The North Kirklees and the Greater Huddersfield Clinical Commissioning Groups (CCGs) said the number of women attending screening across Kirklees dropped from 76.3 per cent in 2013 to 75.9 per cent in 2014.
It means 24.1 per cent of women, aged 50 to 70, who are eligible for the breast cancer test are not taking it up.
The CCGs are urging them to do so, as part of October’s Breast Cancer Awareness Month, warning the test could save their lives.
Health bodies are also using the month to raise awareness of breast cancer symptoms including a lump, dimpling of the skin, a nipple rash or discharge and a change in size, shape or feel of the breast or nipple.
Dr David Kelly, a local GP and chairman of the North Kirklees CCG said: “The older you get, the more important it is to be aware of your body.
“If you do notice a change in your breasts, whether it’s a lump, discharge or a skin change, go and see your GP as soon as you can.
“The chances are that it’s nothing serious but it might be something that needs attention and if diagnosed earlier, treatment can be a lot more successful.”
Dr Steve Ollerton, chair of the Greater Huddersfield CCG, added: “We would also like to ask family and friends to encourage their loved ones to seek medical help if they say they have symptoms or have noticed any changes. Some women feel they are too old for certain things, but unfortunately breast cancer isn’t one of them.”
Breast screening is a method of detecting breast cancer at a very early stage through a mammogram x-ray. It can indicate small changes in breast tissue which may be small cancers too small to be felt by a woman herself or a doctor.
Dr Yasmin Khan an associate medical director for Yorkshire and the Humber said: “We understand that any type of medical testing can be daunting, but a breast screening test is a prime example of how a quick, painless test can save your life.
“We would like to encourage all women aged 50-70 in Kirklees who are eligible for the test to take up the offer and ensure they stay healthy.”