Academics and NHS staff in Leeds will work on the study - said to be urgently needed - after a £155,000 grant was secured.
The funding from the National Institute for Health Research (NIHR) means a team of researchers form Leeds Beckett University’s Centre for Dementia Research will work with University of Leeds colleagues on the study.
They will be the first researchers to examine the size and demographics of the population of people with both cancer and dementia from a large dataset of GP patient records.
The Leeds Beckett team is led by Claire Surr, the university’s Professor of Dementia Studies.
Prof Surr said: “Cancer and dementia are conditions that affect many older people, and the little research we have suggests many may have both conditions, however we don’t currently have any accurate figures on the size of the population or their experiences.”
Previous research has found that people who have dementia and cancer have worse diagnosis and survival rates than those with cancer but not dementia.
The Leeds team will carry out interviews and observations in hospital cancer departments to understand how people with cancer and dementia and their families experience treatment and care.
The findings of the study, funded by the NIHR’s Research for Patient Benefit Programme, will be used to make recommendations on how treatment can be improved.
Prof Surr added: “The research we do have suggests people who have dementia as well as cancer have much worse outcomes in terms of diagnosis, treatment and survival than people who have cancer but not dementia.
“Therefore, our study is urgently needed to inform future research in this area and to identify immediate ways services might be improved.”
The team from Leeds Beckett includes cancer care expert Dr Laura Ashley and dementia specialists Dr Rachael Kelley and Dr Alys Griffiths.
The University of Leeds team includes medical statisticians Prof Amanda Farrin, Michelle Collinson and Ellen Mason.
The academics will collaborate with experts from Leeds Teaching Hospitals NHS Trust, Bradford Teaching Hospitals NHS Foundation Trust and Birmingham City University.
Latest figures show there are more than 60,000 living with dementia in Yorkshire and Humber.
An ageing population means the figure is set to rise to more than 80,000 by 2021.