Determining the growth rate and predictors of malignant transformation in Succinate Dehydrogenase B (SDHB)-related paragangliomas
Nicola Tufton, Queen Mary University of London
Aims
The most important susceptibility gene associated with phaeochromocytomas and paragangliomas (PPGLs) encodes the B-subunit of succinate dehydrogenase enzyme (SDHB). Mutations in SDHB confer a high risk of malignancy (up to 30%), but currently, malignancy can only be defined based on the presence of distant metastases. It is unknown how fast these tumours grow and at what stage they develop malignant potential, yet answers to these questions are essential for the design of safe surveillance programmes.
Cascade genetic testing has resulted in large numbers of asymptomatic carriers being identified, and these individuals are now undergoing 1-3 yearly clinical, biochemical and radiological surveillance review. The optimal frequency of these surveillance programmes is controversial as not enough data is available on the growth rate and malignant risk of these PPGLs. In the UK, there is now a growing cohort of patients that have undergone surveillance imaging for a number of years creating a valuable resource, that can be further interrogated to answer these questions.
To answer the question on when is the best time to intervene when a tumour is identified by:
- Defining the growth rate of SDHB-related PPGLs
- Defining radiological predictors of malignant SDHB-related PPGLs
- Correlate results with clinical and immunohistochemical data (Ki67)
Grant awarded: £2,000