki-67) in giant cell tumors of bone

Abstract

We studied DNA ploidy by smear cytophotometry and proliferation activity by Ki-67 MIB immunohistochemistry in 69 primary and recurrent giant cell tumors (GCT) from 50 randomly selected patients. The obtained results were evaluated with comparisons made to the available clinical data. From the 46 primary tumors 63% showed diploidy and 37% aneuploidy. A significantly (P=0.026) higher recurrence rate (64%) was observed in aneuploid than in diploid tumors (31%). In the course of the recurrences, both the ratio of aneuploid tumors as well as the proliferation index of the tumors increased, though the degree of the latter was non-significant. Aneuploidy did not mean an unambiguous tendency towards malignant transformation; however, a close follow-up of recurrent aneuploid tumors, and wide excision of the recurrence instead of intralesional curettage are the recommended procedures. The DNA cytophotometry and proliferation index of GCTs -as compared to other histologic examinations -are of prognostic value in the evaluation of the recurrence potential of the GCTs.Résumé Les auteurs ont examiné 1'anomalie chromosomique de DNA á 1'aide de cytophotometrie de frottis; et 1'activité de proliferation par le moyen de 1'immunohistochimie Ki-67 MIB dans 69 tumeurs de cellules gé-antes de 50 patients choisis accidentellement. lls ont éva-lué les résultats en les comparant aux données cliniques disponibles. Parmi les 46 tumeurs primaires 63% ont manifesté un caractère diploide et 37% un caractère aneuploide. On a observé une proportion de recidive significativement plus élevée (P=0.026) dans les tumeurs aneuploides (64%) que dans les tumeurs diploides (31%).Au cours des récidives on a remarquè une augmentation tant dans la proportion des tumeurs aneuploides que dans 1'indice de proliferation mais en ce dernier 1'augmentation n'était pas significative. Le caractère aneuploide ne signifie pas forcément une tendance univoque á la transformation maligne cependant dans les tumeurs aneuploides récidivantes il est nécessaire de suivre la maladie avec beaucoup de soin et comme intervention chirurgicale on conseille une excision large au lieu du curettage intralésionel.

Factors Affecting the Recurrence of Giant Cell Tumor of Bone After Surgery: A Clinicopathological Study of 80 Cases from a Single Center

“…1. The experimental data also revealed that the recurrence rate was higher in the Ki-67 >15% group than that in the Ki-67 ≤15% group, consistent with the result obtained in previous reported literature [11]. The mean Ki-67 index in non-recurrent group is 8.73%, while the mean Ki-67 index in recurrent group is 24.17%, which is much higher than that of non-recurrent group.…”

“…Telomeric reduction and telomerase activity may act as oncogenic events, promoting and sustaining the transformed GCTB phenotype [10]. Some studies have shown that a high Ki-67 proliferative index is associated with the malignancy of bone tumors [11]. In some tumors, CD147 acts as a prognostic marker and therapeutic target [12].…”

Giant-Cell Tumour of Bone

“…However, many authors, including ourselves, do not regard these staging systems as predictive of the prognosis. 13,38,76,85,86 Most GCTs show a tendency to progress and without treatment they reach stage 3 sooner or later, as we have seen in many cases of retrospective analysis of radiographs of untreated patients (Fig. 2).…”

“…Two-thirds of non-recurring GCTs were characterised by euploidity and most of the recurrence GCTs by aneuploidity. 76,80 Bridge et al 81,82 found that all but one of their recurrent GCTs had some type of chromosomal abnormality, which could also be detected in highly malignant osteosarcomas. Schoedel et al 44 demonstrated an excessive metalloproteinase expression in recurrent or metastasising GCTs, which is also found in the degradation of extracellular matrix and in tissue invasion.…”

“…There is a relationship, for example, between the increasing rate of proliferation and the probability of recurrence. 30,76,77 The value of flow cytometry is disputed. 78,79 Our results with smear cytometry which allows separate examination of the stromal cell population showed a significant difference in the ploidity of non-recurring and recurring GCTs during follow-up studies.…”