More than 13,000 women in East Lancashire 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 71.5% of the 49,153 women in the East Lancashire Clinical Commissioning Group area due a screening in the three years to the end of last March took up the offer.
This means 13,990 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.
The UK National Screening Committee says at least 70% of women sent an invitation should attend, but that the NHS is expected to achieve 80% uptake.
Of those who were sent an invitation in 2018-19 across England, just 71.1% had attended within six months of their invite, according to NHS Digital.
This was up slightly from the previous year, which had the lowest attendance rate since the current screening programme began in 2007.
Almost a third of the 195 CCGs in England failed to meet the lower target, while only one passed the 80% benchmark.
Baroness Delyth Morgan, chief executive of charity Breast Cancer Now, said: "It's promising that uptake of breast screening in England has improved slightly after reaching a decade-low last year and we hope this now continues.
"But screening uptake is still barely above the minimum target, with hundreds of thousands of women across the country not attending.
"While screening comes with some risks to be aware of, we'd encourage all women to attend their appointments when invited."
Uptake in east Lancashire increased slightly from 71% in 2017-18, despite a drop nationally.
The breast screening programme uses an X-ray test called a mammogram to detect tumours before they are large enough to feel.
Detecting the disease early on gives a better chance of survival.
Dr Anne Mackie, director of screening at Public Health England, said it was "good to see" that uptake has risen for the first time in three years.
She continued: "While screening is a personal choice, we are analysing the barriers that deter some groups of women, to help the NHS improve overall numbers getting screened."
A spokeswoman for the NHS said: "Breast cancer survival is at a record high in England with deaths falling faster than anywhere else in Europe, thanks to earlier detection and advances in treatment.
"It is vital that women attend their test and the NHS is looking at ways to boost uptake, including by making appointments more convenient, as set out by Professor Sir Mike Richards in his recent review of screening services."