Calculation of recurrence risk of ductal carcinoma in situ: open questions, controversies and future perspectives

Ductal carcinoma in situ (DCIS) of the breast is a heterogeneous group of lesions with diverse malignant potential and a range of treatment options (1). In the past, before the introduction of mammography for secondary prevention of breast cancer, diagnosis of DCIS was rare, representing less than 1% of all breast carcinomas. With the advent of mammography screening, its incidence rates rose rapidly, and this rise was seen consistently in different countries around the world (1-4). In the USA, according to SEER data, the incidence rates of DCIS for all women, irrespective of age and race, rose from 5.83 per 100,000 women in 1975 to 34.82 in 2013 (3). Likewise, in the UK, the incidence rates of DCIS for all women rose from 3.3 per 100,000 women in 1979 to 23.5 in 2013 (3). Recently, it has been estimated that in 2016, there will be 61,000 new cases of DCIS in the USA as compared with 246,660 new cases of invasive breast cancer (5).