Novel Dual Tracer Indocyanine Green and Radioisotope Versus Gold Standard Sentinel Lymph Node Biopsy in Breast Cancer: The GREENORBLUE Trial.

BACKGROUND: The methods for sentinel lymph node (SLN) biopsy in breast cancer have been variable in type and number of tracers. Some units have abandoned the use of blue dye (BD) due to adverse reactions. Fluorescence-guided biopsy with indocyanine green (ICG) is a relatively novel technique. This study compared the clinical efficacy and costs between novel dual tracer ICG and radioisotope (ICG-RI) with "gold standard" BD and radioisotope (BD-RI). METHODS: Single-surgeon study of 150 prospective patients with early breast cancer undergoing SLN biopsy (2021-2022) using ICG-RI compared with a retrospective cohort of 150 consecutive previous patients using BD-RI. Number of SLNs identified, rate of failed mapping, identification of metastatic SLNs, and adverse reactions were compared between techniques. Cost-minimisation analysis performed by using Medicare item numbers and micro-costing analysis. RESULTS: Total number of SLNs identified with ICG-RI and BD-RI was 351 and 315, respectively. Mean number of SLNs identified with ICG-RI and BD-RI was 2.3 (standard deviation [SD] 1.4) and 2.1 (SD 1.1), respectively (p = 0.156). There were no cases of failed mapping with either dual technique. Metastatic SLNs were identified in 38 (25.3%) ICG-RI patients compared with 30 (20%) BD-RI patients (p = 0.641). There were no adverse reactions to ICG, whereas four cases of skin tattooing and anaphylaxis were associated with BD (p = 0.131). ICG-RI cost an additional AU$197.38 per case in addition to the initial cost for the imaging system. CLINICAL TRIAL REGISTRATION:  ACTRN12621001033831. CONCLUSIONS: Novel tracer combination, ICG-RI, provided an effective and safe alternative to "gold standard" dual tracer. The caveat was the significantly greater costs associated with ICG.

Intraoperative Pathology Assessment May Lead to Overtreatment of the Axilla in Clinically Node-Negative Breast Cancer Patients Undergoing Upfront Mastectomy.

BACKGROUND: Randomized trials have established the safety of observation or axillary radiation (AxRT) as an alternative to axillary lymph node dissection (ALND) in patients with limited nodal disease who undergo upfront surgery. Variability remains in axillary management strategies in cN0 patients undergoing mastectomy found to have one to two positive sentinel lymph nodes (SLNs). We examined the impact of intraoperative pathology assessment in axillary management in a national cohort of AMAROS-eligible mastectomy patients. METHODS: The National Cancer Database was used to identify AMAROS-eligible cT1-2N0 breast cancer patients undergoing upfront mastectomy and SLN biopsy (SLNB) and found to have one to two positive SLNs, from 2018 to 2019. We constructed a variable defining intraoperative pathology as 'not performed/not acted on' if ALND was either not performed or performed at a later date than SLNB, or 'performed/acted on' if SLNB and ALND were completed on the same day. Adjusted multivariable analysis examined predictors of treatment with both ALND and AxRT. RESULTS: Overall, 8222 patients with cT1-2N0 disease underwent upfront mastectomy and had one to two positive SLNs. Intraoperative pathology was performed/acted on in 3057 (37.2%) patients. These patients were significantly more likely to have both ALND and AxRT than those without intraoperative pathology (41.0% vs. 4.9%; p < 0.001). On multivariate analysis, the strongest predictor of receiving both ALND and AxRT was use of intraoperative pathology (odds ratio 8.99, 95% confidence interval 7.70-10.5; p < 0.001). CONCLUSIONS: We advocate that consideration should be made for omission of routine intraoperative pathology in mastectomy patients likely to be recommended postmastectomy radiation to minimize axillary overtreatment with both ALND and AxRT in appropriate patients.

Outcomes for patients with high-risk endometrial cancer undergoing sentinel lymph node assessment versus full lymphadenectomy.

