Hematology

The study find that The Chronic lymphocytic leukemia (CLL); the rate of disease growth is apt to follow one of three trajectories: relentlessly upward; steadily level, or something in between; therefore scientists at Dana-Farber Cancer Institute, the Broad Institute of MIT and Harvard; Because Massachusetts General Hospital, and the University of Washington report in a new study. The particular course the disease takes is tightly linked to the genetic make-up of the cancer cells; particularly the number of growth-spurring “driver” mutations they contain.

Course the disease takes

genetic changes that occur very early in CLL development exert a powerful influence on the growth pattern the CLL cells will ultimately take. This raises the possibility that physicians may one day be able to predict the course of the disease by its molecular features at the time of diagnosis.

“Our findings provide a framework not only for understanding the differing patterns of CLL growth in patients but also for exploring the basic biological mechanisms that underlie these differences;” said Catherine J. Wu, MD, of Dana-Farber, the Broad Institute; and Brigham and Women’s Hospital; the co-senior author of the study with Gad Getz, Ph.D., of the Broad Institute and Massachusetts General Hospital.

Basic biological mechanisms

“Ultimately, we’d like to be able to tie the genotype of the disease the particular genetic abnormalities in a patient’s cancer cells to its phenotype, or how the cancer actually behaves;” Getz remarked. CLL is a useful model for studying the pace of cancer growth because it progresses at widely different rates from one patient to another; Wu explained.

In many patients; it persists at a very low level for many years before advancing to the point where treatment is necessary. In others; it progresses so rapidly that treatment is required shortly after diagnosis. Because To see if there were different patterns of CLL growth among patients; researchers drew on data from 107 patients diagnosed with the disease.

Particular genetic abnormalities

Beginning at diagnosis, each patient underwent periodic blood tests to track disease progress over the succeeding months and years; and continued until the disease reached a stage where treatment would begin. Each test consisted of a white blood cell count, which served as a proxy measure of CLL: the greater the number of white cells within a blood sample; the greater the burden of the disease.

The tests were conducted over a period ranging from two years in one patient to 19 years in another.The serial testing allowed researchers to calculate growth rates over time for CLL in each patient. Therefore They used a statistical model to determine if the rates were consistent with various patterns of cancer growth.