EDNRA and ductal breast carcinoma in situ: In this study, comparative analysis of expression of these growth factors and their respective receptors in the groups of pure DCIS vs coexistent DCIS revealed that expression of proangiogenic factors such as VEGF-C, KDR, Flt-4, and ETAR was significantly more common in pure DCIS than in DCIS with an adjacent invasive carcinoma (coexistent DCIS).