The diversity of the 76 million baby boomers born between 1946 and 1964, and their projected longer life span, create challenges for all those examining these facts. These demographic issues also inform the discussion of the use of myeloid colony stimulating factors (CSFs) in cancer. Their use is projected to increase and is not uniformly applied across the US, and the new molecular advances in translational cancer medicine may yet alter their use as well.
There are four general ways that CSFs are used in general cancer treatment in a non-transplant setting.The first is as a primary prophylactic measure to prevent severe neutropenia with its attendant morbidity and mortality risks and cost consequences. The ASCO guidelines point out that cost analyses have shown that CSFs save money when the risk of febrile neutropenia (FN) is greater than 40%.2 These guidelines also point out that most moderate-dose-intensity solid tumor cancer regimens have FN rates of approximately 15%, and that primary prophylaxis is not a regular approach for these chemotherapies. The exception to this rule is the older patient where the 15% assumption is not correct. In nine clinical trials of older patients with large cell non-Hodgkin’s lymphoma, the risk of FN was between 21% and 47%, and many authors indicate that primary prophylaxis is appropriate for patients receiving moderate intensity chemotherapy who are aged 70 years or older.3 Furthermore, advances in treatment have made the combination of monoclonal antibody therapy, using Rituxan™, with chemotherapy the standard of care, or at least the benchmark of care, in the lymphoid malignancies, lymphoma, and chronic lymphocytic leukaemia (CLL). This has resulted unexpectedly in increased myelosuppression in some of these combination regimens. Thus, the on-coming aging boomers will require increased use of CSFs in these clinical situations. Clinical practice for primary prophylaxis is also quite varied in the US, as suggested by the aforementioned SEER results statistics, indicating disparity of outcomes. Several studies have indicated that compliance with ASCO guidelines for primary prophylaxis with CSFs is not much better than 50%,4