Cancer and Dementia

Last updated: December 28, 2009
Day 349. Day of eating crap and feeling wreckless.
Image by half alive♦ used under the creative commons attribution no derivs license.

Cancer patients who have dementia die much sooner from their disease than those who have cancer without dementia, researchers from Moffitt Cancer Center in Tampa, Florida, announced this week. After controlling for other factors like age, tumor type, and tumor stage, the research team, led by assistant professor Claire Robb, compared cancer patients with no dementia, mild dementia, and moderate to severe dementia.

The difference was quite dramatic: Cancer patients without dementia lived an average of four and a half years; those with moderate to severe dementia died after an average of eight months. The study was published in the early online edition of the journal Critical Reviews in Oncology/Hematology.

The results are important to talk about, Robb said: "As the population ages and as treatments improve, we're going to see more patients with both dementia and cancer."

No one knows exactly why the patients with dementia in this particular study died so much faster, but previous studies have found that patients with dementia often receive fewer cancer screenings and doctors are less likely to recommend aggressive treatment. For example:

  • One study found that doctors were significantly less likely to recommend a mammogram for a woman with dementia.

  • In another study, people with dementia were twice as likely to have colon cancer discovered only after death.

  • A study of breast cancer patients found that those with dementia were 52 percent less likely to have their tumors removed surgically, 41 percent less likely to undergo radiation therapy, 39 percent less likely to undergo chemotherapy -- and nearly three times more likely to receive no treatment.

What do you think: Does having dementia diminish someone's quality of life so much that they shouldn't bother with treatment for cancer?

Cancer isn't the only disease that's more deadly for those with dementia. In October, researchers reported that patients with dementia who come down with the flu are 50 percent more likely to die than those without dementia. Their hospitalizations were also much shorter, suggesting that people with dementia get to the hospital later -- when they're sicker -- than those without dementia.

And earlier studies have found that patients with dementia who have strokes are twice as likely to die from the stroke, while those who develop post-stroke dementia after a stroke have an eight-fold increase in their risk of death within two years of the original stroke.

For caregivers, this means that our natural instincts are right; when we're caring for someone with dementia, we have to be hyper-vigilant in watching for signs of illness, since it's possible that our loved ones are unable to alert us that something's wrong. And we may have to be stronger advocates to make sure our loved ones get tested and treated for serious diseases like cancer. "A diagnosis of dementia shouldn't discourage the use of cancer screenings and appropriate cancer treatments," says Claire Robb.

Then again, people with moderate to severe dementia may find doctors and hospitals so frightening that as caregivers, we may feel it's kindest to let nature run its course. I'd love to hear your thoughts and experiences on dealing with these difficult choices.

Was this blogpost helpful?

17 Comments So Far. Add Your Wisdom.

2 months ago

My mother 72 was diagnosed with dementia in 2013, we just found out she has
 Breast cancer, she never complained about not feeling well, doesn't remember having the mammogram, ultra sound or the biopsy, I also have a sister that is
 Autistic,(45), she has been dependent on my mother her whole life, and now doesn't understand why mom isn't taking care of things like she used to, we are 
 Trying to obtain guardianship along with another sister , it's very frustrating to watch
 My mother who was an office excitative,until 4 years ago, diminish away.

6 months ago

My Mother who is 53 years old was just diagnosed with colon cancer yesterday. I am meeting with the Doctor in a week to go over all of the results. The issue is my Mother has had schizophrenia her whole life and has had the onset of dementia for the past 3 years. I am 25 years old and am the only child with Power of Attorney. I do not believe that my Mother is fully comprehending what is going on and I am fearing the worst right now because she HATES hospitals due to her fear of being admitted to the physc ward. A colonscopy was performed on my Mother yesterday due to bowel problems and the fact that her Father passed away from colon cancer several years ago. The Doctor could only get to her rectum. Her colon is completely blocked with a softball size mass. The Doctor is 99% sure that it is cancer, but a biopsy, bloodwork and a CT scan results will be in by Monday to determine everything. I am still in a daze from all of this. My Mothers mental illness has truly taken a toll on her and she just admitted that if there is something wrong with her, she wants to live with it and just continue "living". The Mom I know from years ago when she was sane and compotent would have received a colonoscopy back then because of family history and would have taken care of herself. If this cancer hit her back then, she would have been a trooper and gone through the surgery and chemo. Whose wishes do I honor? If my Mom elects not to get surgery, she will have a painful death and I do not want that at all. *I apologize for grammar errors and the structure of my writing. My mind is not in the right mind set

over 1 year ago

Hello Anonymous, Thank you for posting your question and sharing your caregiving experiences. We have a wonderful section where you can get advice and support from others in similar caregiving situations. You can find it here: I hope you find this helpful.

