The impact of intraoperative frozen section in patients with clinically node-negative breast cancer (cN0/ycN0) who received neoadjuvant systemic therapy

BACKGROUND

When surgical axillary staging reveals residual metastatic deposits in breast cancer (BC) patients who had received neoadjuvant chemotherapy (NACT), axillary lymphonodectomy is indicated. In this study, we investigate whether it is reasonable to perform intraoperative frozen section (FS) of the removed sentinel lymph nodes (SLNs) in cases where NACT had been administered in patients who had a clinically negative nodal status at the time of diagnosis.

PATIENTS AND METHODS

We analyzed data from 101 BCE patients with 103 carcinomas who were diagnosed between 2014 and 2021 and met the above-mentioned criteria.

RESULTS

In three cases (2.8% of the study group), histologically active tumor tissue was detected in the removed axillary LNs. Discontinuation of therapy/the use of a low-dose NACT regimen was a significant factor for positive LNs (p = 0.02) at the subsequent surgical procedure; tumor progression during therapy approached borderline significance (p = 0.058). Among patients who had completed NACT with the planned standard dose regimen, and in which the primary tumors showed a response to therapy (n = 94), only one case had histologically detected residual metastases in the SLNs.

CONCLUSIONS

Certified breast centers aim to improve the outcome of the patients. However, these specialized centers should also focus on economic aspects. This means that diagnostic and therapeutic procedures should be continuously critically reviewed in order to avoid unnecessary expenses. In BC patients with clinically node negative disease who completed NACT as planned and in which the tumor showed a good response to therapy, time consuming and costly FS of the SLNs removed should be omitted.

Practical intraoperative pathologic evaluation of sentinel lymph nodes during sentinel node navigation surgery in gastric cancer patients - Proposal of the pathologic protocol for the upcoming SENORITA trial

Over the last decade, as the number of patients with early gastric cancer increased and the subsequent survival rate improved, there has been a consistent effort to verify the applicability of the sentinel node concept in gastric cancer in a bid to improve postoperative quality of life in these patients. During sentinel node navigation surgery in gastric cancer patients, intraoperative pathologic examination of the retrieved sentinel nodes plays a critical role in determining the extent of surgery, but the optimal method is still under debate. Currently, a multicenter, phase III clinical trial is underway to compare laparoscopic sentinel basin dissection with stomach preserving surgery and standard laparoscopic gastrectomy in terms of oncologic outcomes in patients with clinical stage T1N0 gastric cancer. Herein, the currently available intraoperative pathologic techniques are reviewed and their clinical significance and applicability are appraised based on the published literature. The proper pathologic examination of the sentinel lymph nodes in an upcoming clinical trial (SENORITA trial) is also proposed here based on this review.

Evolution of sentinel lymph node biopsy in breast cancer, in and out of vogue?

Sentinel lymph node biopsy (SLNB) was introduced 2 decades ago and thereafter validated for routine surgical management of breast cancer, including cases treated with neoadjuvant chemotherapy. As the number of lymph nodes for staging has decreased, pathologists have scrutinized SLN with a combination of standard hematoxylin and eosin, levels, immunohistochemistry (IHC), and molecular methods. An epidemic of small-volume metastases thereby arose, leading to modifications in the American Joint Committee on Cancer staging to accommodate findings such as isolated tumor cells (ITC) and micrometastases. With the goal of determining the significance of these findings, retrospective followed by prospective trials were performed, showing mixed results. The ACOSOG Z10 and NSABP B-32 trials both independently showed that ITC and micrometastases were not significant and thus discouraged the use of levels and IHC for detecting them. However, the Surveillance Epidemiology and End Results database showed that patients with micrometastases had an overall decreased survival. In addition, the MIRROR (Micrometastases and ITC: Relevant and Robust or Rubbish?) trial, showed that patients with ITC and micrometastases treated with adjuvant therapy had lower hazard ratios compared with untreated patients. Subsequently, the ACOSOG Z0011 trial randomized patients with up to 2 positive SLN to axillary lymph node dissection (ALND) or not, all treated with radiation and chemotherapy, showing no difference in survival or recurrence rates between the 2 groups and causing a shift from ALND. As the rate of ALND has declined, the necessity of performing levels, IHC, frozen section, and molecular studies on SLN needs to be revisited.

Advantages of the rapid double-staining method for intraoperative detection of micrometastasis in sentinel lymph nodes

For rapid intraoperative diagnosis of lymph node micrometastasis, we refined the rapid immunohistochemistry method by combining anti-cytokeratin antibody-labeled nanocrystal beads with rapid hematoxylin and eosin (H&E) staining on the same section, referred to as the rapid double staining (RDS) technique. Two frozen-section slices each were obtained from 372 lymph nodes of 100 breast cancer patients. We performed RDS for 1 slide and rapid H&E staining for the other. The results were compared with the corresponding final pathological data obtained from the permanent specimens. For specimens from patients with pN1(mi) as determined by final pathological examination, the false‑negative rate was 33.3% for rapid H&E staining and 16.7% for RDS. For specimens from patients with pN0(i+) as determined by final pathological examination, the false‑negative rate was 80% for rapid H&E staining and 0% for RDS. These results indicate that RDS is superior to conventional rapid H&E staining for intraoperative diagnosis of nodal micrometastasis and isolated tumor cells.

Quantifying the number of lymph nodes identified in one-stage versus two-stage axillary dissection in breast cancer

PURPOSE

To establish whether a different number of lymph nodes is identified in a delayed versus an immediate axillary lymph node dissection (ALND) in breast cancer patients.

METHODS

Using data from the Danish National Patient Register and the Danish Breast Cancer Cooperative Group Database we identified 864 breast cancer patients with sentinel lymph node dissection (SLND) and delayed ALND and 7393 breast cancer patients with SLND and immediate ALND operated between 2002 and 2010. We compared the number of lymph nodes identified in the two groups by a student's t-test.

RESULTS

The mean number of lymph nodes identified in patients with immediate and delayed ALND was 16.55 and 15.59, respectively. This difference was statistically significant (P < 0.0001).

CONCLUSION

The number of lymph nodes identified in breast cancer patients is slightly reduced if delayed ALND is performed. However, the difference is small and considered to be without clinical significance.

Sentinel lymph node analysis in breast cancer: contribution of one-step nucleic acid amplification (OSNA)

One-step nucleic acid amplification (OSNA, Sysmex, Kobe, Japan) offers an excellent opportunity for accurate exhaustive sentinel lymph node (SLN) examination in breast cancer patients. Calibrated with conventional postoperative histology, this molecular technique yields comparable results intraoperatively, expressed as micrometastasis, macrometastasis or no metastasis depending on the CK19 mRNA copy number amplified in SLN lysates. We applied OSNA to detect metastasis in 810 SLNs from 367 patients with early stage breast cancer. We compared the rate of OSNA-positive SLNs in patients with invasive breast cancer (< 2 cm) versus the rate observed in a historical cohort using conventional histological examination of SLNs. No significant difference was observed, the OSNA assay was positive in 24.4% of patients, compared with positive histology in 24.8% in the historical cohort if including patients with isolated tumour cell (ITC) and in 23.4% excluding them. Opportunities for optimised patient management using OSNA are discussed: intraoperative detection of OSNA-positive SLNs enables axillary lymph node dissection (ALND) during the same procedure; standard OSNA techniques enable the establishment of homogeneous groups based on examination of whole SLNs for valid comparisons between different centres.