OBJECTIVE: The objective of this study was to determine the progression free survival (PFS) and overall survival (OS) among patients with high-risk endometrial cancer (EC) who underwent sentinel lymph node (SLN) mapping and dissection compared to patients who underwent pelvic +/- para-aortic lymphadenectomy (LND). METHODS: Patients with newly diagnosed high-risk EC were identified. Inclusion criteria included patients who underwent primary surgical management from January 1, 2014 to September 1, 2020 at our institution. Patients were categorized into either the SLN or LND group based on their method of planned lymph node assessment. Patients in the SLN group had dye injected followed by successful bilateral lymph node mapping, retrieval, and processing per our institutional protocol. Clinicopathological and follow-up data were extracted from patient's medical records. The t-test or Mann-Whitney test was used to compare continuous variables and Chi-squared or Fisher's exact test were used for categorical variables. Progression-free survival (PFS) was calculated from the date of initial surgery to the date of progression, death, or last follow-up. Overall survival (OS) was calculated from the date of surgical staging to the date of death or last follow-up. Three-year PFS and OS were calculated using the Kaplan-Meier method, and the log-rank test was used to compare cohorts. Multivariable Cox regression models were used to assess the relationship between nodal assessment cohort and OS/PFS while adjusting for age, adjuvant therapy, and surgical approach. A result was considered statistically significant at the p < 0.05 level of significance and all statistical analysis was done using SAS version 9.4 (SAS Institute, Cary, NC). RESULTS: Out of 674 patients diagnosed with EC during the study period, 189 were diagnosed with high-risk EC based on our criteria. Forty-six (23.7%) patients underwent SLN assessment and 143 (73.7%) underwent LND. No difference was observed between the two groups in regards to age, histology, stage, body mass index, tumors myometrial invasion, lymphovascular space invasion, or peritoneal washing positivity. Patients in the SLN group underwent robotic-assisted procedures more frequently than those in the LND group (p < 0.0001). The three-year PFS rate was 71.1% (95% CI 51.3-84.0%) in the SLN group and 71.3% (95% CI 62.0-78.6%) in the LND group (p = 0.91). The unadjusted hazard ratio (HR) for recurrence in the SLN versus LND group was 1.11 (95% CI 0.56-2.18; p = 0.77), and after adjusting for age, adjuvant therapy, and surgical approach, the HR for recurrence was 1.04 (95% CI 0.47-2.30, p = 0.91). The three-year OS rate was 81.1% (95% CI 51.1-93.7%) in the SLN group and 95.1% (95% CI 89.4-97.8%) in the LND group (p = 0.009). Although the unadjusted HR for death was 3.74 in the SLN vs LND group (95% CI 1.39-10.09; p = 0.009), when adjusted for age, adjuvant therapy, and surgical approach, it was no longer significant with a HR of 2.90 (95% CI 0.94-8.95, p = 0.06). CONCLUSIONS: There was no difference in three-year PFS in patients diagnosed with high-risk EC who underwent SLN evaluation compared to those who underwent full LND in our cohort. The SLN group did experience shorter unadjusted OS; however, when adjusting for age, adjuvant therapy and surgical approach, there was no difference OS in patients who underwent SLN compared to LND.

Inequalities in the omission of axillary dissection in sentinel lymph node positive patients in the Netherlands: Innovative hospitals are early adopters of a de-escalating approach.

