Australasian Experience and Trials in Sentinel Lymph Node Biopsy: The RACS SNAC Trial

Update on sentinel node pathology in breast cancer

Pathologic examination of the sentinel lymph nodes (SLNs) in patients with breast cancer has been impacted by the publication of practicing changing trials over the last decade. With evidence from the ACOSOG Z0011 trial to suggest that there is no significant benefit to axillary lymph node dissection (ALND) in early-stage breast cancer patients with up to 2 positive SLNs, the rate of ALND, and in turn, intraoperative evaluation of SLNs has significantly decreased. It is of limited clinical significance to pursue multiple levels and cytokeratin immunohistochemistry to detect occult small metastases, such as isolated tumor cells and micrometastases, in this setting. Patients treated with neoadjuvant therapy, who represent a population with more extensive disease and aggressive tumor biology, were not included in Z0011 and similar trials, and thus, the evidence cannot be extrapolated to them. Recent trials have supported the safety and accuracy of sentinel lymph node biopsy (SLNB) in these patients when clinically node negative at the time of surgery. ALND remains the standard of care for any amount of residual disease in the SLNs and intraoperative evaluation of SLNs is still of value for real time surgical decision making. Given the potential prognostic significance of residual small metastases in treated lymph nodes, as well as the decreased false negative rate with the use of cytokeratin immunohistochemistry (IHC), it may be reasonable to maintain a low threshold for the use of cytokeratin IHC in post-neoadjuvant cases. Further recommendations for patients treated with neoadjuvant therapy await outcomes data from ongoing clinical trials. This review will provide an evidence-based discussion of best practices in SLN evaluation.

Sentinel Lymph Node Biopsy After Initial Lumpectomy (SNAIL Study)-a Prospective Validation Study

Tertiary oncology center clinicians are commonly faced with the problem of managing patients with a diagnosis of breast cancer made after lumpectomy in the Primary Health Care (PHC) setting. There are no studies or guidelines that address the further surgical management in this group of patients regarding sentinel lymph node biopsy (SLNB) and need for breast post-operative cavity excision. Prospective observational study was planned to evaluate the feasibility of SLNB and defining the need for definitive breast surgery in patients diagnosed with breast cancer after lumpectomy in PHC. The study was carried out from January 2015 to August 2017 in Tata Medical Center, India, approved by institutional review board (EC/TMC/36/14). Seventy patients who underwent lumpectomy with a definitive histological analysis of breast cancer were included in this study. Each patient had definitive breast surgery and SLNB using subareoral blue dye injection followed by validation axillary dissection. The identification rate (IR) for SLNB was 92% (64/70). The median number of SLNs removed was 2 (IQR 1, 3). There were 2 patients with false negative results resulting in false negative rate (FNR) of 11%. Overall, SLNB procedure has the sensitivity of 89%, NPV of 96%, and accuracy was 97%. Peri-areoral incision of initial surgery was associated with low IR (84%) and high FNR (33%). Final histopathology showed residual invasive cancer in 43% and ductal carcinoma in situ in 14% of patients. Among 21 patients where initial lumpectomy histopathology margin was free of cancer, residual malignancy was found in 57% of patients. Prior excision of lumps for breast cancer does not affect the accuracy of SLNB. Peri-areoral scar may be associated with high FNR and low IR, although further studies are needed to validate this statement. Definitive breast surgery is required for all patients, irrespective of initial lumpectomy histopathological margin status.

Non-invasive sentinel lymph node mapping and needle guidance using clinical handheld photoacoustic imaging system in small animal

Translating photoacoustic imaging (PAI) into clinical setup is a challenge. Handheld clinical real-time PAI systems are not common. In this work, we report an integrated photoacoustic (PA) and clinical ultrasound imaging system by combining light delivery with the ultrasound probe for sentinel lymph node imaging and needle guidance in small animal. The open access clinical ultrasound platform allows seamless integration of PAI resulting in the development of handheld real-time PAI probe. Both methylene blue and indocyanine green were used for mapping the sentinel lymph node using 675 and 690 nm wavelength illuminations, respectively. Additionally, needle guidance with combined ultrasound and PAI was demonstrated using this imaging system. Up to 1.5 cm imaging depth was observed with a 10 Hz laser at an imaging frame rate of 5 frames per second, which is sufficient for future translation into human sentinel lymph node imaging and needle guidance for fine needle aspiration biopsy.

