Trial Information

A Correlation of the Endoscopic Characteristics of Colonic LSTs With Their Somatic or Germline Mutations. A Prospective, Genome Wide Study

Laterally spreading tumours (LSTs), are polyps that have a lateral extension along the colon
wall with minimal vertical growth. It has become evident over the last few years that rather
than being a single entity requiring an accumulation of mutations, colon cancer is in fact a
heterogenous disease forming via multiple distinct genetic pathways. Additionally, with
improved endoscopic characterization, it has been noted from experience at Westmead hospital
that two macroscopically distinct types of LSTs, "granular" and "non granular", have
different natural histories and risks of invasive cancer. It is therefore hypothesised that
different polyp types have different genetic abnormalities, and potentially form via
distinct genetic pathways, although this theory has not been widely examined.

This knowledge would be important in furthering our understanding of the development of
cancer. There is accumulating evidence that genetic abnormalities may be a better predictor
of cancer behaviour than histological grade. Additionally, guidelines for colonoscopy
surveillance are currently a one size fits all approach that do not reflect the genetic
heterogeneity of the disease and the knowledge that only 5% of polyps progress to cancer.
Genetic studies may assess future cancer risk to a person in polyps once removed and plan
surveillance colonoscopy frequency. This is an area with interest currently due to the
national bowel cancer screening programme, with obvious cost implications for decision
makers.