What to expect during a breast screening

To help detect early breast cancers, all women in the UK aged 50 to their 71st birthday are invited for NHS breast screening every three years. We ask the experts the important questions about breast screening and find out what to expect during the procedure.

Breast cancer is the most common type of cancer in women in the UK. According to Public Health England, approximately one in eight women will get breast cancer, with about 12,000 dying of the disease every year. The risk of developing breast cancer increases with age and about four out of five breast cancers are found in women over the age of 50.

Men can get breast cancer too, but cases only account for 1% of the total.

Survival rates have been improving over time and now three out of four women diagnosed with breast cancer are alive 10 years later. Your chances of surviving breast cancer are vastly improved by early detection.

My first mammogram

I've just turned 51 and recently received a letter from my local health authority inviting me to attend my first mammogram. Mammograms are X-rays which help detect breast cancers in their early stages, before they can be seen or felt.

It's worth noting that you don't get an invitation as soon as you turn 50: in most areas all patients in one practice are invited at the same time, so you may not get an invitation until you're 51 or 52, but it will be before you turn 53.

The appointment was at a mobile screening unit in the car park of a local health clinic, just 10 minutes away. Beforehand, the mammographer asked me a few general questions about my breast health and explained what would happen during the breast screening.

I was asked to undress down to the waist and stand up close against the mammography machine, facing forward. The technician explained that she would position one breast at a time on the plastic plate and lower another plate to flatten it slightly. This prevents any movement during the X-ray, resulting in a clearer image.

The mammographer will usually take two X-rays of each breast - one from above and one from the side. You have to keep still for several seconds each time and the mammogram only takes a few minutes, with the appointment taking about 20-30 minutes in total.

'It was over in a few seconds'

I was a bit nervous before the procedure as I'm an A-cup and was concerned that compressing what little I have between the two plates would be painful! Although it was uncomfortable - more so on one side than the other - the discomfort was over in a few seconds.

"It can sometimes be more uncomfortable for women who have smaller breasts," confirms Addie Mitchell, clinical nurse specialist at charity Breast Cancer Now. "Or if you're still menstruating, as the breasts can become more tender at different points during the menstrual cycle. Not everyone finds it uncomfortable though and it's all over quickly."

Some of the newer machines available on the NHS are specially modified for comfort and for sensitive breasts; they also have different plate sizes to suit different-sized breasts. It is safe for women who have breast implants to have a mammogram, it just requires a variation in the type of X-ray exposure and the breasts need to be compressed differently.

The results

I am awaiting the results which I was told should arrive within two weeks. It's reassuring to know that in the national screening programme 96 out of 100 women will have a normal result. About four receive abnormal findings and will be asked to come back for more tests. Of these four women, one will be found to have cancer.

Dr Kate Downey is a consultant radiologist in the Breast Unit at The Royal Marsden Hospital in London. The hospital runs a specialist clinic for women at 'moderate risk' of breast cancer.

"If you're re-called after a mammogram, an ultrasound will often be performed as the next step to provide further imaging of any abnormality," she explains. "We also look at the lymph nodes with ultrasound. In a small number of cases a biopsy may be required to get a small sample of tissue that can be looked at under a microscope. This is a routine procedure and can be done using local anaesthetic."

What about younger women?

Melanie Sturtevant is policy manager at Breast Cancer Now. She says the AgeX trial, due to report in 2026, may provide a case for a broader age range of women being offered breast screening.

"This age-extension trial will see if women aged 47-49 and 71-73 would benefit from breast screening, in addition to the current 50-70 age bracket," she says. In some regions the younger age group is already being offered mammograms as part of the trial. We might pick up earlier breast cancers that way."

Downey adds that although lowering the age range may be beneficial, other issues may also need addressing to ensure best practice.

"Younger women generally have denser breast tissue which can reduce the sensitivity of mammograms," she explains. "So then comes the question of whether we add in an ultrasound for these women in their forties in conjunction with the mammogram."

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Family history and genetics

A woman who has a first-degree female relative with breast or ovarian cancer (mother, daughter or sister) has about twice the risk of developing breast cancer than a woman without this family history. The faulty BRCA1 and BRCA2 genes also run in some families and account for 5% to 10% of breast cancer cases, which are termed as hereditary.

"It's worth noting though that most cases of breast cancer are found in women who don't have a family history of the disease," says Mitchell, "so it's important to go for a mammogram when you're called, even if you think you're healthy and not at high risk."

Some women will be offered breast screening at a younger age if a family history of the disease is considered to put them at moderate or high risk - you would need to be referred by your GP, so do speak with them if this applies to you. You may also be referred for ultrasound and/or mammography if you go to your GP with breast symptoms such as lumps, nipple discharge or puckering.

Benefits and risks of breast screening

Over-diagnosis

Undoubtedly breast screening saves lives, with about 1,300 lives saved from breast cancer each year in the UK. However, about 4,000 women will be offered treatment they didn't need after being diagnosed with a breast cancer that would never have been found without screening and would never have become life-threatening.

"You can get pre-invasive cancer that in some instances will never develop to become a problem," Sturtevant explains. "The issue is that doctors don't know how many cancers can be safely left alone. Many women don't want to take the 'watch and wait' approach; they'd rather have treatment to be certain."

Researchers are trying to find better ways to tell which breast cancers are life-threatening and which are not - the Loris trial for low-risk DCIS is one such study.

X-ray exposure

"Women I see often worry about the effects of X-ray exposure," says Downey, "but a mammogram is very low-dose radiation. It is less than half of that accumulated over a year from natural background radiation in the UK. So please don't let that put you off going for breast screening."

COVID-19

The national breast screening programme was paused during the COVID-19 lockdown in March and Breast Cancer Now estimates that nearly one million women will have been caught up in the postponement of appointments.

"We looked at cancer detection rates across the UK and found that there could be around 8,600 women living with undetected breast cancer as a result of the pause," says Sturtevant. "Alongside that we saw quite a big drop in the number of women who had gone to see their GP due to breast symptoms who would've been referred on to see a breast specialist."

My mammographer was wearing full PPE, social distancing was in place and the unit was cleaned after every appointment, so I felt at ease in terms of any COVID-19 risk.

Further information

It's crucial that women of all ages are breast aware - getting to know what their breasts feel like normally so they can spot when something changes. If you are worried about a possible breast cancer symptom (such as a lump, skin puckering or nipple discharge), or concerned that you have a family history of breast cancer, consult your GP. Screening and GP appointments might be carried out differently during the pandemic, but they're still going ahead.

Certain lifestyle factors can increase women's risk of developing breast cancer including being overweight, smoking, excessive alcohol intake and lack of exercise. Whatever your background, the message is live a healthy lifestyle and be breast aware.

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