During the last decade completion axillary lymph node dissection (cALND) was gradually omitted in sentinel lymph node positive (SLN+) breast cancer patients. However, adoption varies among hospitals. We analyzed factors associated with the omission of cALND in all Dutch SLN+ patients. As one of the focus hospital-related factors we defined "innovative" as the percentage of gene-expression profile (GEP) deployment within the indicated group of patients per hospital as a proxy for early adoption of innovations. cT1-2N0M0 SLN+ patients treated between 2011 and 2018 were selected from the Netherlands Cancer Registry. Hospitals were defined to be innovative based on their GEP use. Multivariable logistic regression (MLR) was performed to assess the relationship between innovative capacity, patient-, treatment- and hospital-related characteristics and cALND performance. 14 317 patients were included. Treatment in a hospital with high innovative capacity was associated with a lower probability of receiving cALND (OR 0.69, OR 0.46 and OR 0.35 in modestly, fairly and very innovative, respectively). Other factors associated with a lower probability of receiving a cALND were age 70 and 79 years and ≥79 years (ORs 0.59 [95% CI: 0.50-0.68] and 0.21 [95% CI: 0.17-0.26]) and treatment in an academic hospital (OR 0.41 [95% CI: 0.33-0.51]). Factors associated with an increased probability of undergoing cALND were HR-/HER2- tumors (OR 1.46 [95% CI: 1.19-1.80]), macrometastatic lymph node involvement (OR 6.37 [95% CI: 5.70-7.13]) and mastectomy (OR 4.57 [95% CI: 4.09-5.10]). Patients treated in a hospital that early adopted innovations were less likely to receive cALND. Our findings endorse the need for studies on barriers and facilitators of implementing innovations.

Lack of Clinical Value for Immunohistochemistry for Sentinel Lymph Node Assessment in Invasive Lobular Carcinoma.

BACKGROUND: The distinct histologic appearance of invasive lobular carcinoma (ILC) may pose diagnostic challenges for sentinel lymph node (SLN) analysis. We evaluated the impact of cytokeratin immunohistochemistry (IHC) on SLN assessment in ILC and its contribution to pathologic nodal upstaging. METHODS: We identified ILC patients treated with SLN surgery at our institution between September 2008 and August 2021. IHC for SLN assessment was employed at the discretion of the pathologist. Differences between groups evaluated with and without IHC were compared using Chi-square tests. RESULTS: Overall, 608 cases of ILC were identified in patients who underwent SLN surgery. IHC was used in 301 cases (49.5%) and was not associated with cT category, pT category, or tumor grade. Use of IHC increased detection of SLN+ disease when isolated tumor cells (ITCs) were included in the analysis (35.9% with IHC vs. 21.2% without IHC; p < 0.001). There was no effect on nodal upstaging to micrometastatic disease (pN1mi) or greater (21.9% with IHC vs. 21.2% without IHC; p = 0.82). IHC did not increase the number of positive SLNs detected (median 1 with and without IHC) nor did it increase axillary lymph node dissection (ALND) rates (11.6% with IHC vs. 15.3% without IHC; p = 0.18). CONCLUSION: IHC improved detection of pN0(i+) disease among ILC patients undergoing SLN surgery. IHC did not increase upstaging to pN1mi or higher categories of nodal disease, detection of a greater number of positive SLNs, or ALND rates. Our data suggest routine use of IHC for SLN assessment in ILC patients does not add clinical utility.

Validation sentinel lymph node biopsy study in cN0 axilla using low-cost dual dye technique: potential solution for resource poor settings.

BACKGROUND: Sentinel lymph node biopsy (SLNB) using radio-pharmaceutical and a blue dye is gold standard for axillary staging in clinically node-negative breast cancer. High costs and limited availability of radio-pharmaceutical and/or gamma probe are major deterrents in performing SLNB in developing countries. In this study, we evaluated feasibility of SLN identification (SLN-IR) of fluorescein-guided (FG) SLNB in combination with methylene blue dye (MBD). METHODS: This was a prospective cross-sectional non-randomized validation study in patients with clinically node-negative axilla. Patients underwent validation SLNB using fluorescein (and blue LED light) and MBD. Axillary dissection was performed irrespective of SLNB histology. SLIN-IR and False Negative Rate (FNR) were assessed for both groups. RESULTS: The SLNs were identified in 29 (96.6%) pre-chemotherapy patients and 23 (82%) post Neoadjuvant Chemotherapy (NACT) patients. The median number of sentinel lymph nodes identified was 3 (range of 1-5) in pre-chemotherapy patients and 1 (range of 1-3) in post NACT patients. The SLN-IR using MBD was 90%, FD was 86.7% and combined MBD FD was 96.7% in pre-chemotherapy patients. The SLN-IR using MBD was 82%, FD was 71% and combined MBD FD was 82% in in post NACT patients. The false negative rate (FNR) in pre-chemotherapy group was 8.0% (MBD), 8.3% (FD) and 7.4% (MBD + FD). The FNR in post NACT group was 8.7% (MBD), 10% (FD) and 8.7% (MBD + FD). CONCLUSION: This prospective validation study showed adequate SLN-IR and FNR using low-cost dual dyes in early breast cancer patients and can be used in low resource settings. However, SLNB in post NACT axilla though viable along with a satisfactory FNR, is associated with low identification rate and needs further evaluation.

