Evaluation of Sensitivity and Specificity of Ultrasound-Guided FNA of Suspicious Axillary Lymph Nodes in Patients with Breast Cancer

authors:

avatar Farzaneh Khoroushi 1 , avatar Hashem Neshati ORCID 1 , * , avatar Seyed Ali Alamdaran ORCID 2 , avatar Bita Abbasi ORCID 3 , avatar Lida Jarahi ORCID 4

Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
Radiology Department, Omid Cancer Hospital, Mashhad Medical University of Science, Mashhad, Iran
Department of Radiology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
Community Medicine Department, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran

how to cite: Khoroushi F, Neshati H, Alamdaran S A, Abbasi B, Jarahi L. Evaluation of Sensitivity and Specificity of Ultrasound-Guided FNA of Suspicious Axillary Lymph Nodes in Patients with Breast Cancer. Int J Cancer Manag. 2024;17(1):e140041. https://doi.org/10.5812/ijcm-140041.

Abstract

Background:

The axillary lymph node status in breast cancer is a major prognostic factor in survival and establishing a personalized treatment scheme. The ultrasound-guided fine needle aspiration (US-FNA) is a method for taking a lymph node sample. It allows physicians to decide how to manage the axilla.

Objectives:

This study was conducted to investigate the sensitivity of the US-FNA technique on suspicious axillary lymph nodes with a thickness of 3 to 6 mm in breast cancer patients.

Methods:

In a cross-sectional study, all the patients were subjected to preoperative ultrasound evaluation of the axilla to determine the presence of lymph nodes suspicious of malignancy. In cases where the suspicious lymph node cortex size was between 3 and 6 mm, US-FNA was performed. After surgery, the frozen section of the biopsy sample was examined histologically and compared with fine needle aspiration (FNA) cytology results.

Results:

A total of 102 patients were examined in the study. FNA test results indicated that 46 subjects had axillary malignant tissue, and benign cases summed 56. Also, the final results of frozen section surgical histopathology identified 46.1% of patients with involved lymph nodes. The sensitivity and specificity of FNA were 93.62% and 96.36%, respectively. Also, the overall diagnostic accuracy was 95.1%.

Conclusions:

This study showed that the sensitivity, specificity, and accuracy were more than 90% for the ultrasound-guided FNA test in identifying involved lymph nodes in patients with breast cancer. Therefore, the results of this test can be considered clinically reliable. However, there is still a need to examine the sensitivity and specificity of this method in identifying lymph node involvement.

1. Background

Cancer is the second leading cause of death worldwide, with 10,000,000 deaths yearly. The most common type of cancer on this list is breast cancer, which occurs in 1 woman out of 8 (1). Regarding statistics, screening and early diagnosing significantly contribute to a 41% reduction in breast cancer mortality (2). Breast cancer diagnosis in the early stages is more likely to be treated successfully by considering appropriate treatment methods. In addition, choosing accurate treatment methods in other stages of breast cancer can directly increase the patient's survival chances (3). Some factors affect the prognosis and treatment of early or advanced breast cancer (4, 5). For example, clinicopathological factors predict the outcome of breast cancer in terms of risk of recurrence and death from cancer depending upon the tumor and patient’s characteristics. The number of positive lymph nodes, tumor size, and type, histologic grade of tumor, lymphatic and vascular invasion, proliferation rate, human epidermal growth factor receptor 2 (HER2) status, and hormone receptor (HR) positivity are prognostic factors (4, 6, 7).

The axillary lymph node status in breast cancer is a major prognostic factor in the survival and establishment of a personalized treatment scheme. This condition can help assess the progression of the tumor toward metastasis (8). By sampling several nodes and examining the pathology, axillary dissection is performed to prevent the spread of tumor cells to other organs through the lymphatic system (9). The evolution and advances in breast cancer surgical treatment, especially in the axillary approach, have reduced morbidity (10). There are two common axillary lymph node evaluation methods, including sentinel lymph node biopsy (SNB) and axillary lymph node dissection (ALND). Today, the biopsy technique is more widely used than complete removal for finding metastatic nodes (11). Evaluating these two methods in patients showed that ALND had no advantage in increased survival and that both groups had a very low regional recurrence rate (11).

