Is White Blood Cell Variation Diagnostic for Some Cancers?

Devin Koestler, a biostatistician at the Geisel School of Medicine at Dartmouth (Hanover, NH, USA) and colleagues are studying the potential of white cell variation for diagnostic purposes. Dr. Koestler develops and applies statistical methods to large volumes of data, seeking new approaches for understanding disease, cancer in particular. He is focused on the development and application of statistical methods for analyzing genomic data.

Working in the Quantitative Biomedical Sciences Program, Dr. Koestler's focus is the development of computational and statistical tools for investigating the process of DNA methylation. In methylation, a methyl group attaches itself to the DNA sometimes causing the DNA function to change dramatically. For example, the methyl group might block the expression of a tumor-suppressing gene.

“When we have an illness or a disease, that does something to our immune system,” Dr. Koestler explains. “It responds by providing whatever cells are necessary to combat that threat. In the blood, the leukocytes supply that immune response.”

The studies showed differences in methylation patterns in the leukocytes of cancer patients versus cancer-free individuals. Each type of leukocytes, or subset, exhibits its own distinctive signature methylation pattern. The proportions of these identifiable subsets shift, depending on the kind of disease they may be combating.

Using data from studies of ovarian, bladder, and head and neck cancers, the scientists demonstrated statistically significant correlations between the specific cancers and the methylation signatures that characterize leukocyte subsets. Analyzing the relative proportions of the leukocyte types in the blood sample can help predict the onset of a particular cancer or identify and diagnose a cancer in progress. The alternative of sampling a patient’s blood is far preferable to undergoing an invasive surgical biopsy.

The advantages of using methylation patterns to assess proportions of white blood cell subtypes in cancer studies extend beyond the bedside to the lab bench. Dr. Koestler said, “There is promise here for a new diagnostic tool. What we show here is not ready for immediate clinical utility, but I think it is on the right path.”

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Geisel School of Medicine at Dartmouth