Laparoscopic Probe for Sentinel Lymph Node Harvesting Using Magnetic Nanoparticles.

OBJECTIVE: Sentinel lymph node harvesting is an essential step in the surgical treatment of a growing number of malignancies. Various techniques are available to facilitate this purpose. The present study reports a new laparoscopic technique for lymph node harvesting using magnetic nanoparticles containing a superparamagnetic iron-oxide core and dextran coating. This study assesses the clinical relevance of the prototype and provides input for further technological development on the way to clinical implementation. METHODS: A laparoscopic differential magnetometer prototype was built, utilizing a nonlinear detection principle (differential magnetometry) for magnetic identification of lymph nodes. The iron content sensitivity, depth & spatial sensitivity, and angular sensitivity were analyzed to investigate clinical options. RESULTS: The minimum detectable amount of iron was 9.8 µg at a distance of 1 mm. The detection depth was 5, 8, and 10 mm for samples containing 126, 252, and 504 µg iron, respectively. The maximum lateral detection distance was 5, 7, and 8 mm for samples containing 126, 252, and 504 µg iron, respectively. A sample containing 504 µg iron was detectable at all angulations assessed (0°, 30°, 60° and 90°). CONCLUSION: The laparoscopic differential magnetometer demonstrates promising results for further investigation and development towards laparoscopic lymph node harvesting using magnetic nanoparticles. SIGNIFICANCE: The laparoscopic differential magnetometer facilitates a novel method for sentinel lymph node harvesting, which helps to determine prognosis and treatment of cancer patients.

Assessment of Frailty Can Guide Decision Making for Utilization of Sentinel Lymph Node Biopsy in Patients with Thick Melanoma.

BACKGROUND: Sentinel lymph node biopsy (SLNB) is often omitted in selected patients with advanced primary melanoma, although the justification/criteria for omission have been debated. OBJECTIVE: We sought to determine whether assessment of frailty could serve as an objective marker to guide selection for SLNB in patients with advanced primary melanoma. METHODS: Patients presenting with clinical stage IIC (ulcerated, > 4 mm Breslow thickness) cutaneous melanoma from January 1999 through June 2019 were included. Frailty was assessed using the Memorial Sloan Kettering Frailty Index (MSK FI), a composite score of functional status and medical comorbidities. Five-year melanoma-specific survival (MSS) and overall survival (OS) were estimated using Cox regression, and predictors of OS were identified using competing risk models. RESULTS: MSS did not differ between patients who did (n = 451) or did not undergo SLNB (n = 179) [63.2% vs. 65.0%, p = 0.14]; however, omission of SLNB was associated with decreased 5-year OS (29% vs. 44%, p < 0.001). In a multivariable competing risk model, selection for SLNB omission was an independent predictor of death from non-melanoma causes (hazard ratio [HR] 1.7, 95% confidence interval [CI] 1.2-2.3, p < 0.001). After incorporation of the MSK FI score into the multivariable model in this subset, MSK FI (HR 2.4, 95% CI 1.5-4.1, p < 0.001), but not SLNB omission, was an independent predictor of poorer OS. CONCLUSION: We observed worse OS in patients with thick melanoma selected not to undergo SLNB, which was attributed to death due to non-melanoma causes. Formal assessment of frailty may provide an objective prognostic measure to guide selective use of SLNB in these patients.

