Sentinel node biopsy in gastrointestinal-tract cancer

Near-Infrared Fluorescence Image-Guided Surgery in Esophageal and Gastric Cancer Operations

Background

Near-infrared fluorescence image-guided surgery helps surgeons to see beyond the classical eye vision. Over the last few years, we have witnessed a revolution which has begun in the field of image-guided surgery.

Purpose, and Research design

Fluorescence technology using indocyanine green (ICG) has shown promising results in many organs, and in this review article, we wanted to discuss the 6 main domains where fluorescence image-guided surgery is currently used for esophageal and gastric cancer surgery.

Study sample and data collection

Visualization of lymphatic vessels, tumor localization, fluorescence angiography for anastomotic evaluation, thoracic duct visualization, tracheal blood flow analysis, and sentinel node biopsy are discussed.

Conclusions

It seems that this technology has already found its place in surgery. However, new possibilities and research avenues in this area will probably make it even more important in the near future.

Sentinel node biopsy using blue dye and technetium99 in advanced gastric cancer: anatomical drainage and clinical application

Lymph node metastases are an independent prognosis factor in gastric carcinoma (GC) patients. Radical lymphadenectomy can improve survival but it can also increase surgical morbidity. As a principle, sentinel node (SN) navigation surgery can avoid unnecessary lymphadenectomy without compromising prognosis. In this pilot study, 24 patients with untreated GC were initially screened for SN navigation surgery, of which 12 were eligible. Five patients had T2 tumors, 5 had T3 tumors and 2 had T1 tumors. In 33% of cases, tumor diameter was greater than 5.0 cm. Three hundred and eighty-seven lymph nodes were excised with a median of 32.3 per patient. The SN navigation surgery was feasible in all patients, with a median of 4.5 SNs per patient. The detection success rate was 100%. All the SNs were located in N1 and N2 nodal level. In 70.9% of cases, the SNs were located at lymphatic chains 6 and 7. The SN sensitivity for nodal staging was 91.6%, with 8.3% of false negative. In 4 patients who were initially staged as N0, the SNs were submitted to multisection analyses and immunohistochemistry, confirming the N0 stage, without micrometastases. In one case initially staged as negative for nodal metastases based on SN analyses, metastases in lymph nodes other than SN were found, resulting in a 20% skip metastases incidence. This surgery is a reproducible procedure with 100% detection rate of SN. Tumor size, GC location and obesity were factors that imposed some limitations regarding SN identification. Results from nodal multisection histology and immunohistochemistry analysis did not change initial nodal staging.

Comparing the efficacy of routine H&E staining and cytokeratin immunohistochemical staining in detection of micro-metastasis on serial sections of dye-mapped sentinel lymph nodes in colorectal carcinoma

BACKGROUND

The significance of techniques used for detecting micro-metastasis (MM) or isolated tumor cells (ITCs) is a controversial issue among investigators. We evaluated the different techniques used on sentinel lymph node (SLN) to detect MM/ITCs.

MATERIALS AND METHODS

Ninety-one SLNs of 15 patients underwent serial section with 100 μm interval. In each level, two sections were prepared. One section was stained with H&E and another with anti-cytokeratin antibody (immunohistochemistry). Then the sections were evaluated for detecting MM/ITCs. Results were analyzed by chi-square test.

RESULTS

1656 sections of 91 SLNs of 15 patients were evaluated by a pathologist; MM was found in 1 and ITCs in 1 case. Overall, 2 out of 15 cases (13.3% of the patients) showed MM/ITCs by IHC staining. So, serial section along with using IHC was superior than serial section and routine H&E staining. But it did not affect the 5-year survival of the patients (P = 0.47).

CONCLUSION

Using the combined techniques of serial section and IHC staining could up-stage 13.3% of colon cancer patients who were lymph node negative. In other studies with different combination of serial section, IHC staining, and PCR, investigators were able to find MM/ITCs in 3-39% of the cases. In our study, although serial section and IHC staining could up-stage 13.3% of patients, it could not affect the 5-year survival of the patients.

Sentinel lymph node mapping and biopsy using radioactive tracer in gastric cancer

BACKGROUND

Lymph node metastasis is one of the most important prognostic factors in gastric cancer survival. Sentinel lymph node (SLN) mapping and biopsy may reduce the extension of lymph node dissection by determination of lymph node involvement. The current study prospectively evaluates the feasibility and reliability of SLN biopsy in gastric cancer.