Hand-held Clinical Photoacoustic Imaging System for Real-time Non-invasive Small Animal Imaging

Translation of photoacoustic imaging into the clinic is a major challenge. Handheld real-time clinical photoacoustic imaging systems are very rare. Here, we report a combined photoacoustic and clinical ultrasound imaging system by integrating an ultrasound probe with light delivery for small animal imaging. We demonstrate this by showing sentinel lymph node imaging in small animals along with minimally invasive real-time needle guidance. A clinical ultrasound platform with access to raw channel data allows the integration of photoacoustic imaging leading to a handheld real-time clinical photoacoustic imaging system. Methylene blue was used for sentinel lymph node imaging at 675 nm wavelength. Additionally, needle guidance with dual modal ultrasound and photoacoustic imaging was shown using the imaging system. Depth imaging of up to 1.5 cm was demonstrated with a 10 Hz laser at a photoacoustic imaging frame rate of 5 frames per second.

Trends in stage-specific breast cancer incidence in New South Wales, Australia: insights into the effects of 25 years of screening mammography

PURPOSE

Screening mammography aims to improve breast cancer (BC) prognosis by increasing the incidence of early-stage tumours in order to decrease the incidence of late-stage cancer, but no reports have investigated these potential effects in an Australian population. Therefore we aimed to identify temporal trends in stage-specific BC in New South Wales (NSW), Australia, between 1972 and 2012.

METHODS

An observational study of women who received a diagnosis of BC from 1972-2012 as recorded in the NSW Cancer Registry, a population-based registry with almost complete coverage and high rates of histological verification. We analysed trends in stage-specific incidence before screening and compared them to periods after screening began. Our primary group of interest was women in the target age range of 50-69 years, though trends in women outside the target age were also assessed.

RESULTS

Screening was not associated with lower incidence of late-stage BC at diagnosis. Incidence for all stages remained higher than prescreening levels. In women aged 50-69 years, the incidence of carcinoma in situ (CIS), localised and regional BC has more than doubled compared to the prescreening era, with incidence rate ratios ranging from 2.0 for regional (95% CI 1.95-2.13) to 121.8 for CIS (95% CI 82.58-179.72). Before the introduction of screening, there was a downward trend in distant metastatic BC incidence, and after the introduction of screening there was an increase (IRR 1.8; 95% CI 1.62-2.00). In women too young to screen the incidence of late-stage BC at diagnosis also increased, whereas localised disease was stable.

CONCLUSIONS

The incidence of all stages of BC has increased over the past 40 years, with the greatest rise seen during the established screening period for women aged 50-69 years. Our findings suggest that some of the expected benefits of screening may not have been realised and are consistent with overdiagnosis.

Article Commentary: Surgical Management of the Axilla in Breast Cancer

This article offers a review of the literature on current surgical management of the axilla in breast cancer. This includes the decision-making process involved in clinically node-negative patients versus clinically node-positive patients, with discussion of the indications for sentinel lymph node biopsy versus axillary dissection. It also examines the surgical axillary management of patients who receive neoadjuvant chemotherapy. This article will help update practicing surgeons on the evolving research and guidelines for the management of breast cancer axillary disease.

Sentinel Lymph Node Biopsy for Patients With Early-Stage Breast Cancer: American Society of Clinical Oncology Clinical Practice Guideline Update

Purpose

To provide evidence-based recommendations to practicing oncologists, surgeons, and radiation therapy clinicians to update the 2005 clinical practice guideline on the use of sentinel node biopsy (SNB) for patients with early-stage breast cancer.

Methods

The American Society of Clinical Oncology convened an Update Committee of experts in medical oncology, pathology, radiation oncology, surgical oncology, guideline implementation, and advocacy. A systematic review of the literature was conducted from February 2004 to January 2013 in Medline. Guideline recommendations were based on the review of the evidence by Update Committee.

Results

This guideline update reflects changes in practice since the 2005 guideline. Nine randomized clinical trials (RCTs) met systematic review criteria for clinical questions 1 and 2; 13 cohort studies informed clinical question 3.

