Positron emission tomography (PET) provides faster and more accurate diagnosis of aggressive breast cancer

– This method is faster and provides a more accurate diagnosis of HER2-positive aggressive breast cancer. The scan is also easier for the patient and has the advantage of examining the entire body at the same time, says Henrik Lindemann, chief physician and associate professor of oncology and head of hematology and oncology operations, Akademiska sjukhuset/Uppsala University, one of the initiators of the study published in the prestigious journal Nuclear Medicine.

The focus of the current study was to compare different methods for diagnosing HER2-positive breast cancer. It is a special form of breast cancer that accounts for just under 15 percent of all new breast cancer cases in Sweden, and is very aggressive if not treated with special medications with cytostatics.

To be able to determine whether a patient has HER2-positive breast cancer, today it is necessary to take a larger sample of the tumor with a so-called biopsy, which is followed up with microscopic examinations and sometimes special DNA tests. The research group in Uppsala has been experimenting for many years with another method developed in Sweden, in which the patient receives a small dose of small proteins, called aposomes, loaded with radioactive material. The patient is then scanned with PET or SPECT cameras that pick up radioactivity. Researchers have previously shown on a smaller scale that the method using PET cameras (HER2-PET) has the potential to replace the biopsy method, which will now be confirmed in a larger study in which the first 40 patients formed the first step.

Unexpectedly, we found that the HER2-PET method and the biopsy method showed different results in a significant proportion of patients. The question we then asked ourselves was which method could more reliably determine whether a patient would benefit from specific anti-HER2 therapy, and the results suggested that HER2-PET was better than the previously used biopsy method, says Henrik Lindemann.

– He concludes that the new method also means convenience for the patient and benefits for doctors, so we hope that HER2-PET will soon be used in clinical routine.

The study was conducted in collaboration with Afibody AB and the pharmaceutical company Roche. Major funding came from the Cancer Foundation and the Breast Cancer Foundation.

Facts: HER2 positive breast cancer

• It accounts for just under 15 percent of all new breast cancer cases in Sweden. It is an aggressive form of breast cancer in which the cancer cells divide more often and the tumor grows faster.
• HER2 stands for human epidermal growth factor receptor 2. It is a protein that can be found in large quantities on the surface of cancer cells.
• If the disease is detected at an early stage, the prognosis is often very good. It is partly associated with treatment with antibodies against HER2, which resulted in significantly increased survival.

• Treatment mainly consists of: surgery, cytostatics, radiotherapy, anti-HER2 therapy, hormonal therapy for those with hormone-sensitive HER2-positive breast cancer, and bone-strengthening medications.