br Lymph Node Tattooing and TAD
Lymph Node Tattooing and TAD for Axillary Staging After NAC
Figure 3 Microscopic Findings. (A) Tattooed Lymph Node With Extended Areas of Black Pigment Granules in the Cortex (Hematoxylin and Eosin [H&E] Staining, Magnification 325). (B) Black Pigment Granules Found as Small Foci in the Cortex of Additional Lymph Nodes, in the “Sentinel/No Black Pigment” Group, Show Tattoo Ink Migration (H&E Staining, Magnification 3100)
Table 3 Pathological Assessment
Variable Value P
Surgical Retrieval of All Marked Nodes 74 (98.6)
Abbreviations: ALND ¼ axillary lymph node dissection; AxpCR ¼ axillary pathologic complete response; ER ¼ estrogen receptor; pCR ¼ pathologic complete response; SLN ¼ sentinel lymph node; TAD ¼ targeted axillary dissection.
nodes was not statistically associated with the number of initially tattooed lymph nodes but was linked to the number of harvested SLNs (P ¼ .276 and .039, respectively). In these cases, black pigment granules were apparent only microscopically as small foci into the lymph node 88899-55-2 (Figure 3B).
An axillary pathologic complete response (AxpCR) after NAC was observed in 49 of 75 cases (65.3%). The AxpCR rate was similar when only 64 patients, with biopsy-proven positive axilla, were included (41 of 64 patients, 64.0%; P ¼ .875). Three of 11 patients with negative or nondiagnostic axillary biopsy had residual disease in the axilla after NAC. The AxpCR rate was strongly correlated with the tumor type according to immunohistochemistry (estrogen receptor [ER]-positive HER2 , ER HER2 , HER2þ; P < .00001). In 24 patients who underwent complete ALND after TAD, additional positive lymph nodes were found in 8 (33.3%), which was not associated with the number of harvested SLNs or with the number of tattooed lymph nodes (P ¼ .569 and .829, respectively; Table 3).
The optimal axillary staging for clinically node-positive patients, who become clinically node-negative after NAC, remains ques-tionable. The standard approach of ALND is an accurate method but carries unacceptable morbidity. Using modern chemothera-peutic regimens and targeted treatments, a large proportion of these patients will become pathologically node-negative. In the NSABP (National Surgical Adjuvant Breast and Bowel Project) B-18 trial, one of the earliest and largest prospective trials on NAC, AxpCR was observed in 44% of patients.22 AxpCR rates are higher for ER and/or HER2þ patients.23-26 SLNB as axillary staging after NAC, for patients presented as cNþ at diagnosis, has been debated. Concerns were raised for SLN IR and FNRs. In a meta-analysis by El Hage Chehade et al, there was a pooled estimate of SLN IRs and FNRs at 90.9% and 13%, respectively. In this meta-analysis, 19 prospective trials were included, but biopsy-proven axillary posi-tivity was not mandatory.27 A more recent meta-analysis by Tee et al included 13 studies with biopsy-proven cNþ patients, which
showed similar results (pooled estimate for SLN IRs and FNRs were 90% and 14%, respectively). SLN IR was higher when the dual mapping technique was used.28 In our series, the dual tracer tech-nique was used in all patients, with SLN IR at 93.3%.
According to well designed prospective trials, marking of positive nodes before NAC and then retrieving them during surgery, along with SLNB after NAC, has dramatically decreased FNR rates.10,13,14 Many different methods have been proposed to mark positive nodes before NAC and to identify marked nodes after NAC. Diego et al marked positive lymph nodes with a tissue marker (clip) before NAC using ultrasound guidance in 30 patients. After NAC completion, the marked nodes were localized successfully with an I125 radioactive seed using ultrasound or mammography guid-ance in 29 patients (IR of marked nodes 96.7%). In 1 patient, the radiologist was unable to visualize the marked node via ultrasound or mammography. All localized ALNs were retrieved during surgery. Correspondence between marked nodes and SLNs was 91%.29 When Caudle et al used the same method, the clipped node was not identified in the surgical specimen in 5 of 208 patients (IR of marked nodes 97.6%). The clipped node was also identified as a SLN in 77% of patients.14 Plecha et al marked the positive ALNs with a clip before NAC in 91 patients and localized them after NAC with a hook wire with ultrasound guidance. SLNB or ALND was performed and marked ALNs were removed successfully in 97.3% of patients.30 Donker et al used an upfront radioactive seed (I125) to mark positive ALNs before NAC in 100 patients. The intra-operative IR of marked nodes was 97%.13 Choy et al used a carbon suspension (Spot, GI Supply, Inc, Mechanicsburg, PA) to mark positive ALNs in 28 patients. Sixteen patients underwent immediate surgery and 12 patients had surgery after NAC. Overall IR of tat-tooed ALNs was 96.4%, with correspondence between tattooed nodes and SLNs at 96.3%.15 Park et al used an activated charcoal suspension (Charcotrace; Healthdirect, Haymarket, New South Wales, Australia) in 20 patients before NAC. Intraoperative IR was 100%, and correspondence between tattooed nodes and SLNs was 75%.31