Abstract 3192: Positive correlation between serum myeloperoxidase and free iron levels with stage of ovarian cancer: Potential biomarkers for early detection and prognosis of ovarian cancer
Authors: Saed Ghassan M. , Fletcher Nicole M. , Jiang Zhong L. , Levin Nancy K. , Diamond Michael P. , Abu-Soud Husam M. , Munkarah Adnan R. , Tainsky Michael A. 
Published: June 2012

The purpose of this study is to identify a positive correlation between serum myeloperoxidase (MPO) and free iron with ovarian cancer stages, such that they may be utilized as biomarkers for early detection of ovarian cancer (OC). Early-stage OC presents with nonspecific symptoms, and most often diagnosis is not made until after the malignancy has spread beyond the ovaries. Mortality rates for this type of malignancy are high due to the lack of an early-stage OC screening method. The rationale of this work stems from our identification of MPO, a hemeprotein previously recognized to be present only in hematopoietic cells, to be present in epithelial OC tissues, while not in normal tissues. Additionally, we have gathered compelling evidence that under oxidative stress, there is destruction of the MPO heme moiety, which results in the elevation of free iron levels in serum.

Serum samples were collected from women with early-stage (stages I & II, n=9) and late-stage OC (stages III & IV, n=8), benign gynecologic disorders (n=7), inflammation (endometriosis, n=5), and healthy controls (n=8). We have utilized the MPO ELISA assay and VITROS Fe Slide methods to measure serum MPO and free iron levels, respectively. Data were analyzed with a one-way ANOVA and post-hoc tests. A p&lt;0.05 was considered significant.

Both serum MPO and iron are significantly greater in late-stage as compared to early-stage OC (p&lt;0.01). The mean (SD) serum MPO (ng/ml) was 161.0 (33.8) and 98.4(16.3) while mean (SD) serum iron (μg/dl) was 521.3 (110.2) and 289.1(44.70) for the late and early-stage OC, respectively. For serum MPO (ng/ml), both late and early-stage OC were significantly different than healthy control; 43.1 (27.8) and benign gynecologic condition groups; 63.0 (21.0); (p&lt;0.01). The control and benign condition groups were not significantly different.

For serum iron (μg/dl), there was a significant difference between early-stage OC; 289.1 (44.70), the healthy control; 104.0 (27.9); the benign gynecologic; 102.1 (32.4); and inflammation groups; 93.1 (18.8). There was no significant difference between healthy control, benign gynecologic, and inflammation groups.

There was no significant difference in serum MPO levels between early-stage OC and the inflammation group. However, when examining serum iron levels (μg/dl) in these groups, a significant difference between early-stage OC; 289.1 (44.7) and the inflammation group; 93.1 (18.8) was observed (p&lt;0.01).

Collectively, these findings clearly indicate a potential role for the combination of serum MPO and iron as biomarkers for early detection and prognosis of ovarian cancer. In addition, there is a great potential therapeutic value utilizing MPO inhibitors for the treatment of ovarian cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3192. doi:10.1158/1538-7445.AM2011-3192