Comparison of 68Ga-FAPI PET/CT and 18F-FDG PET/CT for staging of the axillary lymph nodes in breast cancer patients

Incidental Radiation Dose to Presumed Uninvolved Internal Mammary Lymph Nodes in Breast Cancer Patients Receiving Post-mastectomy Irradiation Adjuvant Therapy

Background: Pathological evaluation of sentinel lymph nodes of breast cancer patients is a critical factor in determining the treatment strategy including patients’ outcome. Multiple factors have been known to correlate with disease free survival and clinical outcomes such as sentinel lymph node metastases. Recently, real-time RT-PCR which is a very useful, rapid, high sensitivity and specificity tool has been reported to detect micrometastases in sentinel lymph nodes which could be helpful to identify high risk patients. Objectives: The purpose of this study are: To evaluate the sensitivity, specificity, and accuracy of CK19 detection by multiplex real-time RT-PCR and to elucidate the correlation of multiplex real-time RT-PCR results and clinicopathological parameters in sentinel lymph nodes of Thai breast cancer patients. Material and methods: 119 patients diagnosed as breast cancer stage I or II at Siriraj Hospital during October 2008 – June 2010 were enrolled in this study. RNAs were extracted from their sentinel lymph nodes and cDNAs were synthesized. Multiplex real-time RT-PCR for detection of CK19 was performed and analysed. Patients’ characteristics and pathological parameters were compared with multiplex real-time RT-PCR results. Results: Significant correlation between angiolymphatic and perineural invasion status and CK19 expression was demonstrated. The overall concordance of CK19 gene with pathological results was 72.3%. Sensitivity and specificity for CK19 detected by multiplex real-time RT-PCR were 78.3%, and 66.1%, respectively. Conclusion: Significant correlation between angiolymphatic and perineural invasion status and CK19 expression in sentinel lymph nodes of breast cancer patients was found in this study.

18F-Alfatide II has been translated into clinical use and been proven to have good performance in identifying breast cancer. In this study, we investigated 18F-Alfatide II for evaluation of axillary lymph nodes (ALN) in breast cancer patients and compared the performance with 18F-FDG. A total of 44 female patients with clinically suspected breast cancer were enrolled and underwent 18F-Alfatide II and 18F-FDG PET/CT within a week. Tracer uptakes in ALN were evaluated by visual analysis, semi-quantitative analysis with maximum standardized uptake value (SUVmax), mean standardized uptake value (SUVmean), and SUVmax ratio of target/non-target (T/NT). Among 44 patients, 37 patients were pathologically diagnosed with breast cancer with metastatic (17 cases) or non-metastatic (20 cases) ALN. The sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) of visual analysis were 70.6%, 90%, 81.1%, 85.7%, and 78.3% for 18F-Alfatide II, 64.7%, 90%, 78.4%, 84.6%, and 75% for 18F-FDG, respectively. By combining 18F-Alfatide II and 18F-FDG, the sensitivity significantly increased to 82.4%, the specificity was 85%, the accuracy increased to 83.8%, the PPV was 82.4%, and the NPV significantly increased to 85.0%. Three cases of luminal B subtype were false negative for both 18F-Alfatide II and 18F-FDG. The other 2 false negative cases of 18F-Alfatide II were triple-negative subtype and 3 false negative cases of 18F-FDG were luminal B subtype too. The AUCs of three semi-quantitative parameters (SUVmax, SUVmean, T/NT) for 18F-Alfatide II were between 0.8 and 0.9, whereas those for 18F-FDG were more than 0.9. 18F-Alfatide II T/NT had the highest Youden index (76.5%), specificity (100%), accuracy (89.2%), and PPV (100%) among these semi-quantitative parameters. 18F-Alfatide II uptake as well as 18F-FDG uptake in metastatic axillary lymph nodes (MALN) was significantly higher than that in benign axillary lymph nodes (BALN). Both 18F-Alfatide II and 18F-FDG did not show difference in primary tumor uptake irrespective of ALN status. 18F-Alfatide II can be used in breast cancer patients to detect metastatic ALN, however, like 18F-FDG, with high specificity but relatively low sensitivity. The combination of 18F-Alfatide II and 18F-FDG can significantly improve sensitivity and NPV. 18F-Alfatide II T/NT may serve as the most important semi-quantitative parameter to evaluate ALN.

