Sentinel lymph node mapping in colorectal cancer

Methylene Blue Near-Infrared Fluorescence Imaging in Breast Cancer Sentinel Node Biopsy

Simple Summary

Currently the gold standard for sentinel node biopsy in breast cancer patients is radioactive nanocolloid and a blue dye. In the age of fluorescence guided surgery new fluorophores are used and methylene blue presents some fluorescent properties. This study is the first in a clinical series presenting the possible use of methylene blue as a fluorescent dye for the identification of sentinel nodes in breast cancer sentinel node biopsy. We presented a feasibility of this new method and also in additional experiments because of the quenching effect limitation, found possible dilution of methylene blue presenting improved fluorescence.

Abstract

Introduction: Fluorescence-based navigation for breast cancer sentinel node biopsy is a novel method that uses indocyanine green as a fluorophore. However, methylene blue (MB) also has some fluorescent properties. This study is the first in a clinical series presenting the possible use of MB as a fluorescent dye for the identification of sentinel nodes in breast sentinel node biopsy. Material and methods: Forty-nine patients with breast cancer who underwent sentinel node biopsy procedures were enrolled in the study. All patients underwent standard simultaneous injection of nanocolloid and MB. We visualized and assessed the sentinel nodes and the lymphatic channels transcutaneously, with and without fluorescence, and calculated the signal-to-background ratio (SBR). We also analyzed the corresponding fluorescence intensity of various dilutions of MB. Results: In twenty-three patients (46.9%), the location of the sentinel node, or the end of the lymphatic path, was visible transcutaneously. The median SBR for transcutaneous sentinel node location was 1.69 (range 1.66–4.35). Lymphatic channels were visible under fluorescence in 14 patients (28.6%) prior to visualization by the naked eye, with an average SBR of 2.01 (range 1.14–5.6). The sentinel node was visible under fluorescence in 25 patients (51%). The median SBR for sentinel node visualization with MB fluorescence was 2.54 (range 1.34–6.86). Sentinel nodes were visualized faster under fluorescence during sentinel node preparation. Factors associated with the rate of visualization included diabetes (p = 0.001), neoadjuvant chemotherapy (p = 0.003), and multifocality (p = 0.004). The best fluorescence was obtained using 40 μM (0.0128 mg/mL) MB, but we also observed a clinically relevant dilution range between 20 μM (0.0064 mg/mL) and 100 μM (0.032 mg/mL). Conclusions: For the first time, we propose the clinical usage of MB as a fluorophore for fluorescence-guided sentinel node biopsy in breast cancer patients. The quenching effect of the dye may be the reason for its poor detection rate. Our analysis of different concentrations of MB suggests a need for a detailed clinical analysis to highlight the practical usefulness of the dye.

Role of methylene blue in detecting the sentinel lymph node in colorectal cancer: In vivo vs. ex vivo technique

The identification of sentinel lymph nodes is a valuable oncological method, which aims at mapping lymphatic drainage and has the advantage of correctly staging the disease and assessing prognosis. Lymph node invasion is an important prognostic feature. In colorectal cancer, lymphadenectomy is not influenced by the positive or negative status of the sentinel lymph node. The identification of lymph nodes with possible invasion by staining the primary tumor with methylene blue can lead to improved staging and management. In other words, the consequent administration of neoadjuvant therapy (chemotherapy) to the appropriate patients may result in lower recurrence rates. Thus, the aim of the present study was to use methylene blue to identify the sentinel node/nodes in colorectal cancer and to determine whether the dye-capturing nodes were invaded by the tumor. This is a non-randomized prospective study, in which 26 patients with colon cancer with surgical indication were enrolled. Two types of methods were utilized: in vivo (16 patients) and ex vivo (10 patients). The identification rate was 75% for the in vivo technique and 60% for the ex vivo technique, resulting in a 69.26% overall identification rate. Of 18 patients with sentinel lymph nodes identified using dye, routine histological examination detected metastases in 6 (33.33%) of these patients. In conclusion, further research should be conducted into how the clinical application of sentinel node detection can be employed in colorectal cancer.

Multifunctional Transferrin Encapsulated GdF3 Nanoparticles for Sentinel Lymph Node and Tumor Imaging

The transferrin encapsulated GdF₃ nanoparticles have been fabricated via biomineralization method. The obtained GdF₃@Tf NPs show an attractive T2MRI and CT enhancement effect. Furthermore, PET and NIR imaging capacity are integrated into nanoparticles through conjugating with radionuclide ⁶⁴Cu and fluorescent dye Cy7. ⁶⁴Cu-GdF₃@Tf-Cy7 NPs are developed and applied in small animal multimodal imaging in vivo. Compared with the previous multimodal imaging agents, ⁶⁴Cu-GdF₃@Tf-Cy7 NPs enable not only precise sentinel lymph node (SLN) identification, but specific imaging for transferrin receptor overexpressed colorectal tumor in vivo. The results reveal that ⁶⁴Cu-GdF₃@Tf-Cy7 NPs are potential and efficient multimodal imaging agents for SLN and tumor preclinical imaging.