A fine needle aspiration (FNA) is a first-line method of taking a sample of a palpable lymph node. However, before surgery, ultrasound-guided FNA (US-FNA) can also assess non-palpable masses or lymph nodes, allowing physicians to decide how to manage the axilla (12). Ultrasound and biopsy of the axilla before surgery is a practical test to determine the cancer stage (13, 14). Also, diagnosing metastatic carcinoma with preoperative FNA can lead patients to complete ALND or other treatment procedures, such as neoadjuvant chemotherapy followed by SNB and axillary radiotherapy (15). On the other hand, in the absence of metastatic lesions, patients can undergo SNB and not perform axillary surgery, which has been mentioned in several clinical trials (16). So far, we cannot recommend not performing axillary surgery in lymph node-negative cases based on the results of any of the imaging modalities. So, the sensitivity of preoperative FNA and ultrasound in detecting positive lymph nodes is still being investigated (17, 18).

2. Objectives

This study was conducted to investigate the sensitivity of the US-FNA technique on suspicious axillary lymph nodes with a thickness of 3 to 6 mm in patients with breast cancer.

3. Methods

3.1. Study Population

In a cross-sectional study, women with breast cancer, who were referred to the Mashhad’s Hospitals between 2021 and 2023 for pre-operative examination, were selected through the convenience sampling method. It should be noted that the main exclusion criterion in this study was chemotherapy before surgery.

3.2. Study Procedure

All the patients were subjected to preoperative ultrasound evaluation of the axilla to determine the presence of lymph nodes that were suspicious of malignancy. An ultrasound of this region was performed, using a high-frequency (10 MHz) linear-array transducer. All findings were documented, and a lesion’s dimension was recorded. In cases where the suspicious lymph node cortex size was between 3 and 6 mm, FNA was performed under ultrasound guidance. Then, surgery was considered for all cases, and the SNB was performed during that. The frozen section of the biopsy sample was examined. In SNB-positive patients, complete dissection of axillary lymph nodes was performed, and for cases with SNB-negative, axillary surgery was stopped. All tissue samples were histopathologically examined and compared with FNA cytology results. Then, the sensitivity, specificity, and positive and negative predictive value of the FNA method compared to the reference in detecting metastatic involvement of the axillary lymph node were calculated. Also, the false positives and negatives rate of FNA was checked.

3.3. Statistical Analysis

Data analysis was performed, using SPSS version 16.0 (IBM SPSS Statistics for Windows, Armonk, NY: IBM Corp). Descriptive statistics were presented by mean (SD) and number (percentage) for continuous and categorical variables. T-student statistics and the Mann-Whitney U test were used to compare the mean across treatment groups for normal and non-normal distribution variables, respectively. Also, independent quantitative variables, Paired-samples t-test, and Wilcoxon Signed Rank test were used based on normality. Moreover, the chi-Square test was used to compare distributions. Repeated measure analysis of variance was used to compare the mean score of considered factors between the two groups throughout the trial. A P-value less than 0.05 was considered significant.

4. Results

The number of patients was 102 women with breast cancer. Most (33.3%) were between 40 and 49 years old. Fine needle aspiration test results indicated that 46 subjects (45.1%) had axillary malignant tissue, and benign cases summed 56 (54.9%). Also, the final results of frozen section surgical histopathology identified 46.1% of patients with involved lymph nodes. According to the breast imaging-reporting and data (BI-RAD) system, 36 (35.3%) and 66 (64.7%) people were placed in categories 4 (suspicious) and 5 (highly suggestive of malignancy), respectively. The histologic characteristics of the primary breast cancer included 88 cases of invasive ductal carcinoma (86.3%), 5 cases of invasive lobular carcinoma (4.9%), 3 cases of invasive ductal carcinoma with mucinous feature (2.9%), and 6 cases of ductal carcinoma in situ (5.9%). Regarding the primary tumor side, 50 (49.0%) women showed a mass in the left breast, 51 patients (50.0%) in the right breast, and 1 patient (1.0%) in both.