Objective The aim of this study was to evaluate the prognostic significance and to define the optimal cutoff points of nodal ratio and number of dissected nodes in node-positive and node-negative breast cancer patients, respectively, who underwent inadequate axillary lymph node dissection (ALND). Background The absolute number of involved axillary lymph nodes (LNs) is considered the most important prognostic factor in breast cancer. Over the last decade, several studies indicated that the lymph node ratio (LNR) might predict outcome better than the number of positive LNs. Patients and methods This retrospective study included 200 women with invasive breast cancer. Group I included node-positive cases with inadequate ALND; group II included node-positive cases with adequate ALND; group III included node-negative cases with inadequate ALND; and group IV included node-negative cases with adequate ALND. Receiver operating characteristic curve was used to identify cutoff points of LNR in each of the node-positive groups, and number of dissected nodes in node-negative patients, classifying the patients into low-risk and high-risk groups. Results Optimal LNR cutoff points classifying node-positive patients into low-risk and high-risk groups were 0.44 for group I and 0.40 for group II with statistically significant differences in disease-free and overall survival. There were no statistically significant survival differences between groups III and IV. The cutoff point of six dissected nodes classified the node-negative patients into low-risk and high-risk groups with statistically significant differences in disease-free and overall survival. Conclusion LNR could be incorporated into the staging of breast cancer patients, especially those with inadequate axillary dissection. LNR cutoff points of 0.44 and 0.40 can be used to classify node-positive patients with inadequate and adequate axillary dissection, respectively, into low-risk and high-risk groups. For node-negative patients, oncologists can be satisfied with a number of dissected nodes as low as seven axillary LNs.

The solid-state gamma camera is now commercially available offering the advantages of a compact and portable system, currently used mainly in the cardiac region. We evaluate the ability of the solid-state gamma camera to depict axillary sentinel lymph nodes (SLNs) in breast cancer patients. Preoperative SLN lymphoscintigraphy (LSG) was performed in 19 patients with breast cancer using the solid-state gamma camera. Immediately thereafter, we performed a second LSG using a single detector Anger-type gamma camera, and compared the findings from the two cameras. Concordant results were obtained in 12 (63%) patients with both cameras. In 4 (21%) patients, axillary SLNs were correctly identified only with the solid-state gamma camera. In these patients, the distance between the SLN and the radiopharmaceutical injection site was closer than that of patients who had concordant results (p = 0.001). We can depict correctly axillary SLNs with the solid-state gamma camera in comparison with the Anger-type gamma camera. This technique would be useful for assessing SLNs in breast cancer patients.

Abstract #1010 Background: Current practice is to perform a completion axillary lymph node dissection (ALND) for breast cancer (BC) patients with tumor-positive sentinel lymph nodes (SLNs). However, not all patients with positive SLNs have further ALND. Katz et al suggested a nomogram for predicting having four or more positive nodes for SLN-positive BC which could change the adjuvant radiation treatment fields. Our goal is to validate the accuracy in predicting > 4 positive axillary lymph nodes in BC patients with a positive SLN in our institution. Methods: Katz nomogram was developed from the multivariate logistic regression model using tumor histology, primary tumor size, lymphovascular space invasion, extranodal extension, the number of involved SLNs, the number of uninvolved SLNs, and the size of the largest SLN metastasis. Area Under (AUC) Receiver Operating Characteristics Curve (ROC) was calculated for the nomogram and a value more than 0.70 was accepted as providing considerable discrimination. Results: We reviewed the records of 319 patients with invasive BC and positive SLNs who underwent completion ALND at MWH of UPMC. None of these patients received neoadjuvant chemotherapy The mean age was 54.2 (30-84) years. Eighty-nine patients (27.8%) had four or more positive nodes. Histology was invasive ductal carcinoma for 86.2 % of patients. The median tumor size was 2.22 (0.5-8.0) cm. Seventy percent of patients had only one involved SLN. The median size of the largest SLN metastasis on H&E staining was 9.7 mm (range, < 0.2 to 35 mm), and 24.4% of the patients had micrometastases (2 mm). Ninety nine patients (31%) had extranodal extension. The mean predicted probability of having ≥ 4 involved axillary LNs was 31.9 % (range, 1 to 99) in patients with ≥ 4 involved axillary LNs while it was it is 9.1% (range, 0.5 to 80) in patients having < 4 axillary LN metastases (P<0.001). The AUC value was 0.809. Conclusions: The Katz nomogram developed to predict having ≥ 4 involved axillary lymph nodes in BC patients with a positive SLNs is validated in our patients. Nomograms developed at other institutions should be used with caution when counseling patients regarding the risk of additional nodal disease. This nomogram will be helpful to clinicians making adjuvant treatment recommendations in practice. Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 1010.

