1595. Symptomatic Ductal Carcinoma In Situ (DCIS): Risk and Predictors of Upgrade to Invasive Carcinoma
Authors * Denotes Presenting Author
  1. Sheila Venkatesh *; Massachusetts General Hospital
  2. Tawakalitu Oseni; Massachusetts General Hospital
  3. Manisha Bahl; Massachusetts General Hospital
Ductal carcinoma in situ (DCIS) is a noninvasive breast cancer that has the potential to be upgraded to invasive carcinoma at the time of surgery. Given concerns about overtreatment of DCIS with surgery and radiation, clinical trials are currently underway to evaluate the safety and efficacy of active surveillance as an alternative management approach. Since DCIS typically presents as calcifications at screening mammography and uncommonly presents with symptoms (such as a palpable lump or nipple discharge), there is limited research about the subset of DCIS cases that are symptomatic. The purpose of this study is to determine the upgrade risk of symptomatic DCIS diagnosed at biopsy to invasive carcinoma at surgery and to identify patient, imaging, and pathologic features associated with upgrade risk.

Materials and Methods:
This IRB-approved and HIPAA-compliant retrospective study includes symptomatic women who were diagnosed with DCIS at image-guided core needle biopsy from January 2007 to December 2016 at a large academic medical center. Patient characteristics, imaging findings, core needle biopsy pathology results, and surgical outcomes were collected from medical records. Patient, imaging, and pathology features were compared between cases of DCIS that did and did not upgrade to invasive carcinoma at surgery, using the unpaired t-test, chi-square test, and Fisher’s exact test. P-values less than 0.05 were considered statistically significant.

Over the ten-year study period, fewer than 5% (63/1399) of women diagnosed with DCIS presented with symptoms. The study cohort was therefore composed of 63 women (mean age 51, range 27-88 years). 84.1% (n=53) presented for evaluation of an area of clinical concern, and 15.9% (n=10) presented with pathologic nipple discharge. The most common finding type at mammography was calcifications with or without an associated asymmetry or mass (63.5%, 40/63). The upgrade rate of symptomatic DCIS at biopsy to invasive carcinoma at surgery was 34.9% (22/63). The only feature associated with increased upgrade risk was biopsy modality type, with cases that underwent MRI-guided core needle biopsy accounting for 22.7% of upgraded cases versus 4.9% of non-upgraded cases (p=0.03). There were no other features associated with upgrade risk, including patient age, personal or family history of breast cancer, breast density at mammography, imaging findings, nuclear grade of DCIS, or hormone receptor status of DCIS.

DCIS uncommonly presents with symptoms such as a palpable lump or nipple discharge. In our study cohort, the upgrade rate of symptomatic DCIS to invasive carcinoma was high at nearly 35%, and the only feature associated with increased upgrade risk was biopsy modality type of MRI. These results could be used to inform eligibility criteria for active surveillance trials, guide surgical decision-making (eg, whether or not to perform sentinel lymph node biopsy at the time of initial surgery), and counsel patients regarding expected outcomes.