According to the Bloom-Scarff-Richardson grading for breast carcinoma, there were 31 cases of grade 3 (30.4%), 57 cases of grade 2 (55.9%), and 14 cases of grade 1 (13.7%). Moreover, 86 (84.3%) and 16 (15.7%) tumor tissues were estrogen receptor (ER) positive and negative, respectively. Progesterone receptor (PR) and HER2 were expressed in 57.8% and 30.4% of tissues, respectively. Furthermore, 9 patients (8.8%) were included in triple-negative breast cancer (TNBC) group. On the other hand, 35 (34.3%) cases expressing progesterone and ER were HER2-negative. Among 15 tumor tissues (14.7%) that were negative for ER and PR, 6 (5.9%) tissues showed HER2 expression. There were 2 false-positive results of FNA. Of the 56 benign FNA, 55 were confirmed histologically. However, metastases were detected in 3 false-negative cases (Table 1).

Table 1.

Clinicopathological Characteristics of Patients a

CharacteristicsPositive Axila (n = 46)Negative Axila (n = 56)Total (n = 102)
Age, y
20 - 291 (2.2)0 (0.0)1 (1.0)
30 - 3911 (23.9)16 (28.6)27 (26.5)
40 - 4917 (37.0)17 (30.4)34 (33.3)
50 - 5910 (21.7)15 (26.8)25 (24.5)
60 - 693 (6.5)5 (8.9)8 (7.8)
70 - 792 (4.3)3 (5.4)5 (4.9)
80 - 891 (2.2)0 (0.0)1 (1.0)
BI-RADS
Category 418 (39.1)18 (32.1)36 (35.3)
Category 528 (60.9)38 (67.9)66 (64.7)
Side of primary tumor
Right22 (47.8)29 (51.8)51 (50.0)
Left24 (52.2)26 (46.4)50 (49.0)
Bilateral0 (0.0)1 (1.8)1 (1.0)
Grade
I3 (6.5)11 (19.6)14 (13.7)
II32 (69.6)25 (44.6)57 (55.9)
III11 (23.9)20 (35.7)31 (30.4)
Histology of mass
IDC41 (89.1)47 (83.9)88 (86.3)
ILC2 (4.3)3 (5.4)5 (5.9)
DCIS1 (2.2)5 (8.9)6 (4.9)
IDC & mucinous feature2 (4.3)1 (1.8)3 (2.9)
Estrogen receptor status
Positive35 (76.1)51 (91.1)86 (84.3)
Negative11 (23.9)5 (8.9)16 (15.7)
Progesterone receptor status
Positive25 (54.3)34 (60.7)59 (57.8)
Negative21 (45.7)22 (39.3)43 (42.2)
HER2 status
Positive16 (34.8)15 (28.8)31 (30.4)
Negative30 (65.2)37 (71.2)67 (65.7)
Ki-67 status
Positive42 (91.3)41 (82.0)83 (81.4)
Negative4 (8.7)9 (18.0)13 (12.7)
Molecular subtypes
Luminal A14 (25.4)21 (36.8)35 (34.3)
Luminal B8 (14.5)14 (24.6)22 (21.6)
Luminal B-like13 (23.6)12 (21.0)25 (24.5)
HER2-enriched3 (5.4)3 (5.3)6 (5.9)
TNBC7 (12.7)2 (3.5)9 (8.8)
ER-/PR-10 (18.2)5 (8.8)15 (14.7)
Frozen section status
Involved44 (95.6)3 (5.3)47 (46.1)
Non-involved2 (4.4)53 (94.7)55 (53.9)

Proportionally, there was a greater detection of axillary lymph nodes with cytology malignancy in tumors with histological grade II (32 subjects), BI-RADS category 5 (28 cases), invasive ductal carcinoma (41 subjects), and luminal A subtype (14 cases). The sensitivity and specificity of the axillary lymph node FNA in all the patients (including both sentinel and full lymph node dissection subjects) were 93.62% (95% CI) and 96.36% (95% CI), respectively. The PPV of the axillary lymph node FNA was 95.6% (95% CI), and the NPV was 94.6% (95% CI) with an overall diagnostic accuracy of 95.1% (Table 2).

Table 2.