Anonymous said over 1 year ago

My father is only 69 years old but was diagnosed with Lewy Body-type dementia about 5 years ago and has been in a nursing home because of us dementia issues for almost 2 years (he had a number of falls at home and my mother could not count on herself to watch him all the time). He recently had a bout of bronchitis and the facility did a chest X-ray which found a 2.5 cm nodule. We are still in the early stages of figuring out what it is and how we would want to approach it, but I cannot help but feel that my father would most likely want to forgo treatment if is turned out to be malignant. He always took pride in being able to provide for us and tend to himself, and with his current mental state I truly believe he would not want us to put him through the confusion and misery of chemo/radiation/surgery. I deep down know that to be true but cannot help but feel extremely guilty to be considering just "letting him go". Any responses would be greatly appreciated.

over 1 year ago

My 86 year old father with dementia is being treated for lung cancer. The tumor is 10 centimeters and the cancer has not spread. He has had two radiation treatments so far.During both these treatments he moved. I was not expecting this problem. I also feel if he begins to feel to sick he will become suspicious of the treatment and me. I don't know if this is the right way to go or not. If he was farther along with the dementia or the cancer had spread I don't think I would have opted for any treatment. I also am worried the radiation and chemo will worsen the dementia. Which would make this all somewhat futile.

about 2 years ago

I earlier tried to send a lengthy message via this screen And the name was waiting to be accepted. Then I lost the screen! In the middle of It all!! Did u receive my long message re my Father? Thanku Maxine

about 2 years ago

Just lost my mom after 4 rounds of chemo and 30 radiation treatments due to small cell lung cancer. Oddly enough there were no signs of cancer when she died but the last two weeks of her life were difficult for me to witness. She truly lost her mind the last week. Yet no signs of cancer in the brain. I'm wondering if she had dementia that was blasted by the all chemo and radiation. I can't get past this. Lung cancer was diagnosed in February and the Dr. said if she followed his treatment plan she would be with us for at least 2 years. She died 6 months after diagnoses.

Anonymous said over 2 years ago

My father is 93 and has moderate to severe dementia. He is completely bedridden and helpless. My 90 year old mother has an aid that helps her take care of him. He was just diagnosed with a Melanoma which they want to remove under anesthesia. The surgeon said it looks like a deep Melanoma. We feel that even if he withstands the surgery, he would not be able to tolerate any further treatment. We are in a terrible quandry about what to do. He pulls all bandages off whenever he gets a chance. So the post surgical wound has a chance of getting infected. Yet if we don't have the melanoma removed, it will only get worse. My feeling right now is to let my father be...but I have nagging doubts of what is the right thing to do.

over 2 years ago

My wife has been battling stage 4 colon cancer for more than a year. Her thought process has been diminishing over that time but slowly. She suddenly started showing signs of dementia. I am feeling now that this may be Gods way of giving her comfort in her last days from the stress over worrying that she is dying and leaving me with two teenage daughters. This has been the driving force in her fight. It is hard for my girls to watch their mom deteriorate in this way but it is a blessing for her that she is not aware of how grave her situation is. Since it was her desire to fight the cancer as long as she can, I will obey her wishes and continue. Some would think that she should be allowed to "die with dignity". What right do I have to pull the plug on her treatment and go against her decision to fight. This is the hardest thing I have ever gone through but doing what I know my wife would want takes some of the stress away. Trying to make these kinds of moral decisions without a moral compass is an act of futility. I know that I will be with her someday and she will be better than her normal self so a little suffering her and an eternity of perfect bliss in heaven with my sweetheart makes it much easier cope with the situation.

over 2 years ago

I think my husband is going through this now. He has cancer, and he is very weak and foggy brain. It seems to be getting worse It is very hard to deal with. The cancer is one thing and this brain fog is so different . Cancer with a clear mind is easier to deal with.

