Skip to main content
Image of brown paper being ripped back to reveal the word 'disparity'
Bloom Blog

Study shows inequity in cancer survival rates

By Louise Kinross

Ontario adults with disabilities like autism and Down syndrome are 1.5 to 2.7 times more likely to die of breast, colon and lung cancer after receiving a diagnosis than those without, according to a population-based study published in The Canadian Journal of Public Health last month. "We found worse survival for people with intellectual and developmental disabilities, whether they were diagnosed early or late in the disease," says Alyson Mahar, a co-author and scientist in the Cancer Research Institute at Queen's University in Kingston, Ont. We spoke about the research.

BLOOM: Was this the first study of its kind?

Alyson Mahar: As far as we know it's the first study of cancer survival among adults with intellectual and developmental disabilities. This study looked at the likelihood of dying of cancer if you've been diagnosed with it. That is different than a study of cancer mortality. Our study makes direct comparisons between how people with and without disabilities do once they're diagnosed.

BLOOM: Why was there a need for this study?

Alyson Mahar: My own program of research is focused around the inequitable delivery of cancer care in Canada. I previously did work on outcomes for people with severe mental illness, and that got me thinking about who else isn't represented in the current research about cancer-care inequities. Who may be affected by similar barriers? Our team did a literature review on cancer outcomes for adults with intellectual and developmental disabilities, and we saw how little there was to guide or inform treatment decision-making, or to inform prevention, or to inform anything. 

BLOOM: What were the key results of your study?

Alyson Mahar: Among adults with these three cancers, people with intellectual or developmental disabilities are 1.5 to 2.7 times more likely to die following their diagnosis than those without. It depends on the type of cancer. For lung cancer the rate is 1.5 and for breast and colon cancer it's 2.4 and 2.7.

BLOOM: Were you surprised?

Alyson Mahar: Unfortunately no, based on what we've found in other populations where the health system wasn't created with them in mind. Some people argue that the reason for worse survival in this population is that adults with these disabilities are more likely to be diagnosed too late, at a point when the disease has spread throughout their body and is not curable. But we looked at early cancer and late cancer diagnoses and found worse survival for people with disabilities in both.

BLOOM: Why hasn't this population been included in cancer equity work before?

Alyson Mahar: I think the focus previously has been on children with intellectual and developmental disabilities.

I don't work in spaces that provide care, but I've heard from colleagues that the general feeling was that cancer wasn't something they needed to think about because life expectancy was lower in this population, and cancer is a disease of aging populations. Of course, life expectancy has increased. When we did our literature review, it seemed most people were doing research on screening in this population, rather than looking at rates of cancer and outcomes.

BLOOM: Your study doesn't identify why people with intellectual and developmental disabilities have lower survival rates. What factors may make this population more likely to die from these cancers?

Alyson Mahar: I think a few things are happening. One is that the disability may impact whether or not someone is eligible for treatment. There may be contraindications for medications, or possible genetic-specific reasons that survival is worse.

But I think what's more likely, and more amenable to changing, are system level issues that are interfering: Is this structure that provides radiation built to accommodate someone who can't keep their body still for a long time? Are the ways we deliver care adaptable, and are they being adapted to be accessible for people with intellectual and developmental disabilities? 

What about consent to treatment? People providing cancer care may feel they can't adequately consent someone for treatment. Is that a reason not to provide it? I don't think so.

How are we supporting families or caregivers? Are they able to take time off work to attend clinic visits with the person with a disability? Are we putting people in situations where they're making hard decisions about whether to get curative treatment without giving them the necessary financial and practical resources? Are we providing health professionals in the cancer system with the best education?

BLOOM: I've heard from people with disabilities who go to what are called 'accessible' diagnostic screening clinics in a big city like Toronto, and the equipment can't accommodate them, so they leave without having the test.

Alyson Mahar: Yes. Then there's the sensory overload of being in one of these big cancer clinics with maybe 100 other people in the waiting room. That can be a nightmare. Then there's the need to undergo a significant medical procedure and manage pain and symptoms, and the hospitals are trying to get people in and out as quickly as possible. Do patients have the right support to recover well? Are those things influencing their decisions about treatment?

BLOOM: Your study notes a person may have trouble communicating their symptoms, and we've seen cases where even if they can, sometimes a care home may dismiss or minimize what the person says and not get medical help. I'm recalling a study of parent perceptions of disability bias among clinicians, where a doctor suggested a disabled child who had just been diagnosed with a treatable cancer not be treated. Of course that would never be suggested to the parent of a non-disabled child.

Alyson Mahar: We need more education in the different health professions to make sure that cancer is something physicians and nurses are thinking about for people with disabilities and to empower them to feel more confident in treating these individuals. Of course we've heard in some spaces that physicians don't feel comfortable providing care to people with disabilities.

BLOOM: Yes, we did this story about an American study that found 82.4 per cent of 714 doctors don't think it's possible to live well with a significant disability, and only 41 per cent feel confident in their ability to provide the same care to a patient with a disability that they give other patients.

Alyson Mahar: I think it's a challenging topic to bring back to health professionals, to say 'You may be contributing to this problem because of how you feel, and how you're acting on those values.' We've actually gotten a lot of pushback on this. I think there's a lot of ableism out there and it affects how clinicians provide care and even how research like this gets published.

BLOOM: Do you have any personal interest in this research?

Alyson Mahar: When I grew up one of my good friends had Down syndrome. I don't like to suggest that it's why I'm doing this work. But I do think about her all the time when it comes to this research. Now that we know this inequity exists, we're at the point where we can begin to work together to adapt clinical guidelines and change behaviours. It's really important that those conversations are led by adults with disabilities and their caregivers and providers. We need to know how they would like to see things change.

Like this story? Sign up for our monthly BLOOM e-letter, follow @LouiseKinross on Twitter, or watch our A Family Like Mine video series.