Prediction score model for non-sentinel and four or more nodal metastases using a combined method of one-step nucleic acid amplification and histology in sentinel node-positive breast cancer patients

Intraoperative detection of axillary metastasis of breast cancer using nucleic acid amplification methods: review of advantages and limitations

INTRODUCTION

In the management of breast cancer, the need for assessment of axillary status has been questionable in recent years. However, it is still applicable for making a decision on adjuvant therapy and evaluating the prognosis. Molecular tests have been widely used for intraoperative detection of axillary lymph node metastases and have prevented a second surgery for dissection of the lymph nodes in at least 20% of the cases. Unlike histopathological examination, molecular tests do not need a specialized technologist to provide the results.

AREAS COVERED

We have reviewed recent advancements in the assessment of axillary nodes by molecular studies such as one-step nucleic acid amplification (OSNA) assay and metasin test. Our work concentrated on reported thresholds for the tests, economical aspects, and newly developed devices throughout the current literature.

EXPERT OPINION

Well-designed clinical trials on molecular assays could lead to individualized management of the axillary, while preventing additional surgical operations in a large proportion of women with breast cancer.

Sentinel Lymph Node Biopsy Predicts Non-Sentinel Lymph Node Metastases and Supports Omission of Axillary Lymph Node Dissection in Breast Cancer Patients

Background: Current international guidelines recommend omitting axillary lymph node dissection (ALND) based on sentinel lymph node biopsy (SLNB) in early-stage breast cancer patients. However, the evolving landscape of axillary management highlights the need to balance diagnostic accuracy with minimizing invasiveness. The possibility of omitting SLNB itself should also be considered. Methods: In this study, we have evaluated the feasibility of omitting SLNB in a total of 1044 clinically node-negative (cN (-)) breast cancer patients whose SLN status was determined by histopathology and one-step nucleic acid amplification (OSNA) after SLNB. We also analyzed SLN-positive cases to explore the association between non-SLN (NSLN) metastatic status and various biomarkers. We predicted the metastatic status of NSLNs based on patient data using a nomogram and further assessed the prevalence of macro- and micro-metastatic SLN, along with the NSLN status in SLNB cases. Results: Of the 644 cN (-) cases, approximately 70% of SLN-positive cases were NSLN negative, suggesting that ALND could be omitted. SLN (+) was detected approximately 7% more often by OSNA than by histopathology, suggesting that OSNA detection may be an overdiagnosis. Although NSLN-positive cases represented only 5.9% of the 581 cN (-) cases and, therefore, ALND could be omitted, it may be difficult to omit the SLNB itself as the SLN macro-metastasis was 12.5%. Biomarker analysis showed a significant correlation between total tumor load and metastatic SLN copy number with NSLN metastatic status. Based on these tumor characteristics, the nomogram predicted NSLN-positive rates very well. Conclusions: Thus, omitting SLNB itself carries the risk of missing high-frequency macro-metastatic SLN-positive cases and losing important SLN-related information that can predict NSLN metastases. Therefore, SLNB, which provides not only SLN status but also NSLN metastases, is necessary for reassurance in omitting ALND.

Application of the OSNA Technique (One-Step Nucleic Acid Amplification Test) in Breast Cancer

Breast cancer is one of the most common cancers diagnosed in both countries with high and low levels of socio-academic development. Routine, regular screening tests being introduced in an increasing number of countries make it possible to detect breast cancer at an early stage of development, as a result of which the trend in the incidence of metastatic breast cancer has been decreasing in recent years. The latest guidelines for the treatment of this tumor do not recommend axillary dissection, which limits the need for rapid assessment of the nodes during surgery. Regardless of the progression of the disease, lymph node biopsy and their analysis is one of the most common diagnostic methods for detecting metastases. Systems using one-step amplification of nucleic acids have been present in the diagnosis of breast cancer for nearly 20 years. The one-step nucleic acid amplification (OSNA) test semi-quantitatively detects the number of cytokeratin 19 mRNA copies, a well-known tumor marker, which can be used to infer the presence of metastases in non-sentinel lymph nodes (SLN). Aim: OSNA is a widely used molecular method for SLN, intra-, or postoperative analysis. Its high accuracy has been proved over the years in clinical use. In this review, we checked current state of this technology and compared it to its competitors in the field of breast cancer diagnosis in the era of Axillary Lymph Nodes Dissection (ALND) importance decrease with intention to foresee its further potential use. Objectives: To evaluate OSNA current place in breast cancer diagnosis and treatment we compared OSNA to other lymph node assessing methods. We based our review on original articles and metanalyses published in the last decade. The research was conducted with PubMed, Science Direct, Google Scholar, and NCBI databases. The collected data allowed us to assess the accuracy of OSNA, its cost effectiveness, and its application in other cancers. Results: Regardless of the progression of the disease, a lymph node biopsy and its analysis constitutes one of the most common diagnostic methods for detecting metastases. The OSNA method is characterized by high sensitivity and specificity, and its predictive value has been confirmed by many studies over the years. While its cost effectiveness is still a matter of discussion, this method has been tested more thoroughly than other new lymph nodes assessing technologies. Conclusions: Despite the emergence of competing methods, this test is still widely used as a routine intraoperative examination of lymph nodes. Research carried out in recent years has proved its effectiveness in the diagnosis of other cancers, in the research field, and as a provider of additional data for prognosis improvement.

