Predictors of invasive breast cancer and lymph node involvement in ductal carcinoma in situ initially diagnosed by vacuum-assisted breast biopsy: Experience of 733 cases

OBJECTIVE: To predict presence of invasive component and nodal involvement in women diagnosed preoperatively with ductal carcinoma in situ (DCIS) by vacuum-assisted breast biopsy (VABB). MATERIALS AND METHODS: We retrospectively analyzed 733 patients with preoperatively diagnosed DCIS, investigating the association of clinical-radiological variables with invasive component and nodal involvement. RESULTS: Mammographic size >20 mm and residual lesion on post-VABB mammogram were related to invasive component (both p < 0.0001) and nodal involvement (p = 0.001, p = 0.03). Age <40 years was associated with presence of invasive component (p = 0.003). By multivariate analysis residual disease was associated with invasive component, and mammographic tumor size >20 mm with nodal involvement, both highly significant. CONCLUSIONS: Older age, lesion <20 mm, and no residual lesion predict absence of invasion and no nodal involvement in VABB-diagnosed DCIS. However it would be imprudent to routinely forego sentinel node biopsy in such patients as non-negligible proportions of them have invasive disease.