Recommendations

Women without sentinel lymph node (SLN) metastases should not receive axillary lymph node dissection (ALND). Women with one to two metastatic SLNs planning to undergo breast-conserving surgery with whole-breast radiotherapy should not undergo ALND (in most cases). Women with SLN metastases who will undergo mastectomy should be offered ALND. These three recommendation are based on RCTs. Women with operable breast cancer and multicentric tumors, with ductal carcinoma in situ (DCIS) who will undergo mastectomy, who previously underwent breast and/or axillary surgery, or who received preoperative/neoadjuvant systemic therapy may be offered SNB. Women who have large or locally advanced invasive breast cancer (tumor size T3/T4), inflammatory breast cancer, or DCIS (when breast-conserving surgery is planned) or are pregnant should not undergo SNB. These recommendations are based on cohort studies and/or informal consensus. In some cases, updated evidence was insufficient to update previous recommendations.

Rapid synthesis of near infrared polymeric micelles for real-time sentinel lymph node imaging

In this manuscript a synthetic methodology for developing sub 20 nm sized polymeric micellar nanoparticles designed for extravascular imaging and therapy is revealed. A simple, one-pot method is followed, which involves a rapid co-self-assembly of an amphiphilic diblock copolymer (PS-b-PAA) and polyoxyethylene (80) sorbitan monooleate in water. Sorbitan monooleate imparts stability to the micelles and helps to drive down the particle size below 20 nm. The particles are incorporated with a water soluble dye ADS832WS, which absorbs in the near infrared range (λ(ex) = 832 nm) for sensitive detection with optical and photoacoustic imaging techniques. A candidate lipophilic anti-angiogenic therapeutic agent fumagillin was also incorporated with high entrapment (>95%) efficiency. The effectiveness of this theranostic platform for real-time, high-resolution intraoperative photoacoustic imaging for facilitating direct assessment of the sentinel lymph nodes (SLN) in breast cancer staging is demonstrated. The technique offers huge potential providing faster resection of SLN and may minimize complications caused by axillary exploration due to mismarking with dyes or low-resolution imaging techniques. Finally, the biodistribution and organ accumulation of the intravenously and intradermally injected particles are studied in a rodent model by optical imaging. Data suggest that intraveneously injected NIR-polymeric nanoparticles follow a typical bio-distribution clearance path through the reticuloendothelial (RES) system. For the intradermally injected particles, a slower mechanism of clearance is noticed.

Photoacoustic sentinel lymph node imaging with self-assembled copper neodecanoate nanoparticles

Photoacoustic tomography (PAT) is emerging as a novel, hybrid, and non-ionizing imaging modality because of its satisfactory spatial resolution and high soft tissue contrast. PAT combines the advantages of both optical and ultrasonic imaging methods. It opens up the possibilities for noninvasive staging of breast cancer and may replace sentinel lymph node (SLN) biopsy in clinic in the near future. In this work, we demonstrate for the first time that copper can be used as a contrast metal for near-infrared detection of SLN using PAT. A unique strategy is adopted to encapsulate multiple copies of Cu as organically soluble small molecule complexes within a phospholipid-entrapped nanoparticle. The nanoparticles assumed a size of 80-90 nm, which is the optimum hydrodynamic diameter for its distribution throughout the lymphatic systems. These particles provided at least 6-fold higher signal sensitivity in comparison to blood, which is a natural absorber of light. We also demonstrated that high SLN detection sensitivity with PAT can be achieved in a rodent model. This work clearly demonstrates for the first time the potential use of copper as an optical contrast agent.

Noninvasive detection of breast cancer lymph node metastasis using carbonic anhydrases IX and XII targeted imaging probes

PURPOSE

To develop targeted molecular imaging probes for the noninvasive detection of breast cancer lymph node metastasis.

EXPERIMENTAL DESIGN

Six cell surface or secreted markers were identified by expression profiling and from the literature as being highly expressed in breast cancer lymph node metastases. Two of these markers were cell surface carbonic anhydrase isozymes (CAIX and/or CAXII) and were validated for protein expression by immunohistochemistry of patient tissue samples on a breast cancer tissue microarray containing 47 normal breast tissue samples, 42 ductal carcinoma in situ, 43 invasive ductal carcinomas without metastasis, 46 invasive ductal carcinomas with metastasis, and 49 lymph node macrometastases of breast carcinoma. Targeted probes were developed by conjugation of CAIX- and CAXII-specific monoclonal antibodies to a near-infrared fluorescent dye.

