Problematic Aspects of Sentinel Lymph Node Biopsy and Its Relation to Previous Excisional Biopsy in Breast Cancer

Accuracy of Sentinel Lymph Node Biopsy in Breast Cancer: Pitfalls in the Application of Single Tracers

Background

Radioisotopes and blue dyes are used as dual tracers in the current gold standard procedure of sentinel lymph node (SLN) biopsy (SLNB) performed for breast cancer. However, the blue dye or the radioisotope as a single tracer is also being applied in some institutes. We aimed to explore the risk factors for the miss-detection of SLNs with the radioisotope and the blue dye and to describe the distribution of SLNs missed by each tracer.

Patients and Methods

Patients undergoing SLNB with radioisotope and blue dye as dual mapping agents were enrolled between August 2010 and August 2018. Radioactivity count, blue dye staining status, and size and location of each SLN were prospectively documented.

Results

In total, 2382 SLNs from 1010 patients were included for statistical analyses. The sentinel node identification rate was 100% for dual tracers, 99.4% for radioisotope, and 89.1% for blue dye. SLN identification using the blue dye was more likely to fail in patients undergoing breast-conserving surgery (p < 0.001) and mastectomy with reconstruction (p = 0.005). Furthermore, miss-detection was significantly more frequent in smaller and uninvolved nodes. Among all SLNs, 8.2% were located in level II and one was in level III. Notably, single tracer of blue dye tended to fail in the detection of lymph nodes in higher levels (p < 0.001).

Conclusion

This study explored the association between features and the incidence of the failure to detect SLNs using radioisotope and blue dye. The locations of the miss-detected SLNs are demonstrated to provide a reference for SLNBs conducted using blue dye or radioisotope as a single tracer.

The value of 18F-FDG PET/CT imaging in breast cancer staging

The National Comprehensive Cancer Network (NCCN) guidelines recommend assessment with positron emission tomography with 2-deoxy-2-[fluorine-18]fluoro-D-glucose integrated with computed tomography (18F-FDG PET/CT) in staging of breast cancer, starting from the stage IIIA. Previously, PET/CT contributed to the accurate staging from the stage IIB. Our aim is to evaluate the contribution of 18F-FDG PET/CT in staging of breast cancer patients. A total of 234 patients were retrospectively evaluated. PET/CT was performed preoperatively in 114/234 and postoperatively in 120/234 patients. Initial staging was performed based on histopathological results in 125/234 and clinical results in 109/234 patients, according to the American Joint Committee on Cancer (AJCC) classification. All patients had a normal abdominal ultrasound and chest x-ray. Following PET/CT imaging, modification in the staging was performed in patients with the metastatic findings. In 42/234 (17.9%) patients hypermetabolic extra-axillary regional lymph nodes and in 65/234 patients (27.7%) distant metastatic involvement were detected with PET/CT. Modification in the staging was applied in 82/234 (35%) patients. Patient management was changed in 69/234 (29.4%) cases. The percentage of patients with upstaging, according to each stage, was as follows: IIA: 18.6%, IIB: 30%, IIIA: 46.3%, IIIB: 68.8%, and IIIC: 20.8%. In 43/43 patients, 99mTc-methylene diphosphonate (MDP) bone scan did not show additional bone metastasis. In 5/32 patients, metastatic involvement was detected with sentinel lymph node biopsy (SLNB), but preoperative PET/CT scan did not reveal hypermetabolic lymph nodes. Although our study was limited by the referral bias and lack of homogeneity in the referral group, PET/CT still significantly contributed to the accurate staging and management of our breast cancer patients, starting from the stage IIA.

Sentinel Lymph Node Biopsy in Breast Cancer: Review on Various Methodological Approaches

Aims and background

Sentinel lymph node biopsy has been accepted as a standard procedure for early stage breast cancer. In this retrospective analysis, the results obtained with different methodological approaches using radiocolloid with or without blue dye were examined.

Methods

A total of 158 sentinel lymph node biopsies were performed in 152 patients. Group A (85 patients) underwent lymphatic mapping using a combination of periareolar intradermal radiocolloid and subareolar blue dye injections. Group B (73 patients) underwent only periareolar intradermal radiocolloid injection. One large tin colloid and two small radiocolloids (nanocolloid of serum albumin -NC- and colloidal rhenium sulphide -CS-) were used.

