A method of assaying metastasis can include: providing a device of one of the embodiments; introducing the at least one cancer cell into the at least one internal chamber or at least one fluid channel; and studying metastasis of the at least one cancer cell. Optionally: introducing cancer cells into a first internal chamber; detecting escape of the cancer cell from the first internal chamber into the fluid channel; detecting migration of the cancer cell through the fluid channel; detecting adhesion of the cancer cell to a coating on the fluid channel; detecting invasion of the cancer cell into a second internal chamber from the fluid channel; or visualizing metastasis of the cancer cell with a visualization device.