Ductal carcinoma in situ (DCIS), an early-stage form of breast cancer confined to the milk ducts, is appearing with greater frequency in women in their 40s, a demographic previously less affected by this diagnosis. Traditionally, DCIS was more commonly detected in women over 50. However, recent years have seen a notable increase in younger women receiving this diagnosis, with rates in the UK tripling since the early 1990s and rising by 29% since 2019.
Sarah Stirk, a 47-year-old golf presenter, received a DCIS diagnosis after a private mammogram prompted by perimenopause symptoms. Although she did not have a palpable lump, the scan revealed calcifications, which can sometimes signal precancerous changes. Following further testing, she was diagnosed with DCIS just before Christmas. "I can't remember exactly what was said but I remember hearing the word mastectomy," Stirk recalled. "My worst fears were realised. I was in tears and had to walk back through town to my car, crying."
Professor James Harvey, a consultant oncoplastic breast surgeon, explained that DCIS is often asymptomatic and typically detected through screening. He noted the rise in younger patients and stated that international research groups are examining potential contributing factors. "It's likely to be a combination of factors. Something to do with how our lifestyles have changed. No one knows for sure," he said.
Potential lifestyle influences being investigated include delaying childbirth, which alters hormone exposure, as well as the use of oral contraceptives, alcohol consumption, and sedentary lifestyles. Obesity, with its link to inflammation, is also considered a factor. Stirk, who underwent IVF to conceive her son, expressed a belief that the hormones from fertility treatments might have played a role, though research on this specific link remains limited.
Stirk underwent a mastectomy with a synthetic implant, followed by a breast lift and skin tightening on the other side for symmetry, to remove the cancer. She described the emotional turmoil of the decision and the surgery itself. Six months post-operation, she expressed satisfaction with the results but noted ongoing soreness and fatigue.
Sarah is now advocating for a lower mammography screening age, citing her own experience and the accounts of nurses who report seeing more younger women diagnosed with DCIS. She signed a petition, which gathered over 106,000 signatures, to lower the screening age to 40. "DCIS is a silent killer," Stirk stated. "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."
While lowering the screening age could potentially lead to earlier detection and less radical treatments like lumpectomy and radiotherapy for many, some experts raise concerns about the possibility of overdiagnosis and unnecessary treatments in younger women, who tend to have denser breast tissue which can make mammograms less accurate. Currently, NHS breast screening is offered every three years to women aged 50 to 70, with attendance rates between 60% and 70%. The AgeX trial at the University of Oxford is examining the impact of lowering the screening age to 47 and raising it to 73, with initial results anticipated in December. Caught at its earliest, non-invasive stage, DCIS has a cure rate of 99%.