Methylene Blue-Current Knowledge, Fluorescent Properties, and Its Future Use

Methylene blue is a fluorescent dye discovered in 1876 and has since been used in different scientific fields. Only recently has methylene blue been used for intraoperative fluorescent imaging. Here, the authors review the emerging role of methylene blue, not only as a dye used in clinical practice, but also as a fluorophore in a surgical setting. We discuss the promising potential of methylene blue together with the challenges and limitations among specific surgical techniques. A literature review of PubMed and Medline was conducted based on the historical, current and future usage of methylene blue within the field of medicine. We reviewed not only the current usage of methylene blue, but we also tried to grasp its’ function as a fluorophore in five main domains. These domains include the near-infrared imaging visualization of ureters, parathyroid gland identification, pancreatic tumors imaging, detection of breast cancer tumor margins, as well as breast cancer sentinel node biopsy. Methylene blue is used in countless clinical procedures with a relatively low risk for patients. Usage of its fluorescent properties is still at an early stage and more pre-clinical, as well as clinical research, must be performed to fully understand its potentials and limitations.

Robotic complete mesocolic excision using indocyanine fluorescence imaging in colorectal cancer: A case study and technical approach

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Complete mesocolic excision confers a possible survival advantage in right sided colorectal cancer.

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Indocynanine Green (ICG) Fluorescence Imaging may allow for more targeted lymph node clearances.

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Robotic surgery allows for these nodes to be removed with an MIS approach.

Introduction

Colorectal cancer is the second most common malignancy in developed countries and accurate staging is vital for determining the most appropriate management plan, in particular, whether adjuvant chemotherapy is recommended in addition to surgical resection. There is currently no consensus regarding standard practice for lymph node resection in colorectal cancer although there is increasing evidence to support the use of sentinel lymph node mapping to target lymph node sampling and facilitate ultra-staging of nodes.

Presentation of case

We present the case of a 49 year old female who underwent a robotic right hemicolectomy and complete mesocolic excision for caecal adenocarcinoma using indocyanine fluorescence imaging (ICG FI) to guide nodal dissection.

Discussion

ICG FI may be useful for sentinel lymph node mapping in colorectal cancer. This technique can assist to identify the first draining lymph nodes and permit ultra-staging of lymph nodes.

Conclusion

While there is still limited evidence to support ICG FI, the current body of literature suggests that it is likely to be a feasible and sensitive technique for guiding sentinel lymph node sampling in colorectal cancer.

The role of sentinel lymph node in colon cancer evolution

INTRODUCTION

The aim of this study is to evaluate the sentinel lymph node mapping (SLNM) with methylene blue staining "ex vivo" in colon cancer, as well as calculate the upstaging obtained by the determination of micrometastases and its correlation with the evolution of the disease.

METHODS

Between 2008 and 2011, 101 patients with colon cancer undergoing resection were studied prospectively with SLNM and detection of micrometastases. The correlation of SLN micrometastases with the disease evolution was evaluated in patients with a follow-up of more than one year.

RESULTS

The SLNM rate was 92 cases (91%). Only SLN was positive for micrometastases in 9 cases, with a 14% upstaging. The incidence of false negatives was 9 patients (10%). Mean follow of N0 patients (n=74) was 38 months. The SLN- (negative) group (65 patients) had a recurrence rate of 4 patients (7%), whereas this rate was 2 patients (22%) in the group of SLN+(positive) (9 patients), but without significant differences. No differences in survival were observed.

CONCLUSIONS

SLNM is a reproducible technique without significant increase in time and costs. Upstaging was obtained in 14% of patients staged as N0 by conventional technique. At follow-up of N0 patients with SLN+there seems to be a higher rate of recurrence, which could change the guidelines of adjuvant treatment, but we must interpret the results it with caution because the sample is small.

Intra-operative tumour detection and staging in colorectal cancer surgery

AIM

Surgical resection for colorectal cancer involves segmental resection and regional lymphadenectomy. The appropriateness of this 'one-size-fits-all' strategy is questioned as bowel cancer screening programmes result in a shift to earlier stage disease. Currently, the nodal status of a colorectal cancer can only be reliably determined by histopathological examination of the resected specimen. New methods of intra-operative staging are required to allow surgical resection to be tailored to the stage of the disease.

METHOD

A literature search was performed of PubMed and Embase databases using the terms 'colon' OR 'colorectal' AND 'intra-operative detection' OR 'intra-operative staging' OR 'intra-operative detection' OR 'radioimmunoguided surgery'. Articles published between January 1980 and January 2012 were included. Technologies that have the potential to allow intra-operative staging and treatment stratification were identified and further searches performed.

RESULTS

Established techniques such as sentinel lymph node mapping and radioimmunoguided surgery have benefited from combination with other technologies to allow real-time intra-operative staging. Intra-operative fluorescence, using naturally fluorescent biomarkers or fluorescent tumour probes, probably offers the most practical means of intra-operative lymph node staging and may be facilitated using nanotechnology. Optical coherence tomography and real-time elastography have the potential to provide an in vivo'virtual biopsy'.

CONCLUSION

Technological advances may allow accurate intra-operative lymph node staging to facilitate tailored surgical resection. This may become the next paradigm shift in colorectal cancer surgery.

Ultrastaging of colon cancer by sentinel node biopsy using fluorescence navigation with indocyanine green

PURPOSE

Lymph node status is the most important prognostic factor in colon cancer, but the role of sentinel lymph node biopsy (SLNB) as a tool for identification of micrometastatic disease and extraanatomical lymph nodes for adjuvant strategies and a tailored approach still remains unclear. Indocyanine green (ICG) fluorescence detection is a new method for SLNB allowing real-time lymphography and lymph node detection. This study was designed to evaluate the feasibility of fluorescence-guided sentinel lymph node detection in colon carcinoma.

