The Role of Sentinel Node (SN) Mapping in Patients with High Grade Ductal Carcinoma In-Situ (HG-DCIS) Diagnosed by Needle Core Biopsies (NCB)
LF Chiles, YM Brill, J Hinson, H Wright, P McGrath, LM Samayoa. University of Kentucky, Lexington, KY
Background: The current practice recommends SN mapping in all HG-DCIS patients. While this may be indicated in simple mastectomies, concomitant SN mapping in breast conservation remains controversial.
Design: Mammographic, sonographic and magnetic resonance imaging (MRI) data from 95 consecutive patients with initial diagnosis of HG-DCIS only, HG-DCIS suspicious (susp) for microinvasion (Tmic) and HG-DCIS with Tmic disease on NCB were reviewed. Mammographic data included: microcalcifications (Ca++) only versus Ca++ with associated masses/densities, and multifocal versus unifocal disease. Sonographic data was recorded as positive or negative for associated masses. MRI results, when available, were used to evaluate extent of disease and multifocality. All patients underwent SN mapping at the time of their breast surgical procedures (mastectomies or lumpectomies). NCB results were then correlated with the results of the definitive surgical procedures.
Results: The overall incidence for metastatic disease in patients with predominantly HG-DCIS in NCB was 9.4% (9/95). The incidence of metastatic disease in the individual categories was as follows: 1) HG-DCIS only = 2.5 % (1/40); 2) HG-DCIS susp for Tmic: 6.6 % (2/30) and 3) HG-DCIS + Tmic: 24% (6/25). All patients with metastatic disease were N1a, and in retrospect, all had either mammographic, sonographic or MRI breast findings suspicious for invasive carcinoma. Excluding 2 patients with multifocal invasive lobular carcinoma, metastases were associated with high grade primaries > 0.5 cm. None of the patients presenting with microcalcifications without (w/o) associated masses or densities had metastatic disease. The extent of the microcalcifications and evidence of multifocality correlated with increased incidence of Tmic or invasive disease, but not necessarily with metastatic disease. Breast conservation patients had a lesser incidence of metastatic disease (n = 1) than patients undergoing mastectomies for reasons other than cosmetic results (n = 8).
Conclusions: For breast conservation patients with radiographic data showing pleomorphic Ca++ w/o associated masses and NCB diagnoses of HG-DCIS only or HG-DCIS susp for Tmic, SN mapping should be offered only after confirmation of invasive disease.
Tuesday, March 10, 2009 8:30 AM
Platform Session: Section B, Tuesday Morning