RESULTS

Together, these two markers were expressed in 100% of the lymph node metastases surveyed. Selectivity of the imaging probes were confirmed by intravenous injection into nude mice-bearing mammary fat pad tumors of marker-expressing cells and nonexpressing cells or by preinjection of unlabeled antibody. Imaging of lymph node metastases showed that peritumorally injected probes detected nodes harboring metastatic tumor cells. As few as 1,000 cells were detected, as determined by implanting, under ultrasound guidance, a range in number of CAIX- and CAXII-expressing cells into the axillary lymph nodes.

CONCLUSION

These imaging probes have potential for noninvasive staging of breast cancer in the clinic and elimination of unneeded surgery, which is costly and associated with morbidities.

A mammaglobin-A targeting agent for noninvasive detection of breast cancer metastasis in lymph nodes

Pathologic axillary lymph node (ALN) status is an important prognostic factor for staging breast cancer. Currently, status is determined by histopathology following surgical excision of sentinel lymph node(s), which is an invasive, time consuming, and costly procedure with potential morbidity to the patient. Here, we describe an imaging platform for noninvasive assessment of ALN status, eliminating the need for surgical examination of patients to rule out nodal involvement. A targeted imaging probe (MamAb-680) was developed by conjugation of a mammaglobin-A-specific monoclonal antibody to a near-infrared fluorescent dye. Using DNA and tissue microarray, mammaglobin-A was validated as a cell-surface target that is expressed in ALN-positive patient samples but is not expressed in normal lymph nodes. In vivo selectivity was determined by i.v. injection of MamAb-680 into mice with mammaglobin-A-positive and -negative mammary fat pad (MFP) tumors; and by peritumoral MFP injection of the targeted imaging probe in mice with spontaneous ALN metastases. Fluorescence imaging showed that probe was only retained in positive tumors and metastases. As few as 1,000 cells that endogenously express mammaglobin-A were detected in ALN, indicating high sensitivity of this method. Translation of this approach offers considerable potential as a noninvasive clinical strategy to stage breast cancer.

Patient-reported outcomes in sentinel node-negative adjuvant breast cancer patients receiving sentinel-node biopsy or axillary dissection: National Surgical Adjuvant Breast and Bowel Project phase III protocol B-32

PURPOSE

Sentinel lymph node resection (SNR) may reduce morbidity while providing the same clinical utility as conventional axillary dissection (AD). National Surgical Adjuvant Breast and Bowel Project (NSABP) B-32 is a randomized phase III trial comparing SNR immediately followed by AD (SNAD) to SNR and subsequent AD if SN is positive. We report the definitive patient-reported outcomes (PRO) comparisons.

PATIENTS AND METHODS

Eligible patients had clinically node-negative, operable invasive breast cancer. The PRO substudy included all SN-negative participants enrolled May 2001 to February 2004 at community institutions in the United States (n = 749; 78% age > or = 50; 87% clinical tumor size < or = 2.0 cm; 84% lumpectomy; 87% white). They completed questionnaires presurgery, 1 and 2 to 3 weeks postoperatively, and every 6 months through year 3. Arm symptoms, arm use avoidance, activity limitations, and quality of life (QOL) were compared with intent-to-treat two-sample t-tests and repeated measures analyses.

RESULTS

Arm symptoms were significantly more bothersome for SNAD compared with SNR patients at 6 months (mean, 4.8 v 3.0; P < .001) and at 12 months (3.6 v 2.5; P = .006). Longitudinally, SNAD patients were more likely to experience ipsilateral arm and breast symptoms, restricted work and social activity, and impaired QOL (P < or = .002 all items). From 12 to 36 months, fewer than 15% of either SNAD or SNR patients reported moderate or greater severity of any given symptom or activity limitation.

CONCLUSION

Arm morbidity was greater with SNAD than with SNR. Despite considerable fears about complications from AD for breast cancer, this study demonstrates that initial problems with either surgery resolve over time.

Sentinel lymph nodes and lymphatic vessels: noninvasive dual-modality in vivo mapping by using indocyanine green in rats--volumetric spectroscopic photoacoustic imaging and planar fluorescence imaging

PURPOSE

To noninvasively map sentinel lymph nodes (SLNs) and lymphatic vessels in rats in vivo by using dual-modality nonionizing imaging-volumetric spectroscopic photoacoustic imaging, which measures optical absorption, and planar fluorescence imaging, which measures fluorescent emission-of indocyanine green (ICG).

