INTRODUCTION

Hypericin is a potent photosensitizer (a hydroxylated phenantroperylenequinone) derived from the plant Hypericum perforatum. It is a new drug which in clinical trials and studies is showing great promise as an effective treatment for depression, PMS and menopausal symptoms, wounds and gastrointestinal ailments. However, it is showing most promise as an anti-cancer agent and to date has been used in the effective treatment of many different types of cancers. Hypericin has been found to be safe for clinical diagnostics without adverse side effects and also showed no genotoxic and cytotoxic results either in vitro or in vivo [1, 2, 3].

In this study we evaluated the use of hypericin as a selective marker for bladder cancer. Bladder cancer is a prevalent disease being the 4th most common form of malignancy worldwide and accounting for 4% of all cancer cases [4, 5]. In Singapore, it is the 9th most common form of cancer [6]. Mortality rates are very high due to invasive bladder cancer. Early detection and treatment are therefore mandatory in order to reduce mortality rates [7, 8].

While the non-invasive papillary tumours are clearly visible by white light cystoscopy, flat lesions such as carcinoma in situ (CIS) are rarely detectable by this method, sonography or other radiological methods [9]. Regular white light cystoscopies with cold cup biopsies are the current methods of surveillance of patients who are at high risk of recurrent bladder cancer. However,...