For most metastatic cancer types, there are no reliably effective treatments. Therapies may slow the growth of tumors, but they will not eradicate them. Occasionally, however, treating a tumor in one location will cause untreated tumors elsewhere in the body to shrink or even regress completely — a dramatic but exceedingly rare phenomenon known as the abscopal effect. Cancer researchers have sought methods to induce the abscopal effect by design. The abscopal effect is thought to arise when dead or damaged tumor cells release antigens that teach some types of…