METHODS

A total of 30 patients with gastric cancer with a preoperative imaging stage of T1-T2 or T3, N0 and M0 were enrolled in the study. Furthermore, 2-16 h prior to each operation, (99m) Tc-sulphur colloid solution (0.5 mL, 2 mCi/mL) was endoscopically injected into the submucosal layer around the primary lesion. Lymph nodes were examined using a hand-held gamma probe. Subsequently, a total or subtotal gastrectomy and D2 lymphadenectomy was performed in each patient.

RESULTS

The success rate of SLN biopsy was 100%. Sensitivity, specificity, positive predictive value and negative predictive value were 91.7%, 100%, 100% and 75%, respectively. Both of the two false-negative cases were in the T3 group. In cases of T2 tumours, the sensitivity was 100%.

DISCUSSION

SLN biopsy using a gamma probe in early stage gastric cancer seems to be a safe, feasible and accurate procedure with high sensitivity in predicting regional lymph node involvement.

Sentinel lymph node biopsy using intraoperative indocyanine green fluorescence imaging navigated with preoperative CT lymphography for superficial esophageal cancer

BACKGROUND

The sentinel lymph node (SLN) concept has been gaining attention for gastrointestinal neoplasms but remains controversial for esophageal cancer. This study evaluated the feasibility of SLN identification using intraoperative indocyanine green (ICG) fluorescence imaging (IGFI) navigated by preoperative computed tomographic lymphography (CTLG) to treat superficial esophageal cancer.

METHODS

Subjects comprised 20 patients clinically diagnosed with superficial esophageal cancer. Five minutes after endoscopic submucosal injection of iopamidol around the primary lesion using a four-quadrant injection pattern with a 23-gauge endoscopic injection sclerotherapy needle, three-dimensional multidetector computed tomography was performed to identify SLNs and lymphatic routes. ICG solution was injected intraoperatively around the tumor. Fluorescence imaging was obtained by infrared ray electronic endoscopy. Thoracoscope-assisted standard radical esophagectomy with lymphadenectomy was performed to confirm fluorescent lymph nodes detected by CTLG.

RESULTS

Lymphatic vessels and SLNs were identified preoperatively using CTLG in all cases. Intraoperative detection rates were 100% using CTLG and 95% using IGFI. Lymph node metastases were found in four cases, including one false-negative case with SLNs occupied by bulky metastatic tumor that were not enhanced with both methods. The other 19 cases, including three cases of metastatic lymph nodes, were accurately identified by both procedures.

CONCLUSIONS

Preoperative CTLG visualized the correct number and site of SLNs in surrounding anatomy during routine computed tomography to evaluate distant metastases. Referring to CTLG, SLNs were identified using IGFI, resulting in successful SLN navigation and saving time and cost. This method appears clinically applicable as a less-invasive method for treating superficial esophageal cancer.

High FOXP3+ regulatory T-cell density in the sentinel lymph node is associated with downstream non-sentinel lymph-node metastasis in gastric cancer

Background:

We aimed to evaluate the immunologic nature of sentinel lymph nodes (SLNs) in gastric cancer patients and to determine whether it can predict non-SLN metastasis.

Methods:

Sentinel lymph node samples were collected from 64 gastric carcinoma patients who had undergone gastrectomy with SLN biopsy. One representative SLN sample was selected from each patient and was subjected to immunostaining for CD8, CD57, FOXP3, and DC-LAMP. The numbers of marker-positive cells in each sample were counted. The relationships between various immune cell densities and clinicopathologic parameters or metastasis status of SLNs and non-SLNs were sought.

Results:

High FOXP3+ Treg density of the SLN was found to be significantly associated with the presence of metastasis in either SLNs or non-SLNs. DC-LAMP+ cell density of the SLN was the highest at the isolated tumours cell level, and this decreased along with an increase in tumour metastasis in either SLNs or non-SLNs. Univariate and multivariate logistic regression models revealed that high FOXP3+ Treg density of the SLN was an independently significant predictor of non-SLN metastasis.

Conclusions:

This study is the first to indicate an important role of SLNs in metastatic dissemination of gastric cancer. Our findings suggest that Tregs could be a new therapeutic target for regulating the metastasis of gastric cancer.

Is the sentinel node biopsy clinically applicable for limited lymphadenectomy and modified gastric resection in gastric cancer? A meta-analysis of feasibility studies

BACKGROUND

Sentinel node biopsies (SNBs) have been clinically applied in melanoma and breast cancer for limited lymphadenectomy. However, the use of SNB remains controversial in gastric cancer due to unsatisfactory sensitivity and variability. This meta-analysis was performed to determine the sensitivity of SNB in gastric cancer and to identify factors that improve its sensitivity.