Accuracy of Fine Needle Aspiration Cytology of Axillary Lymph Nodes a

FNACHistopathology MalignantHistopathology BenignTotal
Malignant44246
Benign35356
Total, %4755102

5. Discussion

One of the important prognostic factors in aggressive breast cancer is the involvement of axillary lymph nodes. Preoperative knowledge of the axillary lymph node status for metastasis in patients with breast cancer is very valuable because it affects the selection of the next surgical procedure (19). The standard method for staging is SNB. Sentinel lymph node biopsy requires the presence of a multidisciplinary expert group for injection and preoperative diagnosis; so, avoiding an unnecessary SNB is helpful because it is both time and cost-consuming (20). Determining the condition of the axillary lymph nodes affects the selection of the appropriate method of dissection of the lymph nodes; thus, it is very important to know the accuracy of the different techniques used in the preoperative assessment of the axillary lymph nodes. So far, no tumor markers have been identified that can predict axillary lymph node metastases before surgery. Different methods have been used, including palpation, ultrasonography alone, and ultrasonography combined with FNA cytology or core needle biopsy (21). It has been demonstrated that clinical examination alone is insufficient for lymph node assessment, with a sensitivity of 40% to 69% (22, 23). It was also found that approximately 50% of patients with clinically non-palpable lymph nodes showed metastases of these nodes at follow-up (23).

The ultrasound-guided FNA biopsy method is also the second treatment option. If the involvement of the lymph nodes is determined, a complete dissection of the axillary lymph nodes should be performed (24). As a diagnostic method for assessing breast lesions, FNA was introduced by Martin and Ellis in 1930 (25). Depending on the size and location of the lymph node and the operator's and cytologist's experience, FNA guided by ultrasound results vary widely. The results of the initial staging of tumor tissue using this method are different from the final data, possibly due to micrometastases or the low number of involved lymph nodes. Also, another problem with the FNA method is that it cannot distinguish in situ carcinoma from invasive carcinoma (25).

However, several studies have shown that this method is useful for detecting axillary lymph node metastasis in breast cancer (20, 26). Moreover, the results of this study indicated that the overall sensitivity and specificity for FNA in all subjects were 93.62% and 96.36%, respectively. These results compare favorably with those in the literature. The sensitivity range of this test has been reported in previous studies between 40% and 80% and specificity above 95% (20, 27). For example, Alkuwari et al. evaluated 115 patients with breast cancer for FNA and tissue examination. They reported the NPV and PPV of the FNA test of axillary lymph nodes as 60% and 100%, respectively. Also, FNA's overall sensitivity and specificity were 65% and 100% in all investigated cases, respectively. On the other hand, probably due to the small size of the metastatic focus in the SNB group (median 2.5 mm), the sensitivity in these subjects was lower than in the complete lymph node dissection group (16% vs. 88%) (17).

Furthermore, the high PPV of FAN also shows that the predictive value is significant. Fine needle aspiration certainly has its advantages. Due to the use of a smaller needle, it is less invasive and causes lower complication rates. As a result, it is better accepted by patients. One of the key benefits of FNA is the ability to diagnose most breast lesions when performed or assisted by a cytopathologist during the procedure, allowing a patient to obtain their diagnosis immediately. Also, some studies have shown that this method can be used to monitor recurrence in patients. In Europe, FNA continues to remain the initial diagnostic method for the evaluation of the majority of breast lesions (25).

On the other hand, accurate-guided imaging methods such as ultrasound are used to reduce error. However, similar to clinical examination, the accuracy of ultrasound evaluation is variable. A significant limitation of ultrasound is the lack of detection of small metastatic foci (28). Moreover, minimum lymph node involvement, with deposits less than 2 mm, is not associated with significant morphological changes in the lymph node. Indeed, the main challenge of evaluating lymph nodes is the false negative rate because, in some cases, the cortex of the nodes is similar to the early stages of metastatic disease (29).

