The absolute neutrophil count (ANC) in peripheral blood specimens of patients with cancer scheduled to receive chemotherapy/targeted therapy was affected by food consumption, according to results of a retrospective analysis published in Supportive Care in Cancer.
Due to concerns related to increased risks of infection associated with neutropenia, administration of chemotherapy and some targeted therapies is frequently delayed in patients with a peripheral blood ANC of less than 1.5×109/L.
This study included 32 hospitalized patients with a wide range of cancer types and a median age of 61 years who were scheduled to receive chemotherapy or novel targeted agents and had evidence of neutropenia.
On a fasting complete blood count (CBC) taken prior to the administration of antineoplastic therapy, the peripheral blood ANC was less than 1.5×109/L but at least 0.8×109/L in all of the patients included in this analysis, with a median of 1.3 g×109/L. However, at baseline, symptomatic neutropenia, fever, and infection were not observed in any of these patients.
On repeat CBCs performed on specimens of peripheral blood drawn an average of 2 hours after eating breakfast, the median ANC level was 2.1×109/L, representing an increase of 69.5% (P <.05). Systemic therapy was subsequently administered to 31 of the 32 patients, all of whom had an ANC exceeding 1.0×109/L. Furthermore, none of these patients exhibited signs of infection during the 1- to 4-week interval between treatment cycles.
The study investigators characterized the initial peripheral blood ANC results as pseudoneutropenia. “It is worth noting that the circulating pool of neutrophils (measured by the absolute count in the peripheral blood) is only one of four reservoirs of these cells in the body, and its size is influenced not only by their shortage but also by transient shift of these cells between these reservoirs (bone marrow reserve, circulating pool, marginal pool, and tissue pool),” they stated.
In light of the potential detrimental impact of treatment delays in patients scheduled to receive chemotherapy/targeted therapy, they further commented, “We should not let our oncology patients fast before their [CBC] measurements, with the exception of special and rare situations. Factors such as exercise and diet, corticosteroids, beta-blockers in addition to many others are responsible for shifts between granulocyte pools.”
The study investigators emphasized that “oncologists must be mindful of pseudoneutropenia, as the number of granulocytes will improve in certain situations and the patient can be treated with antineoplastic therapy,” but also stressed the importance of conducting prospective studies to evaluate this phenomenon more thoroughly.
Waszczui-Gajda A, Kraj L, Wozniak K, et al. Pseudoneutropenia as a factor-limiting access to chemotherapy for cancer patients: the effect of a simple meal.Support Care Cancer. Published online November 20, 2020. doi:10.1007/s00520-020-05896-x