Tumor-Derived FGF19

This project seeks to develop and test a more convenient detection modality for colorectal cancer and to test feasibility for breast cancer screening through a blood based test for cancer detection. Because detection of cancer is a fundamental need to facilitate treatment and decrease patient mortality, the ultimate objective of this proposal is to test applicability and context for the blood test, especially for patients that either are not eligible or do not want to participate in currently approved screening protocols. Colonoscopy and mammograms are gold standard cancer screening modalities that are recommended for detection of early-staged tumors, but there are many reasons why patients are noncompliant with participation in these screening modalities. Neither colorectal cancer nor breast cancer detection have reliable blood based cancer tests. Availability of blood based cancer tests could increase patient compliance, as well as decrease the associated mortality in finding cancer at later stages. The Altomare laboratory has identified that FGF19 demonstrates unique characteristics that make it an attractive serum marker for this concept. This UCF research group has found that in studies using mice injected with human colorectal cancer cells, that FGF19 is secreted into blood by tumors. The findings support the concept that malignant FGF19 from certain tumors such as colorectal cancer can be leveraged in a diagnostic context to improve cancer detection and access to screening. Both colorectal cancer and breast cancer patients are priority populations for the Florida Cancer Grant Programs. Importantly, FGF19 has not been tested for threshold, sensitive or specificity as a blood marker for colorectal cancer. Baseline FGF19 blood marker levels corresponding to colorectal cancer testing will be compared with those of another cancer type, breast cancer, where aberrant FGF19 levels have been implicated but also not tested. The investigators therefore also will test the applicability of serum FGF19 to detect breast cancer, which has dysregulation of FGF19 and its receptor in certain subtypes of breast tumors. Objectives: The primary marker that the investigators will look for is FGF19, a factor of normally restricted spatially to parts of the intestine and gall bladder, especially following a meal. The investigators will test in cancer patients whether FGF19 (or other associated markers) are higher in the blood of subset of cancer patients. The investigators pose the question of whether FGF19 is actively secreted into blood by human tumors. In further examine its use as a blood biomarker, the investigators will address whether higher levels of FGF19 cutoffs can be detected in the blood of colorectal cancer or breast cancer patients over that of control participants. Successful completion of this goal will, for the first time, establish whether tumor production of FGF19 in human colorectal or breast tumors contributes to elevated levels in either, all or a subset of patients compared to blood levels in people without cancer.