The sensitivity and specificity of sentinel lymph node biopsy for breast cancer at Baylor University Medical Center at Dallas: a retrospective review of 488 cases

Rapid differentiation of estrogen receptor status in patient biopsy breast cancer aspirates with an optical nanosensor

Breast cancer is a substantial source of morbidity and mortality worldwide. It is particularly more difficult to treat at later stages, and treatment regimens depend heavily on both staging and the molecular subtype of the tumor. However, both detection and molecular analyses rely on standard imaging and histological method, which are costly, time-consuming, and lack necessary sensitivity/specificity. The estrogen receptor (ER) is, along with the progesterone receptor (PR) and human epidermal growth factor (HER-2), among the primary molecular markers which inform treatment. Patients who are negative for all three markers (triple negative breast cancer, TNBC), have fewer treatment options and a poorer prognosis. Therapeutics for ER+ patients are effective at preventing disease progression, though it is necessary to improve the speed of subtyping and distribution of rapid detection methods. In this work, we designed a near-infrared optical nanosensor using single-walled carbon nanotubes (SWCNT) as the transducer and an anti-ERα antibody as the recognition element. The nanosensor was evaluated for its response to recombinant ERα in buffer and serum prior to evaluation with ER- and ER+ immortal cell lines. We then used a minimal volume of just 10 μL from 26 breast cancer biopsy samples which were aspirated to mimic fine needle aspirates. 20 samples were ER+, while 6 were ER-, representing 13 unique patients. We evaluated the potential of the nanosensor by investigating several SWCNT chiralities through direct incubation or fractionation deployment methods. We found that the nanosensor can differentiate ER- from ER+ patient biopsies through a shift in its center wavelength upon sample addition. This was true regardless of which of the three SWCNT chiralities we observed. Receiver operating characteristic area under the curve analyses determined that the strongest classifier with an AUC of 0.94 was the (7,5) chirality after direct incubation and measurement, and without further processing. We anticipate that further testing and development of this nanosensor may push its utility toward field-deployable, rapid ER subtyping with potential for additional molecular marker profiling.

Model-based system matrix for iterative reconstruction in sub-diffuse angular-domain fluorescence optical projection tomography

This work concerns a fluorescence optical projection tomography system for low scattering tissue, like lymph nodes, with angular-domain rejection of highly scattered photons. In this regime, filtered backprojection (FBP) image reconstruction has been shown to provide reasonable quality images, yet here a comparison of image quality between images obtained by FBP and iterative image reconstruction with a Monte Carlo generated system matrix, demonstrate measurable improvements with the iterative method. Through simulated and experimental phantoms, iterative algorithms consistently outperformed FBP in terms of contrast and spatial resolution. Moreover, when projection number was reduced, in order to reduce total imaging time, iterative reconstruction suppressed artifacts that hampered the performance of FBP reconstruction (structural similarity of the reconstructed images with "truth" was improved from 0.15 ± 1.2 × 10^-3 to 0.66 ± 0.02); and although the system matrix was generated for homogenous optical properties, when heterogeneity (62.98 cm^-1 variance in µ_s ) was introduced to simulated phantoms, the results were still comparable (structural similarity homo: 0.67 ± 0.02 vs hetero: 0.66 ± 0.02).

Characterization of an angular domain fluorescence optical projection tomography system for mesoscopic lymph node imaging

Transmittance and fluorescence optical projection tomography can offer high-resolution and high-contrast visualization of whole biological specimens; however, applications are limited to samples exhibiting minimal light scattering. Our previous work demonstrated that angular-domain techniques permitted imaging of ∼1cm diameter noncleared lymph nodes because of their low scattering nature. Here, an angle-restricted transmittance/fluorescence system is presented and characterized in terms of geometric and fluorescence concentration reconstruction accuracy as well as spatial resolution, depth of focus, and fluorescence limits of detection. Using lymph node mimicking phantoms, results demonstrated promising detection and localization capabilities relevant for clinical lymph node applications.

