<b>Tests for prognostic markers are usually done on the tumor preserved in the paraffin block.</b>

<b>p53 Protein Test done on paraffin block tumor.</b>
The prognostic marker p53 protein (Cell cycle and TSP-1 Regulator) can provide insight into tumor behavior. It is well known that mutated p53 binds abnormally, thus leading to dysregulation of the cell cycle.  p53 gene is a tumor-suppressor gene that regulates cell cycle progression and cellular proliferation. Accumulation of [mutated and ineffectual] p53 protein in tumor cell nuclei is associated with increased tumor progression and decreased survival in many tumor types [and is often present in LMS]. Overexpression of p53 protein might be an indication for p53 gene replacement therapy.

One or both of two tests could be done: One could test for the p53 GENE, or the p53 GENE PRODUCT [which is the same thing as the p53 PROTEIN]. The FISH method, using DNA probes, is probably more reliable, especially in inexperienced hands, than the immunochemistry method. The test for the p53 gene would tell you what percentage of the tested tumor cells had the p53 gene missing. In testing for p53 protein, the results would indicate whether the protein was OVEREXPRESSED or not. Missing or mutated p53 genes, or overexpressed p53 proteins...are poorer prognostic signs, but might be indications for p53 gene replacement therapy.

<b>DNA Ploidy and Cell Cycle Analysis </b>
Prognostic markers such as DNA Ploidy, and S-phase fraction analysis [cell cycle analysis] correlate significantly with disease recurrence and overall survival. High S-phase fraction and aneuploidy indicate aggressive disease and are associated with shorter survival. DNA ploidy and proliferative index are independent indicators of prognosis. Patients with aneuploid tumors, having high S-phase fractions may have inferior disease-free survival compared with patients whose tumors are diploid and have low S-phase fractions.
