Variables that oncologists should consider when determining when to initiate prophylactic therapy for chemotherapy-induced neutropenia in patients with breast cancer.
Hope S. Rugo, MD, FASCO: It’s important for us to understand when patients are at their greatest risk for CIN [cervical intraepithelial neoplasia], which is after they start chemotherapy. That’s something our patients also want to know, in terms of what their risk is if they’re going to travel or work. I don’t know that the guidelines address this and how it’s taken into our clinical decision-making. Rita, do you want to comment on that, as well as symptoms that patients might have when they develop CIN?
Rita Nanda, MD: Obviously, guidelines are very helpful, but a lot of times we have to make management decisions those guidelines aren’t going to help us with because every patient is a little different. In terms of thinking about patients who are too neutropenia, we need to have a low threshold of trying to keep patients on track and to integrate prophylaxis into our regimens.
In this era of COVID-19, we need to be aggressive about trying to prevent neutropenia and neutropenic fevers because hospitals aren’t great places for our patients to be right now, and emergency departments are even more challenging. In this COVID-19 era, preventing neutropenia and preventing neutropenic fevers is even more critical for our patients.
Hope S. Rugo, MD, FASCO: For most of our drugs, neutropenia occurs 7 to 10 days after chemotherapy is given. But we’ve seen some prolonged neutropenia in agents that are given, that have a longer half-life, such as platinum agents. It’s somewhat unusual to see a patient 2 weeks out who is neutropenic for the first time. It does depend on the agent, and that’s helpful for us to think about and understand. When we evaluate patients with neutropenia, we worry a lot about infections when somebody has grade 4 neutropenia with a neutrophil count less than 500 per µL. Whereas we’ll see patients with a neutrophil count of 980 per µL, which is less than 1000 per µL but not worrisome. Additionally, a neutrophil count of 1200 per µL, which is still grade 2, isn’t at all worrisome. It’s less than 1000 per µL, so there’s some risk, but fewer than 500 per µL there’s an even greater risk.
Transcript edited for clarity.