METHODS

Feasibility studies on SNB in gastric cancer were searched for from 2001 to 2009 in Pubmed, Cochrane, and Embase. Forty-six reports, which included 2,684 patients, were found. Estimated sensitivities, detection rates, and negative (NPV), and positive predictive values (PPV) were calculated using a random effects model. Inter-study heterogeneity, meta-regression, and subgroup analysis for sensitivity was performed.

RESULTS

The estimated sensitivity, detection rate, NPV, and PPV were 87.8%, 97.5%, 91.8%, and 38.0%, respectively, with significant inter-study heterogeneity (P < 0.0001). However, no significant contributor to heterogeneity was identified. By subgroup analysis, sensitivity was found to depend significantly on the number of SNs harvested.

CONCLUSIONS

SNB in gastric cancer is probably not clinically applicable for limited lymphadenectomy due its unsatisfactory sensitivity and heterogeneity between practicing surgeons. To improve sensitivity, more than four SNs should be harvested, and a tumor specific SNB method should be developed.

Computed tomography lymphography for the detection of sentinel nodes in patients with gastric carcinoma

The sentinel node (SN) concept has been found to be feasible in gastric cancer. However, the lymphatic network of gastric cancer may be more complex, and it may be difficult to visualize all the SN distributed in unexpected areas by conventional modalities. In this study, we evaluate the feasibility and efficacy of CT lymphography for the detection of SN in gastric cancer. A total 24 patients with early gastric cancer were enrolled in the study. Three modalities (CT lymphography, dye and radioisotope [RI] methods) were used for the detection of SN. The images of CT lymphography were obtained at 10 min after injection of contrast agents. The SN were successfully identified by CT lymphography in 83.3% of patients; detection rates by the dye and RI methods were 95% and 100%, respectively. Most patients, in whom SN were successfully detected by CT lymphography, had positive results at 5 min after injection of the contrast material. The SN stations detected by CT lymphography were consistent with or included those detected by dye and/or RI methods. In conclusion, CT lymphography for the detection of SN in gastric cancer is feasible and has several advantages. However, based on this initial experience, CT lymphography had a relatively low detection rate compared with conventional methods, and further efforts will be necessary to improve the detection rate and widen the clinical application of CT lymphography for the detection of SN in gastric cancer.

The sentinel node concept in adenocarcinomas of the distal esophagus and gastroesophageal junction

OBJECTIVE

The sentinel node concept is of great value in the treatment of various malignancies. In this study we investigated whether the application of the sentinel node procedure is feasible in esophageal adenocarcinoma and whether it can tailor surgical treatment of the individual patient.

METHODS

In 40 patients with an adenocarcinoma of the distal esophagus or gastroesophageal junction, blue dye was injected around the tumor intraoperatively. Sentinel nodes (blue-stained) and nonsentinel nodes were identified and dissected during transhiatal esophagectomy. In sentinel nodes negative for tumor cells on routine hematoxylin-eosin examination, multilevel sectioning and immunohistochemical staining were performed to search for micrometastases.

RESULTS

The sentinel node procedure was technically successful in 39 of 40 patients (98%). The median number of sentinel nodes identified was 4. Sentinel nodes were present in more than 1 nodal station in 8 patients (21%). In 6 patients in whom the sentinel node was negative for metastasis, nonsentinel nodes were positive for tumor cells (false-negative rate 6/39 = 15%). Micrometastases and isolated tumor cells were detected in 7 of 19 patients (37%) with sentinel nodes, but this finding did not affect the false-negative rate.

CONCLUSION

Detection of sentinel nodes is technically feasible during esophagectomy for cancer. However, given the relatively high false-negative rate of 15% and the high frequency of sentinel nodes in more than 1 nodal station, the clinical relevance of the sentinel node concept (through application of the blue dye technique) in the current treatment of patients with an adenocarcinoma of the distal esophagus or gastroesophageal junction seems limited.

Feasibility of laparoscopic sentinel basin dissection for limited resection in early gastric cancer

BACKGROUND

The clinical applications of sentinel node (SN) biopsies in early gastric cancer are limited because of low sensitivity. Sentinel basin (SB) dissection has been suggested as alternative to SN biopsy to improve sensitivity. The aim of this study was to examine the feasibility of laparoscopic SB dissection.

METHODS

Twenty-one gastric adenocarcinoma patients of cT1N0 were enrolled. Technetium 99 m human serum albumin and indocyanine green were injected into the submucosal layer around tumor using an intraoperative endoscope. Green-stained or radioactive lymphatic basins were detected and defined as SBs. After laparoscopic SB dissection, laparoscopy-assisted gastrectomy with D2 lymphadenectomy was performed. Dissected SB nodes and non-SB nodes were evaluated for metastasis pathologically.