METHODS

Twenty six patients with colon adenocarcinoma were prospectively included in this study. Intraoperatively, a peritumorous injection with a mean of 2.0 ml ICG was performed, followed by lymphatic mapping and SLNB. Clinical feasibility, detection rate, and sensitivity of the method were analyzed.

RESULTS

No adverse reactions occurred due to the injection of ICG. Overall, ICG fluorescence imaging identified 1.7 sentinel lymph node (SLN) in average in 25 out of 26 patients (detection rate, 96%). Metastatic involvement of the SLN was found in nine out of 11 nodal positive patients by conventional histopathology. The sensitivity of the method was 82% for colon carcinoma, respectively.

CONCLUSION

ICG fluorescence imaging is a new, feasible method for SLNB of colon carcinoma and enables ultrastaging with improved accuracy but with limited validity due to the small number of cases. One advantage of this technique is real-time visualization of lymphatic vessels and SLNB without radiation exposure. Further, larger series are necessary to analyze the role of fluorescence-guided SLNB for colon cancer.

Occult tumor metastasis and the prognostic value of sentinel lymph nodes in rectal cancer

The aim of the present study to evaluate the application of sentinel lymph node (SLN) pathology in rectal cancer using ex vivo mapping and to investigate the incidence and prognostic value of occult SLN metastasis in routine node-negative specimens. Specimens (n=117) of rectal cancer were examined using a combination of routine pathology and ex vivo SLN mapping. The inspected SLNs were further treated with immunohistochemical staining for occult cancer foci. The log-rank test was used to assess survival. SLNs were examined in 112 of the included specimens with a total number of 212, resulting in an identification rate of 95.7% (112/117). The status of SLNs accurately reflected N stage in 93.8% (105/112) of cases and the sensitivity was 75.6% (31/41) in detecting nodal metastasis. The accuracy of SLN pathology decreased in cancers of more advanced TNM stages (P=0.001). In 74 cases with routine node-negative (N0) disease, SLN micrometastasis (MIC) and isolated tumor cells (ITC) were examined in 9 and 4 cases, while the remaining 61 were regarded as negative (NEG). The log-rank test revealed poorer disease-free and overall survival of the MIC group compared with the NEG group. However, the findings from the ITC group were not significant compared with those from the MIC and NEG groups. In conclusion, ex vivo SLN pathology is practical and accurate in rectal cancer; however, its utility is limited in cases of advanced disease. Immunohistochemically detected SLN micrometastasis in node-negative cases is therefore a predictor of poorer outcome, and may therefore be listed as a marker for adjuvant therapy.

Suggestion of optimal patient characteristics for sentinel lymph node mapping in colorectal adenocarcinoma

CONTEXT

In a previously published study, the variables lower rectal tumor site, preoperative chemoradiotherapy and large tumors were considered as independent risk factors for the inability of sentinel lymph node identification in patients with colorectal adenocarcinoma.

OBJECTIVES

To determine if these variables could interfere in the precision and upstaging benefit of sentinel lymph node mapping in colorectal cancer.

METHODS

A database composed of 52 patients submitted to lymphatic mapping using technetium-99m-phytate and patent blue was reviewed. Only patients with tumors smaller than 5.0 cm, not submitted to preoperative chemoradiotherapy and without lower rectal cancer were included.

RESULTS

With these parameters, 11 patients remained to be studied. The sentinel lymph node identification rate was 100%, with a sensitivity of 100%, negative predictive value of 100%, no false negatives and accuracy of 100%. Sentinel lymph nodes were the only metastatic nodes in 36.4% of the patients, micrometastases (<0.2 cm or only identified by immunohistochemistry) provided an upstaging rate of 27.1% and metastases an upstaging rate of 9.1%.

CONCLUSION

The parameters proposed in this study for selection of colorectal adenocarcinoma patients to be submitted to sentinel lymph node mapping identified optimal accuracy and good upstaging results. As the number of included patients was low, these results could serve as guidance for proper patient selection in further prospective lymph node mapping studies in colorectal cancer patients.

Rectum-conserving surgery in the era of chemoradiotherapy

BACKGROUND

A complete pathological response occurs in 10-30 per cent of patients with locally advanced rectal cancer undergoing neoadjuvant chemoradiotherapy (CRT). The standard of care has been radical surgery with high morbidity risks and the challenges of stomata despite the favourable prognosis. This review assessed minimalist approaches (transanal excision or observation alone) to tumours with a response to CRT.

METHODS

A systematic review was performed using PubMed and Embase databases. Keywords included: 'rectal', 'cancer', 'transanal', 'conservative', 'complete pathological response', 'radiotherapy' and 'neoadjuvant'. Original articles from all relevant listings were sourced. These were hand searched for further articles of relevance. Main outcome measures assessed were rates of local recurrence and overall survival, and equivalence to radical surgery.

RESULTS

Purely conservative 'watch and wait' strategies after CRT are still controversial. Originally used for elderly patients or those who refused surgery, the data support transanal excision of rectal tumours showing a good response to CRT. A complete pathological response in the T stage (ypT0) indicates < 5 per cent risk of nodal metastases.

