Ductal carcinoma in situ (DCIS), an early-stage breast cancer confined to the milk ducts, is increasingly being diagnosed in women in their 40s, a demographic previously less affected by this condition. The number of DCIS diagnoses in the UK has tripled since the early 1990s and has seen a 29% increase since 2019. This trend has led to growing concern and calls for a lower screening age.
Sarah Stirk, a 47-year-old golf presenter, was diagnosed with DCIS after a private mammogram recommended for perimenopause symptoms revealed abnormal cells. Although DCIS is often considered 'stage zero' cancer because it has not spread, experts warn that it can develop into invasive cancer if left untreated. Stirk's diagnosis led to a mastectomy to remove the affected tissue.
Experts suggest a combination of lifestyle factors may be contributing to the rise in DCIS among younger women. These potential factors include women having children later in life, which alters hormone exposure, increased use of oral contraceptives, alcohol consumption, sedentary lifestyles, and obesity, which can promote inflammation. Sarah Stirk, who underwent IVF for her son, also wonders if the associated hormone treatments may have played a role, though research on fertility drugs and cancer risk is limited.
Professor James Harvey, a consultant oncoplastic breast surgeon, noted that DCIS is typically asymptomatic and often detected through screening. He stated that research groups are actively investigating the reasons behind this increase. He also supports the idea of lowering the mammography screening age, suggesting benefits from screening women as young as 45.
Currently, the NHS offers breast cancer screening every three years to women between 50 and 70, with an attendance rate of 60-70%. Some experts express caution about lowering the screening age, citing concerns that denser breast tissue in younger women could lead to less accurate mammograms, potentially resulting in overdiagnosis and unnecessary treatments. However, proponents argue that early detection, even with potentially less clear scans, can lead to less radical treatments.
Jennifer Rusby, a consultant oncoplastic breast surgeon, emphasized that increased attendance at current screening appointments would also help detect cancers at an earlier, more treatable stage. The AgeX trial, a study run by the University of Oxford, is currently examining the impact of lowering the screening age to 47 and extending it to 73, with initial results anticipated in December.
Sarah Stirk has become an advocate for raising awareness and has supported a petition to lower the screening age to 40. She believes that earlier screening is crucial for catching DCIS before it becomes more advanced. With early detection, the cure rate for non-invasive DCIS is approximately 99%.