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Scientists react to news of Kate Middleton’s cancer diagnosis.
Prof Phil Dash, Professor of Cancer Biology, University of Reading, said:
What is preventative chemotherapy?
“When surgeons remove a tumour it is possible that a few cancer cells remain behind and that these could cause the tumour to regrow if not treated. Preventative chemotherapy kills off any residual cancer cells making it less likely the cancer will recur.
When do patients need it?
“Preventative chemotherapy would be given after surgery to remove the tumour.
What does it do / is it intended to do?
“Traditional chemotherapy treatments aim to kill dividing cells. This would obviously include cancer cells but will often also kill healthy cells in the body which also happen to be dividing such as cells in hair follicles, cells lining the digestive system and cells in the bone marrow. Killing these cells causes some of the common side effects of chemotherapy treatment such as hair loss, loss of appetite, tiredness and nausea. Newer types of chemotherapy treatment make use of more targeted therapies which can exploit specific weaknesses in cancer cells in order to kill them. Targeted therapies can have fewer side effects but won’t work in all patients as only some tumours will have the necessary weakness.
How long does preventative chemo take? Do people normally have one or multiple courses?
“This will depend on the type and stage of the cancer. Chemotherapy can be given as a combination treatment containing several types of drugs and these can be given all at once or spread over multiple courses. Preventative chemotherapy will generally require lower doses, particularly where the cancer was detected early and the tumour removed surgically.
What side effects does it have – fatigue, hair loss, nausea, rashes, etc?
“Chemotherapy can have quite significant side-effects, but preventative chemotherapy can be given at lower doses and therefore be easier on the patients. Targeted chemotherapy treatments can also have fewer side effects than more traditional chemotherapy treatments and are generally better tolerated by patients.”
Prof Iain McNeish, Chair of Oncology, Imperial College London; and Head of Division of Cancer, Hammersmith Hospital, said:
What is preventative chemotherapy?
“Chemotherapy that is given after surgery to try to prevent cancer from returning. Oncologists tend to use the term ‘adjuvant’ to describe the treatment the PoW is receiving.
When do patients need it?
“It’s given after surgery. Although surgery can remove all visible evidence of cancer, we know that there can be microscopic, invisible cancer cells still in the body that can grow back – hence why cancer can sometimes recur. The purpose of adjuvant chemotherapy is to try to kill them and prevent recurrence.
How long does preventative chemo take? Do people normally have one or multiple courses?
“It varies very much from cancer to cancer, but typically patients receive 6 – 8 cycles of treatment, usually given every 2 – 3 weeks.
What side effects does it have?
“Again, it varies hugely on what chemotherapy is being given, which, in turn depends on the type of cancer being treated. However, fatigue is the commonest side effect of all chemotherapy. Hair loss is not universal – some chemotherapy drugs cause inevitable hair loss, others very little. It is sometimes possible to prevent hair loss using a cold cap (the name is fairly self-explanatory – see details here from Macmillan website). Nausea is fairly common, although again it depends on which chemotherapy drug is being given. However, modern anti-sickness medications are usually very effective. Most chemotherapy causes at least some damage to the bone marrow, which can cause anaemia (which can exacerbate chemotherapy-induced fatigue), low white blood cell counts (increasing the risk of infection) and low platelet counts (which can increase the risk of bleeding). Some chemotherapy drugs can cause damage to nerves in the fingers and toes – usually manifests as pins and needles/tingling sensations, but can also causes pain or numbness. Important to say that chemotherapy side effects all improve and most disappear completely. Can take several months (or even 1-2 years for nerve damage) but they definitely all improve.”
Comments sent out on Sunday 24 March:
Prof Lawrence Young, Professor of Molecular Oncology, Warwick Medical School, and Director of the Warwick Cancer Research Centre, University of Warwick, said:
What is preventative chemotherapy?
“Preventative chemotherapy (also called adjuvant therapy) is the use of anti-cancer drugs to mop up any remaining or lurking cancer cells after primary cancer treatment, most often after surgical removal of the tumour.”
When do patients need it?
“This treatment is often used after primary cancer therapy, such as surgery, to reduce the chance of cancer coming back and spreading.”