The aim of this study was to retrospectively determine the accuracy and feasibility of using 99mTc-dextran (DX) lymphoscintigraphy for the localization of sentinel lymph nodes (SLNs) in breast cancer patients. The relevant factors affecting lymphoscintigraphy were also investigated. In this study, 235 breast cancer patients underwent 99mTc-DX lymphoscintigraphic imaging and examination by a γ-probe method in combination with blue dye staining to detect SLNs. The detection results were considered in combination with rapid frozen pathology results to determine whether SLN metastasis was positive or negative. SLNs were identified in 191 patients by γ-probe detection among the 202 patients that tested positive by lymphoscintigraphic imaging, a coincidence rate of 94.6%. This suggested that lymph node metastasis had occurred and could be detected using lymphoscintigraphy. The axillary status of the breast cancer patients was also predicted using lymphoscintigraphy and the false-negative rate, sensitivity, specificity and positive predictive value were 13.3% (4/30), 90.7% (39/43), 23.4% (45/192) and 13.5% (21/155), respectively. The age of the patient, menstrual status, tumor location, tumor size, pathological type, preoperative biopsy and neoadjuvant chemotherapy were unrelated to the success of lymphoscintigraphy (P>0.05). 99mTc-DX lymphoscintigraphy is able to exactly determine the location of SLN in breast cancer patients, and can be used for guiding γ-probe methods and sentinel lymph node biopsy.

Axillary lymph node status is an extremely important prognostic factor in the assessment of new breast cancer patients. Sentinel lymph node biopsy is now often performed instead of axillary dissection for lymph node staging but raises numerous issues of practicality. Sentinel lymph node biopsy can be avoided if lymph node metastasis is documented presurgically, making an alternative staging method desirable. Although not widely performed for axillary lymph node staging, ultrasonography (US)-guided core needle biopsy is a well-established procedure for the breast and other organs, with a higher success rate in terms of tissue diagnosis than fine-needle aspiration biopsy. Improvements in US have established it as a valuable method for evaluating lymph nodes. US findings in abnormal lymph nodes include cortical thickening and diminished or absent hilum. In addition, color Doppler US of abnormal axillary lymph nodes often shows hyperemic blood flow in the hilum and central cortex or abnormal (nonhilar cortical) blood flow. US-guided core needle biopsy of axillary lymph nodes in breast cancer patients can yield a high accuracy rate with no significant complications, given the use of a biopsy device with controllable needle action, a clear understanding of anatomy, and good skills for controlling the needle.

Introduction: Sonographic evaluation of the axilla and percutaneous biopsy of abnormal lymph nodes with fine needle aspiration (FNA) or core needle biopsy (CNB) has become more common practice in patients with newly diagnosed breast cancer prior to neoadjuvant chemotherapy (NAC). Sentinel lymph node (SLN) biopsy is considered the gold standard for axillary staging in clinically node negative breast cancer patients. Currently, there is no clear correlation of sonographically detected abnormal lymph nodes and open surgical assessment. We conducted an exploratory pilot study which marked suspicious axillary lymph nodes with black tattoo ink at the time of percutaneous needle biopsy prior to NAC. Black nodes visualized during axillary surgery were evaluated in comparison to SLNs. Methods: Breast cancer patients with clinical and/or sonographically suspicious axillary lymph nodes prior to NAC were included in the study. Following FNA or CNB biopsy of node, 0.1 to 0.5 ml of a sterile, highly purified, biocompatible fine carbon suspension (Spot™) was injected into the cortex of the lymph node and adjacent soft tissue. A total of 12 patients were injected with black ink prior to NAC. Intraoperative presence of black pigment was assessed and correlation between sentinel and tattooed nodes were evaluated. Results: Nine patients had a positive percutaneous lymph node biopsy prior to NAC. The average number of days that elapsed between injection and to surgery was 130 days. A successful SLN procedure was performed in all patients. A black tattooed node was identified in all patients and correlated to a SLN. 7 patients were down-staged in the axilla and 6 patients did not go onto completion axillary dissection. One patient with a negative SLN had a completion axillary dissection, but no additional positive lymph nodes were found. Four patients with positive SLN had a completion axillary dissection (1 of whom was a false negative percutaneous biopsy). In all four patients, the positive sentinel node contained visible black ink. There was one patient who had an additional positive sentinel node, which was not black. Two axillary dissections contained additional positive nodes. Conclusion: Black ink tattooing with sterile black ink (Spot™), successfully marked suspicious lymph nodes prior to NAC. These correlated to a SLN. In node positive patients with a partial response in the axillary lymph nodes following neoadjuvant chemotherapy, previously marked, black-inked node proved to be the persistent positive node. Tattooing of lymph nodes at the time of percutaneous biopsy may improve the accuracy of surgical axillary staging by aiding in the intra-operative identification of previously biopsied nodes. Citation Format: Nicole Choy, Jafi Lipson, Sunita Pal, Debra Ikeda, Long Trinh, Kimberly Allison, Michael Ozawa, Amanda Wheeler, Irene Wapnir. Correlation of percutaneously biopsied axillary lymph nodes marked with black tattoo ink prior to neoadjuvant chemotherapy with sentinel lymph nodes in breast cancer patients [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P2-01-05.