CONCLUSION

Rectal tumours showing an excellent response to CRT may be suitable for local excision, with equivalent outcomes to radical surgery. This approach should be the subject of prospective clinical trials in specialist centres.

Human epidermal growth factor receptor-2 family in colorectal adenocarcinoma: correlation with survival and clinicopathological findings

BACKGROUND AND PURPOSE

Erb-B1 (epidermal growth factor receptor, EGFR) and Erb-B2 (HER-2) are two of the best-characterized members in the EGFR pathway. In many tumor types, overexpression of these proteins is associated with enhanced malignant potential. The aim of this study was to determine the prognostic impact of EGFR and HER-2 protein expression on colorectal cancer.

METHOD

Immunohistochemistry was carried out in paraffin-embedded specimens of 115 colorectal carcinomas for the assessment of EGFR and HER-2 expression. Immunostaining for EGFR was graded negative, weak or strong according to extension and staining intensity. The results were correlated with traditional clinicopathologic parameters and patients' outcome.

RESULTS

The mean survival time was 64 (range 9-78) months in the EGFR-negative group, 166 (range 2-293) months in the group with a low EGFR expression, and 51 (range 4-71) months in the group with a high EGFR expression. The median survival time was 31 (range 2-114) months in the HER-2 negative group, and 30 (range 4-293) months in the HER-2 positive group. None of the clinicopathologic parameters or patient prognoses had statistically significant association with EGFR or HER-2 expression.

CONCLUSION

Conventional immunohistochemistry was unable to reveal any association between EGFR or HER-2 expression and outcome predicted by the biologic role of EGFR in tumor behavior and the established prognostic role of HER-2 in breast cancer.

Intraoperative methylene blue sentinel lymph node mapping in colorectal cancer

BACKGROUND

Isosulfan blue is not available for clinical use in Malaysia. This study describes the use of methylene blue as an alternative to isosulfan blue in colorectal sentinel node mapping.

METHODS

Methylene blue dye was injected around colonic and rectal tumours and the first blue-stained nodes were suture tagged and harvested after standard colorectal resection. Standard histopathological examination was then carried out to detect nodal metastasis. All negative sentinel lymph nodes (SLN) were subjected to 10 further step sectioning and immunoperoxidase staining for cytokeratin 20 to detect tumour deposits.

RESULTS

Thirty-one patients were enrolled from August 2005 to July 2006. Twenty-five attempts at identifying the SLN were successful (80.7%). Of the 18 (58.1%) who had nodal metastases (stage III), 3 had negative SLN but positive other lymph nodes (false-negative rate of 21.4%). In one (4%), the SLN was the exclusive site of metastasis.

CONCLUSION

Methylene blue can be used as an alternative sentinel node marker for rectal cancer (above the peritoneal reflection) and colonic cancer.

Upstaging benefits and accuracy of sentinel lymph node mapping in colorectal adenocarcinoma nodal staging

BACKGROUND AND OBJECTIVES

Sentinel lymph node (SLN) mapping is an additional method for improving colorectal cancer nodal staging. The purpose of the study was to define the method's accuracy in nodal staging, its upstaging benefits and to identify the predictive factors for its failure.

METHODS

Lymphatic mapping was performed using technetium-99m-phytate and patent blue in 52 consecutive colorectal adenocarcinoma patients. Enhanced pathological examination was carried out on SLNs with hematoxylin-eosin step-sectioning and immunochemistry.

RESULTS

The patients studied had an average tumor size of 6.5 cm; 85% had T3/T4 tumors; and rectal tumors represented 57.7% of the group. Overall SLN mapping accuracy was 79.5%, with sensitivity of 65.2% and 34.8% false negatives. Upstaging with SLN mapping was 23.1%. Colon tumors had an SLN identification rate of 90.9% and rectal tumors had 63.3% (P = 0.023). Multivariate statistical analysis identified lower rectal tumor (P = 0.009), neoadjuvant treatment (P = 0.029) and tumor size (P = 0.036) as independent risk factors for the inability to detect SLNs.

CONCLUSIONS

Upstaging benefits of SLN mapping should be considered in colon and mid- and upper rectal tumors. The method should be avoided in patients with lower rectal tumors, large tumors and having had neoadjuvant therapy.

Could lymphatic mapping and sentinel node biopsy provide oncological providence for local resectional techniques for colon cancer? A review of the literature

BACKGROUND

Endoscopic resectional techniques for colon cancer are undermined by their inability to determine lymph node status. This limits their application to only those lesions at the most minimal risk of lymphatic dissemination whereas their technical capacity could allow intraluminal or even transluminal address of larger lesions. Sentinel node biopsy may theoretically address this breach although the variability of its reported results for this disease is worrisome.

METHODS

Medline, EMBASE and Cochrane databases were interrogated back to 1999 to identify all publications concerning lymphatic mapping for colon cancer with reference cross-checking for completeness. All reports were examined from the perspective of in vivo technique accuracy selectively in early stage disease (i.e. lesions potentially within the technical capacity of endoscopic resection).

RESULTS

Fifty-two studies detailing the experiences of 3390 patients were identified. Considerable variation in patient characteristics as well as in surgical and histological quality assurances were however evident among the studies identified. In addition, considerable contamination of the studies by inclusion of rectal cancer without subgroup separation was frequent. Indeed such is the heterogeneity of the publications to date, formal meta-analysis to pool patient cohorts in order to definitively ascertain technique accuracy in those with T1 and/or T2 cancer is not possible. Although lymphatic mapping in early stage neoplasia alone has rarely been specifically studied, those studies that included examination of false negative rates identified high T3/4 patient proportions and larger tumor size as being important confounders. Under selected circumstances however the technique seems to perform sufficiently reliably to allow it prompt consideration of its use to tailor operative extent.