What does it do / is it intended to do?
“The drugs are used to kill off any cancer cells that might be in the body after removal of the primary tumour. Cancer chemotherapy drugs mostly target rapidly growing cells and will destroy any cancer cells that are remaining in the body.”
How long does preventative chemo take?
“The sort of chemotherapy and the time length (usually 3-6months) of treatment depends on the type and stage of cancer as confirmed by examining the cancer removed at surgery.”
Do people normally have one or multiple courses?
“This also depends on the nature of the original tumour as detected in tissue after the initial surgery. An incidental finding of cancer during surgery for other conditions is often associated with the tumour being at an early stage when subsequent chemotherapy is much more effective. This is likely to mean that a single course of chemotherapy will be sufficient to ensure that if any cancer cells are present, they will be destroyed.”
What side effects does it have?
“The side effects of chemotherapy also depend on the type of drugs used but commonly include tiredness, nausea, increased risk of getting an infection and loss of appetite.”
Dr Mangesh Thorat, Honorary Reader, Queen Mary University of London; and Consultant Breast Surgeon, Homerton University Hospital, said:
“The term “preventative chemotherapy” is not used medically, or indeed in scientific communications (“preventive therapy” is a different term, more on that below). Without wanting to speculate, the most likely nature of chemotherapy in this scenario is what is commonly referred to (in medical language) as “adjuvant chemotherapy”. Patients may understand it as “preventive chemotherapy” since the purpose of such treatment is to prevent cancer from coming back, a possibility that exists even in very early stages of cancer.
“One of the hallmarks of invasive cancer cells is their ability to spread, within the organ of origin and beyond (referred to as metastasis). The likelihood of such metastasis is driven by the biology and stage of cancer. The more aggressive the biology, for example, higher grade or more advanced the stage, for example, larger tumour or cancer having spread to nearby lymph nodes, the greater are the chances of metastasis. Such metastasis or spread of cancer cells to distant organs like lung or liver or bone starts at microscopic level. The cancer cells start residing in these organs and start growing. The tests and scans we currently have available can detect such cancer cell populations only after they reach a certain size (at least a few mm) and therefore in early stages of metastasis, these remain under the radar or undetectable. In an early-stage cancer patient with normal tests/scans for metastasis, two possibilities exist, either the microscopic spread of cancer cells has occurred but not detectable or more favourably, such spread has not occurred. As it is not possible to know which of the two categories an individual patient belongs, we often use probabilities of such spread based of the features of surgically removed tumour and estimate benefit-harm balance of adjuvant systemic treatment. The goal of adjuvant systemic treatment is to kill or keep under control the cancer cells that may have spread to other organs. There are many types of adjuvant systemic treatments.
“Chemotherapy is one such type of treatment that uses drugs which particularly act on rapidly dividing cells, for example, cancer cells and kills such cells. As these drugs cannot distinguish between the cell types, they also end up killing many rapidly dividing normal cells in the body, for example, white blood cells or cells from the mucosal linings. It is this collateral damage that often leads to some of the side-effects of chemotherapy e.g. low blood counts with increased risk of infection or mucositis/mouth ulcers or diarrhoea or hair loss. The other side-effects, e.g. nausea and vomiting are often directly induced by the drugs. The risk of some side-effects and their consequences is often lower in younger individuals due to greater functional reserves and ability of young tissues to heal more rapidly.
“There are a very large number of chemotherapy drugs and combinations resulting in many different regimens, even for a single type of cancer. The duration of regimens can vary from as short as four months, to as long as a year. Some uncommonly used low dose regimens can be even longer. Recovery from chemotherapy also varies depending on the regimen used but there are parts in a chemotherapy cycle when the patient may feel well enough to function completely normally.
A note on preventive therapy:
“In individuals who are otherwise healthy, but at an increased risk of developing a cancer, we often discuss use of drugs to reduce their risk of developing cancer. This is referred to as “preventive therapy” or “chemoprevention”. The drugs used for such purpose do not belong to the “chemotherapy” class of drugs. Some examples are tamoxifen, or anastrozole, a drug recently approved by MHRA (and recommended by NICE) to reduce risk of breast cancer in women who are at a high risk of developing breast cancer. Aspirin in individuals with Lynch syndrome to reduce their risk of developing bowel cancer is another such example.”