RESULTS

The SB detection rate was 95.2%. Numbers of SBs were one in 6, two in 10, and three in 4 patients. The mean number of SB nodes was 7.0. Two patients with lymph node metastasis were diagnosed by SB dissection. Mean time of laparoscopic SB dissection procedure was 15.2 min.

CONCLUSIONS

Above findings suggest that laparoscopic SB dissection is technically feasible, and it might have better sensitivity than SN biopsy. However, the validity of this procedure should be evaluated in a larger series before being clinically applied.

Radiation dose to surgical staff from positron-emitter-based localization and radiosurgery of tumors

Surgical tissue characterization based on radiotracer uptake has become much more common in recent years, particularly due to the advent of the sentinel lymph node biopsy technique. Radiolabeled pharmaceuticals are used with hand-held gamma-sensitive probes, which are capable of localizing small tumors and lymph nodes that are first identified via scintigraphy. The radiation safety of such radioguided procedures, which typically employ 99mTc, has been well established. Now, with the emergence of 18F-fluorodeoxyglucose (18FDG) as a widely used tracer for PET imaging of cancer patients, there is increasing interest in the possibility of utilizing 18FDG for intraoperative tumor detection. First, though, the exposure to operating room personnel must be shown to be at a safe level. Due to the short half-life of 18F, the exposure rate will vary significantly with the start time post-injection as well as the duration of the procedure. The aim of this investigation is to determine empirically an exposure rate equation that can be integrated to estimate the exposure to a surgeon and assistants, from patients injected with 18FDG, over an arbitrarily chosen time interval. The study was conducted by measuring the radiation exposure rate from hospital in-patients receiving 18FDG-PET scans at various times from one to seven hours post injection; the empirical equation was determined from the plot of exposure rate vs. time for all patients. The resulting effective dose equivalent for the surgeon for typical values of injected activity, delay time and procedure duration was approximately 60 microSv.

Sentinel node biopsy in synovial sarcoma

AIMS

To examine the relevance of sentinel node biopsy in patients with synovial sarcoma.

METHODS

Between July 2004 and February 2007 11 consecutive patients with synovial sarcoma treated in our clinic underwent sentinel node biopsy after a preoperative lymphoscintigraphy. A handheld gamma-probe was used during the procedure to identify the sentinel nodes, which were then resected and submitted for histopathologic evaluation.

RESULTS

At least one sentinel node was identified in every patient. Of a total of 15 sentinels, one was positive and 14 negative. The patient with the positive sentinel underwent a regional lymph node dissection and remains disease-free 17 months later. One patient developed regional nodal metastases despite negative sentinel node biopsy and died 12 months after the procedure. No biopsy-associated complications were observed.

CONCLUSIONS

Sentinel node biopsy can be successfully and safely applied to patients with synovial sarcoma. Further prospective studies are required to determine the optimal treatment approach, the false negative rate and the prognostic significance of a positive sentinel node biopsy.

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.

The application of sentinel lymph node mapping in colon cancer

Lymph node status is the most important prognostic factor for colorectal carcinoma. Complete lymph node dissection has historically been an integral part of the surgical treatment of these diseases. Sentinel lymph node mapping is a newer technology that allows selective removal of the first node draining a tumor. Sentinel node mapping is well accepted for the management of breast carcinoma and cutaneous melanoma, and has resulted in reduced morbidity without adversely affecting survival. Sentinel node mapping is currently being investigated for treatment of colorectal cancers. Recent studies show promise for incorporating the sentinel node mapping technique for treatment of several gastrointestinal malignancies.

Radio-guided sentinel node mapping in patients with superficial esophageal carcinoma: feasibility study

The aim of this study was to assess whether the sentinel node concept could be applicable to clinically early carcinoma of the esophagus. We studied ten consecutive cT1N0 patients who underwent radical esophagectomy with regional lymph node dissection. On the day before surgery, 99m-Tc tin colloid was injected endoscopically around the primary tumor. Lymphoscintigraphy was also performed about three hours after injection. Immediately after surgery, the radioactivity of all dissected lymph nodes was measured with a hand-held gamma probe. The radioactivity and the metastatic status assessed by routine histopathologic examination were compared. A total of six patients had hot spots detected by lymphoscintigraphy, of which the detection rate was 60% (6 of 10). The ex vivo hot node detection rate was 90% (9 of 10). Three patients were found to have metastatic nodes. In one patient, sentinel node mapping failed to identify any hot spot or hot node. In the other two patients, the metastatic nodes did not correspond to hot nodes. The accuracy of hot node status was 77.8% (7 of 9), and the false-negative rate was 100% (2 of 2). The present study showed that radio-guided sentinel node detection is insufficiently reliable at present due to the high false-negative rate and low accuracy.