A unique diagnostic method was designed for the intraoperative pathological evaluation of sentinel lymph nodes (SLNs) in breast cancer patients, and the results were verified with 2 years of experience. Excised lymph nodes were cut into 2-mm-thick slices and rinsed thoroughly in CytoRich Red(®). The sliced tissues were embedded in a paraffin block. Three cytological glass slides of the cells exfoliated in CytoRich Red(®) were prepared by the SurePath(®) liquid-based cytology (LBC) technique. Two slides were stained by the Papanicolaou method, and the remaining slide was immunostained with an anti-keratin antibody. This process is called tissue rinse liquid-based cytology (TRLBC). The results of TRLBC were compared with those of the final pathological diagnoses, including immunostaining with an anti-keratin antibody on paraffin blocks (PB). This study analysed 444 SLNs from 247 consecutive breast cancer patients. It required 35 minutes to complete the intraoperative diagnosis on a single node, and it took an additional 5 minutes per node if more than one node was submitted. When the results of PB were assumed to be the gold standard, the sensitivity and specificity of TRLBC were 81.9% and 96.1%, respectively. TRLBC detected all nodes with macrometastasis and 23 of 24 nodes with micrometastasis. Fifteen false-negative TRLBC results were 'isolated tumour cell clusters' on PB, but there was one with micrometastasis histologically. Four of 14 false-positive TRLBC results were proven to be true positive by supplementary examination using step sectioning of the paraffin blocks of the nodes. TRLBC is a feasible and promising intraoperative cytopathological tool showing a comparable efficacy to PB while still allowing the conventional postoperative histological examination.