CONCLUSION

The specific question of whether sentinel node biopsy can augment the oncological propriety for endoscopic resective techniques (including Natural Orifice Transluminal Endoscopic Surgery [NOTES]) cannot be definitively answered at present. Study heterogeneity may account for the variability evident in the results from different centers. Enhanced capacity (perhaps to the level necessary to consider selective avoidance of en bloc mesenteric resection) by its confinement to only early stage disease is plausible although not proven. Specific study of the technique in early stage tumors is clearly essential before proffering this approach.

Detection of metastatic disease with sentinel lymph node dissection in colorectal carcinoma patients

BACKGROUND

In curative colorectal cancer surgery, radical lymph node dissection is essential for staging and decision-making for adjuvant treatment.

PURPOSE

The aims of the study were to analyse to what extent sentinel lymph node dissection (SLND) in colorectal cancer could upstage N0 patients and how lymphatic mapping could demonstrate micrometastatic disease.

PATIENTS AND METHODS

In a prospective study, patients were selected by CT scanning, avoiding bulky disease and distant metastasis. When standard staining (HE) was negative, micrometastases were searched for by immunohistochemistry (cytokeratin 11, CEA and Ca19-9 antibodies). Micrometastatic lymph nodes were classified N+(i).

RESULTS

Detection of sentinel lymph nodes was successful in 48 out of 52 colorectal cancer patients. Among the 44 M0 patients, 22 were N0 (i-) and 22 were N+ (13 with standard HE procedure, three were N+ (macrometastasis) with the SN as the only positive node and six patients had 1-4 micrometastatic SN (N+(i)). An overall potential upstaging of 9/44 could be considered after SLND. With a mean follow-up of 48 months survival, analysis showed that disease-specific survival of the group of six N+(i) patients was intermediate between the group of 22 N0 (i-) patients and the group of 16 N+ patients.

CONCLUSION

SLND may improve the detection of metastasis in conventionally bivalved nodes. Further studies could assess if micrometastatic disease detected in SN could be integrated into the risk factors for stage II patients in order to consider adjuvant chemotherapy.

Sentinel node staging in colon carcinoma: value of sentinel lymph node biopsy with radiocolloid and blue staining

BACKGROUND

Nodal staging accuracy is important in the prognosis and selection of patients for chemotherapy. This prospective study aims to assess the feasibility and accuracy of the sentinel lymph node procedure (SNP) using radiocolloid and blue dye in colon carcinoma.

METHODS

In 56 patients, lymphatic mapping was accomplished by means of intraoperatively injecting patent blue and nanocoll subserosally around the tumour. Sentinel nodes (SNs) were harvested ex-vivo. Nodes were stained with H&E. If lymph nodes were interpreted as negative for metastatic tumour, serial sectioning and immunohistochemical staining were performed.

RESULTS

At least one SN was detected in 49 of 53 patients (92.5%). Three patients were excluded because of preoperatively detected metastases. Overall, 121 SN were harvested with a mean of 2.2 SN/patients. Eighteen patients had tumour positive nodes. In four patients, pathological nodes were palpable during operation and were excluded. The SN was histologically negative in 2 of 14 patients with positive nodes (false-negative rate 14.3%). In 5 of 14 patients with positive nodes, the SN was the exclusive site of regional nodal metastasis. Four patients were upstaged by immunohistochemical staining (28.6%). The negative predictive value was 93.9% and the overall accuracy 95.6%. Scintigraphy was done in 17 patients. In three patients the SN was detected only by this modality.

DISCUSSION

The SN biopsy with the combined technique proved a feasible technique with a steep learning curve. It can change the initial staging from stage II to stage III colon carcinoma. Scintigraphy can improve the success rate of the technique.

Preliminary Study on Radioguided Sentinel Node Identification in Colon Cancer

The purpose of this study was to prove the prognostic value of the sentinel node (SN) in colon tumors, and to validate radioguided surgery in identifying the SN. Nodal metastases are a strong prognostic factor in patients operated on for colon or rectal cancer, decreasing the 5-year survival rate by approximately 20 per cent and dropping it to 30 per cent. Unfortunately, of 50 per cent of patients judged to be nodal disease-free at surgery, about 20 to 30 per cent will die from a local tumor relapse or distant metastases within 5 years of diagnosis. These data suggest that other steps are needed for more precise staging of patients, and specifically, to accurately harvest and study the nodes on which to base the prognosis. Mapping lymph nodes predictive of the whole basin status, referred to as SN, may help focus the pathologist's attention on a small but representative target, and achieve correct nodal harvesting, which includes atypical drainage pathways, when present. Twenty selected patients with colon tumor were administered a subserosal, peritumoral, intraoperative injection of blue dye and 99mTc-marked colloidal particles. The SN was identified visually and with a handheld gamma probe and was subsequently stitch-labeled. The operation was then conducted after standard surgical procedures, and the required lymphadenectomy was performed. Later, the probe was used to confirm radioactivity in the excised specimen and the absence of radioactivity in the operative field after resection; the purpose of the latter was to exclude the presence of aberrant routes of lymphatic drainage. The labeled SN were stained with hematoxylin and eosin and, in case of negative findings, cytokeratin immunostaining was performed. The remaining resected nodes were stained with hematoxylin and eosin. The probe identification of SN was 95 per cent overall (19/20); in 13 patients, a single SN was labeled, and two were labeled in six patients, harvesting 25 SN. In the 19 patients in whom a radio-emitting SN was labeled, we recorded only one false-negative; in one case, a micrometastasis in the SN was the only extracolonic site. The blue dye identified the SN in 14 cases; in some of them, the number of nodes was overestimated (five single, seven double, and two triple SN) in comparison with the radioisotope, but at least one of the dyed nodes was also radioemitting. SN identification in colon cancers is a safe, fast, and easy procedure for ultrastaging the nodal basin. The technique involves a relatively flat learning curve and could become standard care for identifying the presence of nodal micrometastases at a low cost, thereby also making it affordable at small health centers.

