Information for scientists

Ductal carcinoma in situ (DCIS) has always been treated as cancer. It was virtually unknown before breast screening and now accounts for 25% of all ‘breast cancers’ detected. Over 51,000 women are diagnosed with DCIS each year in the USA over 7,000 in the UK and over 2,300 in the Netherlands. DCIS is usually treated by surgery, radiotherapy and endocrine therapies with the associated ongoing lifelong consequences of treatment. However, there is no evidence that treating low and intermediate grade DCIS saves lives and there is good evidence that women diagnosed with DCIS perceive their risk of dying from DCIS as the same as that of women with invasive disease.

Women with DCIS are turned into ‘cancer patients’ with all the concomitant anxiety and implicit negative impact on family life that is almost certainly unwarranted for many. For example, in the United States it is estimated that almost 500,000 women have been treated for in situ cancers in the last 10 years with negligible impact on breast cancer mortality for up to 80% of these women. Moreover, estimates

suggest that mammographic screening has resulted in overdiagnosis and overtreatment in over 1 million women in the United States in the past 30 years. The majority of this due to the overtreatment of DCIS.

The Marmot Report in 2012 recognized the cost to women’s wellbeing of overtreatment. Understanding how DCIS evolves and developing markers for which DCIS may or may not progress to invasive breast cancer, are pressing needs for the tens of thousands of women diagnosed with DCIS each year and all women of breast screening age. To date, there is no widely adopted risk model or set of markers to distinguish indolent from aggressive DCIS. PRECISION has been designed to address this issue in a comprehensive multidisciplinary fashion, producing validation of an experimental proof of concept for the DCIS risk stratification model and after the project, its rapid translation into a tool for testing in clinical practice. Back to Information for scientific community