title: The relevance of the DNA index and proliferation rate in the grading of benign and malignant soft tissue tumors.
abstract: The relevance of the DNA index (DI) to malignancy grading and the relationships between mitotic score, Ki-67 score, and the proportion of cells in the G1-phase (G1PF) of the cell cycle, as proliferative indicators, were investigated in benign (n = 8) and malignant (n = 46) soft tissue sarcomas. Although DI was not found to be related to the histology of the sarcomas, it was associated with malignancy grade, i.e., 14%, 25%, 42%, and 86% of benign, Grade 1, Grade 2, and Grade 3, respectively had a DI greater than 1. The relevance of aneuploidy in benign tumors is discussed and the literature reviewed. A subgroup of the malignant tumors (n = 13) had both a low mitotic score and a low Ki-67 value. However, a distinct correlation between Ki-67 and the mitotic score could not be shown. For malignant tumours G1PF was related to DI, i.e., low G1PF occurred in tumors with diploid DNA content. Low Ki-67 scores were observed in 59% of diploid tumors and in 20% of aneuploid tumors. However, it appeared that G1PF and Ki-67 were not correlated. In conclusion, (1) benign and Grade 1 tumors were predominantly diploid with high G1PF and low Ki-67 values, (2) most of Grade 3 tumors were aneuploid (86%) with low G1PF and high Ki-67 values, and (3) the group of Grade 2 tumors could be divided into two subgroups either with the characteristics displayed by benign and Grade 1 tumors (DI = 1, low Ki-67 scores, and high G1PF) or with the characteristics exhibited by Grade 3 tumors (DI greater than 1, high Ki-67 scores, and low G1PF). Hence, supplementary to the grading of soft tissue tumors, DI, G1PF, and Ki-67 score could be useful as prognostic parameters in soft tissue tumors.
authors.affiliation: Institute of Radiotherapy, University Hospital, Utrecht, The Netherlands.
authors.forename: M C
authors.initials: MC
authors.lastname: Kroese
authors.forename: D H
authors.initials: DH
authors.lastname: Rutgers
authors.forename: I S
authors.initials: IS
authors.lastname: Wils
authors.forename: J A
authors.initials: JA
authors.lastname: Van Unnik
authors.forename: P J
authors.initials: PJ
authors.lastname: Roholl
mesh_terms: D000469:Alkaline Phosphatase / Q000032:analysis; D000782:Aneuploidy; D002453:Cell Cycle; D002455:Cell Division; D002467:Cell Nucleus / Q000648:ultrastructure; D004273:DNA, Neoplasm / Q000032:analysis* / Q000235:genetics; D004171:Diploidy; D005434:Flow Cytometry; D018219:Histiocytoma, Benign Fibrous / Q000235:genetics / Q000473:pathology; D006801:Humans; D007399:Interphase; D008938:Mitosis; D011379:Prognosis; D012509:Sarcoma / Q000235:genetics / Q000473:pathology; D012983:Soft Tissue Neoplasms / Q000235:genetics* / Q000473:pathology
chemical_list: D004273:DNA, Neoplasm; D000469:Alkaline Phosphatase