Current status of sentinel lymph node navigation surgery in breast and gastrointestinal tract

Sentinel lymph node biopsy (SLNB) has been developed as a new diagnostic and therapeutic modality in melanoma and breast cancer surgery. The purpose of the SLNB include preventing the operative morbidity and improving the pathologic stage by focusing on fewer lymph nodes using immunocytochemic and molecular technology has almost achieved in breast cancer surgery. The prognostic meaning of immunocytochemically detected micrometastases is also evaluating in the SLN and bone marrow aspirates of women with early-stage breast cancer. SLNB using available techniques have suggested that the lymphatic drainage of the gastrointestinal tract is much more complicated than other sites, skip metastasis being rather frequent because of an aberrant lymphatic drainage outside of the basin exist. At the moment, the available data does not justify reduced extent of lymphadenectomy, but provides strong evidence for an improvement in tumor staging on the basis of SLNB. Two large scale prospective multi-center trials concerning feasibility of gamma-probe and dye detection for gastric cancer are ongoing in Japan. Recent studies have shown favorable results for identification of SLN in esophageal cancer. CT lymphography with endoscopic mucosal injection of iopamidol was applicable for SLN navigation of superficial esophageal cancer. The aim of surgical treatment is complete resection of the tumor-infiltrated organ including the regional lymph nodes. Accurate detection of SLN can achieve a selection of a more sophisticated tailor made approach. The patient can make a individualized choice from a broader spectrum of therapeutic options including endoscopic, laparoscopic or laparoscopy-assisted surgery, modified radical surgery, and typical radical surgery with lymph node dissection. Ultrastaging by detecting micrometastasis at the molecular level and the choice of an adequate treatment improve the postoperative quality of life and survival. However these issues require further investigation.

Interim results of sentinel node biopsy during laparoscopic gastrectomy: possible role in function-preserving surgery for early cancer

INTRODUCTION

Intraoperative detection of sentinel nodes (SNs) has been used clinically to predict regional lymph node (LN) metastasis in patients with breast cancer and malignant melanoma. Intraoperative lymphatic mapping and SN biopsy can potentially be combined with minimally invasive surgery. However, few reports have demonstrated the validity of SN biopsy during laparoscopic gastrectomy. The aim of this study was to investigate the feasibility and accuracy of laparoscopic lymphatic mapping in predicting LN status in patients with gastric cancer.

METHODS

A total of 35 patients with gastric cancer diagnosed preoperatively as T1, N0 were enrolled. Endoscopic injection of technetium-99m-radiolabeled tin colloid was completed 16 hours before surgery, and radioactive SNs were identified with a gamma probe intraoperatively. Isosulfan blue dye was injected endoscopically during the operation. Laparoscopy-assisted gastrectomy with LN dissection was performed. All resected LNs were evaluated by routine pathology examination.

RESULTS

SNs were detected in 33 (94.3%) of 35 patients. The mean number of SNs was 3.9, and the diagnostic accuracy according to SN status was 97.0% (32/33), as one patient with a false-negative result was observed. The patient with the false-negative specimen was finally diagnosed as having advanced gastric cancer with invasion into the proper muscular layer and severe lymphatic vessel invasion, causing destruction of normal lymphatic flow by the tumor.

CONCLUSIONS

Radio-guided SN mapping during laparoscopic gastrectomy is an accurate diagnostic tool for detecting lymph node metastasis in patients with early-stage gastric cancer. Validation of this method requires further studies on technical issues, including indications, tracers, methods of lymph node retrieval, and diagnostic modalities of metastasis.

Gastroesophageal carcinoma: individualized surgical therapy

During the twentieth century, surgical management of gastroesophageal carcinoma was developed by an establishment of standard procedures with lymph node dissection according to the metastatic distribution. The "fear" of invisible micrometastasis caused surgeons to perform more aggressive resection with lymphadenectomy to control the disease locally. Although several promising results of extensive lymph node dissection have been reported, the prognostic benefits of extensive surgery have not been proven by prospective randomized trials. A novel technology to detect micrometastasis without extensive surgical resection is required to gastroesophageal carcinoma. The lymphatic mapping technique is one of the attractive candidates for a novel tool to approach this issue.

