[1754] Xpress-ed Tissue Materials for Molecular Surgical Pathology

A Serizawa, T Itoh, N Kato, H Itoh, RY Osamura. Tokai University School of Medicine, Isehara, Japan

Background: Recently, it has been recommended to rapid-process the surgical materials in order to expedite the pathology reporting. It has to be pointed out that these rapidly processed tissues are not infrequently subjected to the molecular studies for more accurate diagnosis, prognosis and for molecular targeted therapy. This study is aimed at to elucidate whether rapidly processed and paraffin embedded tissues are suitable for molecular analysis, FISH amplification, mutational analysis and RT-PCR.
Design: Biopsied or surgically resected specimens were subjected immediately to Xpress-x50(Sakura Finetek), which uses microwave fixation. Whole processing into paraffin require approximately 40minutes. After regular H&E staining, the entire through-put is less than two hours. The Xpress-x50-processed paraffin embedded sections were subjected to the following molecular analysis, EGFR FISH, EGFR mutation, p53 mutation and real time RT-PCR. Results were compared with those by FFPE materials.
Results: From the Xpress-x50-ed tissue sections, pulmonary bronchiloalveolar carcinoma(BAC) showed EGFR Point mutation (CGCCCC) in Exon21 at 26^th : Arg832Pro, or Point mutation (GTCATC) in Exon19 at 40^th : Val742Ile. EGFR FISH showed comparable ratio of EGFR/CEP17 to that of FFPE. P53 point mutation (CGCCAC) in Exon7 at 71^th : Arg248His was detected in colorectal cancer. These molecular changes were exactly comparable to those by FFPE section. Recovery of mRNA is appreciable, even though less than that of fresh frozen or FFPE materials.
Conclusions: Our studies showed that rapidly processed tissues could be subjected to molecular studies such as mutation analysis, FISH and RT-PCR. For prognostication and therapeutic application, molecular analyses can be also expedited using this technique in order to provide appropriate personalized therapy without delay.
Category: Techniques

Wednesday, March 11, 2009 1:00 PM

Poster Session VI # 221, Wednesday Afternoon