Peritoneal Carcinomatosis Leveraging ctDNA Guided Treatment in GI Cancer Study (PERICLES Study)

This clinical trial collects biospecimen samples to create a personalized ctDNA test to guide treatment for patients with gastrointestinal cancer with peritoneal carcinomatosis. Deoxyribonucleic acid, or DNA, is the material that carries all the information about how a living thing will work and function. Everyone is born with the same DNA in all our cells throughout our body. Sometimes, some of the cells in the body develop abnormalities in the DNA that cause those cells to grow abnormally and uncontrollably. Cancer occurs when there is abnormal and uncontrolled growth of cells. The DNA in cancer cells is therefore different from the DNA someone is born with. The Signatera ctDNA assay is a laboratory test that takes tumor (cancer) tissue and evaluates it for unique tumor DNA. This evaluation is used to create a report (otherwise known as an assay) personalized to each person's cancer. The personalized assay creates a personalized blood test to detect the level of abnormal DNA from the cancer that may be circulating in the body. Once this personalized blood assay is designed, it may be used to monitor a person's blood for the presence of ctDNA, which will indicate the presence or absence of cancer over time, even after treatment.