Corrections: 2009 San Antonio Breast Cancer Symposium Abstracts

Background: Axillary lymph node metastasis is associated with a high risk of breast cancer recurrence and is the single most powerful predictor of patient prognosis. Various imaging tests alone or in combination with preoperative fine needle aspiration (FNA) cytology are used to evaluate suspicious lymph nodes (LNs). However, these methods have low sensitivity (70%) and their utility varies depending on the local surgical practice and experience of the cytologists. In previous work, we have demonstrated higher than 90% sensitivity/specificity of a panel of ten hypermethylated biomarkers in FNA to distinguish between cancer and benign breast lesions. Analysis of methylated genes in FNA of suspicious LNs may improve sensitivity of cancer detection and assist in staging disease more accurately. Methods: We used Quantitative Multiplex Methylation-Specific PCR (QM-MSP) to determine the utility of the 10-gene panel for detecting tumor cells in LN FNAs. Two studies were performed to test the accuracy of a newly developed automated, cartridge-based GeneXpert® Breast Cancer Detection Assay (RUO*). First, we conducted a prospective case-control study in China in breast cancer patients with palpable LNs undergoing sentinel lymph node biopsy. FNA specimens were collected intraoperatively from a single palpable LN and assayed. Histopathology of the same LN (88 metastatic and 104 benign), was used as the gold standard for comparison. Next, using the automated assay, a pilot validation study was conducted on archival ultrasound-guided FNAs (69 metastatic and 53 benign by cytopathology) collected preoperatively from enlarged axillary LNs in patients with and without breast cancer in the outpatient centers in China and U.S.A. We calculated sensitivity, specificity and area under the receiver operating characteristic curve (AUC) for the marker panel tested by the GeneXpert® assay compared to histopathology for the case control study, and cytopathology for the pilot validation study. We also compared its performance to the highly sensitive laboratory assay, QM-MSP. Results: In the case-control study in China, compared to histopathology, cytopathology of the palpable enlarged LNs achieved cancer detection sensitivity of 85% and specificity of 95% (ROC; AUC=0.898, 95% CI: 0.843-0.953). Using the GeneXpert® assay on the same samples, compared to histopathology, the methylated biomarker panel showed a sensitivity of 92.0% and a specificity of 98.1% based on receiver operating characteristic statistics (ROC; AUC = 0.960, 95% CI: 0.928-0.993). QM-MSP yielded a similar sensitivity of 91.8% and a specificity of 97.7% (ROC; AUC = 0.966, 95% CI: 0.934-0.998). In the pilot validation set, compared to cytopathology, the automated assay achieved a sensitivity of 94.2% and a specificity of 92.5% (ROC; AUC=0.976 (95%CI: 0.950-1.001). Conclusions: We have developed and piloted a 5-hour, automated GeneXpert® Breast Cancer Detection Assay (RUO*) on FNA to detect cancer in suspicious LNs. This assay performs with an accuracy equivalent to that of the highly sensitive but labor-intensive assay, QM-MSP. This test has the potential to determine axillary involvement with higher sensitivity than cytopathology within a very short time in the outpatient setting. A positive test preoperatively could provide guidance for decision-making regarding eligibility of patients for neoadjuvant treatment, post-mastectomy radiotherapy and breast reconstruction. Further evaluation of this automated assay in larger, blinded, prospective studies is warranted. Citation Format: Juanjuan Li, Bradley Downs, Leslie Cope, Xiuyun Zhang, Chuan-gui Song, Kejing Zhang, Yong Han, Mary Jo Fackler, Edwin Lai, Suzana Tulac, Neesha Venkatesan, Timothy Guzman, Chuang Chen, Jingping Yuan, Saraswati Sukumar. Automated molecular diagnosis of suspicious axillary lymph nodes in breast cancer patients [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P4-02-06.