Incidence and prognostic influence of lymph node micrometastases in rectal cancer

AIMS

The aim of this study was to determine the rate of lymph node micrometastases and evaluate their prognostic significance in rectal cancer.

METHODS

Patients with either Dukes A or B rectal carcinoma who had undergone curative resection by either low anterior resection or abdominal perineal resection between 1991 and 2000 were selected from a prospectively collated database. None of the patients had metastasis at the time of surgery and none received adjuvant or neoadjuvant therapy. A single section from each lymph node was stained with haematoxylin and eosin (H+E) and with CAM 5.2 by immunohistochemistry. Statistical analyses were performed with Chi-square test.

RESULTS

A total of 774 lymph nodes with a median of 14 lymph nodes per patient were examined, from a cohort of 56 patients with a median age of 66 years. In the 56 patients in whom lymph node metastases were not detected by haematoxylin-eosin staining, cytokeratin staining was positive in 15 lymph nodes from 10 patients. Nine patients had disease recurrence at a median follow-up of 98 months. The presence of lymph node micrometastases by immunohistochemistry did not predict either disease-free (p=0.44) or overall survival (p=0.63).

CONCLUSION

Immunohistochemical staining detects micrometastases in rectal cancer which are not observed with H+E staining. However, no significant relationship was observed between disease relapse and rectal micrometastases detected by immunohistochemistry.

Tumor invasion of lymph node capsules in patients with Dukes C colorectal adenocarcinoma

PURPOSE

The objective of this study was to investigate the correlation between the microscopic findings of positive lymph nodes, especially focusing on capsular invasion, and the outcome after curative surgical resection of colorectal cancer.

METHODS

We analyzed 480 positive lymph nodes from 155 consecutive patients with Stage III colorectal cancer to determine the frequency and significance of lymph node capsular invasion. Recurrence-free and cancer-specific survival rates were assessed in the patients with and without lymph node capsular invasion.

RESULTS

Between April 1995 and December 2000, 406 consecutive patients with primary colorectal cancer underwent curative resection. Regional lymph node metastases were present in 155 cases (38.2 percent). During the median follow-up period of 4.8 years, 41 patients (26.5 percent) developed recurrent disease and 28 patients died of cancer. Lymph node capsular invasion was detected in one or more lymph nodes from 75 cases (48.3 percent). The five-year recurrence-free rate was 56.1 percent in this group, whereas in the 80 patients without lymph node capsular invasion the rate was 88 percent (P<0.01). Features that were associated with recurrent disease were greater number of positive lymph nodes, venous invasion in primary tumor, infiltrative growth pattern of intranodal tumor, and presence of lymph node capsular invasion. Multivariate analysis identified lymph node capsular invasion as the only significant prognostic factor for recurrence. In multivariate analysis with regard to survival, lymph node capsular invasion, venous invasion, and number of positive nodes remained as significant prognostic factors.

CONCLUSIONS

Lymph node capsular invasion, determined by routine hematoxylin-eosin staining, is a potent prognostic factor in Stage III colorectal cancer.

Does the EGFR and VEGF expression predict the prognosis in colon cancer?

BACKGROUND/AIM

Epidermal growth factor receptor (EGFR) and vascular endothelial growth factor (VEGF) are frequently encountered with aggressive tumor phenotype and poor prognosis, but the relationship between EGFR/VEGF expression and survival remains unclear. The aim of our study was to further investigate the prognostic value of EGFR and VEGF expression in colon cancer.

MATERIALS AND METHODS

The pathological specimens of 60 colon carcinoma patients were retrospectively evaluated and grouped according to EGFR and VEGF staining intensity and percentage of stained neoplastic cells. A final score was assigned to each case by multiplying percentage and staining score. The patients were stratified into the following categories: negative (score 0), low expression (score 1 or 2), and high expression (score 4). The remaining patient data were filtered out from the institutional cancer database.

RESULTS

The mean survival time was 28.93 +/- 14.1 (range 2-52) months in the EGFR-negative group, 23.92 +/- 14.0 (range 6-46) months in the group with a low EGFR expression, and 17.00 +/- 12.8 (range 10-40) months in the group with a high EGFR expression. The median survival time was 27.50 +/- 14.7 (range 4-52) months in the VEGF-negative group, 29.33 +/- 12.8 (range 6-48) months in the group with a low VGEF expression, and 14.50 +/- 14.2 (range 2-40) months in the group with a high VGEF expression. The expression of EGFR and VEGF was not an independent factor that affects survival.

