Our impact: Pioneering a new laser therapy for cancer
1st November 2020
Thanks to the kindness and generosity of our supporters, we have been starting cancer cures from day one. In the 1980s and early 1990s, we funded several projects led by Professor Stephen Bown, which allowed him to propel a laser therapy called photodynamic therapy from the lab into the clinic. Photodynamic therapy is now available as a treatment option for patients with some types of cancer. And it can even lead to a cure for some people if used early enough.
With a background in physics before he went to medical school, Professor Stephen Bown's research career has focused on using lasers to treat many different diseases, particularly cancer. Stephen is a pioneer in his field and was a key person involved in the establishment of the National Medical Laser Centre at University College London in 1984.
In the late 70s and early 80s, Stephen was looking at how to use endoscopes to direct laser beams to stop stomach ulcers bleeding. This led on to the use of lasers with endoscopes to relieve obstructions to major organs such as the gullet, major airways and bowels caused by advanced cancers. Stephen and his team treated the first oesophageal cancer patient in 1981 and these techniques are now used in routine clinical practice.
While we were studying the use of laser to treat disease, people kept coming to us and saying you know about lasers, we know about many cancers, can’t we work together? The difficult thing to overcome was that using lasers to treat stomach ulcers and unblock hollow organs was actually quite crude. To treat smaller tumours you need to be a bit more sophisticated.
What is photodynamic therapy?
With support from Worldwide Cancer Research throughout the 80s and 90s, Stephen propelled Photodynamic Therapy (PDT), a less developed treatment for cancer, from the lab into the clinic. PDT is now available as a treatment option for patients with some types of cancer. And it can even lead to a cure for some people if used early enough.
In the 1980s, Stephen was awarded funding from Worldwide Cancer Research to study this experimental therapy. Research into PDT had already begun in labs around the world, but in a rush to get PDT into the clinic, some patients were suffering from complications caused by the effect of PDT on normal tissues adjacent to cancers.
PDT involves the use of a drug that is triggered when activated by light. For some types of early skin cancer, the drug is applied as a cream which can be activated by a range of sources of red light. It is widely available and gives good cosmetic results. For internal cancers, the light source is usually a laser and the drug is given by mouth or injection. PDT involves the patient taking the drug, which accumulates in the cancerous area. A laser is then used to shine light on the cancer, which activates the drug and causes local tissue destruction. Both the medicine and the laser are basically harmless until combined.
Understanding the basics
“We knew that to properly establish PDT as a technique we needed to understand the basics. My mission was to establish exactly what PDT did to a wide range of normal and diseased tissues. It was then possible to identify which diseases would be most likely to benefit from PDT. Top of the list were early cancers and pre-cancers in tubular organs like the lungs and gullet”, explained Stephen.
“Destroying the cancer is relatively easy, what is difficult is destroying it where it joins the normal tissue in such a way that the treated organ can maintain or restore its normal structure and function.
“The charity really helped us to understand what PDT did to normal tissue as well as the diseased tissue. This was vital for us to show how PDT could be used in cancer across a range of sites, including mouth, oesophagus, lungs, pancreas, prostate and bladder.”
“Undoubtedly, this all contributed to that pool of knowledge, which has got us to a point where we understand PDT and in what cancers it could be used.”
Progressing PDT as a treatment
PDT has found its place in today’s treatment arsenal as a therapy for early stage cancer and is approved by the NHS for use in oesophageal, skin and oral cancers. It’s also a highly effective treatment for conditions such as Bowen’s disease, where some very early cancer cells have emerged on the outermost layer of the skin.
Stephen’s research into PDT has continued throughout his career. His latest venture has been to team up with the US government and research groups in Boston and in India to develop technology that uses LED lights instead of a laser to activate the PDT drug. These drugs that accumulate in cancer cells and react to light can also be used to visualise early cancers in the mouth using a mobile phone, another valuable advance for countries with limited resources.
We believe that backing innovative ideas in research will find new cures cancer. Giving scientists the opportunity to make a start on their idea is what sparks discoveries that lead to kinder, more effective treatments. This was the vision that Worldwide Cancer Research was founded on over 40 years ago. Stephen’s research certainly captures that philosophy. Thanks to the generosity of our supporters, we have been able to be there, starting cancer cures from day one.
We are currently testing our technology in India because mouth cancer is highly prevalent there and PDT may be able to offer a cure for early cases. The LED light source runs on a couple of AA batteries so there’s no reliance on electricity. We are trying to bring a relatively cheap curative option to an area of the world that can’t normally get access.Professor Stephen Bown
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