Health experts have called for NHS screening for cervical cancer to be rolled out to women over 64 after research found one in five new cases is diagnosed in this age group.
Around 3,000 cases of cervical cancer are diagnosed in the UK each year and it is the most common cancer in women under the age of 35.
But researchers at Keele University said that on average, 20% of the 3,121 new cases diagnosed each year were in women aged 65 and over - the age at which the screening programme, commonly known as smear testing, currently ends.
Women over this age also accounted for half of deaths from cervical cancer.
A separate report by the charity Jo's Cervical Cancer Trust also found that a lack of knowledge about the cause of the disease and who can be affected seems to be contributing to women aged 50 and 64 not attending screening.
Almost all cases of cervical cancer are caused by the sexually transmitted human papillomavirus (HPV), but three in five women in this age group did not know this and many failed to see historic sexual activity as a threat with the virus laying dormant and developing into cervical cancer later in life.
Screening is the most effective way of preventing cervical cancer and is offered to women aged from 25 to 64 on the NHS, yet figures show that last year there was a significant drop as women's age increased.
In England, numbers fell from 82% of 50 to 54-year-olds to 75% of 55 to 59-year-olds and 73% of 60 to 64 year-olds.
There is concern that if attendance for cervical screening continues to decline among older women, more will face a later stage diagnosis of cervical cancer and potentially lose their lives.
The charity wants to see other ways to increase uptake and is calling for more research into a self-administered urine test for HPV, which can be carried out at home.
It found more than half (54%) of those who had delayed a cervical screening test said they would prefer to carry out their own test to see if they had HPV.
Reality TV star Jade Goody's battle with cervical cancer drew significant attention to the disease and there was a spike in women getting themselves tested following her death in 2009, but numbers have declined since.
Sue Sherman, senior lecturer in psychology at Keele University, said: "This review suggests that older women not getting themselves screened to prevent cervical cancer has become a significant contributor to the number contracting the disease.
"Despite all the attention on younger women – in part due to the Jade Goody effect – 20% of new diagnoses and nearly 50% of cervical cancer deaths occur in women over the age of 64.
"We need to change the perception of cervical cancer so it is thought of just like breast and bowel cancer – that it can affect women well into old age.
"Encouragingly we found that women with three negative tests for cervical cancer between 50 and 64 are considerably less likely to get the disease in the next 20 years. So regular screenings have the potential to catch the disease early and reduce the victims of cervical cancer dramatically."
Robert Music, chief executive of Jo's Cervical Cancer Trust, said: "This research from Keele University backs up our own investigations that there is an urgent need to not only increase survival rates for women in this age group but decrease the numbers diagnosed altogether.
"It's absolutely vital that women of all ages are educated around the cause of cervical cancer and their risk of HPV. Responses from women questioned in our research were worrying with some citing they had been 'celibate' for several years and therefore did not consider themselves to be at risk.
"We must remind all women that HPV is very common and can lie dormant for very long periods of time, and that the best way of reducing one's risk of cervical cancer is to attend screening promptly whilst eligible."
A Department of Health spokesman said: "Cervical screening is estimated to save around 4,500 lives a year in England, and Public Health England and NHS England are working together to raise awareness of cervical cancer and HPV and to increase uptake in communities with low screening rates.
"National screening programmes are based on the advice of the expert UK National Screening Committee and are kept continually under review."