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A.T. Kristensen1
1Oncology and Veterinary Clinical Pathology, Department of Veterinary Clinical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Dyrlægevej 16, 1870 Frederiksberg C, Denmark
Hematology is a key tool and discipline in oncology. Hemograms are collected as part of routine work up and staging in all cancer patients to determine if any hematologic abnormalities are present either as a complication to cancer, as a paraneoplastic condition, as part of other disease, or to identify neoplastic cells. In addition, hemograms are performed as part of Standard of Care (SOC) prior to and during chemotherapy
and other treatment modalities to evaluate adverse hematologic effects as defined in the most recent Veterinary Comparative Oncology Group publication, VCO, 2016.
Common hematologic abnormalities include anemia, thrombocytopenia, leukopenia and paraneoplastic conditions such as immune-mediated thrombocytopenia (IMT) and immune-mediated hemolytic anemia (IMHA).
Baseline evaluation and later monitoring of hemostatic abnormalities is not routine or part of SOC despite the fact that up to 83 % of canine cancer patients have been reported to show abnormal coagulation tests.
Hematologic evaluation and monitoring
Ability to monitor hematologic abnormalities of leukocytes, platelets and red cells over time including trending is essential in the management of canine and feline cancer patients. In clinic hematology analyzers
for Point of Care (POC) testing are often preferred
as information about hematologic parameters is
needed in a timely fashion. Sending blood to reference laboratories may delay detection and evaluation of any changes important to address speedily. Awareness of the advantages and challenges of the precision of the measured parameters when using in clinic analyzers and the importance of having quality control measures in place is imperative. A recent study by Rishniw et al, VCP, 2016 illustrates this and underscores the importance of evaluating blood smears as part of routine hematology. Despite this POC hematology instruments on the
market continuously increase in quality and usefulness of measured and reported parameters. The latest released advanced optical-based instruments using 2-dimensional laser light scattering technology all report
both quantitative variables (cell counts) with information on leukocyte count and differential, platelet parameters including platelet count, size, shape and activation, red cell parameters including reticulocytes and qualitative distribution data in the format of histograms and color coded dot plots. Unfortunately most veterinarians do not take advantage of this valuable information about the patients overall “hematologic state”.
“Novel” platelet parameters
The addition of several useful platelet parameters including plateletcrit (PCT, platelet percentage of blood volume), mean platelet volume (MPV, average volume of particles in blood counted as platelets), platelet volume distribution width (PDW, platelet size distribution),
mean platelet component concentration (MPC, platelet granularity), mean platelet component distribution width (PCDW, variation in platelet shape), mean platelet dry mass (MPM, product of MPV and MPC) and presence
of reticulated (immature) platelets may indicate increased platelet turnover and presence of platelet activation (increased MPV, MPM, MPC, PCDW and decreased MPC). This can help guide the clinician to underlying concurrent hemostatic disorders including disseminated intravascular coagulation (DIC), immune-mediated thrombocytopenia (IMT), and procoagulant conditions. Furthermore the dot plots available on most instruments can qualitatively show presence of platelet aggregates as well as the platelet size distribution.
“Novel” red cell parameters
Several useful red cell parameters in addition to the usual red cell indices MCV and MCHC are available. Most POC hematology instruments on the market today report reticulocyte counts as well as additional red cell parameters such as RDW (red cell distribution width).
Leukocyte evaluation
Color coded dot plots available on some instruments may help indicate abnormalities in leukocyte distribution and the presence of abnormal cells such as blasts.
On the horizon
Recent research has placed increased emphasis on hemostatic and inflammatory evaluation of cancer patients including thromboelastography (TEG), TPA modified thromboelastography (TPA-TEG), evaluation
of endogenous thrombin potential, C reactive protein (CRP) and cytokines, which in the future may be able to identify patients with concurrent inflammatory, thrombotic or fibrinolytic conditions. TEG guided transfusion is becoming increasingly available in specialty practice
as an option to guide coagulation factor product administration in the bleeding cancer patient.
An Urban Experience

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