Sentinel node biopsy using dye and isotope double tracers in early gastric cancer

BACKGROUND

The results of sentinel node (SN) biopsy have been improved by the use of dye and isotope double tracers in melanoma and breast cancer. However, the usefulness of this double tracer technique has not been determined in gastric cancer. The aim of this study was to investigate the possibility of improving SN biopsy results by using double tracers in gastric cancer.

METHODS

Sixty-four gastric adenocarcinoma patients preoperatively diagnosed as cT1N0, were enrolled in the study. (99m)Tc tin colloid was injected by preoperative endoscopy, and lymphoscintigraphy was performed prior to operation. After laparotomy, isosulfan blue was intraoperatively injected using an endoscope. Blue-stained or radioactive nodes were identified and defined as SNs. Gastrectomy with D2 lymphadenectomy was performed in all patients. All dissected lymph nodes were evaluated for metastasis by hematoxylin and eosin staining and immunohistochemistry.

RESULTS

SN detection rates using dye, isotope, or both tracers were 95.3%, 84.4%, and 96.9%, respectively, and their corresponding sensitivities were 52.9%, 52.9%, and 70.6%. In the pT1 subset, the sensitivity of the double tracer was 87.5%; and in a subset of tumors with diameter <4.5 cm, this was also 87.5%.

CONCLUSIONS

These findings confirm that SN biopsy results are improved by using double tracers in gastric cancer and suggest that SN biopsy is suitable in cases of small-sized early gastric cancer.

Visualization of lymphatic basin from the tumor using magnetic resonance lymphography with superparamagnetic iron oxide in patients with thoracic esophageal cancer

OBJECTIVE

To evaluate magnetic resonance (MR) lymphography with submucosal injection of superparamagnetic iron oxide (SPIO) for imaging lymphatic pathways from thoracic esophageal cancer.

METHODS

In 24 patients with esophageal cancer, SPIO was injected into the submucosal layer of the peritumoral region endoscopically and MR lymphography was conducted. In study 1, fast spoiled gradient-recalled acquisition using a steady-state (FSPGR) sequence was performed from the neck to the upper abdomen before and at 20, 40, and 60 minutes after injection in 10 patients. In study 2, FSPGR and spin echo T1-weighted images were obtained after injection in 14 patients. Areas scanned were the neck to the upper mediastinum and the upper abdomen.

RESULTS

In study 1, at 20 minutes after injection, the signal of each lymph node appeared attenuated when compared with precontrast images. The signal-to-noise ratio in lymph nodes exhibiting influx of SPIO was significantly lower than that found on precontrast images (P < 0.0005). In study 2, influx to the neck lymph nodes was detected in 8 patients (64.3%), whereas influx to the upper abdominal lymph nodes was detected in 13 (92.9%).

CONCLUSIONS

Magnetic resonance lymphography with SPIO could visualize the lymphatic pathways draining from the injection site and the location of lymph nodes exhibiting influx of SPIO in patients with thoracic esophageal cancer.

Comparative study of the subserosal versus submucosal dye injection method for sentinel node biopsy in gastric cancer

AIMS

To determine the most efficient injection method for a sentinel node (SN) biopsy in gastric cancer.

METHODS

Gastric adenocarcinoma patients without serosal invasion and distant metastasis were prospectively enrolled in this study. Isosulfan blue was injected into the subserosa (SS) of the first set of 71 consecutive patients and an intraoperative endoscopic submucosal (SM) injection of the same dye was injected into the second set of 50 consecutive patients. After the biopsy of blue-stained SNs, a gastrectomy with a D2 lymphadenectomy was performed. All dissected lymph nodes were evaluated for metastasis. The results of the SN biopsies were compared between the SS and SM dye injection methods.

RESULTS

Detection rate (0.92 vs 0.94), mean number of SNs (2.5 vs 2.9) and sensitivity (0.61 vs 0.46) of the SN biopsies were not significantly different between the SS and SM injection methods (P>0.05). The operation time was significantly shorter in the SS than the SM injection method (159.7 vs 172.7 min, P=0.030).

CONCLUSIONS

Both injection methods were equally efficient in their roles for a SN biopsy in gastric cancer. However, the SS injection method was more preferable due to its easy technique and short operation time.

