High P4HA2 expression within tumour epithelial cells was associated with shorter LRFI in the whole cohort of pure DCIS (HR = 2.3, 95%CI = 1.3–4.1; p = 0.003, Fig. 2) and in the luminal ER-positive/HER2-negative subgroup (HR = 3.3, 95%CI = 1.1–5.2; p = 0.001). Here, P4HA2 is linked to ductal breast carcinoma in situ.