For decades, the diagnosis of mucosal cancers has relied on a familiar approach.

Clinicians take a small sample of tissue and examine it under a microscope. Histopathology remains the gold standard for confirming cancer and has transformed patient care. But it also has major limits.

A biopsy captures only a tiny region of tissue and reflects a single moment in time – it’s a snapshot of a disease that is constantly changing. Cells shift their metabolism, tissue architecture evolves and molecular signals change long before a tumour becomes visible.

Cancer is a dynamic process, but biopsy-based diagnosis remains fundamentally static.

Biophotonics offers a different way of seeing. By using light to probe living tissue, it allows us to measure biochemical, structural and microvascular changes in real-time. Instead of removing tissue, we can study it in place, without labels, dyes or complex processing and open up new possibilities for monitoring and detecting cancer earlier.

Some of these advanced technologies are already beginning to move closer to the clinic. Fibre-based optical probes compatible with endoscopes, or handheld devices that could allow clinicians to examine tissue during routine procedures are examples showing what’s currently possible. A range of promising technologies including optical coherence tomography, Raman spectroscopy, multiphoton imaging and photoacoustic imaging can detect subtle changes in molecular composition and tissue structure that may signal the earliest stages of disease.

A more complete picture of cancer

To detect the earliest and most subtle changes in tissue, a single optical measurement is unlikely to be sufficient. Cancer affects multiple aspects of biology at the same time, from molecular composition to cellular structure and the surrounding microenvironment. Different biophotonic techniques capture different parts of this process, each offering a distinct view of how tissue is changing.

Bringing these approaches together can provide a more complete and meaningful picture. By combining complementary technologies in multimodal systems, researchers are beginning to build a richer understanding of disease in living tissue, one that reflects its dynamic and evolving nature.

Work in this area, including in our lab, is focused on developing these multimodal strategies for precision diagnostics to better map the biological landscape that underpins early disease in vivo. At the same time, advances in artificial intelligence are helping to make sense of the data. Optical measurements can generate large and complex datasets, often revealing patterns that are not immediately visible. Artificial intelligence can help translate these patterns into tools that support clinical decision-making.

Towards earlier and more proactive diagnosis

Looking ahead, these approaches could help shift cancer diagnosis from reactive to proactive. Instead of waiting for symptoms to appear, clinicians could use optical tools to detect the earliest signs of change.

Routine check-ups might one day include quick, non-invasive scans to identify areas of concern in the earliest stages of cancer development. For people at higher risk, repeated measurements over time could help track subtle changes and guide decisions about when to intervene.

Turning this vision into reality will take collaboration – engineers, clinicians and cancer researchers will need to work closely together. It will also require continued investment to move technologies from the lab into clinical use. The UK is in a strong position to lead this effort. Many of the technologies are currently maturing so turning this into health impact will really depend on strengthening commercial support at universities and ensuring clear and supportive regulatory pathways.