Researchers have identified several potentially useful breast cancer biomarkers that indicate the presence and risk of malignancy.

By comparing healthy contralateral breast tissue of patients with malignant breast tumours and benign breast tumours, they found that multiple differences in biomarkers can be assessed with PET/MRI imaging, which could impact risk-adapted screening and risk-reduction strategies in clinical practice. In breast cancer, early detection remains key to improved prognosis and survival. While screening mammography has decreased mortality for breast cancer patients by 30 per cent, its sensitivity is limited and is decreased in women with dense breast tissue.

"Our study aimed to assess the differences in 18F-FDG PET/MRI biomarkers in healthy contralateral breast tissue among patients with malignant or benign breast tumors," said study researcher Doris Leithnert Memorial Sloan Kettering Cancer Centre in New York.

The study, published in the The Journal of Nuclear Medicine, included 141 patients with imaging abnormalities on mammography or sonography on a tumour-free contralateral breast. The patients underwent combined PET/MRI of the breast with dynamic contrast-enhanced MRI, diffusion-weighted imaging (DWI) and the radiotracer 18F-FDG. In all patients, several imaging biomarkers were recorded in the tumour-free breast: background parenchymal enhancement and fibroglandular tissue (from MRI), mean apparent diffusion coefficient (from DWI) and breast parenchymal uptake (from 18F-FDG PET).

According to the findings, differences among the biomarkers were analysed by two independent readers. A total of 100 malignant and 41 benign lesions were assessed, the researchers said. In the contralateral breast tissue, background parenchymal enhancement and breast parenchymal uptake were decreased and differed significantly between patients with benign and malignant lesions. "Based on these results, tracer uptake of normal breast parenchyma in 18F-FDG PET might serve as another important, easily quantifiable imaging biomarker in breast cancer, similar to breast density in mammography and background parenchymal enhancement in MRI," Leithner explained.

"As hybrid PET/MRI scanners are increasingly being used in clinical practice, they can simultaneously assess and monitor multiple imaging biomarkers -- including breast parenchymal uptake--which could consequently contribute to risk-adapted screening and guide risk-reduction strategies," Leithner added.