Interleukin-18 and −10 may be associated with lymph node metastasis in breast cancer

Reports on the expression of interleukin (IL)-10 in breast cancer are rare. The present study investigated the correlation between IL-18 and −10 in breast cancer, and assessed their clinical significance. Breast cancer (n=104) and breast fibroadenoma (n=31) tissues that were surgically removed and pathologically confirmed at Jinan Central Hospital Affiliated to Shandong University (Jinan, China) between November 2016 and January 2019 were collected. The expression of IL-18 and −10 was observed via immunohistochemistry. Breast cancer tissues were positive for IL-18 expression, which was primarily located in the cell membrane and cytoplasm. A significant difference in IL-18 expression was observed between breast cancer and fibroadenoma tissues (75.0 vs. 19.4%; P<0.001). IL-10 was expressed in breast cancer tissues and primarily located in the cytoplasm. Breast cancer tissues showed a significantly higher level of IL-10 expression compared with breast fibroadenoma tissues (78.8 vs. 22.6%; P<0.001). The regions of positive IL-18 and −10 expression were consistent. Tissues with positive expression of IL-18 and/or −10 had a significantly higher rate of lymph node metastasis than those with negative expression (IL-18: 67.9 vs. 42.3%; P=0.035; and IL-10: 67.1 vs. 40.9%; P=0.047). In conclusion, IL-18 is highly expressed in breast cancer and correlates positively with IL-10. Both IL-18 and −10 may correlate positively with lymph node metastasis in breast cancer.