MATERIALS AND METHODS

Institutional animal care and use committee approval was obtained. Healthy Sprague-Dawley rats weighing 250-420 g (age range, 60-120 days) were imaged by using volumetric photoacoustic imaging (n = 5) and planar fluorescence imaging (n = 3) before and after injection of 1 mmol/L ICG. Student paired t tests based on a logarithmic scale were performed to evaluate the change in photoacoustic signal enhancement of SLNs and lymphatic vessels before and after ICG injection. The spatial resolutions of both imaging systems were compared at various imaging depths (2-8 mm) by layering additional biologic tissues on top of the rats in vivo. Spectroscopic photoacoustic imaging was applied to identify ICG-dyed SLNs.

RESULTS

In all five rats examined with photoacoustic imaging, SLNs were clearly visible, with a mean signal enhancement of 5.9 arbitrary units (AU) + or - 1.8 (standard error of the mean) (P < .002) at 0.2 hour after injection, while lymphatic vessels were seen in four of the five rats, with a signal enhancement of 4.3 AU + or - 0.6 (P = .001). In all three rats examined with fluorescence imaging, SLNs and lymphatic vessels were seen. The average full width at half maximum (FWHM) of the SLNs in the photoacoustic images at three imaging depths (2, 6, and 8 mm) was 2.0 mm + or - 0.2 (standard deviation), comparable to the size of a dissected lymph node as measured with a caliper. However, the FWHM of the SLNs in fluorescence images widened from 8 to 22 mm as the imaging depth increased, owing to strong light scattering. SLNs were identified spectroscopically in photoacoustic images.

CONCLUSION

These two modalities, when used together with ICG, have the potential to help map SLNs in axillary staging and to help evaluate tumor metastasis in patients with breast cancer.

Near infrared photoacoustic detection of sentinel lymph nodes with gold nanobeacons

Detection of sentinel lymph node (SLN) using photoacoustic imaging is an emerging technique for noninvasive axillary staging of breast cancer. Due to the absence of intrinsic contrast inside the lymph nodes, exogenous contrast agents are used for photoacoustic detection. In this work, we have demonstrated near infrared detection of SLN with gold nanobeacons (GNBs) providing the photoacoustic contrast in a rodent model. We found that size dictates the in vivo characteristics of these nanoparticles in SLN imaging. Larger nanobeacons with high payloads of gold were not as efficient as smaller size nanobeacons with lower payloads for this purpose. Colloidal GNBs were designed as a nanomedicine platform with "soft" nature that is amenable to bio-elimination, an essential feature for in vivo efficacy and safety. The GNBs were synthesized as lipid- or polymer-encapsulated colloidal particles incorporating tiny gold nanoparticles (2-4 nm) in three tunable sizes (90 nm, 150 nm and 290 nm). Smaller GNBs were noted trafficking through the lymphatic system and accumulating more efficiently in the lymph nodes in comparison to the bigger nanoagents. At 20 min, the GNBs reached the SLN and were no longer observed within the draining lymphatic vessel. Within 1 h post-injection, the contrast ratio of the lymph nodes with the surrounding blood vessels was 9:1. These findings were also supported by analytical measurements of the ex vivo tissue samples. Results indicate that cumulative nanoparticle deposition in lymph nodes is size dependent and that high payloads of gold, although offering greater contrast in vitro, may yield nanoagents with poor intradermal migration and lymphatic transport characteristics.

High-speed dynamic 3D photoacoustic imaging of sentinel lymph node in a murine model using an ultrasound array