The reported sensitivity of the evaluation of axillary lymph node status by ultrasound alone has ranged from 35% to 82%. In contrast, its specificity was more than 70% (27, 30). For example, the study by Rocha et al. reported the sensitivity of US-FNA as 79.4%. The positive and negative predictive values were 100% and 69.5%, respectively. Also, in evaluating invasive breast tumors in stages T1, T2, and T3, the sensitivity was 69.6%, 83.7%, and 100%, respectively. They stated that the US-FNA technique could have prevented SNB in 54% of cases (18). Furthermore, Krishnamurthy et al. reviewed 103 patients with breast cancer. Fifty-one cases (49.5%) had the results of US-FNA and histopathology of metastasis, and in 24 subjects, the results of both tests were negative. US-FNA did not observe lymph node involvement in 11.6% of cases, but metastasis was confirmed in histological examination. Also, the false positive in 16 cases could be explained by the complete response of the metastatic lymph node to neoadjuvant chemotherapy in the interval between FNA and axillary dissection. The US-FNA method detected 93% of lymph nodes larger than 5mm and 44% smaller than 5mm. The overall sensitivity and specificity of US-FNA were 86.4% and 100%, respectively. Finally, the negative predictive value was 67% (31). Moreover, in another study, the PPV and NPV of ultrasound alone were 92% and 49%, respectively (23).

5.1. Conclusions

This study showed that the sensitivity, specificity, and accuracy were more than 90% for the ultrasound-guided FNA test in identifying involved lymph nodes in patients with breast cancer. Therefore, the results of this test can be considered clinically reliable. However, according to the results of previous studies, ultrasound is not accurate to replace the histological examination to determine the metastatic status of lymph nodes. There is still a need to examine the sensitivity and specificity of this method in identifying lymph node involvement.

Acknowledgements

References

  • 1.

    Sung H, Ferlay J, Siegel RL, Laversanne M, Soerjomataram I, Jemal A, et al. Global Cancer Statistics 2020: GLOBOCAN Estimates of Incidence and Mortality Worldwide for 36 Cancers in 185 Countries. CA Cancer J Clin. 2021;71(3):209-49. [PubMed ID: 33538338]. https://doi.org/10.3322/caac.21660.

  • 2.

    Duffy SW, Tabar L, Yen AM, Dean PB, Smith RA, Jonsson H, et al. Mammography screening reduces rates of advanced and fatal breast cancers: Results in 549,091 women. Cancer. 2020;126(13):2971-9. [PubMed ID: 32390151]. [PubMed Central ID: PMC7318598]. https://doi.org/10.1002/cncr.32859.

  • 3.

    Mittra I, Mishra GA, Dikshit RP, Gupta S, Kulkarni VY, Shaikh HKA, et al. Effect of screening by clinical breast examination on breast cancer incidence and mortality after 20 years: prospective, cluster randomised controlled trial in Mumbai. BMJ. 2021;372:n256. [PubMed ID: 33627312]. [PubMed Central ID: PMC7903383]. https://doi.org/10.1136/bmj.n256.

  • 4.

    Stankov A, Bargallo-Rocha JE, Silvio AN, Ramirez MT, Stankova-Ninova K, Meneses-Garcia A. Prognostic factors and recurrence in breast cancer: experience at the national cancer institute of Mexico. ISRN Oncol. 2012;2012:825258. [PubMed ID: 22830047]. [PubMed Central ID: PMC3399427]. https://doi.org/10.5402/2012/825258.

  • 5.

    Seedhom AE, Kamal NN. Factors affecting survival of women diagnosed with breast cancer in El-Minia Governorate, Egypt. Int J Prev Med. 2011;2(3):131-8. [PubMed ID: 21811654]. [PubMed Central ID: PMC3143525].

  • 6.

    Saip P, Cicin I, Eralp Y, Kucucuk S, Tuzlali S, Karagol H, et al. Factors affecting the prognosis of breast cancer patients with brain metastases. Breast. 2008;17(5):451-8. [PubMed ID: 18455400]. https://doi.org/10.1016/j.breast.2008.03.004.

  • 7.

    Takalkar UV, Advani S. Prognostic indicators in breast cancer patients. J Cancer Res Forecast. 2018;1(1):2018.

  • 8.

    Lee YW, Huang CS, Shih CC, Chang RF. Axillary lymph node metastasis status prediction of early-stage breast cancer using convolutional neural networks. Comput Biol Med. 2021;130:104206. [PubMed ID: 33421823]. https://doi.org/10.1016/j.compbiomed.2020.104206.

  • 9.

    Ravdin PM, De Laurentiis M, Vendely T, Clark GM. Prediction of axillary lymph node status in breast cancer patients by use of prognostic indicators. J Natl Cancer Inst. 1994;86(23):1771-5. [PubMed ID: 7966415]. https://doi.org/10.1093/jnci/86.23.1771.

  • 10.

