Professor Kefah Mokbel outlines the optimal treatment of ductal carcinoma in situ (DCIS) in an editorial published in the August issue of World Jounal of Clinical Oncology
Ductal carcinoma in situ (DCIS) represents an intra-ductal epithelial proliferation of malignant cells and is considered to be a non-obligate precursor of invasive breast cancer. It currently accounts for approximately one fifth of newly-diagnosed breast cancers and its incidence has been rising due to the wider adoption of screening mammography and the introduction of high spatial resolution magnetic resonance imaging (MRI)[1,2]. DCIS usually presents as mammographic micro-calcifications or non-mass enhancement (with segmental distribution) on MRI. The latter is more sensitive imaging modality than mammography in detecting intermediate and high grade DCIS and is more accurate in estimating the disease extent. Symptomatic DCIS is much less common nowadays and clinically presents as a palpable mass or nodularity, pathological nipple discharge or occasionally found as an incidental pathological finding during surgery for other reasons such as reduction mammoplasty. Furthermore symptomatic DCIS is associated with higher rates of local recurrence (LR) after treatment compared with screen-detected disease.
The overall risk of DCIS progressing to invasive breast cancer has been reported to range from 14% to 75% depending upon the nuclear grade. This indicates that a significant proportion of DCIS cases are not life -threatening and do not require any treatment. The challenge however is to accurately identify such cases in order to ovoid overtreatment. Unfortunately the current clinico-pathological parameters used in clinical practice are unable to identify clinically less relevant disease and therefore all DCIS lesions require at least surgical excision.