For children with rare, aggressive and advanced cancer, precision medicine may help doctors determine their best treatment options, a new study finds. Using information from a patient’s entire genome helped suggest personalized treatment options for nearly half of children with cancer, and led to specific treatment changes in a quarter of these patients.

A new marker already linked to other types of cancer was found to play a role in retinoblastoma, a rare but lethal form of cancer. When advanced forms of RB affect both eyes, this cancer causes partial or full loss of vision in about 50 percent of patients. This tumor is normally treated by eye removal or administration of chemotherapy drugs that are often toxic to the normal retina, and thus can jeopardize vision. No targeted therapy, which selectively kills tumor cells but spares normal retinal cells, exists.