- Participants must have sufficient tissue from prior surgery for confirmation of diagnosis and correlative studies. Submission of tissue is to occur within 30 days after registration. The following amount of tissue is required: a) 25 unstained formalin fixed paraffin embedded (FFPE) sections (standard 4-5 micrometer thickness AND b)one of the following: i) At least 200 micrograms of frozen tissue OR ii)At least 10 (preferably 20) unstained FFPE sections of 10 micrometer thickness OR iii) At least 8 tissue cores from an FFPE block (200 micrometer total thickness of tissue from a block with a total surface area of 0.5 cm2)