Interleukine-2 serum level in breast cancer patients.

Background: Breast cancer is a form of cancer that typically affects females. In general, cancer is caused by an imbalance between oncogene and supressor gene factors, including immunity factors against cancer cells. This study aims to compare the levels of IL-2 between breast cancer patients and healthy women, and also compare the levels of IL-2 between HER-2 positive and HER-2 negative, ER/PR positive and ER/PR negative, and among different malignancy grades of breast cancer patients.

Methods: This is an observational study using case control method. We include 46 breast cancer patients and 40 healthy women. Blood samples were taken from 46 breast cancer patients (20 HER-2 negative and 26 HER-2 positive patients); 40 of them received hormonal status (29 ER/PR negative and 11 ER/PR positive patients); and from 46 breast cancer patients, 37 of them were divided into malignancy grade. The level of IL-2 was compared between cases and controls and also among the breast cancer patients with HER-2 negative and positive; ER/PR negative and positive; and breast cancer with low, moderate and high grade.

Results: IL-2 level was higher in breast cancer patients than in controls (9.400 pg/mL and 3.990 pg/mL respectively, P=0.003). IL-2 level is significantly higher in the breast cancer cases with positive HER-2 compared to negative HER-2 expression (11.154pg/mL and 7.120pg/mL respectively, P=0.001. No association between ER/PR expression nor breast cancer grading with IL-2 level.

Conclusion: IL-2 level is higher in breast cancer patients, especially breast cancer patients with HER-2 positive expression.