A recent study from several UK universities reveals new insights about the genetic origins of colorectal cancer. Using data from the 100,000 Genomes Project, researchers performed the most comprehensive genetic analysis of colorectal cancer to date, identifying new driver genes and potential drug targets.

What is colorectal cancer?

Colorectal cancer, also known as bowel cancer, is the third most common cancer worldwide.

It originates in the large bowel of the digestive system, but can spread to other parts of the body in its later stages.

The size and severity of colorectal cancer can vary case to case, but it is consistently among the most common cancers in the UK each year. This means it is vital that our approaches to diagnosis and treatment continue to improve.

What is whole genome sequencing?

The human genome is the complete set of genetic code present in each person. It is an end-to-end sequence of DNA that acts as an instruction manual, allowing us to survive, function and grow.

Whole genome sequencing is a type of genetic testing that allows us to look at this entire code, all at once.

It lets researchers to look for any changes or ‘glitches’ in the instruction manual that might be causing problems, such as cancer.

Why is whole genome sequencing helpful for cancer?

Previously, research into colorectal cancer has used methods that only analyse a portion of the genome. For example, panel sequencing, a technique that looks at a handful of specific, pre-selected genes rather than the whole genome at once.

By looking at the entire genome instead of just small sections, we can gain a much clearer and more complete picture of which genetic changes might be causing the cancer.

A recent study by Cornish and colleagues published in Nature, analysed genomes from over 2,000 individuals with colorectal cancer, making it the largest genetic analysis of this cancer to date.

All individuals in the study were participants in the 100,000 Genomes Project, a landmark research study led by Genomics England in partnership with the NHS.

Discovering new cancer-related genes

Using data from whole genome sequencing, the researchers built a detailed map of the genetic landscape of colorectal cancer.

One of the most significant findings from this analysis was the identification of more than 250 genes that play a crucial role in colorectal cancer.

The majority of these genes had not been previously linked to colorectal or other cancers, meaning their discovery helps to expand our understanding of how cancer develops. Furthermore, many of these genetic changes could potentially be targeted with existing treatments that are currently used across other cancer types.

In addition to identifying new genetic changes, the researchers also uncovered new colorectal cancer subgroups. These are categories of cancer with specific genetic characteristics that affect how cancer behaves and responds to treatment.

Genomic data in healthcare

The findings here show that analysing large sets of genomic data, such as from the 100,000 Genomes Project, can greatly improve our understanding of cancer and how it could be treated.

By linking both genomic and medical data from patients in the NHS, we can study the relationship between genes and our health, helping to shape our approaches to treatment.

Ultimately, this could allow clinicians to tailor treatment to each individual patient, according to which genetic changes are causing their cancer. This is called ‘personalised medicine’, and you can learn more about it in our podcast: What is personalised medicine?

As we continue to analyse genomic data, our understanding of cancer continues to improve. This study provides valuable evidence to support the use of whole genome sequencing in standard cancer care, to help give patients the best outcomes possible.

The research and its findings would not have been possible without participants from the 100,000 Genomes Project consenting to donate their data for research purposes, which Genomics England thanks them for.