Could a Blood Test Help Clinicians Diagnose Multiple Myeloma Earlier?
Levels of hemoglobin, combined with ESR, PV, and calcium values, were determined to be the blood parameters with the most diagnostic value in multiple myeloma.
There may be a way to detect multiple myeloma (MM) earlier — effectively shortening the longer diagnostic interval that is typically associated with the diagnosis of MM — using basic information derived from routine blood panels already used in the primary care setting, according to a study published in British Journal of General Practice.1
The National Institute for Health and Care Excellence (NICE) uses an urgent cancer threshold for referral of 3%, which is calculated through the measurement of the levels of certain blood components and inflammatory markers.
The investigators of the current study sought to identify which specific markers would be the best predictors of early disease and could be used to either to rule out or rule in symptomatic myeloma. They hypothesized information from a simple blood panel could be a launch point for early detection; this screening could occur prior to the performance of protein electrophoresis and urinary Bence Jones protein confirmatory tests.
The study was an extension of a previous 2015 study that predicted the risk of MM across 14,860 patients in the Clinical Practice Research Datalink (CRPD). That study linked reports of symptoms (11 distinct symptoms) with abnormal blood values associated with myeloma, including measurements of cytopenia, hypercalcemia, and raised levels of inflammatory markers, creatinine, and mean corpuscular volume.
Building on this model, the researchers looked into which marker or blood component had the most predictive power. They linked the appearance of common symptoms of MM with the blood components and biomarkers collected up to 5 years before a diagnosis of MM, and compared these results with controls.
An abnormal erythrocyte sedimentation rate (ESR) was determined to be the biomarker most associated with MM; 85% of patients had an abnormal ESR reading during the year before diagnosis (P< .001). Following closely behind was plasma viscosity (PV); during this same period, 81% of patients had an abnormal PV prior to receiving a confirmatory diagnosis of MM (P< .001).
While no single blood test alone could predict the likelihood of MM, the best markers to rule out MM were ESR and PV, which were shown to increase approximately 2 years before diagnosis. Levels of C-reactive protein (CRP) were found to be of least value in making a MM diagnosis, demonstrating no difference between cases and controls. In total, the investigators decided the observation of normal levels of hemoglobin, calcium, and PV levels, in combination, allowed researchers to effectively rule out MM. In addition, hemoglobin levels started to decrease approximately 3 years before diagnosis, leading the researchers to conclude that full blood counts were the most useful tests to rule out MM.
In the presence of MM symptoms, data from a full blood count, combined with ESR, PV, and calcium values, could help expedite an official diagnosis of MM, the researchers concluded. Using this approach, “it would be possible to integrate a system within the electronic health record that identifies relevant symptoms or changes in blood parameters over time to alert the clinician to the (small) possibility of myeloma,” the authors wrote.1
- Koshiaris C, Van den Bruel A, Oke JL, et al. Early detection of multiple myeloma in primary care using blood tests[published online August 14, 2018]. Br J Gen Pract. doi: 10.3399/bjgp18X698357