Clinical significance of discordances in sentinel lymph node reactivity between radioisotope and indocyanine green fluorescence in patients with cN0 breast cancer

BACKGROUND

/Objective: To evaluate the usefulness of combining radioisotopes (RI) and indocyanine green (ICG) and investigate discordances in sentinel lymph node (SN) reactivity using each tracer in cN0 breast cancer patients.

METHODS

In total, 338 cN0 primary breast cancer patients who underwent SN biopsy with RI and ICG and axillary lymph node (ALN) dissection were included. SN positivity with RI, ICG, and a combination of RI and ICG was denoted as SN(RI), SN(ICG), and SN(RI+ICG), respectively. We retrospectively estimated metastatic SN detection rates, each method's discordance rate, and the correlation of discordances in SN reactivity with postoperative N staging.

RESULTS

The combination of RI and ICG had higher metastatic SN detection rates (99.7%) than RI or ICG alone (91.7% and 96.4%, respectively; p < 0.01). The discordance rate between SN(RI) and SN(ICG) in detecting metastatic SNs was 11.3% (38/337 cases). The absence of SN(RI), cT stage (cT2-3), higher histological grade (G3), and histological type (special type) were identified as risk factors of pN2-3 disease (odds ratios: 8.64, 2.56, 1.92, and 3.28, respectively; p < 0.01).

CONCLUSION

Discordances in SN reactivity between RI and ICG helps in identifying SN metastasis. Although the absence of SN(RI) is rare, it is a significant sign of advanced ALN metastases. The findings of our study indicate that ALN dissection should be considered for accurate nodal staging in such cases.

Development and validation of a pre- and intra-operative scoring system that distinguishes between non-advanced and advanced axillary lymph node metastasis in breast cancer with positive sentinel lymph nodes: a retrospective study

Background

There are currently no scoring-type predictive models using only easily available pre- and intraoperative data developed for assessment of the risk of advanced axillary lymph node metastasis (ALNM) in patients with breast cancer with metastatic sentinel lymph nodes (SLNs). We aimed to develop and validate a scoring system using only pre- and intraoperative data to distinguish between non-advanced (≤ 3 lymph nodes) and advanced (> 3 lymph nodes) ALNM in patients with breast cancer with metastatic SLNs.

Methods

We retrospectively identified 804 patients with breast cancer (cT1-3cN0) who had metastatic SLNs and had undergone axillary lymph node dissection (ALND). We evaluated the risk factors for advanced ALNM using logistic regression analysis and developed and validated a scoring system for the prediction of ALNM using training (n = 501) and validation (n = 303) cohorts, respectively. The predictive performance was assessed using the receiver operating characteristic (ROC) curve, area under the curve (AUC), and calibration plots.

Results

Ultrasound findings of multiple suspicious lymph nodes, SLN macrometastasis, the ratio of metastatic SLNs to the total number of SLNs removed, and the number of metastatic SLNs were significant risk factors for advanced ALNM. Clinical tumor size and invasive lobular carcinoma were of borderline significance. The scoring system based on these six variables yielded high AUCs (0.90 [training] and 0.89 [validation]). The calibration plots of frequency compared to the predicted probability showed slopes of 1.00 (training) and 0.85 (validation), with goodness-of-fit for the model. When the cutoff score was set at 4, the negative predictive values (NPVs) of excluding patients with advanced ALNM were 96.8% (training) and 96.9% (validation). The AUC for predicting advanced ALNM using our scoring system was significantly higher than that predicted by a single independent predictor, such as the number of positive SLNs or the proportion of positive SLNs. Similarly, our scoring system also showed good discrimination and calibration ability when the analysis was restricted to patients with one or two SLN metastases.

Conclusion

Our easy-to-use scoring system can exclude advanced ALNM with high NPVs. It may contribute to reducing the risk of undertreatment with adjuvant therapies in patients with metastatic SLNs, even if ALND is omitted.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12957-022-02779-9.

Development and Validation of a Preoperative Scoring System to Distinguish Between Nonadvanced and Advanced Axillary Lymph Node Metastasis in Patients With Early-stage Breast Cancer

BACKGROUND

It has been determined that axillary lymph node dissection after the detection of limited axillary lymph node metastasis does not improve the prognosis of patients with breast cancer. Thus, a need exists for less-invasive axillary surgery. However, it remains unclear whether a predictive model based on preoperative data would be sufficient to accurately predict the probability of pN2-N3 (> 3 lymph node metastases). We sought to develop an easy-to-use scoring system to distinguish between pN0-N1 (0-3 lymph node metastases) and pN2-N3 using only preoperative data and validate its predictive performance.

PATIENTS AND METHODS

We retrospectively identified 2687 patients diagnosed with cT1-3cN0-N1 who had undergone surgery in our hospital from 2013 to 2019. We evaluated the risk factors associated with pN2-N3 by logistic regression analysis and developed a scoring system. Predictive performance was assessed by calculating the receiver operating characteristic area under the curve (AUC) and was validated using K-fold cross-validation.

RESULTS

We identified 1987 patients with stage pN0, 522 with pN1, and 178 with pN2-N3. Multivariate analysis revealed tumor size, number of suspicious lymph nodes on axillary ultrasound examination, histologic type, histologic grade, and receptor status were significant risk factors for pN2-N3. The AUC value was 0.87, and the mean AUC of the 10-fold cross-validation was 0.88. When the cutoff score was set at 6, the negative predictive value for excluding patients with pN2-N3 was 98.4%.

CONCLUSION

Our easy-to-use scoring system could be useful to preoperatively identify patients at lower risk of pN2-N3 and avoid unnecessary axillary lymph node dissection.