A research team led by the Medical University of Vienna has demonstrated in a recent study that the biological characteristics of a subgroup of head and neck tumours – which are very aggressive in many cases – are reflected in modern imaging techniques. PET/CT scans can thus provide clues to particularly active and prognostically unfavourable tumour types, thereby opening up new prospects for personalised treatment strategies for a type of cancer that has hitherto been difficult to treat. The results were published in the journal Molecular Cancer.

Head and neck squamous cell carcinomas are among the most common tumours affecting the oral cavity, pharynx and larynx. The study focused on a group of head and neck tumours caused not by the human papillomavirus (HPV) but by excessive alcohol and tobacco consumption. These are considered particularly difficult to treat and often have a poor prognosis. At the same time, there still is a lack of reliable markers that would enable a more accurate assessment of the disease course and targeted treatment planning. The study by the research team led by Stefan Stoiber (Centre for Pathophysiology, Infectiology and Immunology, MedUni Vienna) and Lukas Kenner (Department of Pathology, MedUni Vienna) shows that modern imaging techniques can help to detect particularly aggressive forms of head and neck cancer at an early stage. Specific patterns in positron emission tomography/computed tomography (PET/CT) scans, which are routinely performed in cancer diagnostics, reflect the biological activity of the tumour and could enable more targeted treatment in the future.

Specific signalling pathway particularly active in tumours
As the retrospective analysis of patient data shows, in HPV-negative head and neck tumours, a specific signalling pathway (the Hedgehog pathway) is often particularly active in the cancer cells, driving tumour growth. This activity can be indirectly detected in PET/CT images, for example through particularly strong uptake of a radioactive sugar molecule ([¹⁸F]FDG), which visualises the tumour’s metabolism. "We were able to show that the images reveal how biologically aggressive a tumour is," explains study leader Lukas Kenner. "This means that imaging can provide more information than just the size and location of the tumour or whether there are metastases."

In further experiments, the research team tested what happens when the identified growth-promoting signalling pathway is specifically blocked. In cell cultures and animal models, this significantly slowed tumour growth. At the same time, the image signals in the PET/CT scans also changed. "This is particularly exciting because it means we are not only influencing the tumour, but can also see whether a treatment is working simply by looking at the modern imaging," explains lead author Stefan Stoiber.

The results suggest that PET/CT scans could in future help to better assess the progression of tumours and tailor therapies to individual patients. "Further studies are needed before this approach can be used in routine clinical practice. However, the work represents another important step towards personalised cancer therapy," says Lukas Kenner.