At the age of 28, my patient was already a war-weary veteran of leukemia.

When his cancer was diagnosed, we treated him with a multi-drug cocktail of chemotherapy over months, first with more intensive regimens that sidelined him from being able to work, and then with milder medicines.

His leukemia came raging back, though, so we treated him again, this time with one of the new, expensive immunotherapies that has been approved recently by the Food and Drug Administration. These are not curative, but in his case eliminated enough of the leukemia to enable him to receive a bone-marrow transplant, which did have the potential of curing him.

But when he called my office six months after his transplant complaining of excruciating back pain, we feared the worst. The vertebrae are the major site of bone marrow production in the body. Cells that grow too rapidly within the rigid confines of the bones can actually hurt, and it was the same symptom he had when we first met.

A bone marrow biopsy confirmed that the leukemia had returned, and he was quickly admitted to the hospital, both to manage his pain and treat his cancer.