Predicting invasion in patients with DCIS in the preoperative percutaneous biopsy.

When ductal carcinoma in situ (DCIS) is suspected in mammography, core needle biopsy or vacuum assisted biopsy is recommended. However, invasion remains undetected with percutaneous biopsy techniques in 10-20% of the patients. Our aim was to evaluate the prevalence of and predictive factors for invasion in the surgical specimen in patients with DCIS in the preoperative biopsy. Sixty-seven consecutive participants of the Helsinki City Mammography Screening program with DCIS in the preoperative percutaneous biopsy were included. The palpability, the mammographical size and appearance and the visibility of the lesion in breast ultrasound were evaluate as factors predictive for invasion, as well as the histopathological features of DCIS in the preoperative biopsy. Twenty patients had invasion in the surgical specimen. The only predictive factor for invasion was the visibility of the lesion in ultrasound, but even this finding failed to reach statistical significance. Thirteen of the 26 patients with lesions visible in US had invasion in their surgical specimens, while only seven of the 41 patients without such a lesion had invasive or microinvasive cancer, Pc = 0.0686. In conclusion, the visibility of the lesion in US may predict detecting invasion in the surgical specimen in patients with DCIS in the preoperative biopsy.