Cultured Circulating Tumor Cells in Prostate and Other Cancers

The purpose of this study is to evaluate the number of circulating tumor cells (CTC) before and after treatment using an experimental method for detecting CTC, compared to commercial CTC assay results, in patients with prostate, breast or colorectal cancers. Experiments will be done to develop a new assay technique and also test how CTC react to commonly used drugs. This information will be analyzed to determine if the experimental assays can be helpful in the future to predict how a patient's cancer may react to certain treatments. The research experiments will also attempt to grow CTC for long-term or "immortal" cell lines that can be further studied for proteins and gene mutations related to the specific tumor (not familial), and testing for sensitivity to drugs. Blood samples will be collected at specific time points during routine medical care from patients with prostate, breast, colorectal or other solid tumor cancer. Samples will also be collected from patients with no cancer for comparison purposes. Samples for the experimental tests will be identified only by codes and results will not be shared with participants. Patients with prostate, breast or colorectal cancer will also have blood samples drawn for commercial CTC assays as part of their standard care.