Is Sentinel Lymph Node Biopsy Indicated at Completion Mastectomy for Ductal Carcinoma In Situ?

Abstract

Background Sentinel lymph node biopsy (SLNB) is recommended when mastectomy is performed for ductal carcinoma in situ (DCIS). The role of SLNB for women with DCIS who undergo mastectomy following ≥1 attempts at breast-conserving surgery (BCS) is uncertain. We examined the upgrade rate and SLNB yield in women who converted to mastectomy after ≥1 attempts at BCS for DCIS. Methods All patients who underwent ≥1 attempts at BCS prior to conversion to mastectomy with SLNB for DCIS were identified. Margin status as the indication for mastectomy was confirmed. Comparisons were made between patients with/without upgrade on final pathology. Results From 2/2006–11/2012, 233 patients underwent completion mastectomy following ≥1 attempts at BCS for positive/close margins (median age,50 years; range 34–84). Median number of BCS attempts was 1 (range 1–4). Overall, 20 (9%) patients were upgraded on final pathology; 15 (6%)stage I, 5(3%) stage II (3 micrometastasis,2 macrometastasis). In 2 of 5 cases with a positive SLN, invasive carcinoma was not identified in the mastectomy specimen. The only factor associated with any upgrade was the presence of micropapillary DCIS (80% versus 55%, with and without upgrade; p = 0.03). Conclusion In this cohort of patients with DCIS who converted to mastectomy for positive/close margins after ≥1 attempts at BCS, 18 (8%) would have required second-stage axillary surgery had a SLNB not been performed and in 2 (1%) patients the SLN provided the only evidence of invasion. These findings support the recommendation for SLNB at the time of completion mastectomy.

Sentinel lymph node positivity in patients undergoing mastectomies for ductal carcinoma in situ (DCIS)

“…We found the upstage rate to invasive carcinoma to be 29%. This is consistent with the reported 8%‐40% upstage rate and corresponds with Brennan et al's meta‐analysis which found 26% (95% CI: 23%‐30%) of patients with an initial diagnosis of DCIS on PCB had invasive disease on final pathology. In our study, the rate of SLN positivity among these upstaged patients was small but clinically significant (10%).…”

“…These factors were palpability, extent of disease on imaging larger than 1.20 cm and mass on pre‐op imaging. Other studies have demonstrated the utility of these preoperative markers of upstage risk . Multicentricity, patient reported symptoms and the presence of necrosis have also been reported as predictive factors; our study did not corroborate the significance of these additional findings.…”

“…In our study, the rate of SLN positivity among these upstaged patients was small but clinically significant (10%). Previous studies have reported a similar rate of 4%‐15% SLN positivity among patients with DCIS upstaged to invasive cancer . Among patients with a final diagnosis of DCIS on mastectomy, there were no cases of SLN involvement.…”

“…However, there is a risk of underestimating invasion on PCB due to sampling error. DCIS diagnosed on PCB is upstaged to invasive disease on final surgical pathology at a rate of 8%‐40% . When DCIS is upstaged to invasive disease, the rate of SLN positivity is reported in the literature as 4%‐15% …”

Current Trends in the Management of Phyllodes Tumors of the Breast

“…A second explanation is that surgeons may be concerned about finding an occult primary invasive cancer in the mastectomy specimen and are therefore performing a prophylactic sentinel lymph node biopsy as is the standard recommendation for patients undergoing mastectomy for ductal carcinoma in situ (DCIS). 15–17 Another explanation is that patients are taken to the operating room with a presumed diagnosis of adenocarcinoma and undergo lymph node sampling. It is only on final pathology that the diagnosis of phyllodes is made.…”