    Maxwell F, de Margerie Mellon C, Bricout M, Cauderlier E, Chapelier M, Albiter M, et al. Diagnostic strategy for the assessment of axillary lymph node status in breast cancer. Diagn Interv Imaging. 2015;96(10):1089-101. [PubMed ID: 26372221]. https://doi.org/10.1016/j.diii.2015.07.007.

  • 11.

    Giuliano AE, Hunt KK, Ballman KV, Beitsch PD, Whitworth PW, Blumencranz PW, et al. Axillary dissection vs no axillary dissection in women with invasive breast cancer and sentinel node metastasis: a randomized clinical trial. JAMA. 2011;305(6):569-75. [PubMed ID: 21304082]. [PubMed Central ID: PMC5389857]. https://doi.org/10.1001/jama.2011.90.

  • 12.

    Kim DW. Ultrasound-guided fine-needle aspiration for retrojugular lymph nodes in the neck. World J Surg Oncol. 2013;11:121. [PubMed ID: 23721570]. [PubMed Central ID: PMC3671968]. https://doi.org/10.1186/1477-7819-11-121.

  • 13.

    Cools-Lartigue J, Meterissian S. Accuracy of axillary ultrasound in the diagnosis of nodal metastasis in invasive breast cancer: a review. World J Surg. 2012;36(1):46-54. [PubMed ID: 22037691]. https://doi.org/10.1007/s00268-011-1319-9.

  • 14.

    Cools-Lartigue J, Sinclair A, Trabulsi N, Meguerditchian A, Mesurolle B, Fuhrer R, et al. Preoperative axillary ultrasound and fine-needle aspiration biopsy in the diagnosis of axillary metastases in patients with breast cancer: predictors of accuracy and future implications. Ann Surg Oncol. 2013;20(3):819-27. [PubMed ID: 22972506]. https://doi.org/10.1245/s10434-012-2609-7.

  • 15.

    Reimer T, Hartmann S, Stachs A, Gerber B. Local treatment of the axilla in early breast cancer: concepts from the national surgical adjuvant breast and bowel project B-04 to the planned intergroup sentinel mamma trial. Breast Care (Basel). 2014;9(2):87-95. [PubMed ID: 24944550]. [PubMed Central ID: PMC4038316]. https://doi.org/10.1159/000360411.

  • 16.

    Gentilini O, Veronesi U. Abandoning sentinel lymph node biopsy in early breast cancer? A new trial in progress at the European Institute of Oncology of Milan (SOUND: Sentinel node vs Observation after axillary UltraSouND). Breast. 2012;21(5):678-81. [PubMed ID: 22835916]. https://doi.org/10.1016/j.breast.2012.06.013.

  • 17.

    Alkuwari E, Auger M. Accuracy of fine-needle aspiration cytology of axillary lymph nodes in breast cancer patients: a study of 115 cases with cytologic-histologic correlation. Cancer Cytopathology. 2008;114(2):89-93. [PubMed ID: 18286535]. https://doi.org/10.1002/cncr.23344.

  • 18.

    Rocha RD, Girardi AR, Pinto RR, de Freitas VA. Axillary ultrasound and fine-needle aspiration in preoperative staging of axillary lymph nodes in patients with invasive breast cancer. Radiol Bras. 2015;48(6):345-52. [PubMed ID: 26811550]. [PubMed Central ID: PMC4725394]. https://doi.org/10.1590/0100-3984.2014.0121.

  • 19.

    Kuenen-Boumeester V, Menke-Pluymers M, de Kanter AY, Obdeijn IM, Urich D, Van Der Kwast TH. Ultrasound-guided fine needle aspiration cytology of axillary lymph nodes in breast cancer patients. A preoperative staging procedure. Eur J Cancer. 2003;39(2):170-4. [PubMed ID: 12509948]. https://doi.org/10.1016/s0959-8049(02)00501-4.

  • 20.

    Ciatto S, Brancato B, Risso G, Ambrogetti D, Bulgaresi P, Maddau C, et al. Accuracy of fine needle aspiration cytology (FNAC) of axillary lymph nodes as a triage test in breast cancer staging. Breast Cancer Res Treat. 2007;103(1):85-91. [PubMed ID: 17033920]. https://doi.org/10.1007/s10549-006-9355-0.