Results

Successful lymphatic mapping was attained in 157 of 158 procedures (99.4%). Radiocolloids localized sentinel lymph nodes in 99.4% and blue dye in 75.3% of the cases. The number of sentinel lymph nodes removed was greater in nanocolloid and colloidal rhenium sulphide groups ( P ≤0.05). Among 60 metastatic sentinel lymph nodes, frozen section analysis using hematoxylin and eosin staining failed to detect 1 macro- and 10 micrometastasis. Radiocolloid uptake was higher in sentinel lymph nodes accumulating blue dye (1643 ± 3216 counts/10 sec vs 526 ± 1284 counts/10 sec, P <0.001). Higher count rates were obtained by using larger sized colloids (median and interquartile range: tin colloid, 2050 and 4548; nanocolloid, 835 and 1799; colloidal rhenium sulphide, 996 and 2079; P = 0.01). Only 2 extra-axillary sentinel lymph nodes were visualized using periareolar intradermal injection modality.

Conclusions

Radiocolloids were more successful than blue dye in sentinel lymph node detection. More sentinel lymph nodes were harvested with small colloids, but different sized radiocolloids were similarly successful. Sentinel lymph nodes having higher radiocolloid uptake tended to accumulate blue dye more frequently. Sentinel lymph nodes manifested higher count rates when a larger colloid was used. Frozen section was very successful in detecting macrometastatic disease in sentinel lymph nodes, but the technique failed in most of the micrometastates.

[Selective biopsy of the sentinel lymph node in patients with breast cancer and previous excisional biopsy: is there a change in the reliability of the technique according to time from surgery?]

AIM

To assess the influence of time on the reliability of sentinel lymph node biopsy (SLNB) in breast cancer patients with previous excisional biopsy (EB), analyzing both the sentinel lymph node detection and the lymph node recurrence rate.

MATERIAL AND METHODS

Thirty-six patients with cT1/T2 N0 breast cancer and previous EB of the lesion underwent a lymphoscintigraphy after subdermal periareolar administration of radiocolloid, the day before SLNB. Patients were classified into two groups, one including 12 patients with up to 29 days elapsed between EB and SLNB (group A), and another with the remaining 24 in which time between both procedures was of 30 days or more (group B). Scintigraphic and surgical detection of the sentinel lymph node, histological status of the sentinel lymph node and of the axillary lymph node dissection, if performed, and lymphatic recurrences during follow-up, were analyzed.

RESULTS

Sentinel lymph node visualization at the lymphoscintigraphy and surgical detection were 100% in both groups. Histologically, three patients showed macrometastasis in the sentinel lymph node, one from group A and two from group B. None of the patients, not even those with malignancy of the sentinel lymph node, relapsed after a medium follow-up of 49.5 months (24-75).

CONCLUSION

Time elapsed between EB and SLNB does not influence the reliability of this latter technique as long as a superficial injection of the radiopharmaceutical is performed, proving a very high detection rate of the sentinel lymph node without evidence of lymphatic relapse during follow-up.

Preoperative lymphoscintigraphy and tumor histologic grade are associated with surgical detection of the sentinel lymph node

OBJECTIVE

To study which variables involved in the process of selective sentinel node biopsy (SSNB) influence the intraoperative detection of the sentinel lymph node.

MATERIAL AND METHODS

This was a prospective cross-sectional study in 210 patients (mean age, 54 years) diagnosed with breast cancer who underwent SSNB. We recorded clinical, radiological, radioisotope administration, surgical, and histological data as well as follow-up data. We did a descriptive analysis of the data and an associative analysis using multivariable regression.

RESULTS

Deep injection alone was the most common route of radioisotope administration (72.7%). Most lesions were palpable (57.1%), presented as nodules (67.1%), measured less than 2 cm in diameter (64.8%), were located in the upper outer quadrant (49.1%), were ductal carcinomas (85.7%), were accompanied by infiltration (66.2%), and had a histologic grade of differentiation of ii (44.8%). Preoperative scintigraphy detected the sentinel node in 97.6% of cases and 95.7% were detected during the operation. One axillary relapse was observed. In the associative study, the variables "preoperative lymphoscintigraphy" and "histologic grade of differentiation of the tumor" were significantly associated with the detection of the sentinel lymph node during the operation.

CONCLUSION

The probability of not detecting the sentinel lymph node during the surgical intervention is higher in patients with high histologic grade tumors or in patients in whom preoperative lymphoscintigraphy failed to detect the sentinel node.