Ductal carcinoma in situ (
DCIS) accounts for up to half of screen-detected breast
cancers and thus constitutes a major public health problem. Despite effective current treatment many patients with
DCIS are either over- or undertreated because of the paucity of precise models to predict recurrence or progression. The combination of clinical and molecular factors as already applied for invasive disease may help to build such models also for
DCIS. We compared 53
DCIS (36.6 %) and 92 (63.4 %) invasive
breast cancer cases and found no significant differences in
age, receptor status of ER, PR, and HER2, and the use of
radiotherapy. Interestingly, the proportion of disseminated
tumor cells (DTC) did also not significantly differ between
DCIS and invasive cases (p = 0.57). A negative PR status was associated with the detection of DTCs (p = 0.026). We then compared relationships of clinical parameters and
biomarkers with patients' prognosis in 43
DCIS and 40 small invasive
tumors ≤ 5 mm (T1a). ER negativity was associated with shorter relapse free survival in the complete cohort (p = 0.004) and showed a trend in both subgroups (p = 0.053 for
DCIS and p = 0.046 for T1a, respectively). In conclusion, we found markedly similar properties of both
DCIS and small invasive breast
cancers with respect to the distribution of several parameters as well as to the prognostic value of
biomarkers.
DCIS with a
luminal phenotype seem to be characterized by a favourable prognosis.