ABSTRACT
Cell cycle analysis by flow cytometry has not been adequately studied in pediatric brain tumors. We investigated the value of a modified rapid (within 6 min) cell cycle analysis protocol for the characterization of malignancy of pediatric brain tumors and for the differentiation of neoplastic from nonneoplastic tissue for possible intraoperative application. We retrospectively studied brain tumor specimens from patients treated at our institute over a 5-year period. All tumor samples were histopathologically verified before flow-cytometric analysis. The histopathological examination of permanent tissue sections was the gold standard. There were 68 brain tumor cases. All tumors had significantly lower G0/G1 and significantly higher S phase and mitosis fractions than normal brain tissue. Furthermore low-grade tumors could be differentiated from high-grade tumors. DNA aneuploidy was detected in 35 tumors. A correlation between S phase fraction and Ki-67 index was found in medulloblastomas and anaplastic ependymomas. Rapid cell cycle analysis by flow cytometry is a promising method for the identification of neoplastic tissue intraoperatively. Low-grade tumors could be differentiated from high-grade tumors. Thus, cell cycle analysis can be a valuable adjunct to the histopathological evaluation of pediatric brain tumors, whereas its intraoperative application warrants further investigation.
Subject(s)
Aneuploidy , Brain Neoplasms/diagnosis , Cell Cycle/physiology , Ependymoma/diagnosis , Flow Cytometry/methods , Medulloblastoma/diagnosis , Adolescent , Child , Child, Preschool , Clinical Protocols , Female , G1 Phase/physiology , Humans , Immunohistochemistry , Infant , Ki-67 Antigen/analysis , Male , Mitosis/physiology , Neoplasm Grading , Resting Phase, Cell Cycle/physiology , Retrospective Studies , S Phase/physiologyABSTRACT
PURPOSE: Cell cycle analysis by flow cytometry has not been adequately studied in pediatric brain tumors. We investigated the value of cell cycle analysis by propidium-iodine (PI) staining of CD56+ (gated) cells for the characterization of pediatric brain tumor's malignancy. METHODS: Patients that underwent surgery for an intracranial lesion and tissue sample was available were included in the study. All tumor samples were histopathologically verified before flow cytometric analysis. RESULTS: There were 46 pediatric brain tumor cases. As control we used samples from three cases of brain tissue obtained during surgery for epilepsy. All tumors had significant lower G0/G1 and significant higher S-phase, G2/M fraction, S+G2/M and S+G2/M/G0/G1-phase fraction than normal brain tissue. Low-grade tumors had significant lower S-phase than high grade tumors. Grade IV tumors had significant lower G0/G1 fraction and higher S+G2/M/G0/G1 index than grade III tumors. DNA diploidy was detected in 24 tumors and DNA aneuploidy was detected in 23 tumors. There was a significant correlation between Ki-67 index and both S+G2/M and S+G2/M/G0/G1 phase fraction. CONCLUSIONS: Cell cycle analysis by PI staining of CD56+ cells is a promising method for the assessment of pediatric brain tumors malignancy and could be a valuable adjunct to histopathological evaluation.