Breast cancer is the most common malignancy among women, leading to approximately 45 000 deaths per annum in the United States (1). The presence of axillary lymph node metastases has major prognostic implications in breast cancer patients (2,3), and it is an important criterion in determining the need for adjuvant chemotherapy (4). Sentinel lymph node (SLN) biopsy has become routine practice in the surgical treatment of patients with breast cancer because the disease status of the SLNs accurately reflects the status of the remaining axillary lymph nodes (5–7). Hence, patients who present with a negative SLN (no metastases) can be spared from having a more traumatic axillary lymph node dissection (ALND), which has been shown to be associated with substantial shortand long-term sequelae (8,9). Despite the enormous advantages of SLN biopsy over ALND in regard to post-operative complications in nodenegative patients, it would be of great clinical benefit if a reliable non-invasive method to assess lymph node status in breast cancer patients could be found. Positron emission tomography (PET) reflects the biochemical and physiologic processes occurring in the tissues being imaged and has been used in diagnosing a variety of malignancies (10, 11). The most frequently used positron emitting radiopharmaceutical is 18-fluor labeled 2-deoxy-D-glucose (F-FDG), a radioactively labeled glucose analog. The clinical use of F-FDG–PET is based on the premise that cancer cells exhibit a higher glycolytic rate than do non-neoplastic cells. Thus, F-FDG accumulates predominantly in the tumor tissue and can be visualized by a PET camera. Since the first reported visualization of lymph node metastases with F-FDG–PET in a preclinical animal study in 1990 (12), several investigations (13–19) have assessed the accuracy of PET in evaluating the nodal status of patients with breast cancer. These investigations have yielded conflicting results, with some investigators doubting that F-FDG–PET is capable of accurately assessing the nodal status of breast cancer patients (13–16) and others believing that a noninvasive PET scan could replace SLN biopsy at predicting the disease status of the axillary lymph nodes (17–19). In a recent investigation by an Italian group (18), preoperative F-FDG–PET was compared with the histologic findings of ALND in 167 clinically node-negative T1 (tumor size 2cm) and T2 (tumor size >2cm to 5cm) breast cancer patients, the largest patient collective published. F-FDG–PET detected 68 of 72 patients with axillary metastases, resulting in an overall sensitivity for PET of 94%. In the subset of T2 patients, the sensitivity was even higher (98%; 48/49), with only one false-negative finding. Based on these results, the authors claimed that F-FDG–PET can safely predict axillary lymph node status in patients with breast cancer and is a reliable and accurate method to identify patients who can avoid ALND. In the second largest published patient collective (19), preoperative F-FDG–PET was compared with the histologic findings of ALND in 124 pT1–T3 (T3 tumor size >5cm) breast cancer patients. PET scanning correctly identified all 44 patients with axillary lymph node metastases, resulting in an overall sensitivity for PET of 100%. These findings led the investigators of that study to suggest that F-FDG–PET should be considered as the initial test in evaluating axillary lymph nodes in breast cancer patients and that those patients without increased axillary F-FDG-uptake may not require ALND. Other investigations (17,20–23) with smaller patient numbers have reported similar findings, with sensitivities of pre-operative F-FDG–PET at detecting axillary lymph-node metastases ranging from 90% to 100%. In contrast to the above-mentioned investigations, several studies have found that F-FDG–PET has a low sensitivity at detecting SLN or axillary lymph node metastases. Indeed, Avril et al. (14) suggest that F-FDG–PET scanning cannot substitute for histologic analyses of axillary lymph nodes. Their study compared the diagnostic potential of F-FDG–PET with ALND in 41 breast cancer patients and reported an overall sensitivity for PET of 79% (19/24). PET sensitivity in the subset of patients with pT1 tumors was, however, only 33%; four of six patients had false-negative results, and the largest metastasis undetected by F-FDG–PET measured 12 mm in diameter. Kelemen et al. (15) also found low PET sensitivity when they compared F-FDG–PET scanning with the histolopathologic findings of SLN biopsies in clinically node-negative T1 and T2 breast cancer patients. If the SLN biopsies were negative by hematoxylin and eosin (H&E) staining, further biopsy sections were obtained for immunohistochemical (IHC) analyses using polyclonal anticytokeratin (CK) antibodies. Four of five patients with SLN metastases had false-negative F-FDG–PET scans (i.e., F-FDG–PET sensitivity was only 20%), and the missed metastases ranged from a micro-metastasis (defined as a cohesive cluster of malignant cells >0.2 mm to 2.0 mm in diameter), which was identified by IHC only, to macro-metastases up to 11 mm in

Background: Detection of malignant infiltration in axillary lymph node remains a significant predictive factor in breast cancer with a significant impact on prognosis and staging. Elastography new ultrasound method developed that measures the stiffness of tissue can diagnose early malignant change in the cortex of lymph node and can help to decrease the use of invasive procedures. Aim of the study: Analyzing strain elastography findings in borderline axillary lymph nodes in breast cancer patients. Patients and method: This is a prospective cohort study conducted in the Breast Center/Shar Hospital / Sulaymaniyah City/ Iraq, in a period of one year between October 2022 and October 2023. Forty-two patients 2 males and 40 females with newly diagnosed breast cancer were included in the study, we examined the patients with conventional ultrasound and elastography with a 7.5-12MHz superficial linear transducer using Samsung HS60 and Samsung V7 ultrasound machines. After determining whether borderline axillary LNs were present ultrasound elastography was performed for the borderline lymph node, and each case was properly described and reported. After gray-scale ultrasonography, Elastography (real-time Elastography) was conducted. In our study, we used a 5-point scoring system. To determine the strain ratio, a circular region of interest (ROI) was positioned in the axillary fat, and the second ROI was set at the same level and of the same size over the stiffest part of the lymph node being studied. The final reference was the histopathological result of the core needle biopsy of the examined lymph node. Results: A total of 42 patients were studied, the age range was between 33- 77 years old. 54.8% (n=23) of our patients were negative for malignant cells, whereas 45.2% (n=19) were positive. The strain ratio (SR) of the negative results for malignant cells (1.8 ± 0.9) was much lower than the positive results (4.7 ± 1.4). Two-thirds (65.2%, n=15) of the negative results had SR less than 2.1 and the rest 34.8% (n=8) were ≥ 2.1. On the contrary, the positive results, (94.7%, n=18) were ≥ 2.1, and only 5.3% (n=1) was below 2.1, with a statistically highly significant difference (P<0.001). Regarding elasticity score, more than half (56.5%, n=13) of the patients with negative results for malignant cells have score 2, about one-third (34.8%, n=8) have score 3, and 4.3% (n=1)have score 4, also, score 1 was 4.3% (n=1). Paradoxically, the majority of the positives (52.6%, n=10) have score 3, followed by score 4 (21.1%, n=4) then score 2 (15.8%, n=3) then score 5 (10.5%, n=2). With a significant difference (P=0.027). Conclusion: The strain ratio and elasticity score of malignant borderline axillary lymph node is much higher than that of benign lymph node, making this new ultrasound method superior to Bmode in the detection of early malignant infiltration to the cortex of axillary lymph node. These two non-invasive methods (B-mode ultrasound and elastography) can be used together to increase diagnostic accuracy. 65.2%, (n=15) of the negative results had SR less than 2.1 whereas 94.7% (n=18) of malignant cases had a strain ratio ≥ 2.1. Regarding elasticity score 60% of benign cases had scores 2 and 1, whereas 84% of malignant cases had scores 3,4, and 5.

