To explain what the likelihood is that someone living with Lynch syndrome will develop cancer, we first need to explain what the likelihood is that someone in the general population will develop cancer.

What does it mean when my doctor or nurse talks about cancer in the general population?

Unfortunately, cancer is common, and in the majority of cases is not inherited. As many as 1 in 2 people will develop cancer in their lifetime. That is 50% of the world’s population.

Most cancers are not inherited and occur out sporadically or ‘out of the blue’. Their origin is based on the tumour cells themselves. Some common reasons for cancer are ageing, exposure to chemicals, radiation, hormones or other factors in the body or environment. Sporadic cancers usually occur at a later age in life because people are not born with a predisposition, and the development of cancer usually takes many years to generate.

It’s important to be aware of this because nobody is free from cancer risk. When clinicians explain to people with inherited cancer predisposition syndromes that they have an increased likelihood of developing certain cancer types, they make comparisons to the general population, so it is helpful to know that everyone is at risk to some extent.

If you are reading this, and you don’t have an inherited cancer predisposition syndrome, it is important to still take steps to prevent cancer from occurring. For instance, take part in national cancer prevention programme such as the National Bowel Cancer Screening programme or the National Cervical Cancer Screening Programme if you are eligible and invited to participate.

Likelihood of developing cancer in Lynch syndrome

The risk or likelihood of developing cancer is there, even in the general population. Lynch syndrome makes certain (not all) cancer types more likely to develop. This is due having less protection from the cancer mismatch repair genes. This doesn’t mean that you will definitely develop cancer, but having less protection makes it more likely.

However, there is a way in which you can balance out this increased likelihood, and that is by taking control and remain vigilant. If you have a new concerning symptom (such as a change in bowel habit, unusual bleeding in between menstrual periods, lumps/swelling in the abdomen, or new/changing or unusual skin growth or lesion) that last for over 2 weeks, we recommend that you seek medical advice.

In addition, it is recommended that you take control of your personalised surveillance programme, and follow a healthy lifestyle that will help you to reduce, and balance out, this increased risk of developing cancer, or at least enable it to be detected and treated early. If you have been diagnosed with Lynch syndrome, you can find some general recommendations in the Screening and risk reducing strategies section. Your team will discuss these recommendations, and some other gene specific recommendations, with you.

Not everyone living with Lynch syndrome will develop cancer. The chance of developing cancer is considerably lower in individuals who know that they have Lynch syndrome and follow their enhanced screening programme, compared to individuals who have Lynch syndrome but are unaware of their diagnosis. This is because knowing about the risk gives individuals the chance to take action in a timely manner, and can help to ensure that cancer is detected at an early stage so it can be treated more effectively.

It is important to highlight that Lynch syndrome doesn’t usually affect children. This is why the enhanced cancer prevention programs for Lynch syndrome starts between the ages of 25 to 35. The start age of your family cancer prevention programme will depend on which gene is implicated. For instance, individuals with genetic changes in the PMS2 gene have a lower likelihood of developing cancer compared to those who have a genetic change in the MLH1 gene.

However, what really makes a difference is to follow your personalised screening programme, and make sure you make the most of your regular check-ups. In any case, if you have a family history of earlier onset of cancers, make your clinician aware, as you and your family might begin screening a little earlier.

In addition to that, regardless of the age in which your cancer prevention programme starts, it is important to always be symptom aware and to remain vigilant. If you have a new symptom that lasts for over 2 weeks, it is recommended that you seek medical advice, regardless of your age.

It is impossible to know your exact risk or likelihood of developing cancer due to Lynch syndrome because other factors influence the risks such as lifestyle, the foods you eat, and environmental toxins. The way Lynch syndrome behaves in you and your family can be very different as the affected Lynch syndrome genes interact with other genes as well. Family history should be taken into consideration, but each family member will be affected differently.

There are other general lifestyle recommendations that will reduce your likelihood of developing cancer. You can find these lifestyle recommendations in the gene-specific information in the Screening and risk reducing strategies section.

Is there a cure?

There is no cure for Lynch syndrome, but your clinicians will help you put together a personalised screening programme that will help you manage Lynch syndrome so you can balance out your increased risk of cancer and live a normal life.

I have Lynch syndrome and I have already had cancer. Can I get cancer again?

Yes, cancer can happen again. This is why is important to follow your personalised cancer prevention programme, as this will significantly reduce your risk of cancer, or catch it and treat it early.