Intraoperative Assessment of Sentinel Lymph Nodes in Breast Cancer Patients Post-Neoadjuvant Therapy

BACKGROUND

Shift toward minimizing axillary lymph node dissection in patients with breast cancer post neoadjuvant therapy has led to the assessment of sentinel lymph nodes by frozen section intraoperatively to determine the need for axillary lymph node dissection. However, few studies have examined the accuracy of sentinel lymph node frozen section after neoadjuvant therapy. Our objective is to compare the accuracy of sentinel lymph node frozen section in patients with breast cancer with and without neoadjuvant therapy and to identify features that may influence accuracy.

DESIGN

We identified 161 sentinel lymph node frozen section from 77 neoadjuvant therapy patients and 255 sentinel lymph node frozen section from 88 non-neoadjuvant therapy patients diagnosed between 2010 and 2016 in 2 institutions. The frozen section diagnoses were compared to the final diagnoses, and clinicopathologic data were analyzed.

RESULTS

The sensitivity, specificity, and accuracy of frozen section analysis were comparable between neoadjuvant therapy patients and non-neoadjuvant therapy patients (71.9% vs 50%, 100% vs 100%, and 88.3% vs 81.8%). Nine (11.7%) of 77 neoadjuvant therapy patients had discordant results, most often due to undersampling (tumor absent on frozen section slide). Four of these patients subsequently underwent axillary lymph node dissection. Discordant results (all false negatives) were significantly more likely in neoadjuvant therapy patients with Estrogen Receptor-positive/HER2-negative status, and in sentinel lymph node with pN1mic and pN0i+ deposits; age, preneoadjuvant therapy lymph node status, histotype, nuclear grade, tumor size, and response to neoadjuvant therapy showed no significant differences. For non-neoadjuvant therapy cases, large tumor size, lobular histotype, and sentinel lymph node with pN1mic and pN0i+ were associated with false-negative frozen section assessment.

CONCLUSION

Sentinel lymph node frozen section diagnosis post-neoadjuvant therapy has comparable sensitivity, specificity, and accuracy to the sentinel lymph node frozen section diagnosis in the non-neoadjuvant therapy setting.

Pooled long-term outcomes from two randomized trials of axillary node sampling with axillary radiotherapy versus axillary node clearance in patients with operable node-positive breast cancer

BACKGROUND

The aim was to determine long-term overall, breast cancer-specific and metastasis-free survival as well as axillary relapse rate from a pooled analysis of two randomized trials in women with operable breast cancer. These trials compared axillary node sampling (ANS), combined with axillary radiotherapy (AXRT) if the sampled nodes were involved, with axillary node clearance (ANC).

METHODS

Data from two clinical trials at the Edinburgh Breast Unit that randomized patients between 1980 and 1995 were pooled. Long-term survival was analysed using Kaplan-Meier curves and Cox regression, with separate analyses for patients with node-positive (ANS + AXRT versus ANC) and node-negative (ANS versus ANC) disease.

RESULTS

Of 855 women randomized, 799 were included in the present analysis after a median follow-up of 19·4 years. Some 301 patients (37·7 per cent) had node-positive disease. There was no evidence of a breast cancer survival advantage for ANS versus ANC in patients with node-negative disease (hazard ratio (HR) 0·88, 95 per cent c.i. 0·58 to 1·34; P = 0·557), or for ANS + AXRT versus ANC in those with node-positive breast cancer (HR 1·07, 0·77 to 1·50; P = 0·688). There was no metastasis-free survival advantage for ANS versus ANC in patients with node-negative tumours (HR 1·03, 0·70 to 1·51; P = 0·877), or ANS + AXRT versus ANC in those with node-positive disease (HR 1·03, 0·75 to 1·43; P = 0·847). Node-negative patients who underwent ANS had a higher risk of axillary recurrence than those who had ANC (HR 3·53, 1·29 to 9·63; P = 0·014). Similarly, among women with node-positive tumours, the risk of axillary recurrence was greater after ANS + AXRT than ANC (HR 2·64, 1·00 to 6·95; P = 0·049).

CONCLUSION

Despite a higher rate of axillary recurrence with ANS combined with radiotherapy to the axilla, ANC did not improve overall, breast cancer-specific or metastasis-free survival. Axillary recurrence is thus not a satisfactory endpoint when comparing axillary treatments.

