A practical approach to febrile cancer patients:  Diagnostic stewardship in Oncology units

Cancer and cytotoxic chemotherapy used for its treatment predispose to severe and often fatal infections. Prompt diagnosis and timely antibiotic therapy are crucial, with delays in therapy initiation having high mortality. Complete blood count (CBC) is an inexpensive, standardized, and preliminary investigation for the management and follow-up of cancer patients with diagnostic and prognostic value.

We studied the types of infections associated with various cancers treated with chemotherapy, their etiologies and susceptibility patterns, and the hematological profile of these patients as predictors of infection.

A total of 21 patients (12 solid and 9 hematological malignancies) presented with 31 febrile episodes. White Blood cell count (2079 cells/cu. mm), percentage of neutrophils (52.9%), absolute neutrophil (137.5 cells/cu. mm), and platelet count (1,77,507 cells/cu. mm) were significantly lower in the 11 patients with febrile neutropenia. The absolute lymphocyte count (412.7 cells/cu. mm) was reduced with a strikingly low Neutrophil-to-lymphocyte ratio (NLR) (6.07) in patients with neutropenia. Laboratory and radiological evidence were present in 14/15 episodes of hematological malignancies (p-0.218) whereas unexplained clinical sepsis was common in solid malignancies (p-0.0202). The majority of documented infections were bacterial, caused by gram-negative bacilli, often showing multi-drug resistance. Infectious etiologies were identified in 71.4% of the patients with febrile neutropenia for >5days. Bacterial infections developed within 2 days of neutropenia, whereas viral and fungal infections manifested in prolonged neutropenia. Multi-site infections and higher mortality rates were observed in patients with febrile neutropenia. (p<0.04).

Febrile neutropenia is a common complication among patients receiving chemotherapy for cancer, with an increased risk of morbidity and mortality. Early, rapid, and accurate diagnosis is key to prompt intervention. Hematological parameters such as Total Leukocyte count, platelet count, NLR, and Platelet-to-lymphocyte ratio are promising biomarkers in conjunction with morphological changes in neutrophils, thus proving that CBC and peripheral smears are simple, easily available, cost-effective, and highly dependable screening tools, especially in resource-poor settings.