Clinical Photobiology

Clinical Photobiology is located on the site of the Royal Cornwall Hospital in Truro with experimental facilities in the Public Health Laboratories and an office in the Knowledge Spa, the result of successful collaboration between the NHS and the Peninsula Medical School. Clinical Photobiology (formerly Cornwall Dermatology Research Project) was originally formed in 1997 as a medical research organisation with charitable status gaining support from collaborations formed with the Royal Cornwall Hospital, Cornwall College and the Duchy Health Charity.

In the summer of 2005 the group was officially incorporated into the Institute of Biomedical Sciences, Peninsula Medical School. The laboratory facilities enable the use of state of the art molecular biology techniques in conjunction with aseptic cell culture to investigate the action of a range of natural occurring compounds in respect of the DNA damage they either create or prevent in human cells, usually in association with a light insult. This is particularly relevant to the health of the population of Cornwall as the region exhibits one of the highest rates of skin cancer and the highest incidence of malignant melanoma (the most dangerous form of skin cancer) in the UK. Compounds with chemical properties that prevent irradiation-induced DNA damage could potentially be incorporated into topical sunscreens to prevent this damage occurring at source and thus may help to reduce skin cancer incidence.

Alongside the experimental research, in the clinic, novel modes of treatment are being used to treat patients with non-melanoma related skin cancers such as basal cell carcinoma, Bowen’s disease, and actinic keratoses. One such treatment is that of dermatological photodynamic therapy (PDT). In PDT a cream containing a compound (5-aminolaevulinic acid (ALA)) is applied to a patient’s skin on the lesion to be treated. After a period of time (3 hours) the excess cream is removed and the area is exposed to red light (wavelength 635 nm) for 7-9 minutes. The ALA in the cream is assimilated by a biosynthetic pathway (present in all nucleated cells and used to produce haem) which produces an intermediate product called protoporphryn IX (PPIX) which is light sensitive. The presence of light, PPIX and oxygen creates a volatile environment of reactive oxygen species which ultimately leads to the death of the tumour cell.

Patients with cancer that is superficial in nature, in problematic areas or in regions where excellent cosmesis is desirable benefit greatly from this non-invasive form of treatment. The patients are seen in the Outpatients department of the Dermatology Unit and can be treated by trained nursing staff as well as doctors. Tumour response is fairly rapid following treatment of superficial conditions with high levels of complete clinical clearance. However some of the more prevalent tumours, such as nodular basal cell carcinoma, generally greater in size and depth are more problematic to treat successfully and Clinical Photobiology is investigating the modification of standard dermatological PDT using novel compounds to improve treatment in patients with these types of lesions.

Other research the group is currently conducting, monitors some of the less well understood aspects of the mechanisms involved during PDT in collaboration with partners from the Universities of Plymouth and Exeter.

Contact details:
 Mrs Christine Middleton
Clinical Photobiology,
Peninsula Medical School
F.39 Knowledge Spa
Royal Cornwall Hospital
Truro
Cornwall
TR1 3HD
Tel: +44 (0)1872 256432 Fax: +44 (0)1872 256497
or visit the PMS website