Frozen section evaluation of breast carcinoma sentinel lymph nodes: a retrospective review of 1,940 cases

Many sentinel lymph node biopsies (SLNBs) are evaluated intraoperatively by frozen section, which may impact the need for further axillary dissection (AD). However, the need for AD in patients with small metastases has been recently called into question, meaning that frozen SLNB may be unnecessary. Furthermore, frozen section can compromise tissue for further study. At our institution, we grossly evaluate all SLNB and freeze half of the node. Here, we evaluate the frozen SLNB discrepancy rate using this method, focusing on cause of discrepancy and need for further surgery. We reviewed surgical pathology records for all breast cancer resections with frozen section of SLNB examined from 2003 to 2012. For cases with a frozen section discrepancy, we compiled clinicopathologic data. In total, 1,940 cases involved frozen section evaluation of SLNB. In 95 cases (4.9% of total cases, 23.8% of positive node cases), the SLNB was called negative on frozen but positive on final examination (false negatives). The majority of missed metastases are isolated tumor cells or micrometastases. A trend was observed toward fewer patients receiving completion AD after a discrepant frozen SLNB in the later years of the study. The protocol of freezing half of a SLNB is a reasonable method, with results similar to or better than other studies. The main adverse outcome is the need for separate AD; however, additional positive nodes are uncommon. The trend of fewer patients getting additional AD after a discrepant frozen SLNB suggests that clinicians may be using this information differently recently.

Assessment of suitability of the one step nucleic acid amplification (OSNA) assay as an intraoperative procedure for detection of metastasis in sentinel lymph nodes of breast cancer

AIM

We aimed to assess the one step nucleic acid amplification (OSNA) assay as an intraoperative method in comparison with frozen sections (FS) for detection of metastasis in sentinel lymph nodes (SLNs) of breast cancer.

METHOD

100 SLNs from patients with breast carcinoma were enrolled within a 3-month period. Alternate 2 mm node slices were subjected to routine FS, and later to permanent histology, and the rest for automated molecular detection of CK19 mRNA using OSNA. FS and OSNA findings were compared with permanent histology results. Difference in turnaround time was also noted.

RESULTS

With permanent histology as gold standard, OSNA was discrepant in 8 of 98 (3 false negative, 5 false positive) included SLNs whereas FS had 2 false negative cases. FS had higher sensitivity (89%, p=<0.001), specificity (100%, p=0.001) and concordance rate (98%) than OSNA (83%, 94% and 92%, respectively). FS showed almost perfect agreement (κ=0.929) whereas OSNA showed substantial agreement (κ=0.740) when compared with permanent histology. OSNA turnaround time was twice longer (mean of 47.7 min) than FS.

CONCLUSIONS

Automation of SLN assessment using OSNA is a potentially useful intraoperative diagnostic tool with acceptable accuracy. Discordant findings in this study may be due to sampling allocation. Since OSNA is more time-consuming, its practical advantage over routine FS requires further study in view of current technical workflow considerations.

Role of positron emission tomography/computed tomography in breast cancer

Although positron emission tomography (PET) imaging may not be used in the diagnosis of breast cancer, the use of PET/computed tomography is imperative in all aspects of breast cancer staging, treatment, and follow-up. PET will continue to be relevant in personalized medicine because accurate tumor status will be even more critical during and after the transition from a generic metabolic agent to receptor imaging. Positron emission mammography is an imaging proposition that may have benefits in lower doses, but its use is limited without new radiopharmaceuticals.

Detection of axillary node metastasis using diffusion-weighted MRI in breast cancer

Breast magnetic resonance imagings (MRIs) including diffusion-weighted MRI (DWI) of 110 breast cancers (26 with pathologically proven axillary node metastasis and 84 without metastasis) were retrospectively studied. Axillary nodes were detected as high-signal-intensity areas on DWI in 71 cancers (24 with metastasis and 47 without) and not detected in 39 cancers (2 with metastasis and 37 without). The ADC of metastatic nodes was significantly greater than that of the benign ones (1.08 ± 0.18 × 10(-3) mm(2)/s vs. 0.92 ± 0.22 × 10(-3) mm(2)/s, P=.004). When detectability of axillary nodes on DWI and ADC over 1.05 × 10(-3) mm(2)/s was applied as a threshold, 53.8% sensitivity, 86.9% specificity, and 79.1% accuracy were provided.