The Impact of Chemotherapy-Induced Myelosuppression - Episode 2
Gary H. Lyman, MD, MPH, FASCO, FRCP: The myelosuppressive effects of systemic chemotherapy have a direct impact on the patient, the bone marrow, and the multiple lineages of the hematopoietic system. If neutropenia infection occurs, patients may need to be evaluated in the emergency department or even hospitalized. Although we try to manage many of these patients in the ambulatory setting, members of the more vulnerable populations—older patients, patients with comorbidities, or those with clear sepsis—still need to be hospitalized. Hospitalization, or at least emergency department evaluation, is often a consequence of chemotherapy-induced myelosuppression.
We’ve talked about fatigue. That’s what patients experience the most. But it’s usually because of the underlying anemia, infection, or even bleeding that might be occurring because of the chemotherapy-induced myelosuppression.
We try to intervene. Traditional strategies in recent years have involved the use of a myeloid growth factor given after the chemotherapy, but prior to the onset of severe neutropenia, to lessen the myelosuppression. It usually doesn’t prevent it, but it may reduce the nadir of neutrophil suppression or shorten the period of severe neutropenia.
Similarly, erythroid-stimulating agents have been utilized and continue to be utilized. However, they have come with additional concerns, based on some trials, that sometimes the adverse events from these agents may be worse than the anemia itself. That, for a while, was a black box warning around the use of erythroid-stimulating agents.
We’ve learned how to better use them and in which patients to use them, so these are available. But we generally don’t use them broadly anymore. If the anemia becomes profound, the patient may need to come in for a transfusion. Again, the issue will be at what threshold or cut point we should administer transfusion.
All this may eventually lead to dose reductions, dose delays, reduction in the relative dose intensity chemotherapy, or a change to a different regimen that’s less myelosuppressive. In the extreme and most unfortunate situation, it may result in the stopping of chemotherapy, either because the patient refuses to go on or because it’s not thought to be in the best interest of the patient.
Paul Bunn, MD: Because myelosuppression is a common problem in chemotherapy treatment, there are several issues that arise. One is what’s going to happen in subsequent treatments with chemotherapy. In general, severe myelosuppression is going to lead to dose reductions. It may lead to transfusions. There are growth factors now that can help us with severe myelosuppression. Obviously, for patients with neutropenia, especially febrile neutropenia, we have the GCSF growth factors. For patients in whom anemia becomes the more common problem, we have the ESAs [erythropoietin-stimulating agents] to treat chemotherapy-induced anemia. We do have a growth factor for thrombocytopenia as well. That is used in patients with severe neutropenia, anemia, or thrombocytopenia. For severe anemia and thrombocytopenia, we also have blood transfusion.
We use these in a minority of patients, but the use of growth factors is not going away for patients who have severe effects. Unfortunately, each of these growth factors—myelosuppression for neutropenia, anemia, or thrombocytopenia—only affects that particular type of blood count. More recently, there have been some drugs that affect cell cycle and can prevent all types of myelosuppression. Those may supplant the individual types of growth factors, or just neutrophils, red blood cells, or platelets. We will be discussing new ways to prevent all sorts of myelosuppression—white blood cells, red blood cells, and platelets.
Transcript Edited for Clarity