Iron levels in cysts from patients with ovarian endometriosis are significantly higher than in patients with endometriosis-associated ovarian cancer, a distinction that can be used to differentiate between the two conditions.
The study, “Transverse Relaxation Rate of Cyst Fluid Can Predict Malignant Transformation of Ovarian Endometriosis,” published in the journal Magnetic Resonance in Medical Sciences, suggested that the method used in the study could be a non-invasive way of predicting which ovarian endometriosis patients are at risk to develop cancer.
Using the approach in a clinical setting could also aid physicians in determining when surgery is needed, instead of simply monitoring the disease.
Ovarian endometriosis increases the risk of ovarian cancer. Researchers believe that one mechanisms that may trigger the conversion of tissue from endometriosis to tumor is the repeated exposure to heme (an iron-containing compound in hemoglobin) and iron released during bleeding.
A recent study showed that patients with endometriosis-associated ovarian cancer have lower levels of iron in cyst fluid compared to patients with ovarian endometriosis but no cancer.
Researchers at Nara Medical University in Japan, therefore, designed a study to examine if cyst fluid iron levels could be a marker for endometriosis-associated ovarian cancer.
The study recruited 82 patients, 67 with ovarian endometriosis and 15 with cancer. When the women underwent surgery, researchers collected fluid from their cysts for analysis. Measurements using traditional biochemical methods showed that fluid in cysts of patients with endometriosis-associated ovarian cancer held significantly less iron than cysts from patients with endometriosis.
The difference could not be explained by differences in age, menopause status, or by the size of the investigated cysts.
Next, the research team evaluated if a non-invasive method — a magnetic resonance imaging (MRI) technique called MR relaxometry — was as accurate in determining the iron levels as traditional methods.
Results showed that it was — MR relaxometry measurements were in agreement with traditional method measurements, both when analyzing the cyst samples in the lab, and when measuring iron levels in the women before surgery.
The new method also correctly identified 86 percent of women with cancer, and 94 percent of those only with endometriosis, providing a potential tool for predicting the conversion from endometriosis to cancer.