The identification of several plasma biomarkers that appear to predict the risk of metastasis in melanoma could lead to more convenient and less costly monitoring of persons with this form of cancer.
With melanoma incidence on the rise—it is currently the fifth most common cancer in men and the seventh most common in women—an increasing number of patients are undergoing surveillance for disease recurrence. Metastasis risk is as low as less than 10% for persons with stage IA melanoma to as high as 70% in those with stage IIIC disease.
Monitoring usually involves a combination of physical examination, blood testing, and imaging, with no clear consensus regarding how frequently these tests should be done or how reliable they are.
However, researchers have discovered that seven biomarkers found in blood plasma were higher in melanoma patients with unresected stage IV disease than in those with resected stage I/II disease. These biomarkers include CEACAM (carcinoembryonic antigen-related cell adhesion molecule), ICAM-1 (intercellular adhesion molecule 1), osteopontin, MIA (melanoma inhibitory activity), GDF-15 (growth differentiation factor 15), TIMP-1 (tissue inhibitor of metalloproteinase 1), and S100B.
In the study of 108 persons with metastatic melanoma and 108 age- and gender-matched controls with resected stage I/II disease, split into equal-sized training and test cohorts, “About 81% of the of the stage I/II patients in the training set had no marker elevation, whereas 69% of the stage IV patients had elevation of at least one marker,” wrote Harriet M. Kluger, MD, associate professor of medicine at Yale University, New Haven, Connecticut, and colleagues in their report for Clinical Cancer Research (2011;17:2417-2425).
The team also calculated that area under the curve (AUC)—a measure of the blood test’s reliability—was 0.898. AUC calculations range from 0.5 to 1, with 1 being optimal and 0.5 being useless.
These findings led the investigators to conclude that plasma markers, particularly when assessed in combination, can be used to monitor persons with melanoma for disease recurrence and can complement currently used lactate dehydrogenase and imaging studies.
“This finding will need to be confirmed prospectively before it is used in the clinic,” cautioned Kluger in a separate statement, “but it shows that such testing is possible.”