A breast cancer cell Credit: London Research Institute EM Unit
This entry is part 6 of 23 in the series Science Surgery
Our Science Surgery series answers your cancer science questions.
If you have a question that you’d like us to answer, send it to us using the email address at the bottom of this post.
Tommy asked: “Does having had one type of cancer (and cured) make you more susceptible to getting any other type?”
To begin answering this question, you have to know the difference between second cancers, which this relates to, and secondary cancers. Second cancers are those that develop after a person has already had one cancer, and the two diseases are unrelated. Secondary cancers are where a person’s cancer comes back or spreads to another part of the body.
Now that more people are surviving cancer, scientists can follow more patients after they’ve been treated and record their health over time. And this includes seeing if they develop second cancers.
It’s this research that’s answering Tommy’s question. And it seems that the basic answer is ‘yes’, but the risk of developing a second cancer is very small. It also depends on many factors, which we’ll now explore in more detail.
One of the main culprits behind the risk of a second cancer is the type of treatment a patient had for their first, or primary cancer.
Certain chemotherapy drugs work by fatally damaging the DNA of fast-growing cells, a characteristic of cancer cells. But these drugs can also inadvertently affect healthy cells that are naturally dividing in the body, such as those in the blood.
This is what causes treatment side effects. And if the damaged cells don’t die, it’s possible this damage could lead to these cells becoming cancerous. That’s why some chemotherapy drugs have been linked with leukaemia, a type of blood cancer.
Radiotherapy also works by inflicting deadly damage to the DNA of cancer cells. While this has become a very precise, sophisticated treatment over the years, the radiation can still damage healthy cells around the tumour, which could increase the likelihood they one day become cancerous.
The risk from radiotherapy also depends on the amount of radiation given, and where in the body. For example breast cancer patients may have a higher risk of developing lung cancer, as the lungs are near the breast tissue.
To get a good look at what’s going on inside a person – whether that’s to help diagnose cancer, or monitor a cancer they’ve already been diagnosed with – doctors can use a variety of imaging techniques. Some of these, like x-rays and CT scans, use radiation to create pictures of the body’s inner workings.
These types of scans carry a very small risk of damaging healthy cells which, similar to radiotherapy, depends on how much radiation a person has received. But they’re an important part of some people’s cancer diagnosis and treatment, which is why the benefits outweigh the small potential risks when these scans are necessary.
The factors discussed so far relate to a person’s first cancer. But there are also many other factors that can raise the risk of a second cancer that aren’t related in this way. These include:
- Genetics: Some people inherit faults in genes that raise their risk of developing a number of different cancers, such as the BRCA1 or BRCA2 genes. So it’s possible that people whose cells carry these faults could develop second cancer as a result of their genes, following treatment and recovery from another cancer caused by the same underlying genetics.
- Lifestyle and environment: Certain things that fall under these categories, like smoking, can cause many different cancers. This means that if a person develops one type of cancer because of smoking, such as bladder cancer, it’s possible that the harm from smoking could lead to another later, like lung cancer.
- Age: Ageing is the biggest risk factor for most cancers. As many of us are living longer, the cells in our bodies have more time to go awry as they build up years of wear and tear. So if a person develops cancer when they’re young, unfortunately they’ll have a greater risk of developing a second cancer than someone who was diagnosed late in life, simply because they’ll be alive for longer after treatment.
The key difference between these risk factors and others is that the risk of a second cancer is tied to the person’s already heightened risk of developing cancer throughout their life, rather than being linked to their primary cancer.
So what does all of this mean?
This question can’t be answered with a simple ‘yes’ or ‘no’.
“We’ve known for decades that certain treatments carry risk of developing cancer,” says Professor Anthony Moorman, a Cancer Research UK-funded scientist working to improve the outlook for blood cancer patients.
“That’s why treatment schedules are constantly reviewed and, wherever possible, the intensity of the drugs is reduced in order to minimise the risk of second cancer but without reducing the chance of curing the primary cancer.”
“Ultimately, not taking cancer treatment is going to open up so many more problems than the small risk of developing a second cancer”
– Professor Moorman
“We need to continue and expand research into the long-term effects of cancer therapy because, fortunately, more and more people, especially children, are being cured of their primary cancer and we want them to go on and enjoy long healthy lives.”
Moorman says that while second cancers have been recognised for some time, the risk is still very small. A recent study carried out in Denmark found that the risk of cancer developing in people who have had cancer before was only 1.1 times greater than people who have no history of cancer.
“Ultimately, not taking cancer treatment is going to open up so many more problems than the small risk of developing a second cancer,” says Moorman. “Taking the recommended treatment is the patients’ very best chance of surviving.”
We’d like to thank Tommy for asking us this question. If you’d like to ask us something, email [email protected], leaving your first name and location (optional).
- Introducing our Science Surgery series
- Science Surgery: ‘What factors lead to a cell becoming cancerous?’
- Science Surgery: ‘Could more cancers be caused by inherited faulty genes than we now think?’
- Science Surgery: ‘Will cancer ever be cured?’
- Science Surgery: ‘Is the one-size-fits-all treatment approach obsolete?’
- Science Surgery: ‘Does having had cancer make you more likely to develop it again?’
- Science Surgery: ‘What’s being done to use treatments in different types of cancer?’
- Science Surgery: ‘Do we all have potentially cancerous cells in our bodies?’
- Science surgery: “What’s the difference between the words genome, gene and chromosome?”
- Science Surgery: ‘Will cancer ever be eradicated completely?’
- Science Surgery: ‘How quickly do tumours develop?’
- Science Surgery: ‘Why do never-smokers get lung cancer?’
- Science Surgery: ‘Why doesn’t the immune system attack cancer cells?’
- Science Surgery: ‘How do tumours ‘know’ where to spread?’
- Science Surgery: ‘How is skin cancer related to sun exposure?’
- Science Surgery: ‘Does cancer attack every age group?’
- Science Surgery: ‘Why do some cancer treatments stop working after so long?’
- Science Surgery: ‘Does cancer affect the future development of children?’
- Science Surgery: ‘How do cancer cells remain dormant for many years?’
- Science Surgery: ‘Why do some cancers metastasise, but others don’t?’
- Science Surgery: ‘Are benign tumours different from cancerous tumours?’
- Science Surgery: ‘How are children’s cancers different from adults’ cancers?’
- Science Surgery: ‘Can cancers develop in the heart?’
Frances February 28, 2018
I had Squamous cell carcinoma skin cancer on my calf i had it removed they got it all once you have cancer does that you will get again
Mrs b morris January 19, 2018
Cancer there is a cure but government won’t allow it as all industries wouald be out of busdinesd especially big pharma companies and any on To do with cancer mrs b morris they spread it in first place with injections and then all these pharadimic that supposing come from nowhere open your eyes people and see real truing keep on looking and then to the you will see true facts about cancer