Comments sent out on Saturday 23 March:
Prof Richard Sullivan MD PhD, King’s College London & Guy’s Comprehensive Cancer Centre, Global Oncology Group & Institute of Cancer Policy, said
“In terms of a broader comment I can share what is essentially driving what we as clinical leadership across the UK wrote about in Lancet Oncology (https://www.thelancet.com/journals/lanonc/article/PIIS1470-2045(23)00511-9/abstract).
“Broadly,
Prof Andrew Beggs, MRC Senior Clinical Fellow and Consultant Colorectal Surgeon, University of Birmingham, said:
“There are a number of reasons why cancer rates in young people might be rising (I run a inherited cancers clinic in Birmingham):
“Cancers in the abdomen in young people use the same kind of treatment as those for older people, but in younger people there is a higher likelihood that the cancer will be due to a specific cause and can be treated using targeted chemotherapy agents that really improve prognosis.”
Comments sent out on Friday 22 March:
Chief Executive of Cancer Research UK, Michelle Mitchell, said:
“On behalf of everyone at Cancer Research UK, I wish Her Royal Highness a full, swift recovery and return to good health. During this difficult time, it’s important that the Princess is given the time and space to focus on her treatment and that we respect the family’s privacy.
“Nearly one in two of us will develop cancer during our lifetimes, but many more are affected when someone they love is diagnosed with cancer. Thanks to research there is hope – cancer survival has doubled in the last 50 years.
“High profile cancer cases often act as a prompt to encourage people to find out more or think about their own health. If people spot something that’s not normal for them or isn’t going away, they should check with their GP. It probably won’t be cancer. But if it is, spotting it at an early stage means treatment is more likely to be successful.”
Dr Mangesh Thorat, Honorary Reader, Queen Mary University of London and Consultant Breast Surgeon, Homerton University Hospital, said:
“Surgery is the most curative form of treatment for early-stage cancers of solid organs. However, occasionally some cancer cells escape the organ of their origin and start residing in other organs such as lung or liver. Tests and scans currently available are unable to detect such microscopic spread and therefore to improve chances of cure, presumptive treatment of such likely spread is often undertaken even after the cancer in the solid organ of origin is completely removed. Depending on the type of cancer, a range of drugs that can reach all organs of body where such spread might have occurred are used. Chemotherapy is one such type of treatment that uses drugs which particularly act on rapidly dividing cells, for example, cancer cells and kills such cells. As these drugs cannot distinguish between the cell types, they also end up killing many rapidly dividing normal cells in the body, for example, white blood cells or cells from the mucosal linings. It is this collateral damage that often leads to some of the side-effects of chemotherapy e.g. low blood counts with increased risk of infection or mucositis/mouth ulcers or diarrhoea. The other side-effects, e.g. nausea and vomiting are often directly induced by the drugs. The risk of some side-effects and their consequences is often lower in younger individuals due to greater functional reserves and ability of young tissues to heal more rapidly.
“There are a very large number of chemotherapy drugs and combinations resulting in many different regimens, even for a single type of cancer. The duration of regimens can vary from as short as four months, to as long as a year. Some uncommonly used low dose regimens can be even longer. Recovery from chemotherapy also varies depending on the regimen used but there are parts in a chemotherapy cycle when the patient may feel well enough to function completely normally.”
Prof Lawrence Young, Professor of Molecular Oncology, University of Warwick, said:
“Preventative chemotherapy (also called adjuvant therapy) is often used after primary therapy, such as surgery, to reduce the chance of cancer coming back and spreading. Even after successful removal of all visible cancer by surgery, microscopic cancer cells can remain lurking in the body and can’t be detected by current tests. The sort of chemotherapy and the time length of treatment depends on the type and stage of cancer as confirmed by examining the cancer removed at surgery. The side effects of chemotherapy also depend on the type of drugs used but commonly include tiredness, nausea, increased risk of getting an infection and loss of appetite. Cancer survival is generally higher in younger people e.g. those diagnosed under 40 years of age. A combination of early diagnosis and better treatments (including different drug combinations and novel targeted therapies) is resulting in improved outcomes with survival rates doubling in the last 50 years. An incidental finding of cancer during surgery for other conditions is often associated with the tumour being detected at an early stage when subsequent chemotherapy is much more effective.”
