Hematology The Role of Complete Blood Cell Count in Prognosis—Watch this Space! Nicole M Rochet, BS, 1 Svetomir N Markovic, MD, PhD 2 and Luis F Porrata, MD 3 1. MD/MS Student, Division of Hematology; 2. Professor of Medicine and Oncology, Department of Medical Oncology and Division of Hematology; 3. Assistant Professor, Division of Hematology, Department of Medicine, Mayo Clinic College of Medicine, Rochester Abstract Prognostic factors in cancer patients provide information about possible clinical outcomes and help classify patients into different risk groups. Treatment and clinical management decisions are often challenging, thus the availability of reliable and accessible prognostic markers is vital when designing treatment plans and discussing them with patients. This article discusses the prognostic value of the complete blood cell count components (i.e., white blood cell count, absolute neutrophil count, absolute lymphocyte count, absolute monocyte count, hemoglobin level, and platelet count) in regard to clinical outcomes in patients with malignant disorders. Keywords Complete blood cell count, white blood cell count, hemoglobin level, platelet count, neutrophil count, lymphocyte count, monocyte count, survival, cancer, prognosis Disclosure: The authors have no conflicts of interest to declare. Received: January 3, 2012 Accepted: January 16, 2012 Citation: Oncology & Hematology Review, 2012;8(1):76–82 Correspondence: Luis F Porrata, MD, Assistant Professor, Mayo Clinic, 200 First Street SW, Rochester, Minnesota 55905. E: porrata.luis@mayo.edu Prognostic factors of clinical outcomes in patients with cancer are a useful tool in the practice of medicine, especially in the fields of oncology and malignant hematology. A good prognostic factor should reflect the biology of its targeted disease, be inexpensive, reliable, reproducible, and standardized. Furthermore, a universal prognostic factor that can predict survival regardless of the type of cancer will help to simplify the management of cancer patients. In this article, we describe the undermined universal prognostic value of a low-cost, standardized, reliable, and reproducible prognostic factor in cancer: the complete blood cell (CBC) count and its components. White Blood Cell Count The absolute white blood cell (WBC) count obtained from the CBC count has been historically used as a marker of infection and inflammation. It is a widely available tool for clinicians to identify the presence of infection and monitor the patient’s response to treatment, such as antibiotics. Nonetheless, the role of the WBC count has gone beyond the assessment of infectious processes and it has become an important prognostic measurement of outcomes in cancer treatment. The inflammatory process that takes place during cancer development and progression are, in part, reflected in abnormalities of the WBC count. In hematologic malignancies, the WBC count is a prognostic factor for clinical outcomes included in international prognostic systems. For example, in advanced Hodgkin’s lymphoma (HL), the International Prognostic Score (IPS) alerts cancer specialists of worse clinical outcomes in patients presenting with a WBC count ≥15,000/mm 3 . 1 Another international prognostic system that associates a higher WBC 76 count count with adverse clinical outcomes is the Mantle Cell Lymphoma International Prognostic Index (MIPI). The MIPI has been validated in several population-based cohorts, confirming that a high WBC count is a negative predictor of survival. 2,3 In addition to hematologic malignancies, the WBC count has been reported to be of prognostic value in solid tumors. Pre-treatment leukocytosis, defined as a WBC count >10,000/μl, has been shown to be an independent prognostic factor of survival in cervical cancer patients. 4 In non-small cell lung cancer (NSCLC), the prognostic importance of the WBC count has been studied in patients before the initiation of systemic treatment and as a pre-operative measure, in both cases showing that an elevated WBC count is a significant predictor of overall survival (OS) and time to progression of disease. 5–7 Mandrekar et al. 5 developed a survival prediction model for newly diagnosed advanced-stage NSCLC that incorporates WBC count as one of the variables. Additionally, patients with metastatic melanoma who exhibit a high pre-treatment leukocyte count (>10 x 109/l) have poor clinical outcomes following biochemotherapy in both OS (hazard ratio [HR]=1.7; p=0.0005) and progression-free survival (PFS) (HR=1.5; p=0.008). 8 Interestingly, 143,748 post-menopausal women were studied, as part of the Women Health Initiative, to determine the association of WBC count with the incidence of cancer and cancer mortality. The study concluded that within this population, women with higher WBC counts have an increased risk of developing invasive breast, colorectal, endometrial, and lung cancer, as well as a higher risk of overall mortality in breast and lung cancer. 9 As a biomarker of inflammation, © TOUCH BRIEFINGS 2012