Detection of lymph node micrometastases and isolated tumor cells in sentinel and nonsentinel lymph nodes of colon cancer patients

About 20% to 30% of colon cancer patients classified as node negative by routine hematoxylin-eosin (H&E) staining are found to have micrometastases (MM) or isolated tumor cells (ITC) in sentinel lymph nodes (SLNs) if analyzed by step sections and immunohistochemistry (IHC). Whether SLNs are in this respect representative for all lymph nodes was addressed in this study. SLNs were identified using the intraoperative blue dye detection technique. If all lymph nodes (SLNs and non-SLNs) of a patient were negative by routine H&E staining, they were step-sectioned and analyzed by IHC using pancytokeratin antibodies. We identified at least one SLN in 47 of the 55 patients (85%) and examined a median of 26 lymph nodes per patient (range 10-59). By routine H&E staining, 14 of the 47 patients showed lymph node metastases (30%); the remaining 33 were classified as node-negative. In this group (33 patients), 1011 lymph nodes were analyzed by step sections and IHC: 14 of 70 SLNs. (20%) but only 37 of 941 non-SLNs (4%) had MM/ITC (p < 0.001). Furthermore, 13 of the 33 H&E-negative patients were found to have MM/ITC (39%). In 11 of the 13 patients, MM/ITC were identified in both SLNs and non-SLNs in 1 patient in the SLN only, and in 1 patient in a non-SLN only (sensitivity for the identification of MM/ITC: 92%; negative predictive value: 95%). The SLN biopsy is a valid tool to detect, as well as exclude, the presence of MM/ITC in colon cancer patients. Our results may be of prognostic relevance and influence patient stratification for adjuvant therapy trials.

Endoscopic therapy of early gastric cancer

Endoscopic therapy of early gastric cancer is applicable for differentiated-type mucosal carcinomas that have an extremely low potency of lymph-node metastasis. Among various kinds of endoscopic therapy, endoscopic mucosal resection is the most recommended procedure, because pathological evaluation of affected tissues is available using this method. Recently, endoscopic submucosal dissection, a novel method of endoscopic mucosal resection, has gained interest as a more reliable therapeutic procedure. In the present chapter several issues will be presented on endoscopic therapy for early gastric cancer, including endoscopic diagnosis of early gastric cancer, currently accepted indications of endoscopic therapy, and the possibility of extending the indication and techniques used for mucosal resection.

Extended lymphadenectomy (D2) in patients with early gastric cancer

AIMS

To investigate the survival benefit of extended lymphadenectomy (D2) in EGC patients in one European Institution.

METHODS

A review was made of our prospective gastric database from January 1980 to December 2001. Of 527 patients with primary gastric adenocarcinoma, 119 with EGC underwent potentially curative resection (R0) with D2 lymphadenectomy.

RESULTS

There were two post-operative deaths. Of the 117 evaluable cases, 96 were classified as N0 and 21 as N+, with metastases in the perigastric lymph nodes (level 1) in 13, and beyond this site (level 2) in eight. Five-year survival was 85.9 and 83.0% in N0 and N+ patients, respectively. During a median follow-up of 90 months, five of the eight patients with level 2 metastases died of recurrent disease and three were alive. The estimated survival benefit for 119 patients with EGC was 2.5% (3/119 cases).

CONCLUSIONS

In patients with EGC, metastases to level 2 are rare. Our results indicate that D2 lymphadenectomy has a limited survival benefit and that in these cases a less extensive lymphadenectomy (D1) could be performed.

The feasibility and reliability of sentinel node mapping in colorectal cancer

AIMS

Sentinel node mapping (SNM) has been introduced in colorectal cancer (CRC) to improve staging by facilitating occult tumour cell (OTC) assessment in lymph nodes that are most likely to be tumour-positive. In this paper, studies on the feasibility and reliability of SNM in CRC are reviewed.

METHODS

A literature search was conducted in the National Library of Medicine by using the keywords colonic, rectal, colorectal, neoplasm, adenocarcinoma, cancer and sentinel. Additional articles were identified by cross-referencing from papers retrieved in the initial search.

RESULTS

There is a large variation in identification rates and false-negative rates mainly due to the learning curve effect, differences in SNM technique and tumour stage.

CONCLUSIONS

We conclude that SNM in CRC is technically feasible. Standardization of SNM procedures is mandatory to resolve the debate on the reliability of sentinel node status for predicting the tumour status of all lymph nodes. Only then can adjuvant treatment of patients upstaged by OTC detection in sentinel nodes be justified.

