The NHS provides a variety of screening programmes for cancer, which aim to identify the disease as early as possible to allow for successful treatment. However, whether it be a mammogram or at-home faecal immunochemical tests, eligibility for national screening programmes varies across ages and locations.

Ahead of World Cancer Day (February 4), we spoke to Dr Rachel Orritt, health information manager at Cancer Research UK, to unpack what the aims of each NHS cancer screening programme are and what they entail to help you understand which ones might be relevant to you.

Cancer screening available on the NHS in the UK Breast screening

"Breast screening helps to find cancer an early stage, which is when treatment is more likely to be successful," explains Dr Orritt. "It involves a mammogram of your breast or chest that looks for breast cancer, essentially when it's too small to see or feel. "In most cases, people are invited every three years for a breast screening between the ages of 50 and 70."

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Nevertheless, you may qualify for an earlier mammogram if you're at increased risk.

"You can have screening at a younger age if your risk is higher, for example if you have family history of breast cancer, or if you have a gene fault that puts you at a higher risk such as BRCA1 and BRCA2 mutation," explains Dr Orritt. "If you are concerned, talk to your GP and they'll be able to help you understand your particular risk and can see if it might be suitable for you to have a breast screening sooner."

During a mammogram, two X-ray pictures are taken of each breast from different perspectives - one from above and one from the side, she explains.

"That X-ray is then reviewed by someone to see if there's any changes in your breast that might mean require further follow-up tests," says Dr Orritt. "You'll receive results after your appointment which will tell you if you need to go back for further tests or not."

Cervical screening

"Anyone who has a cervix will be invited for a cervical screening every five years between the ages of 25 and 64 in Wales, Scotland and England," says Dr Orritt.

In Northern Ireland, however, the process differs slightly - invitations arrive every three years for those aged 25 to 49, then switch to five-yearly intervals until age 64, as outlined on Cancer Research UK's website. Dr Orritt acknowledges that anxiety around this screening is common, and encourages patients to discuss any worries or queries with their GP or nurse beforehand.

"A nurse will use a small, soft brush to take a sample of cells from the cervix and then that sample is then tested for HPV, human papillomavirus," explains Dr Orritt. "The reason that it looks for HPV is because high-risk HPV causes almost all cases of cervical cancer. So, by focusing the test on HPV we can pick up people who might be at risk of developing the disease."

If your result comes back as HPV negative, there will be no further testing for cell changes. However, if you test positive for a high-risk type of HPV, the sample will then be examined under a microscope for any cellular abnormalities, as per Cancer Research UK's website. You'll receive your results and subsequent steps either through a letter or via the NHS app"

"The main aim for cervical screening is to help prevent cervical cancer from developing in the first place," explains Dr Orritt.

Bowel screening

The NHS utilises a faecal immunochemical test (FIT) to detect blood in a stool sample.

"Bowel screening is offered to individuals between the ages of 50 and 74 in the UK, however, in Northern Ireland it's offered to those aged 60 to 74," says Dr Orritt. "People within these age ranges will automatically receive a FIT kit in the post every two years."

For those aged 75 or over, biennial bowel cancer screening is also available. However, you need to ring the bowel cancer screening helpline on 0800 707 6060 and request the test, as stated on the NHS website.

"The aim of bowel screening is to help find cancer at an early stage and to also find any changes in the bowel that could lead to cancer," explains Dr Orritt. "Eligible people are sent a poo testing kit that can be done in the privacy of your own home and then is returned safely in the post. That sample is then tested to spot any possible tiny traces of blood in your poo which could be a sign of bowel cancer, or changes in the bowel that could put you in increased risk of bowel cancer."

Lung screening

"The lung screening is for people aged between 55 and 74 who either currently smoke or have smoked in the past," Dr Orritt continues. "At the moment it's not currently available at all in Wales, Scotland or Northern Ireland, just England, but Wales do have plans to introduce it. Similar to some of the other screening programmes, it helps find lung cancer at an early stage, when treatment is more likely to be successful."

The targeted lung cancer screening programme is still in its infancy, so it may take some time before it becomes universally accessible, as per Cancer Research UK's website.

"When it's up and running, anyone between the ages of 55 and 74 who smokes or used to smoke will be invited to take part," Dr Orritt adds. "They will be first invited for a risk assessment and, based on those results, some people will then also be invited to have a CT scan of the lungs if they're deemed to be a higher risk of lung cancer."

Do you need to be registered with a GP to receive a cancer screening invitation?

"To ensure that you receive your cancer screening invitations, make sure you're registered with a GP and your address information is all up to date," advises Dr Orritt. "In most cases, once you become eligible you will be sent an invitation in the post. However, we're starting to see things like the NHS app notifications be used more, and over the next few years we'll probably see a bit of a move towards digital invites."

If you believe you're eligible but haven't yet received a screening invitation, Dr Orritt suggests getting in touch with your GP.

"It's okay to contact your GP because it might be that your address is wrong or isn't up to date on their records, for example," says Dr Orritt. "There could be a number of reasons for this, and the GP can help investigate that for you."

Should you wait for a screening appointment to check for cancer?

"One of the main things that I think is really important to get across when we're talking about cancer screening, is that these programmes are for people without any symptoms," highlights Dr Orritt. "If you have symptoms or are worried about something, you don't need to wait for screening invite. Talk to your GP about any concerns straight away."

For more information about which screenings may be appropriate for you, visit screeningchecker.com