Is it true that chemotherapy increases the likelihood of cancer returning in new cells later?

[OutofSyncGirl]

So says a friend of mine who had stage 4 cancer about 3 years ago but refused chemo (even though it was advised) because of an autoimmune condition she has. She is thankfully ok and the cancer has gone into remission.

She says that while chemo kills the cancer it also increases the likelihood of it returning later in different cells.

Is there any evidence to support this?

Cancers cells proliferate uncontrollably. Chemotherapy agents bind to cells that are actively dividing and cause serious genectic mutations that kill them off. Chemotherapy is not specific just to cancer cells but all cells that are dividing. Hence why hair falls out and they get horrrifc side effects. So yes chemotherapy is seriously carcinogenic. But usually the benefits outweigh the risks.

radiotherapy also increases risk of future cancers (afaik)

Having chemo at the moment do have some experience of this (not medical professional though). There are some links with some chemo and secondary cancer - particularly leukemia (www.cancer.org/treatment/treatments-and-side-effects/physical-side-effects/second-cancers-in-adults/chemotherapy.html). However odd are still low and chances of cancer returning without chemo usually much higher. Your friend will have been fully informed by her oncology team re the risks and then it is her decision to make - although appreciate is hard for you. Maybe she felt her quality of life with side effects of chemo wouldn't be worthwhile? Personally I'm trying to blitz mine with everything they've got but it won't be everyone's choice. Chemo is toxic and works on all the targeted cells not just cancerous. Here's hoping for more research advances for more targeted therapies.

Link fail
www.cancer.org/treatment/treatments-and-side-effects/physical-side-effects/second-cancers-in-adults/chemotherapy.html

@Andnoneforgretchenweiners if your DH does have to have a picc he might not find it too bad. I have one and so much better than getting a new IV each time. Bit weird getting put in and a faff having line care etc but not having to get poked all the time is worth it.

Chemotherapy is poisonous. That’s the whole point of it. (My background is in development/genetics/cancer.)
Different types work in different ways - so one type just hammers anything that’s dividing rapidly which cancerous cells do. Other types zap cancerous cells in different ways, by using the immune system for example.

Cancer is a symptom and a process rather than a monolithic ‘thing.’ A bit like fever - many causes. Many diseases. Many treatments.
A cancer cell has escaped the usual checks and controls that stop our cells from multiplying rapidly and invading tissues they shouldn’t be in.

If she had stage four cancer that means that cells from the primary tumour have invaded elsewhere (metastasis) and this generally is what kills you. If that’s the case then unfortunately the chances of her cancer returning are fairy high. It may take a few years or she may get sick again fast.

Anyway your question: does chemo increase the likelihood of further cancerous developments?

Well it can. Chemo damages and kills cells - that’s how it works. Some methods are more targeted than others. Some methods are so precisely targeted that the chances of knock on effects are tiny. Others are fairly crude but effective. It will depend on what she was offered.

But... if you have stage four cancer and you refuse chemo, you need to accept that’s it. And people do refuse because chemo is hard, and of it’s only going to give you an extra few months and those will be gruelling then that’s your choice and it’s a valid one.

Treatment choices should weigh up risk. So for example if I was fairly young, and had a tumour that was operable (which it sounds like she had) then I’d be very unwise to refuse chemo - the small chance of issues down the line is vastly outweighed by the fact that without the chemo I’m dead, and with it I stand a good chance.

I work in clinical drug development these days and I can assure you that the science side of pharma is not some big conspiracy. (Marketing I reserve the right to consider rather unpleasant...) the process of researching and bringing to market new cancer drugs is done by thousands of very dedicated people who are not in it for any nefarious reasons

So if she refused chemo does that mean that it could come back in the future? Because the only treatment she's has is surgery. I know this will have been her choice but I think it's worrying.

My son had a stage IV brain tumour. Without his op he would have died two days after diagnosis. Without chemo and radiotherapy he would have died.

The chemo he received had a high chance of resulting in a different cancer later on. This would have been untreatable and would have killed him as he had already had his lifetimes worth of chemo and radiotherapy.

My son died anyway aged 18 just two and half years after diagnosis.

Everybody is different. Everybody reacts differently to chemo/radio/cancer itself.

Some survive against all the odds. Some die even though their chances were seemingly high.

Even if she had had chemo that would still be a risk. Chemotherapy can reduce the risk of cancer returning, but there are no guarantees.

Chemotherapy isn't without risk, and certainly no walk in the park, but it is only offered when there is likely to be a benefit to the patient.

I know it must be worrying, but rightly or wrongly this is the choice your friend has made. And, without wishing to be insensitive, if she declined the treatment several years ago then there isn't really much to be done now. Hopefully she will remain well

Yes the same cancer could return in the same or different tissue. Cells from the primary tumour can spread throughout the body. They can lurk, and stay dormant a while or they can begin to divide rapidly. If she has stage 4 cancer then it will have spread. There’s no hard and fast rule about how quickly or indeed if a cancer would return. It could be in many tissues but brain, bone and liver and frequent sites for metastases.
Or she could remain healthy - you said she might not have had stage four? It’s possible the surgery got the whole mass - it does happen. It’s not a given which is why surgery is often accompanied by radiotherapy and chemotherapy

At the end of the day it’s her choice, although I think her choice wasn’t a truly informed one.

to all going through chemo and to those who have lost someone.

Minmooch - I'm sorry to hear about your DS

What happened with my friend was that she kept going back to the GP and they told her the lump was a cyst over and over. She kept pressing for a biopsy and eventually one was done and it was found to be cancer. I think this caused her to lose faith in medical care. From what she said the cancer went from stage 3 to stage 4 between the biopsy and surgery. I think it had gone into some lymph nodes which was why it was stage 4 and these were also removed.

I'm sorry to hear that OutofSync and I can understand her losing faith after being let down like that.

There is some information about breast cancer staging on the Breast Cancer Care website. If it was "only" in lymph nodes near the original tumour site then that would be stage 3.

Stage 4 is where it has spread to other organs or to lymph nodes further afield.

i couldn't agree more. This was your response to a previous comment. Without being rude I'm afraid you have no idea what your reaction would be if you actually did have cancer. Each persons reactions and decisions are just that, their own. What you 'might' do is if no consequence to the person going through it.

Please respect your friend's decisions that she made a while back. She may have had reasons that you do not know and she may wish you not to know.

I'm sure your concern is coming from a place of kindness but when you are going through cancer, or in my case my son, other people saying they would do this or that is quite wearying and rather frustrating.

I would never say that to her. That's why I'm posting here about it. Sometimes when you wouldn't say something IRL you post on an anonymous forum.