Purpose: To evaluate the factors determining the survival possibility by analysing the appearance on MR imaging and detecting the protein expression of p53 or PTEN gene in osteosarcoma.
Methods and Materials: 53 cases of osteosarcoma were all proved by surgery and pathology. The protein expression of p53 and PTEN was detected by immunohistochemistry in all cases. 28 cases of them were also examined by a 0.38T MRI system before operation. Pulse sequences are spin-echo (SE) T1-weighted imaging (T1WI), T2WI, short TI inversion recovery (STIR) and gadolinium (Gd-DTPA) enhanced SE T1WI. Tumor size, invasive extension, metastasis, contrast enhancement were recorded. All patients were closely followed-up in 3 years. The patients are considered survival when the three year post-operative follow-up period is completed.
Results: There is a close relation between tumor size and extension on T1WI and pathology. No relation was found between average tumor size and survival patient number. A negative correlation was found between p53 gene expression and the patients survival rate of osteosarcoma. A positive correlation exists between the PTEN expression and the survival rate. The correlation with PTEN expression has entered the regress model which was analysed by logistic regression, but not with p53 expression. There was no significant difference between the protein expression of p53, PTEN and the three-year survival ratios of osteosarcoma patients. The patients who had the positive expression of p53 have higher survival rate than those had the negative expression in both PTEN and p53. The difference is significant (x2=35.95, p<0.005).
Conclusion: The size and extension of the tumor on MRI can not predict the prognosis of osteosarcoma. Osteosarcoma with a positive protein expression of p53 gene or negative in PTEN gene expression is higher malignant. The PTEN expression is an important factor in predicting the patient's survival.
(L. Z. : Tongji Hospital, Employee (Self With Financial Support); Z. Y. : Tongji Hospital, Employee (Self); R. T. : Tongji Hospital, Employee (Self); S. Z. : Tongji Hospital, Employee (Self With Financial Support))
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