Relevance between clinical behavior and bionomical findings of acoustic neuromas

Objective To evaluate the relationship between labeling index（LI） Ki-67, proliferating cell nuclear antigen （ PCNA ） and transforming growth factor-β1 （ TGF-β1 ） with the clinical behavior of acoustic neuroma. Methods Expression of Ki-67, PCNA and TGF-β1 was detected by immunohistochemistry in 53 specimens of acoustic neuromas. The relationship among tumor proliferation, histological representation, size of tumor, clinical proliferation index of tumor and tumor proliferation activity were analyzed. Results In all 53 cases, the positive rate of Ki-67 was 77.4% （41/53） but the positive rate of PCNA was 84.9% （45/53）. There was significant difference between the proliferate index, clinic growth rate and course of disease（t =2. 14, t =2. 70; P <0. 05）. The positive rate of TGF-β1 was 83. 0% （44/53）. The correlation of TGF-β1 with LI（ Ki-67 ） was significant difference （r = 0. 36 ,P < 0. 05 ）. Cystic degeneration often occurred in large-size tumor （Z = 4. 44 ,P < 0.05 ）. There was no significant relationship between the expression of LI（ Ki-67 ）, LI（PCNA） and TGF-β1 and the course of disease as well as between the cystic degeneration and the non-cystic degeneration. Although clinic growth rate of cystic degeneration was bigger than that of non-cystic degeneration, there was not statistically significant. Conclusions Ki-67 and PCNA are reflected proliferation activities of tumor cells in acoustic neuromas. Cell proliferation-labeling index LI（ PCNA）was related with clinical growth rates. TGF-β1 might participate in the biological behavior of acoustic neuroma. Cystic degeneration was one of special pattern of acoustic neuroma, however, tumor enlargement might due to the volume of the cystic but unrelate to fast proliferation of parenchyma cell. Key words: Neuromas, acoustic; Ki-67 antigen; Proliferating cell nuclear antigen; Transforming growth factor beta