More than 20,000 women in Nene missed their last screening for breast cancer, NHS figures reveal.
Women are invited for a breast screening every three years between the ages of 50 and 70, to help catch cancer early.
But new statistics show the proportion of women accepting the invitation has declined across England over the last decade.
Only 76.1% of the 86,500 women in the Nene Clinical Commissioning Group area due a screening in the three years to the end of last March took up the offer.
This means 20,704 women were not up to date with their checks.
The data shows how many eligible women were checked at least once in the three-year period, meaning some women could be years overdue.
Across England, 71.6% of women eligible for screening attended their last check.