Can colon tumors be seen on a lumbar spine mri?

Possibly: Though unlikely. Generally, a spinal MRI is focused on the spinal structures. However, it is possible. A bigger question would be why you think you have colon cancer.

Not really: It is windowed to focus on the lumbar spine so you don't really appropriately visualize the colon on the lumbar spine mri. This particular study is not a good study at all to evaluate the colon. To properly evaluate the colon, ask your doctor to inform you on what study is needed to properly visualize the colon.