Multimodal treatment of gastrointestinal tract tumors: consequences for surgery

Formerly an exclusive business of surgery, gastrointestinal (GI) tumors are nowadays increasingly approached with multimodal strategies. Neoadjuvant concepts have had a particularly far-reaching impact on surgery and have contributed to improved survival. Modern pre-treatment staging and risk assessment provide the basis for decision on one of three general treatment concepts (1) Early cancers, confined to the mucosal/submucosal layers, are approached with primary surgery, without prior antineoplastic therapy. (2) Systemically metastasized tumors receive merely palliative treatment. (3) Locally advanced cancers are increasingly approached with neoadjuvant strategies. The benefit from these preoperative protocols is proven for diverse entities, but is evidently confined to a specific subgroup patients, i.e., the responders to neoadjuvant treatment. These are the ones benefiting most from subsequent surgical resection, which is required to ensure complete removal of the residual tumor tissue, as complete tumor regression occurs very rarely and cannot be proven without a specimen. The fact that responders will benefit and non-responders will not benefit or will even deteriorate during the neoadjuvant treatment makes early response prediction most demanding. An amazing new approach is the use of position emission tomography with fluro-desoxyglucose (FDG-PET) to assess the "metabolic response," which is possible as early as 14 days after initiation of the neoadjuvant protocol. This strategy offers the chance for modulating the surgical approach in accord i.e., with such metrobolic response termination of the protocol and proceeding to resection in the case of nonresponse. The future of GI cancer surgery is multimodal therapy in a response-based fashion and requires reponse-based trials for further evaluation.

Prognostic relevance of p53 and bcl-2 immunoreactivity for early invasive pT1/pT2 gastric carcinomas: indicators for limited gastric resections?

BACKGROUND

Laparoscopic or endoscopic limited resection is intended to be an additional therapeutic option for the treatment of early gastric cancer. However, tumorbiologic markers to predict the outcome for patients after limited resections are missing. This study therefore investigated the prognostic relevance of p53 and bcl-2 immunoreactivity as well as the percentage of apoptotic tumor cells in early invasive pT1/pT2 tumors managed with standard operations for gastric adenocarcinoma.

METHODS

Histologic slides of 65 pT1/pT2 gastric carcinomas were investigated for bcl-2 and p53 immunoreactivity. For 35 patients, DNA fragmentation of tumor cell nuclei was determined by the terminal uridine 5'-triphosphate (UTP) nick end-labeling (TUNEL) method. Follow-up evaluation of the patients was prospectively documented for 53.4 +/- 4.1 months.

RESULTS

Findings showed that bcl-2 immunoreactivity was associated with tumors of the intestinal type according to Lauren s classification (p = 0.042), and that p53 immunoreactivity was increased in more invasive tumors (pT1 vs pT2 tumors; p = 0.047). Mean survival time was significantly longer for patients with bcl-2-negative tumors (74.3 +/- 6.8 months) than for patients with bcl-2-positive tumors (50.8 +/- 7.6 months; p = 0.024). The percentage of apoptotic tumor cell nuclei did not have prognostic relevance in the population studied and was not associated with several histopathologic parameters or bcl-2 and p53 immunoreactivity. Subgroup analysis indicated that the survival of patients with differentiated G2 and bcl-2-negative/p53-negative tumors was significantly longer (82 +/- 6 months) than the survival of patients with G2 bcl-2- and/or p53-positive tumors (41.8 +/- 12.5 months; p = 0.005), with independent prognostic relevance determined by multivariate analysis (p = 0.024).

CONCLUSION

The data reported indicate that the analysis of bcl-2 and p53 immunoreactivity seems to have prognostic implications for early invasive (pT1/pT2) gastric adenocarcinomas and may subclassify patients for minimally invasive laparoscopic or endoscopic gastric resections.

Organic Alternatives to Quantum Dots for Intraoperative Near-Infrared Fluorescent Sentinel Lymph Node Mapping

Intraoperative near-infrared (NIR) fluorescence imaging provides the surgeon with real-time image guidance during cancer and other surgeries. We have previously reported the use of NIR fluorescent quantum dots (QDs) for sentinel lymph node (SLN) mapping. However, because of concerns over potential toxicity, organic alternatives to QDs will be required for initial clinical studies. We describe a family of 800 nm organic heptamethine indocyanine-based contrast agents for SLN mapping spanning a spectrum from 775 Da small molecules to 7 MDa nanocolloids. We provide a detailed characterization of the optical and physical properties of these contrast agents and discuss the advantages and disadvantages of each. We present robust methods for the covalent conjugation, purification, and characterization of proteins with tetra-sulfonated heptamethine indocyanines, including mass spectroscopic site mapping of highly substituted molecules. One contrast agent, NIR fluorescent human serum albumin (HSA800), emerged as the molecule with the best overall performance with respect to entry to lymphatics, flow to the SLN, retention in the SLN, fluorescence yield and reproducibility. This preclinical study, performed on large animals approaching the size of humans, should serve as a foundation for future clinical studies.