Women aged between 50 and 70 are being urged to attend their breast-screening appointments after it emerged more than a third did not take up the offer last year.
More than two million eligible women have not been screened in the last three years, according to NHS England.
NHS breast screening uses X-rays, known as mammograms, to look for cancers that are too small to see or feel.
Women will be invited to make an initial appointment between the ages of 50 and 53, and will be invited for screening every three years after that until they turn 71.
Data analysed by NHS England showed 8.59 million breast-screening appointments were attended within six months between 2018/19 and 2022/23 out of 13.05 million invitations.
Uptake increased last year, according to officials, although some 35.4% of women did not take up the offer of screening.
NHS England estimates 2.18 million eligible women have not been screened in the last three years.
Dr Louise Wilkinson, NHS England’s national speciality adviser for breast screening and consultant radiologist, said: “Breast screening saves lives by allowing cancers to be identified and treated earlier – in fact, discovering breast cancer at the earliest stage may give you a 98% chance of surviving for five years or more.
“Screening can often pick up breast cancer before you can even see or feel any changes to your breasts yourself and your mammographer will do everything she can to make the experience as comfortable as possible for you, which is why I would urge anyone invited to take up the offer.”
Kathryn Cowley, 58, was diagnosed with breast cancer after a routine mammogram in 2022 revealed an abnormality.
She underwent surgery followed by radiotherapy, and said that attending appointments was “vital”.
“My breast cancer journey has a positive outcome and it’s very lucky that I attended my regular breast screening,” Ms Cowley said.
“I have now had my one-year follow-up mammogram and I was very relieved that this was normal.
“Attending routine screening is vital – I was fortunate that I attended my appointment and did not put it off.
“My mammogram detected my cancer before it could be felt, which was a game changer.”
Women who have had a mammogram should still check their breasts regularly.
The NHS recommends a “touch, look, check” (TLC) approach.
Claire Rowney, chief executive at Breast Cancer Now, said: “These figures serve as a timely reminder, during Breast Cancer Awareness Month, that far too many people are missing out on the vital breast screening that saves lives from breast cancer.
“The stark reality is that thousands of women miss having their breast cancer detected each year. We look forward to working with NHS England to ensure breast screening services are accessible and convenient for everyone who is eligible.
“We encourage eligible women to attend their breast screening appointments when invited and to regularly check their breasts to get to ‘know their normal’ and get any new or unusual breast changes checked out by a GP, including between screening appointments.”
Health minister Andrew Gwynne said: “When it comes to fighting cancer, every second counts. We know that early diagnosis leads to more effective treatment, and in many cases, can save lives.
“The Government is working alongside NHS England to make the shift from hospital to community, making getting tested easier than ever.
“I would urge anyone who is invited for a screening appointment to attend.”