  • 21.

    Popli MB, Sahoo M, Mehrotra N, Choudhury M, Kumar A, Pathania OP, et al. Preoperative ultrasound-guided fine-needle aspiration cytology for axillary staging in breast carcinoma. Australas Radiol. 2006;50(2):122-6. [PubMed ID: 16635029]. https://doi.org/10.1111/j.1440-1673.2006.01545.x.

  • 22.

    Bruneton JN, Caramella E, Hery M, Aubanel D, Manzino JJ, Picard JL. Axillary lymph node metastases in breast cancer: preoperative detection with US. Radiol. 1986;158(2):325-6. [PubMed ID: 3510440]. https://doi.org/10.1148/radiology.158.2.3510440.

  • 23.

    De Freitas R, Costa MV, Schneider SV, Nicolau MA, Marussi E. Accuracy of ultrasound and clinical examination in the diagnosis of axillary lymph node metastases in breast cancer. Eur J Surg Oncol. 1991;17(3):240-4. [PubMed ID: 2044777].

  • 24.

    Huang Y, Zheng S, Lin Y. Accuracy and Utility of Preoperative Ultrasound-Guided Axillary Lymph Node Biopsy for Invasive Breast Cancer: A Systematic Review and Meta-Analysis. Comput Intell Neurosci. 2022;2022:3307627. [PubMed ID: 36203726]. [PubMed Central ID: PMC9532070]. https://doi.org/10.1155/2022/3307627.

  • 25.

    Cangiarella J, Simsir A. Advantages and disadvantages of FNA and core biopsies: diagnostic accuracy and precision for aspiration biopsy in the diagnosis of lesions of the breast. In: Cangiarella J, Simsir A, Tabbara SO, editors. Breast Cytohistology. Cambridge, England: Cambridge University Press; 2013. p. 19-26. https://doi.org/10.1017/cbo9780511979941.002.

  • 26.

    Houssami N, Diepstraten SC, Cody HS, Turner RM, Sever AR. Clinical utility of ultrasound-needle biopsy for preoperative staging of the axilla in invasive breast cancer. Anticancer Res. 2014;34(3):1087-97. [PubMed ID: 24596347].

  • 27.

    Davis JT, Brill YM, Simmons S, Sachleben BC, Cibull ML, McGrath P, et al. Ultrasound-guided fine-needle aspiration of clinically negative lymph nodes versus sentinel node mapping in patients at high risk for axillary metastasis. Ann Surg Oncol. 2006;13(12):1545-52. [PubMed ID: 17009156]. https://doi.org/10.1245/s10434-006-9095-8.

  • 28.

    Attieh M, Jamali F, Berjawi G, Saadeldine M, Boulos F. Shortcomings of ultrasound-guided fine needle aspiration in the axillary management of women with breast cancer. World J Surg Oncol. 2019;17(1):208. [PubMed ID: 31801564]. [PubMed Central ID: PMC6894218]. https://doi.org/10.1186/s12957-019-1753-y.

  • 29.

    Abe H, Schmidt RA, Kulkarni K, Sennett CA, Mueller JS, Newstead GM. Axillary lymph nodes suspicious for breast cancer metastasis: sampling with US-guided 14-gauge core-needle biopsy--clinical experience in 100 patients. Radiol. 2009;250(1):41-9. [PubMed ID: 18955508]. https://doi.org/10.1148/radiol.2493071483.

  • 30.

    van Rijk MC, Deurloo EE, Nieweg OE, Gilhuijs KG, Peterse JL, Rutgers EJ, et al. Ultrasonography and fine-needle aspiration cytology can spare breast cancer patients unnecessary sentinel lymph node biopsy. Ann Surg Oncol. 2006;13(1):31-5. [PubMed ID: 16372147]. https://doi.org/10.1245/aso.2005.01.024.

  • 31.

    Krishnamurthy S, Sneige N, Bedi DG, Edieken BS, Fornage BD, Kuerer HM, et al. Role of ultrasound-guided fine-needle aspiration of indeterminate and suspicious axillary lymph nodes in the initial staging of breast carcinoma. Cancer. 2002;95(5):982-8. [PubMed ID: 12209680]. https://doi.org/10.1002/cncr.10786.