Several trials are underway to evaluate the safety and efficacy of active surveillance (AS) for women with ductal carcinoma in situ (DCIS). The purpose of this study is to identify patient, imaging, and pathological features associated with surgical upstaging of DCIS to invasive disease, in order to inform eligibility criteria for AS trials.
Medical records were retrospectively reviewed of women with screen-detected calcifications who were diagnosed with DCIS from 2007-16. Multiply imputed multivariable logistic regression models were fit to assess features associated with risk of upstaging to (1) any invasive disease (microinvasive disease [≤1 mm of invasive disease] or non-microinvasive disease) or (2) non-microinvasive disease only.
The upstaging rate of DCIS to invasive disease was 16% (161/1029). Of 161 upgrades, 35% (n=57) were upstaged to microinvasive disease and 65% (n=104) to non-microinvasive disease. Features associated with upstaging to any invasive disease were menopause above the age of 50, breast MR imaging, and intermediate or high nuclear grade of DCIS at biopsy (all p<0.05) The only feature associated with upstaging to non-microinvasive disease was MR imaging (p=0.004).
Identification of features associated with upstaging risk could be used to exclude certain women with high-risk DCIS from AS trials.