The pilot study allowed for earlier detection of neoplastic lesions that could be missed in standard tests.

The doctors used HER2 receptor imaging in a 41-year-old patient suffering from metastatic breast cancer, using an affibody molecule labelled with Gallium-68. Specialists, led by Professor Gabriela Kramer-Marek, were able to detect neoplastic lesions that remained invisible during standard 18F-FDG imaging.

According to the institute, the results of the initial phase of the pilot clinical trial are very promising. The team conducted research on the possibility of predicting the response to treatment of patients with breast cancer using immuno-PET imaging. The key target of the study was the HER2 receptor, a protein important for the development of breast cancer. High levels of HER2 are associated with more aggressive tumours and their poorer response to therapy.

'Doctors recommend testing every invasive breast cancer for HER2, as it can significantly influence decisions about further treatment. HER2 testing is usually performed in a hospital laboratory using a tissue sample taken from the breast cancer during a biopsy or surgery. Results are usually available within 1-3 weeks, but invasive tumour biopsies, commonly performed to assess HER2 status, may give an incomplete picture due to the heterogeneity of receptor expression, which can occur in different areas of the tumour', says Professor Kramer-Marek.

According to the institute’s press release, there are several approved therapies targeting the HER2 receptor, such as Herceptin, but the effectiveness of these drugs depends on the receptor status in the tumour. Clinicians and scientists from Gliwice used a PET radiotracer to image HER2 throughout the patient's body.

'This gives us the ability to visualize the level of receptor expression in the entire tumour and in the patient's entire body. In addition, these imaging examinations can be repeated to monitor changes in receptor expression during treatment', says Professor Kramer-Marek.

The radiotracer tested by the Gliwice team is based on an Affibody molecule - a small protein designed to bind to the HER2 receptor with high specificity and affinity. With this radiotracer, the receptor can be detected within an hour of administration. This is a much faster method compared to traditional methods that require tissue collection and several days for analysis.

Additionally, the radiotracer does not interfere with the binding process of HER2-targeted drugs, which makes it possible to monitor the treatment effectiveness in real time. In the case of a patient with metastatic breast cancer, the radiotracer detected more neoplastic lesions than the standard 18F-FDG, confirming high levels of HER2 in the analysed areas.

'The data collected from these PET scans will allow us to tailor treatment plans to each patient individually, based on the current status of their HER2 receptors. With this knowledge, we want to design more effective strategies for personalized medicine, thus improving treatment outcomes', Professor Kramer-Marek says.

She adds that doctors also aim to avoid administering therapies to patients that will not be effective for them, and are often associated with significant toxicity. In this way, they want to spare them unnecessary side effects.

Affibody AB provided the Affibody molecule, which was used for non-invasive HER2 imaging using the PET radiotracer in the study conducted by the National Research Institute of Oncology in Gliwice. (PAP)

Julia Szymańska

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