Underestimation of DCIS at MRI-guided vacuum-assisted breast biopsy.
False Negative Reactions
Magnetic Resonance Imaging, Interventional
Carcinoma in Situ
Carcinoma, Ductal, Breast
The study objective was to assess the rate of underestimation of ductal carcinoma in situ (DCIS) at MRI-guided 9-gauge vacuum-assisted breast biopsy.
An institutional review board-approved retrospective review was performed of 373 consecutive lesions that had undergone MRI vacuum-assisted breast biopsy. In 34 lesions with subsequent surgery, vacuum-assisted breast biopsy yielded DCIS without frank microinvasion or invasion. DCIS underestimates were lesions for which vacuum-assisted breast biopsy yielded DCIS without frank microinvasion or invasion at biopsy and surgery yielded invasive cancer. Records and pathology findings were reviewed.
Among 34 lesions, vacuum-assisted breast biopsy histology was DCIS in 29 and DCIS with possible microinvasion in five. Of 29 lesions yielding DCIS at MRI vacuum-assisted breast biopsy, surgical excision revealed invasive cancer in five (17%; 95% CI, 6-36%). The DCIS underestimation rate was significantly higher in lesions 6 cm or larger versus smaller lesions (60% vs 8%, p = 0.02). MRI lesion type, kinetics, number of specimens, menopausal status, and target sampling versus excision did not significantly affect underestimation. Of five lesions yielding DCIS with possible microinvasion at MRI vacuum-assisted breast biopsy, surgery revealed invasive carcinoma in four (80%; 95% CI, 28-99%). DCIS underestimation was significantly more likely if MRI vacuum-assisted breast biopsy showed possible microinvasion than if it did not (80% vs 17%, p =0.01).
Underestimation occurred in 17% of lesions yielding DCIS and in 80% of lesions yielding DCIS with possible microinvasion at MRI vacuum-assisted breast biopsy. DCIS underestimation was significantly more likely in lesions measuring 6 cm or larger. No other patient or lesion factors significantly affected DCIS underestimation at MRI vacuum-assisted breast biopsy.