Management of ductal carcinoma in situ in the modern era.

Ductal carcinoma in situ (DCIS) has been the subject of much controversy since the advent of population based breast screening programs. An increasing number of asymptomatic women are being diagnosed with this condition and there is uncertainty over the best treatment algorithm for this condition if treatment is to be considered at all. Different subtypes of DCIS show innate differences in developmental pathways and biological behavior. This is not only determined by pathological subtypes but there is increasing understanding of molecular biomarkers related to DCIS progression. The ultimate management aim is to identify a subgroup of patients in whom DCIS will not progress to invasive disease such that they can avoid morbidity from surgical and adjuvant therapies. This has to be balanced by the potential risk of undertreatment of patients in whom DCIS is likely to progress to invasive cancer and hence a reduced life expectancy. Results of current ongoing prospective randomized trials assessing the safety of omitting surgery for what is considered to be low risk DCIS are eagerly awaited for by patients and clinicians. However the definition of what is considered to be "low risk" DCIS is still to be ascertained.