Noninvasive photoacoustic sentinel lymph node (SLN) mapping with high spatial resolution has the potential to improve the false negative rate and eliminate the use of radioactive tracers in SLN identification. In addition, the demonstrated high spatial resolution may enable physicians to replace SLN biopsy with fine needle aspiration biopsy, and thus reduce the risk of associated morbidity. The primary goal of this study is to demonstrate the feasibility of high-speed 3D photoacoustic imaging of the uptake and clearance dynamics of Evans blue dye in SLNs. The photoacoustic imaging system was developed with a 30 MHz ultrasound array and a kHz repetition rate laser system. It acquires one 3D photoacoustic image of 166 B-scan frames in 1 s, with axial, lateral, and elevational resolutions of 25, 70, and 200 microm, respectively. With optic-fiber based light delivery, the entire system is compact and is convenient to use. Upon injection of Evans blue, a blue dye currently used in clinical SLN biopsy, SLNs in mice and rats were accurately and noninvasively mapped in vivo using our imaging system. In our experiments, the SLNs were found to be located at approximately 0.65 mm below the skin surface in mice and approximately 1.2 mm in rats. In some cases, lymph vessels and lymphatic valves were also imaged. The dye dynamics--accumulation and clearance--in SLNs were quantitatively monitored by sequential 3D imaging with temporal resolution of as high as approximately 6 s. The demonstrated capability suggests that high-speed 3D photoacoustic imaging should facilitate the understanding of the dynamics of various dyes in SLNs and potentially help identify SLNs with high accuracy.

In vivo carbon nanotube-enhanced non-invasive photoacoustic mapping of the sentinel lymph node

Sentinel lymph node biopsy (SLNB), a less invasive alternative to axillary lymph node dissection (ALND), has become the standard of care for patients with clinically node-negative breast cancer. In SLNB, lymphatic mapping with radio-labeled sulfur colloid and/or blue dye helps identify the sentinel lymph node (SLN), which is most likely to contain metastatic breast cancer. Even though SLNB, using both methylene blue and radioactive tracers, has a high identification rate, it still relies on an invasive surgical procedure, with associated morbidity. In this study, we have demonstrated a non-invasive single-walled carbon nanotube (SWNT)-enhanced photoacoustic (PA) identification of SLN in a rat model. We have successfully imaged the SLN in vivo by PA imaging (793 nm laser source, 5 MHz ultrasonic detector) with high contrast-to-noise ratio (=89) and good resolution ( approximately 500 microm). The SWNTs also show a wideband optical absorption, generating PA signals over an excitation wavelength range of 740-820 nm. Thus, by varying the incident light wavelength to the near infrared region, where biological tissues (hemoglobin, tissue pigments, lipids and water) show low light absorption, the imaging depth is maximized. In the future, functionalization of the SWNTs with targeting groups should allow the molecular imaging of breast cancer.

Noninvasive photoacoustic identification of sentinel lymph nodes containing methylene blue in vivo in a rat model

Sentinel lymph node biopsy (SLNB) has become the standard method of axillary staging for patients with breast cancer and clinically negative axillae. Even though SLNB using both methylene blue and radioactive tracers has a high identification rate, it still relies on an invasive surgical procedure with associated morbidity. Axillary ultrasound has emerged as a diagnostic tool to evaluate the axilla, but it can only assess morphology and cannot specifically identify sentinel lymph nodes (SLNs). In this pilot study, we propose a noninvasive photoacoustic SLN identification system using methylene blue injection in a rat model. We successfully image a SLN with high optical contrast (146+/-41, standard deviation) and good ultrasonic resolution (approximately 500 microm) in vivo. We also show potential feasibility for clinical applications by imaging 20- and 31-mm-deep SLNs in 3-D and 2-D, respectively. Our results suggest that this technology would be a useful clinical tool, allowing clinicians to identify SLNs noninvasively in vivo.

Sentinel lymph node detection ex vivo using ultrasound-modulated optical tomography

We apply ultrasound-modulated optical tomography (UOT) to image ex-vivo methylene-blue-dyed sentinel lymph nodes embedded in 3.2-cm-thick chicken breast tissues. The UOT system is implemented for the first time using ring-shaped light illumination, intense acoustic bursts, and charge-coupled device (CCD) camera-based speckle contrast detection. Since the system is noninvasive, nonionizing, portable, relatively cost effective, and easy to combine with photoacoustic imaging and single element ultrasonic pulse-echo imaging, UOT can potentially be a good imaging modality for the detection of sentinel lymph nodes in breast cancer staging in vivo.

Sentinel lymph node detection using methylene blue in patients with early stage cervical cancer

OBJECTIVE

To evaluate the feasibility of sentinel lymph node (SLN) detection in patients with cervical cancer using the low-cost methylene blue dye and to optimize the application procedure.