Dr Shivan Sivakumar, Associate Professor in Oncology, University of Birmingham, said:
What is preventative chemotherapy?
“Unclear what this actually is. I presume it is what the medical profession call adjuvant chemotherapy. This is chemotherapy after an operation to prevent recurrence after an operation. This is to attempt to destroy any circulating cancer cells.”
Does age affect the success of chemotherapy and the survival rate from cancer?
“Ultimately it is the biology of your cancer and how you tolerate chemotherapy that determines its success. How you tolerate chemotherapy is determined by your performance status (known as your baseline health status). The younger you are, the more likely you are to tolerate chemotherapy well.”
What is the general length of time of chemotherapy treatment?
“It really depends on the cancer, but adjuvant regimes are 3-6 months.”
What are the general side effects of chemotherapy?
“Fatigue, nausea, vomiting, sepsis, anaemia, constipation, diarrhoea are general side-effects.”
What is the recovery time after chemotherapy?
“The recovery time is usually a couple of weeks.”
Any other general comments of use.
“There is an epidemic currently of young people getting cancer (under 50s). It is unknown the cause of this, but we are seeing more patients getting abdominal cancers.”
Prof Andrew Beggs, MRC Senior Clinical Fellow and Consultant Colorectal Surgeon, University of Birmingham, said:
“Young onset cancer is by no means rare. I run a clinic for early-onset cancer in adults and we are seeing more and more people in their 40s with cancer.
“It is difficult to give exact information without knowing the type of cancer.
“Preventive chemotherapy after surgery is given to reduce the risk of the cancer coming back in the future – a bit like mopping a floor with bleach when you’ve spilt something on it, chemotherapy kills any spilt cells.
“Age has no effect on the success rate of chemotherapy except when the cancers are “immune hot” which are commoner in young people – in this case a type of chemotherapy called immunotherapy could be given.
“Young people also better tolerate higher doses of chemotherapy and so can be given stronger regimens that are more likely to kill any left over cells.
“Chemo is generally given for between 3-12 months, depending on what type of cancer it is.
“The side effects of chemotherapy can be very varied depending on the type given, and can range from very few to severe problems.
“Recovery time once again varies depending on the type of chemotherapy.”
Prof Bob Phillips, Professor of Paediatric Oncology, University of York, said:
What is preventative chemotherapy?
“For some types of cancers, chemotherapy can be given after to act to “mop up” if there are any cancer cells left. The value of this varies between cancer types, and even the size and place of the same cancer type.”
Does age affect the success of chemotherapy and the survival rate from cancer?
“Sort of, but not in a simple way. Generally speaking, the healthier someone is before cancer treatment, the closer-to-optimal the amount of chemo and the gaps-between-chemo can be. Generally, the younger someone is the healthier they will be.”
What is the general length of time of chemotherapy treatment?
“Hugely variable, but traditionally between 4 and 6 ‘cycles’ (blocks) of chemo, each cycle lasting 21 days and consisting of a day or few days of chemo, then time for the body to recover from it (while the chemo keeps damaging the cancer cell). There are also some which are daily, some which are 4-weekly, and some which are 2-weekly.”
What is the recovery time after chemotherapy?
“Again, very variable to the person and type of chemo but when all treatment is finished, it can be a few months before the person is back to nearly full strength. Side effects can still be causing problems many years down the line if treated as a child though, for example.
Any other general comments of use.
“’Chemo’ is a word used to describe a huge variety of medicines used to treat cancer. There are a number of families of chemo and chemo-like drugs which all have their own varied schedules and side effects.”
Useful links for info:
https://www.gresham.ac.uk/watch-now/series/cancer-fight-we-are-steadily-winning
Declared interests
Dr Mangesh Thorat: No conflicts.
For all other experts, no reply to our request for DOIs was received.