Clinical utility of interleukin-18 in breast cancer patients: A pilot study

Aim: The aim of this study is to analyze the protein expression of interleukin 18 (IL-18) in patients with untreated breast cancer and further to evaluate its clinical efficacy in predicting treatment outcome. Methods: In the present study, a total of 50 untreated patients with invasive ductal carcinoma of breast were included in the study. Expression of IL-18 was studied by immunohistochemistry method. Statistical analysis was carried out using Statistical Package for Social Sciences statistical software and P ≤ 0.05 was considered statistically significant. Results: Seventy-two percent of the breast cancer patients showed the presence of cytoplasmic and/or nuclear IL-18 immunoreactivity. IL-18 expression was significantly and positively correlated with the stromal response (χ2 = 3.97, r = 0.282, P = 0.044). Further, the IL-18 immunoreactivity was significantly higher in patients with HER2 amplification as compared to luminal B (χ2 = 2.82, r = −0.523, P = 0.047) breast cancer patients. Moreover, a trend of increased IL-18 expression was observed in estrogen/progesterone receptor (ER/PR) negative patients as compared to ER/PR positive patients (χ2 = 3.41, r = −0.282, P = 0.066). Conclusion: IL-18 could be used as a potential predictive marker and guide clinicians for recommendations to newer treatment. It might serve as a potential therapeutic target to establish novel treatment approaches along with the current treatment protocol used.