Anonymous said almost 3 years ago

I feel your pain. my mom has mod to severe dementia and stage 4 colon cancer. She won't eat hardly anything. She has fallen 3 times in the last week. She can't stand on her own. She can;t tell us what hurts and how she feels. It breaks our hearts. She had teh right side of her colon removed but the cancer in in 7 lymph nodes. She couldn't tollorate the cemo. We have hospice and they are a big help. I just want to make heer comfortable and as happy as possible for the time she has left' We lost dad 2 years ago as well. I just wish she could tell us what she needs and wants. It.'s sooo hard. praying for peace and comfort.

about 3 years ago

My mother was recently diagnosed with probably lung cancer. Has two masses - one is 2.2 cm. The doctor says because of the size she doesn't know what else it could be. We are not going to put her through a biopsy because she couldn't take chemotherapy or radiation. She is 90 years old. Her dementia is terrible. The doctor says the lung problem is making the dementia worse. Has anyone heard of this. We have her at home and my husband has had to pick her up out of the floor three times today. All morning she was trying to get out the door to go home. So sad.

Anonymous said over 3 years ago

It is illogical and unkind to force treatment on someone that has a poor quality of life. Death should be accepted as part of life and the remaining time should offering comfort and love. Families should visit, see old friends, make arragements for death. Treatment is painful, confusing and expensive. Death in our 70sand 80s should be expected. Just because we can prevent death does not mean we should.

Anonymous said about 4 years ago

My step-father of 30 years, who I love very much, has moderate dementia which is swiftly moving to towards severe. He has recently been diagnosed with Grade 4 skin cancer. My mother is is prime carer and my step-sister and I are also as carers, offering them constant support. My father died of cancer when I was a teen and so my mother has decided she couldn't cope with the diagnosis and prognois and has turned the big decisions/hospital appointments over to us. We discussed long and hard as whether he should receive chemo/radiotherapy if offered. We decided, as it would be purely paliative, it would not increase his 'quality' of life, it might in fact worsen the short time he has left with us. The hopsital informed us they would not be treating him with either chemo/radiotherapy, as it would not make a major difference to his prognosis and they felt it would confuse him and also diminish his remaining time. It's tough, but we feel we couldn't explain 50+ times a day why he was having to go to hospital and the constant non-stop 'breaking the news', as each time you tell him something, it's 'new' to him. We will offer him all the love and care we can and make him as comfortable as we possibly can and try and enjoy our remaining time with him.

over 4 years ago

My Dad is 91 and my mom is 81. We have been dealing with dementia and all that entails for several years now. The drs just found a spot on her lungs and she is at the oncologist as I write this. I haven't a clue where we go from here or even what my mother will say or do. She's been having some good days, but of course the bad ones are always just around the corner. Having lost my husband to cancer I know the battle ahead. His mind was clear and he could make his own decisions. I cannot imagine what my mother (a retired registered nurse) is thinking when her mind is clear. She will shut us down immediately if she thinks we are ganging up on her and getting in her business. I have read and I understand the posts here, and I thank you for sharing your thoughts. It is definitely food for thought to me. The last thing we want is to add to her anxiety.

almost 5 years ago

I was troubled with this article when I read the question "Does having dementia diminish someone's quality of life so much that they shouldn't bother with treatment for cancer?" This is an inflammatory way of discussing the issue ... assuming that the choice not to do testing, procedures and surgeries is always "not bothering". As the daughter of 2 90+ parents with various conditions and mid to late stage dementia, I think the only humane thing to do is consider the quality of the days they have left and make decisions that will make them comfortable and keep their cognitive and physical abilities at the highest level possible. This often means foregoing things like colonoscopy or any invasive diagnostic procedure that only makes them go out of their comfortable environment, possibly have anesthesia that can make for big mental setbacks and creates an enourmous amount of anxiety and possibly pain. We need to face the fact that all the medicine in the world will not make people live forever, and we need to allow the physical body to pass on at some point. If you don't want them to die of the cancer they have once dementia sets in, what do you want them to die of? There has to be some consideration of quality of life and quality of death for every person.

almost 5 years ago

my father is 73 and has aliz., he can no longer reconize pain, he cannot always verbalize his needs, he nearly died from a uti that went septic, 3 months later kidney stones, it took us nearly six weeks to figure out what was going on, the removal of the kidney stones was very hard on him, he thought we were being mean on purpose, denied being sick, said we were all crazy, we didn't sleep for 3 weeks, reguired min to min care, had stent in kidney for 2 weeks, he understood none of it, I will not put him throught anything like this again. no chemo, no surgery, no radiation, he doesnt understand and he thinks we are torturing him. May God help us, but you have to draw the line somewhere. The treatment scares him, he doesn't understand why we put him through what we put him through. We will be very selective in the treatments that we allow, wieghting the trauma and benefits to him.

Stay Connected With

Receive the latest news and tips in your inbox

Join our social communities:

Best in Health News