Use and Costs of Sentinel Lymph Node Biopsy in Non-Ulcerated T1b Melanoma: Analysis of a Population-Based Registry.

BACKGROUND: The utility of sentinel lymph node biopsy (SLNB) for non-ulcerated T1b melanoma is debated and associated costs are poorly characterized. Prior work using institutional registries may overestimate the incidence of nodal positivity in this population. OBJECTIVE: The aim of this study was to estimate the use of SLNB, positivity prevalence, and procedural costs in patients with non-ulcerated T1b melanoma using a population-based registry. METHODS: We identified patients with clinically node-negative, non-ulcerated melanoma 0.8-1.0 mm thick (T1b according to the 8th edition standard of the American Joint Committee on Cancer) in the Surveillance, Epidemiology, and End Results database from 2010 to 2016. The prevalence of SLNB procedures and positive sentinel nodes were calculated. Factors associated with SLNB and sentinel node positivity were assessed using logistic regression. Medicare reimbursement costs and patient out-of-pocket expenses for SLNB and wide local excision (WLE) versus WLE alone were estimated. RESULTS: Among 7245 included patients, 3835(53%) underwent SLNB, 156 (4.1%, 95% confidence interval 3.5-4.7) of whom had a positive SLNB. Younger age, >1 mitosis per mm2, female sex, and truncal tumor location were associated with higher odds of positivity. The estimated SLNB cost to identify one patient with stage III disease was $71,700 (range $54,648-$83,172). Out-of-pocket expenses for a Medicare patient were estimated to be $652 for a WLE and SLNB and $79 for a WLE alone. CONCLUSIONS: In this population-based study, only 4% of selected non-ulcerated T1b patients had a positive SLNB, which is lower than prior reports. At the population level, SLNB is associated with high costs per prognostic information gained.

A cost-effectiveness analysis of three approaches for lymph node assessment in patients with low- and intermediate-risk endometrial cancer.

OBJECTIVE: To assess the cost-effectiveness of sentinel lymph node mapping compared to risk factor assessment and routine full lymph node dissection for the assessment of lymph nodes in patients with low- and intermediate-risk endometrioid endometrial cancer. METHODS: A decision-analytic model was designed to compare three lymph node assessment strategies in terms of costs and effects: 1) sentinel lymph node mapping; 2) post-operative risk factor assessment (adjuvant therapy based on clinical and histological risk factors); 3) full lymph node dissection. Input data were derived from systematic literature searches and expert opinion. QALYs were used as measure of effectiveness. The model was built from a healthcare perspective and the impact of uncertainty was assessed with sensitivity analyses. RESULTS: Base-case analysis showed that sentinel lymph node mapping was the most effective strategy for lymph node assessment in patients with low- and intermediate-risk endometrial cancer. Compared to risk factor assessment it was more costly, but the incremental cost effectiveness ratio stayed below a willingness-to-pay threshold of €20,000 with a maximum of €9637/QALY. Sentinel lymph node mapping was dominant compared to lymph node dissection since it was more effective and less costly. Sensitivity analyses showed that the outcome of the model was robust to changes in input values. With a willingness-to-pay threshold of €20,000 sentinel lymph node mapping remained cost-effective in at least 74.3% of the iterations. CONCLUSION: Sentinel lymph node mapping is the most cost-effective strategy to guide the need for adjuvant therapy in patients with low and intermediate risk endometrioid endometrial cancer.

Sentinel lymph node biopsy is associated with increased cost in higher risk thin melanoma.

