One way to predict survival of many types of cancer is by counting the number of tumor-attacking immune cells that have migrated into the tumor in an effort to eradicate it – a sign of the body’s immune response to the cancer. Scientists at Fred Hutchinson Cancer Research Center have developed a new method for counting a special class of cancer-fighting cells, called tumor-infiltrating T lymphocytes, or TILs, reliably, quickly and cheaply in patients with early stage and advanced ovarian cancer. They describe their findings online in Science Translational Medicine.
Such technology, a DNA-amplification technique, has the potential to predict treatment response, cancer recurrence and disease-free survival earlier and more effectively than any current method, according to lead researcher and cancer geneticist Jason H. Bielas, PhD.
Researchers developed the digital assay to count TILs, determine their frequency, and develop a grouping system to determine their “clonality,” a measure of the tumor’s T-cell population. Bielas and his team devised a way to easily screen T cells by capturing the genetic information of unique proteins these cells carry on their surface. In the present study, the team tested this novel technique, called “QuanTILfy,” on tumor samples from 30 ovarian cancer patients with known survival outcomes ranging from one to 22 months. They looked at the levels of TILs in their tumors and compared those levels to the women’s survival. They found that higher TIL numbers correlated with better survival. For example, the percentage of TILs was approximately threefold higher on average for patients with a survival rate of more than five years as compared to patients with a survival rate of less than two years. Read the study abstract.