IL-2 Blood Test Detects Breast Cancer

A laboratory test that measures the amount of interleukin-2 (IL-2) in blood is able to distinguish patients with breast cancer from those with benign breast disease and can also differentiate patients with node-positive and node-negative cancer, according to a new study.

IL-2 is a protein involved mainly in the proliferation and control of T cells, which are key regulators of the immune system and the cells most responsible for recognizing cancer cells and cancer cell antigens. Researchers at Fox Chase Cancer Center (Philadelphia, PA, USA; www.fccc.edu) found that patients whose cancer had invaded the lymph nodes had exceptionally low levels of IL-2.

If these findings can be validated in larger studies, doctors may some day be able to take a blood sample from a patient with suspected breast cancer and decide where aggressive therapy is needed, without resorting to expensive gene array technology or surgical removal and pathologic analysis of lymph node tissue. The study results were presented at the annual Clinical Congress of the American College of Surgeons in New Orleans (LA, USA) in October 2004.

Levels of IL-2 appear to correlate with nodal status, the principal indicator of locally advanced breast cancer. As such, these levels provide a means for obtaining reliable prognostic information. In the study, blood samples were obtained from 60 patients before they underwent surgical treatment for breast cancer or benign breast disease. T cells were activated and IL-2 levels were quantified using a standard laboratory isolation method. Histologic tests confirmed malignancy, and radiologic scans staged systemic disease.

"From a simple and basic laboratory methodology, we appear to have results that may not be directly comparable with, but would be suggestive of, the results obtained from gene array analysis,” noted Malcolm Kell, MD, FRCSI, a surgical fellow at Fox Chase Cancer Center. Gene arrays that analyze massive numbers of genes at once have identified breast cancer cohorts of patients that have much worse prognosis than others. Gene array analysis is not only expensive but is not widely available.

"It appears that with T cell interleukin, we can stratify node-positive from node-negative disease, which currently is the most important prognostic indicator for breast cancer patients who require adjuvant therapy,” concluded Dr. Kell.




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