Genetic testing for colorectal cancer: What is it?

The risk of colorectal cancer can be increased significanty due to genetic factors. Leading consultant colorectal and general surgeon, Mr Ashish Sinha, explains genetic testing for the disease.

What is genetic testing for colorectal cancer, and how does it aid in preventing this type of cancer?

All cancers have a genetic component. As we age, errors in our DNA can occur, leading to cancer development, including colorectal cancer, which is commonly seen in older individuals.

Genetics plays a crucial role in identifying colorectal cancer at an early age, making genetic testing particularly significant. It allows us to tailor treatment plans for patients based on their genetic profile. Additionally, if we diagnose colorectal cancer resulting from an underlying genetic predisposition, we can offer screening to the patient's close relatives.

Which specific genetic markers or mutations are commonly tested for in individuals at risk of colorectal cancer?

Researchers continue to discover genes associated with colorectal cancer development.

Currently, two main syndromes are prominent in our investigation. One is linked to polyps; individuals with a higher number of polyps are at an increased risk of developing colorectal cancer.

The second is Lynch syndrome, which encompasses several diseases caused by up to five different genes. Importantly, Lynch syndrome can affect organs beyond the bowel.

How is the colorectal cancer genetic test performed?

Genetic testing for colorectal cancer is typically performed in a laboratory setting. Following a colonoscopy, an endoscopist collects a biopsy sample. The laboratory-based tests specifically search for genetic mutations within the tumour to determine the individual's genetic risk.

What are the implications and advantages of undergoing genetic testing for colorectal cancer in terms of prevention and early detection?

The most significant advantage of genetic testing is early detection. If colorectal cancer is identified at an early stage, the chances of successful treatment and cure are significantly higher. Therefore, it's essential to consider colorectal cancer screening if any related symptoms, such as changes in bowel habits, are noticed.

How do the results of genetic testing guide personalised risk assessment and screening recommendations for individuals with a higher risk of developing colorectal cancer?

Genetic testing plays a critical role in assessing individual risk. By analysing relevant data, such as genetic risk, polyp types, and early-onset cases, we can determine the appropriate frequency of surveillance and recommend prophylactic surgery for at-risk organs. The ultimate goal is cancer prevention. In cases of established colorectal cancer, genetic test results can also help inform additional or adjuvant treatment strategies.

If you require genetic testing and would like to book a consultation with Mr Sinha, simply visit his Top Doctors profile today.