If inmate has cancer and needs chemo treatment will they release them or treat them?

They might treat him depending on the stage of the cancer and where it is in the body. Also, their cancer treatment previous to the incarceration will have some bearing. It's not a good idea to get sick in jail because the overall treatment is minimal at best. Cancer treatment, dialysis or other life threatening ailments does not usually get an offender released. They will transport them to the prison-ward of a hospital that is equipped for handling inmates (requiring the patient to be shackled while in treatment).