May 24 2008
Researchers from the Peninsula Medical School in Cornwall, UK, have modified a photodynamic therapy (PDT) treatment that combines a topically applied cream with visible light to destroy cancer cells while leaving surrounding tissue unharmed.
The cream is applied directly to skin cancers and pre-cancers, which then naturally produces a photosensitive drug. A special red light is then shone on the tumour a few hours later, to activate this light sensitive compound. This results in cellular damage and the destruction of the tumour.
This technique results in reduced scarring and little or no damage to the surrounding healthy cells.
By adding the iron chelator CP94 to the cream, the research team have found that the effects of PDT are greatly improved and achieve greater reductions in tumour depth in tumours currently too thick to be treated easily by the non-enhanced form of this treatment.
This is the first time in the world that PDT trials of this modified PDT treatment have been carried out involving humans. Trials involving patients have taken place at clinics at the Royal Cornwall Hospitals NHS Trust in Truro.
PDT is achieving success in the treatment of actinic keratoses (lesions that can develop after years of exposure to UV light); Bowen’s disease (the growth of abnormal calls that can turn into skin cancer, and that is partly due to long-term exposure to the sun); and basal cell carcinoma (the most common form of skin cancer).
The work of the Peninsula Medical School in this area of research is funded in part by the Duchy Health Charity in Cornwall.
Dr. Alison Curnow from the Peninsula Medical School in Cornwall, commented: “PDT is very effective non-surgical treatment for certain types of dermatological cancers and precancers. It normally destroys the tumour without scarring or damage to surrounding healthy cells.”
She added: “Through years of research we have been able to develop a modified PDT treatment enabling for the first time for thicker nodular basal cell carcinomas to be treated effectively with a single PDT treatment. This is important, as this is a very common form of skin cancer.”
The work of Dr. Curnow and her team are part of a developing research theme for the Peninsula Medical School, which is Environment and Human Health. Operated mainly from the Peninsula Medical School in Cornwall, but with collaboration from colleagues within the institution across the South West of England, this research theme seeks to identify and study the links between our health and well-being and the environment.
Care Study
Graham O’Neill, 54, is technical marketing director at Imerys Minerals in Cornwall and lives near Mevagissey.
Graham was raised in the West Indies, and although his mother was very careful about protecting him from the sun, his exposure to the sun’s rays at an early age led to the discovery of melanomas on his skin in 1983.
“Back then the treatments were quite severe,” said Graham. “It involved liquid nitrogen, scraping out the melanoma and cauterizing it. Not only was this very painful, but it also left scarring.”
He now receives treatment with PDT, which is much better for him. He said: “The treatment is extremely good. From a personal point of view it is much less unpleasant and seems to be more effective. It also treats quite a big area in one go, which means fewer treatments in the long run. The other issue with melanomas is that they keep coming back. With PDT I have found that they do not return as frequently and, when they do, they are far less severe.”
On balance Graham is delighted with the treatments, which he has been receiving at Treliske Hospital, Royal Cornwall Hospitals NHS Trust in Truro. He said: “Compared with the old way of doing things, PDT is a fantastic therapy and one which I would recommend to other patients. It is very exciting that the Peninsula Medical School is taking such a worldwide lead in research in this area.”