INTRODUCTION: National Comprehensive Cancer Network guidelines recommend that sentinel lymph node biopsy (SLNB) be discussed with patients with thin melanoma at higher risk for lymph node metastasis (T1b or T1a with positive deep margins, lymphovascular invasion, or high mitotic index). We examined the association between SLNB and resource utilization in this cohort. METHODS: We conducted a retrospective cohort study of patients that underwent wide local excision for higher risk thin melanomas from 2009 to 2018 at a tertiary care center. Patients who underwent SLNB were compared to those who did not undergo SLNB with regard to resource utilization, including total hospital cost. RESULTS: A total of 70 patients were included in the analysis and 50 patients (71.4%) underwent SLNB. SLNB was associated with increased hospital costs ($6700 vs. $3767; p < .01) and increased operative time (68.5 vs. 36.0 min; p < .01). This cost difference persisted in multivariable regression (p < .01). Of patients who underwent successful SLN mapping, 3 out of 49 patients had a positive SLN (6.1%). The cost to identify a single positive sentinel lymph node (SLN) was $47,906. CONCLUSION: In patients with a higher risk of thin melanoma, SLNB is associated with increased cost despite a low likelihood of SLN positivity. These data better inform patient-provider discussions as the role of SLNB in thin melanoma evolves.

What is the Cost-Effective Treatment for Melanoma Patients with a Positive Sentinel Node?

BACKGROUND: Survival for positive sentinel lymph node (SLN) patients does not differ between completion lymph node dissection (CLND) and nodal observation (OBS). However, treating these patients with CLND and checkpoint inhibitors, such as pembrolizumab (PEM), improves outcomes. This study evaluated the cost-effectiveness of OBS, CLND, and CLND with PEM (CLND-PEM) treatments. METHODS: A Markov model was designed to simulate treatment for a theoretical cohort of 1000 positive SLN patients per therapy with a 5-year follow-up period. An intervention was cost-effective if its incremental cost-effectiveness ratio among therapies was below the willingness-to-pay threshold of $100,000 per quality-adjusted life year (QALY). RESULTS: Compared with CLND or CLND-PEM, OBS resulted in fewer lymphedema cases but in more disease recurrences. Compared with OBS, CLND had higher costs and lower QALYs. Although CLND-PEM had a lower number of recurrences and deaths than OBS or CLND, it had higher costs and lower QALYs than OBS, and thus was not cost-effective. However, with the effects of CLND from CLND-PEM removed, allowing evaluation of PEM effects alone (PEM alone), the resulting QALYs were the highest, but PEM alone still was not cost-effective compared with OBS ($1.2 million per QALY). By reducing the drug cost to less than $14,404 per patient, PEM alone would become cost-effective. CONCLUSIONS: Compared with CLND, CLND-PEM, and PEM alone, OBS was cost-effective for managing positive SLN patients. Although CLND-PEM and PEM alone result in fewer recurrences and deaths, these therapies were not cost-effective due to the quality-of-life decrement of CLND and the current high drug cost of PEM.

Sentinel Lymph Node Biopsy for T1b Melanoma: Balancing Prognostic Value and Cost.

BACKGROUND: The purpose of this study is to report the additional prognostic information and cost associated with sentinel lymph node biopsy (SLNB) for patients with T1b melanoma. PATIENTS AND METHODS: An institutional database was queried for patients with T1b melanoma (0.8-1.0 mm or < 0.8 mm with ulceration) with at least 5 years of follow-up. Results of SLNB, completion lymphadenectomy (CLND), recurrence, and melanoma-specific survival (MSS) were assessed. Institutional costs of melanoma care were converted to Medicare proportional dollars. A Markov model was created to estimate long-term costs. RESULTS: Among the total 392 patients, 238 underwent SLNB. Median follow-up was 10.5 years. SLNB was positive in 19 patients (8.0%). Patients who underwent SLNB had higher 10-year nodal recurrence-free survival (98.6% vs. 91.2%, p < 0.001) but not MSS (94.4% vs. 93.2%, p = 0.55). Ulceration (HR 4.7, p = 0.022) and positive sentinel node (HR 11.5, p < 0.001) were associated with worse MSS. Estimates for 5-year costs reflect a fourfold increase in total costs of care associated with SLNB. However, a treatment plan that forgoes adjuvant therapy for resected stage IIIA melanoma but offers systemic therapy for a node-basin recurrence would nullify the additional cost of SLNB. CONCLUSIONS: SLNB is prognostic for T1b melanoma. Its impact on the overall cost of melanoma care is intimately tied to systemic therapy in the adjuvant and recurrent settings.