Just one hour after a mammogram that changed her life, Sarah Stirk arrived for her TV presenting job at Sky Sports and fought to put on a brave face.

The breast screening had revealed abnormal cells in her milk ducts, the tiny tubes that carry milk to the nipple, and while not always cancerous, Sarah had a gut feeling something wasn’t right.

‘I saw the doctor’s face and could tell straight away it wasn’t good news,’ recalls Sarah, 47, a golf presenter and mother of one from York.

‘I asked if there was a lump and she said: “no, but there are abnormal cells…”. Afterwards, I went straight to work. I was a bit of a mess. I didn’t know for sure but no part of me expected good news.’

And she was right. Sarah was later diagnosed with ductal carcinoma in situ (DCIS) in her left breast, an early-stage breast cancer within the milk ducts.

Sometimes known as a ‘stage zero’ cancer (as it hasn’t spread), DCIS is on the rise, particularly among women in their 40s. Until recently, it was usually only seen in women over 50.

Aged 47, three years before the NHS invites women for routine screening, Sarah only went for the mammogram as the private specialist she’d seen for perimenopause symptoms including hot flushes advised her to have the scan before starting HRT.

Sarah Stirk learned she had abnormal cells after a breast screening, and was later diagnosed with an early-stage breast cancer in the milk ducts

‘I had a feeling something wasn’t right so wanted to go for the appointment,’ says Sarah. ‘I’ve always had a fear of breast cancer. The fear was maybe irrational as size has nothing to do with cancer risk, but my breasts are quite large.’

The radiographers spotted a large area of calcifications, small white calcium deposits that sometimes indicate cancer – calcium deposits can occur with age but they can also form as a result of breast cells being replaced faster than usual, which can indicate pre-cancerous changes.

Sarah was referred to the NHS for a further mammogram and biopsy, which was carried out last December.

This time doctors said it was ‘50/50’ as to whether it was cancer. Two weeks later – just days before Christmas – Sarah had her hair cut and was standing outside the hairdresser’s when a consultant phoned and delivered the bad news.

She recalls: ‘I can’t remember exactly what was said but I remember hearing the word mastectomy. I was devastated.

‘My worst fears were realised. I was in tears and had to walk back through town to my car, crying. I knew I had a gruelling journey ahead of me.’

Professor James Harvey, a consultant oncoplastic breast surgeon at the private The Alexandra Hospital in Manchester, says DCIS is only picked up during screening as typically it’s symptomless.

‘The breast is full of milk ducts and inside each of those ducts is a lining of cells,’ he says.

‘DCIS is a cancerous overgrowth of those cells. They haven’t yet developed the ability to grow or spread. But if you leave them long enough, one of them will turn into invasive cancer, bursting out of the duct. It might create a lump and spread.’

A lumpectomy or radiotherapy are usually first-line treatments. But a mastectomy may be required if a large area is affected.

It is increasingly common – ‘we are seeing more younger women with DCIS, particularly in the last two or three years,’ explains Professor Harvey, who also works at the NHS Nightingale and Prevent Breast Cancer Centre in Manchester. The number of diagnoses has tripled in the UK since the early 1990s. Rates have increased by 29 per cent since 2019.

There is strong evidence in favour of doing mammography screening younger, Sarah says. She has signed a petition to lower the screening age to 40

‘Research groups are being set up internationally to try to get to the bottom of why this is happening,’ says Professor Harvey.

‘It’s likely to be a combination of factors. Something to do with how our lifestyles have changed. No one knows for sure.’

Possible factors include women having children later as this changes exposure to oestrogen and other hormones, use of the contraceptive pill, alcohol and sedentary lifestyles.

Obesity is another factor, likely due to how it encourages inflammation in the body.

Sarah had IVF to have her son Milo, now four, and she believes the hormones she was given as part of the treatment might have had an impact.

Most studies suggest fertility drugs do not increase the risk of cancer, but evidence is limited and experts believe more research is needed.

Whatever the cause, Sarah’s cancer might have spread if she’d waited until 50 for a mammogram on the NHS.

‘I think there is good evidence that there is benefit of doing mammography screening younger, certainly from the age of 45,’ Professor Harvey explains.

‘It comes down to the resources available and whether we can afford that as a society.’

Sarah needed a mastectomy to remove all her cancer and choosing the right surgeon caused her ‘emotional turmoil’.

Sarah had IVF to have her son, Milo, and believes the hormones she was given as part of that treatment might have had an impact

‘I’ve always had body confidence and liked my boobs,’ she says. ‘The decision I made was going to affect what I looked like for the rest of my life and it was very overwhelming.’

Using her private health insurance, she chose to have a mastectomy with a synthetic implant with Professor Harvey at The Alexandra Hospital. The procedure included a mastopexy, a breast lift and skin tightening on the right side to help her breasts look symmetrical.

‘On the day, I had a bit of a cold,’ recalls Sarah.

‘I was half hoping they’d say I was too unwell and to come back another day. The anxiety was horrific. I was worried that losing a breast would make me less of a woman somehow, less feminine.

‘I vividly remember walking to the anaesthetic table. I nearly said “I can’t do this”.

‘It was fear. I didn’t feel unwell and yet I was going into surgery and I knew I’d come out with a different body and have weeks of recovery ahead of me.’

Sarah’s four-hour surgery was a success and though she says ‘it was three months before I was able to look at myself in the mirror’, six months later she remains ‘sore and tired’ – but she is ‘delighted’ with the results. She has gone from a 35F to a 34DD.

‘After breastfeeding, my breasts had become heavy and saggy and were too big for my frame,’ she says. ‘But I didn’t want small boobs. Appearance matters to me, especially with the job I do.’

Sarah attends six-monthly scans and takes tamoxifen to cut the risk of her cancer returning.

She is now on a mission to raise awareness of DCIS and has signed a petition, organised by a chemotherapy nurse, to lower the screening age to 40. The petition, now closed, gathered more than 106,000 signatures.

‘DCIS is a silent killer,’ says Sarah. ‘The only way you catch this is with screening. If I’d waited until I was 50, my cancer might have been stage three or four. It might have been too late.’

She adds: ‘All the nurses told me they are seeing more younger women with DCIS. Lowering the screening age would save lives.’ Professor Harvey says if the screening age was lowered, the majority of women diagnosed would be offered radiotherapy and a lumpectomy and could keep their breasts.

This wasn’t an option for Sarah’s as the abnormal cells had spread to a larger area.

Some experts argue that as younger women have denser breast tissue, which can make mammograms less accurate, reducing the screening age may lead to overdiagnosis and unnecessary treatment.

Caught at its earliest stage, the cure rate for non-invasive DCIS is 99 per cent.

Jennifer Rusby, a consultant oncoplastic breast surgeon at The Royal Marsden NHS Foundation Trust in London, says if more women attended screenings when invited it would help catch breast cancer at this early stage and save more lives.

‘Breast screening is offered every three years to all women between the ages of 50 and 70. But, currently, only 60 to 70 per cent of women attend screening appointments when invited.’

The AgeX trial, run by the University of Oxford, has been looking at whether breast cancer outcomes could be improved if the screening age was lowered to 47 and raised to 73. Initial results are expected in December.

Treatment would be much less radical and invasive if caught early, says Ms Rusby.

Sarah returned to work in April: ‘I love my job and it’s great to get back to work and keeping busy,’ she says. ‘The team at Sky are like a little family and they have all been incredibly supportive.

‘But the diagnosis has changed me. I really embrace the small things in life and I’m incredibly grateful for everything I have and for catching it early.’