CONCLUSIONS

The EGFR and VEGF expression rates of colon tumors do not predict the survival. In addition, the EGFR expression in the primary tumor was not predictive of metastatic lymph nodes. The prognostic value of EGFR/VEGF staining may be further questioned.

Detection of Thymidylate Synthase Expression in Lymph Node Metastases of Colorectal Cancer Can Improve the Prognostic Information

Purpose

The level of thymidylate synthase (TS) in primary colorectal cancer (CRC) has been reported as a prognostic marker. The purpose of this study was to determine whether TS expression in lymph node metastases of Dukes' C CRC is a prognostic marker.

Patients and Methods

TS expression in the primary tumor and lymph node metastases from 348 patients with Dukes' C CRC was retrospectively assessed using immunohistochemistry and the monoclonal antibody TS 106. The patients had all been enrolled onto our previous study of 862 CRC patients who were included in Nordic trials that randomly assigned the patients to either surgery alone or surgery plus adjuvant chemotherapy.

Results

TS expression in lymph node metastases was a distinct prognostic marker in the entire study group for overall survival (OS; P = .02) and disease-free survival (DFS; P = .04). A low TS expression in the lymph node metastases correlated with a better clinical outcome. In the subgroup of patients treated with surgery alone, the expression of TS in lymph node metastases also had a prognostic value for OS (P = .04) and DFS (P = .03), but this was not the case for the other subgroup who received adjuvant fluorouracil-based chemotherapy (OS, P = .5; DFS, P = .2). The expression of TS in the primary tumor only had a significant prognostic value among patients who were treated with surgery alone (OS, P = .03; DFS, P = .03) and not among the entire patient population.

Conclusion

These data show that TS expression in lymph node metastases is a prognostic marker for patients with Dukes' C CRC.

Is the lateral lymph node compartment relevant?

Lateral pelvic lymphadenectomy is routinely performed in advanced lower rectal cancers by Japanese surgeons, whereas in the western world it has not progressed to a frequently performed technique. Claimed benefit for this extensive surgery is an improved locoregional control; on the other hand, low positive lateral lymph node yields, questionable prognostic significance, and high morbidity (urinary and sexual dysfunction) are main reasons against this procedure. Clinical results published on lateral lymphadenectomy in the literature are conflicting. Due to major improvements in local control and survival of rectal cancer patients mainly based on preoperative radiotherapy and total mesorectal excision (TME), only a few patients may profit from lateral lymph node dissection. This article gives an overview of the current status and the clinical relevance of the lateral lymph node compartment in rectal cancer surgery.

Sentinel nodes are identifiable in formalin-fixed specimens after surgeon-performed ex vivo sentinel lymph node mapping in colorectal cancer

BACKGROUND

In recent years, the technique of sentinel lymph node (SLN) mapping has been applied to colorectal cancer. One aim was to ultrastage patients who were deemed node negative by routine pathologic processing but who went on to develop systemic disease. Such a group may benefit from adjuvant chemotherapy.

METHODS

With fully informed consent and ethical approval, 37 patients with primary colorectal cancer and 3 patients with large adenomas were prospectively mapped. Isosulfan blue dye (1 to 2 mL) was injected around tumors within 5 to 10 minutes of resection. After gentle massage to recreate in vivo lymph flow, specimens were placed directly into formalin. During routine pathologic analysis, all nodes were bivalved, and blue-staining nodes were noted. These later underwent multilevel step sectioning with hematoxylin and eosin and cytokeratin staining.

RESULTS

SLNs were found in 39 of 40 patients (98% sensitivity), with an average of 4.1 SLNs per patient (range, 1-8). In 14 of 16 (88% specificity) patients with nodal metastases on routine reporting, SLN status was in accordance. Focused examination of SLNs identified occult tumor deposits in 6 (29%) of 21 node-negative patients. No metastatic cells were found in SLNs draining the three adenomas.

CONCLUSIONS

The ability to identify SLNs after formalin fixation increases the ease and applicability of SLN mapping in colorectal cancer. Furthermore, the sensitivity and specificity of this simple ex vivo method for establishing regional lymph node status were directly comparable to those in previously published reports.

Sentinel lymph node mapping of the colon and stomach using lymphoseek in a pig model

BACKGROUND

Lymphoseek is a radiopharmaceutical designed for sentinel lymph node (SLN) mapping. The purpose of this study was to compare Lymphoseek colon and gastric pharmacokinetics with filtered [(99m)Tc]sulfur colloid (fTcSC).

METHODS

Eight anesthetized pigs received an endoscopic injection of Lymphoseek or fTcSC in the stomach and colon. Scintigraphy was obtained of both administration sites at 15-minute intervals up to 3 hours after injection, after which all SLNs were identified by a handheld gamma probe through a laparotomy incision. Isosulfan blue was administered at the injection site 5 minutes before SLN mapping. The percentage of injected dose (%ID) was measured for all harvested nodes, and the clearance half-life (T(c)) was calculated for all injection sites.