PATIENTS AND METHODS

Patients with stage Ib(1)-IIa cervical cancer and subjected to abdominal radical abdominal hysterectomy and pelvic lymphadenectomy were enrolled. Methylene blue, 2-4 ml, was injected into the cervical peritumoral area in 77 cases (4 ml patent blue in the other four cases) 10-360 min before the incision, and surgically removed lymph nodes were examined for the blue lymph nodes that were considered as SLNs.

RESULTS

High SLN detection rate was successfully achieved when 4 ml of methylene blue was applied (93.9%, 46/49). Bilaterally SLN detection rate was significantly higher (78.1% vs. 47.1% P=0.027) in cases when the timing of application was more than 60 min before surgery than those with timing no more than 30 min. The blue color of methylene blue-stained SLNs sustained both in vivo and ex vivo, compared with the gradually faded blue color of patent blue that detected in 3 of 4 cases unilaterally. In the total of 112 dissected sides, the most common location of SLNs was the obturator basin (65.2%, 73/112), followed by external iliac area (30.4%, 34/112) and internal iliac area (26.8%, 30/112). Three patients who gave false negative results all had enlarged nodes.

CONCLUSION

Methylene blue is an effective tracer to detect SLNs in patients with early stage cervical cancer. The ideal dose and timing of methylene blue application are 4 ml and 60-90 min prior surgery, respectively.

Surmounting the challenges of sentinel lymph node biopsy for breast cancer in non-tertiary centres and community-based practices

BACKGROUND

Sentinel lymph node biopsy (SLNB), a procedure associated with low morbidity, has been shown to be an accurate technique for determining axillary lymph node status in breast cancer. It is now a standard of care in many tertiary oncology centres. The purpose of this study was to determine the feasibility of carrying out SLNB in non-tertiary centres and community practices without full nuclear medicine facilities and lower patient volume.

METHODS

From November 2002 to February 2005, 50 women diagnosed with clinically node-negative breast cancer underwent 52 sentinel lymph node procedures. Surgery was carried out in five hospitals with different access to nuclear medicine facilities. Lymphatic mapping was therefore carried out with blue dye only. Patients were divided into two groups: group 1 comprised those with invasive disease who went on to have an axillary clearance, and group 2 comprised those who underwent SLNB only for a negative node. Routine pathological examination was carried out for sentinel nodes.

RESULTS

There were 31 SLNB with axillary dissection and 21 SLNB only. The identification rate was 96.2%. Among those who had concomitant axillary dissection, there were no false-negative results. The overall accuracy was 94%, sensitivity was 82% and specificity was 100%.

CONCLUSION

Consistent results in non-tertiary centres can be achieved with adequate attention to appropriate preceptorship and meticulous technique. Women who elect to have surgical treatment for breast cancer in these hospitals need not be denied the benefits of SLNB.

Molecular analysis improves sensitivity of breast sentinel lymph node biopsy: results of a multi-institutional prospective cohort study

BACKGROUND

Pathologic evaluation may lack the sensitivity required for accurate staging of the axilla in breast cancer patients. We have completed enrollment of a multi-institutional prospective cohort study designed to determine if molecular analyses can improve axillary staging. In subset analyses, we have attempted to address the following questions: (1) Does molecular analysis improve the sensitivity of sentinel lymph node biopsy (SLNB) and (2) is the sentinel lymph node (SLN) hypothesis valid at the molecular level?

METHODS

Four hundred eighty-nine subjects with T1, T2, or T3 breast cancer and no evidence of axillary lymph node (ALN) involvement were enrolled. ALNs were analyzed by routine pathology (hematoxylin-eosin staining), and by multimarker real-time reverse transcriptase-polymerase chain reaction analysis CRT-PCR to detect breast cancer metastases. Pathology and molecular data for both SLNs and nonsentinel ALNs were available for a subset of 207 subjects.

RESULTS

The sensitivity of pathologic analysis of the SLN to predict the pathologic status of ALNs was 84.1%. The sensitivity of combining pathologic with molecular analysis of the SLN to predict the pathologic status of ALNs was 92.8%, a statistically significant increase in sensitivity (P = .031 by the McNemar test for correlated proportions). Finally, the sensitivity of combining pathologic with molecular analysis of the SLN to predict the pathologic or molecular status of ALNs was 85.4%.

CONCLUSIONS

The combination of pathologic and molecular analysis of SLNs resulted in the highest sensitivity for prediction of the pathologic status of ALNs. The data also provide evidence that the SLN hypothesis remains valid at the molecular level.