Background: The semi-dry dot-blot (SDB) method is a diagnostic technique used to detect lymph node (LN) metastases by identifying cytokeratin (CK) proteins in the lavage fluid of sectioned LNs. This method is based on the principle that CK, an epithelial marker, is absent in normal lymphatic tissue. We prospectively evaluated novel SDB kits incorporating a newly developed anti-CK19 antibody and an automatic reader for diagnosing LN metastases in breast cancer patients. In a previous analysis of 1734 sentinel LNs (SLNs) from patients not receiving neoadjuvant chemotherapy (NAC), the kit demonstrated a sensitivity of 93.0%, specificity of 97.1%, and overall agreement of 96.7% for detecting macrometastases (>2.0 mm). However, the impact of NAC—especially in triple-negative and HER2-positive subtypes—on the diagnostic performance of the SDB method remains unclear, given that chemotherapy can cause cancer cell degeneration. This study aimed to evaluate whether the SDB kit could accurately detect macrometastases in patients undergoing NAC. Methods: A total of 127 LNs were collected from 74 breast cancer patients who underwent NAC followed by surgery between May 2022 and December 2024 at Nagasaki University Hospital. Both patients with and without axillary LN metastases were eligible. Eligible LNs were defined as all SLNs in patients who underwent SLN biopsy and two axillary LNs in patients who underwent axillary LN dissection. Each LN was sliced at 2-mm intervals and rinsed with phosphate-buffered saline. The resulting lavage fluid was centrifuged, and the cells were lysed to extract protein, which was then analyzed using the SDB kit and automatic absorbance reader. Pathologists, blinded to the SDB results, independently diagnosed LN metastasis using hematoxylin and eosin (H&E) staining. SDB-based diagnoses were compared with permanent histopathological diagnoses. Results: Among the 127 LNs, 56 were obtained via SLN biopsy and 71 via axillary LN dissection. Histological evaluation identified 16 macrometastases and 111 non-macrometastases (including 4 micrometastases and 1 case with isolated tumor cells). Using a CK19 absorbance cutoff of 11.9 milli-absorbance units (mAbs) for detecting macrometastases, the SDB kit correctly identified 15 of the 16 macrometastases and all 111 non-macrometastases. The resulting sensitivity, specificity, and overall agreement were 93.8%, 100%, and 99.2%, respectively. The single false-negative case involved a sparsely distributed residual tumor measuring 2.1 mm. The diagnostic process required approximately 20 minutes and cost less than USD 30 per kit. Conclusions: The novel SDB kits combined with an automatic reader provided rapid, accurate, and cost-effective detection of LN macrometastases without tissue loss, even after NAC. These findings support the potential utility of this method in clinical decision-making. A prospective multi-center study is planned to further validate clinical performance. Citation Format: R. Otsubo, Y. Hara, S. Urakawa, A. Tanaka, M. Akashi, S. Kuba, M. Matsumoto, R. Yamaguchi, K. Matsumoto. Evaluation of novel diagnostic kits for detecting metastatic lymph nodes in breast cancer patients treated with neoadjuvant chemotherapy using the semi-dry dot-blot method: A single-center prospective study [abstract]. In: Proceedings of the San Antonio Breast Cancer Symposium 2025; 2025 Dec 9-12; San Antonio, TX. Philadelphia (PA): AACR; Clin Cancer Res 2026;32(4 Suppl):Abstract nr PS2-05-20.