RESULTS

The mean Lymphoseek clearance for colon (T(c), 2.56 +/- 1.04 hours) and gastric (T(c), 3.83 +/- 1.18 hours) injection sites was statistically faster (P =.030) compared with fTcSC (colon T(c), 14.98 +/- 3.41 hours; stomach T(c), 14.52 +/- 4.08 hours). After 3 hours, Lymphoseek exhibited a mean SLN %ID of 1.32% +/- 1.71% in the colon and 2.04% +/- 2.12% in the stomach; this was not statistically different from fTcSC (colon,.63% +/-.39%; stomach, 2.35% +/- 2.90%). SLN uptake of Lymphoseek was significantly different from second-echelon node %ID for the colon (P =.011) and gastric (P =.029) injection sites. All SLNs exceeded 10 times background, and there was no discordance between isosulfan blue and Lymphoseek or fTcSC.

CONCLUSIONS

Three hours after colon stomach administration, Lymphoseek demonstrated rapid injection site clearance, detectable SLN uptake, and low second-echelon node uptake.

Ex vivo sentinel lymph node mapping in colorectal cancer

INTRODUCTION

Sentinel lymph node mapping has been used in clinical work in malignant melanoma and breast cancer and shown an advantage over routine regional lymphadenectomy. The technique has been applied to colorectal cancer, but concerns over accuracy and high false-negative rates have restricted its use in the routine clinical setting. Most published series have used the in vivo technique and only three studies have been published in which the ex vivo technique was used. The aim of this study was to report the results of a larger study of ex vivo sentinel node mapping.

METHODS

All patients with colorectal cancer were considered for the trial, except patients who received preoperative radiotherapy for rectal cancer. All specimens were examined in the operating room within 30 minutes of resection. After opening the bowel, 0.5 ml of patent blue dye was injected submucosally at four sites immediately adjacent to the tumor (2 ml). The pathologic examination of the sentinel nodes and of an equal number of nonsentinel nodes consisted of standard hematoxylin and eosin sectioning, followed by multiple sectioning for further hematoxylin and eosin staining and immunohistochemistry if initial samples did not show tumor metastases.

RESULTS

A total of 58 tumors in 57 patients were studied. One or more sentinel nodes were found in relation to 56 tumors, with one of the two failures being attributed to gross mesenteric metastases obstructing lymphatic flow. A mean of 2.93 (0-8) sentinel nodes were found per patient. There was concordance between the sentinel nodes and nonsentinel nodes in 43 patients (76.8 percent). There were nine false-negative sentinel nodes (16 percent). Two patients were upstaged by detailed pathologic examination of the sentinel nodes (micrometastases), and in a further two patients the sentinel node was the only positive node on simple hematoxylin and eosin sectioning.

CONCLUSIONS

The technique of ex vivo sentinel node mapping is feasible and accurate in defining sentinel nodes in colorectal cancer. There is, however, a significant false-negative rate making the sentinel nodes not representative of the lymph node basin. This precludes the use of this technique in routine clinical practice. There may be a role in a research setting to help define the prognostic significance of micrometastases.

Clinical value of immunohistochemically detected lymphovascular invasion in endometrioid endometrial cancer

INTRODUCTION

Lymphovascular Invasion (LVSI) of tumour cells is marked as an important step in the process of tumour metastases and is an important prognostic factor in Endometrial Cancer (EC). Currently, the standard method for assessing LVSI is light microscopic examination of H&E stained sections. Tumour cells within lymphovascular spaces can evade detection on H&E staining if they are present in very small numbers or surrounded by a greater number of circulating cells. Dual immunostaining for epithelial and endothelial cell markers cell markers has been shown to increase detection rate of LVSI significantly.

OBJECTIVES

To investigate the clinical significance of LVSI as detected by H&E (LVSI-H&E) and immunohistochemically (LVSI-IHC) in clinically stage I endometrioid EC patients. Methods. Single representative section of 90 patients with stage I endometriod EC were immunostained in accordance with established streptavidin-biotin peroxidase method using a mouse monoclonal pancytokeratin (PCK), clone AE1/AE3 and CD31 endothelial cell marker. The H&E sections and their corresponding immunostained sections were re-examined to identify LVSI. Clinical records were available on 72 patients. The following data were collected: age, race, parity, presentation, associated medical disorders (obesity, diabetes and hypertension), use of Tamoxifen or HRT, menopausal state, recurrence and survival.

RESULTS

Overall, LVSI was present in 45 (50%) cases and absent in 45 (50%) cases on IHC, as compared with 17 (19%) and 73 (81%) cases, respectively, on H&E. Statistical analysis revealed significant association between LVSI-H&E and depth of myometrial invasion (P < 0.0001). The median follow-up period was 161 months (range 5-207 months). During the follow-up period, six of 14 cases with evidence of LVSI-H&E presented with recurrence as opposed to six of 58 patients with no evidence (OR = 6.26, 95%: CI = 1.3-30.6). There was a significant association between tumour recurrence rate and LVSI-H&E (P = 0.01). The 5-year recurrence-free survival was 54% for the group with H&E evidence of LVSI (95%: CI = 44-64%) compared with 89% for the group without (95%: CI = 82-97%). There was a significant difference in the recurrence-free survival between the two groups (Chi-square = 6.96, P = 0.008). In contrast, LVSI-IHC was found to be significantly associated only with high-grade tumours (P = 0.01) and survival analysis revealed no statistically significant association with recurrence or survival.

CONCLUSIONS

LVSI-H&E in stage I EC remains an important predictive factor of recurrent disease and reduced disease-free interval. Immunohistochemically detected LVSI is a common event, associated with tumour grade and appears to be of no statistically significant clinical value.