Occult lymph node metastases detected by cytokeratin immunohistochemistry predict recurrence in "node-negative" colorectal cancer

Positive relationship between number of negative lymph nodes and duration of gallbladder cancer cause-specific survival after surgery

Background

Although the prognostic implications of negative lymph nodes (NLNs) has been reported for a variety of tumors, little information has been published about the NLNs in gallbladder cancer (GBC).

Patients and methods

In this study, clinicopathological characteristics and survival times of patients who had undergone surgery for GBC were collected from the Surveillance, Epidemiology, and End Results Program-registered TNM stage database and analyzed. Univariate and multivariate Cox proportional hazards models were used to identify the predictors of survival.

Results

It was found that a cutoff of one to two NLNs is optimal when assessing the association with survival, survival rates being consistently better with two or more NLNs than with fewer than two. This optimal cutoff value of 2 was identified as an independent prognostic factor by univariate and multivariate analyses (all P<0.001). Specifically, patients with two or more NLNs had better 5-year gallbladder cancer cause-specific survival than those with fewer than NLNs examined for stage I/II, stage III/IV, and all TNM stages (all P<0.001).

Conclusion

Our findings indicate that the number of NLNs is an independent prognostic factor after GBC surgery, and, together with the number of positive lymph nodes, this will provide better prognostic information than the number of positive lymph nodes alone.

Lymph node micrometastasis in gallbladder cancer

BACKGROUND

Prognosis of gallbladder cancer (GBC) is grim even after curative surgery. Lymph node metastasis is the most important prognostic factor, but distant relapses occurring in their absence point towards additional factor. Lymph node micrometastasis could be one. The present study aimed to evaluate the incidence and clinical significance of lymph node micrometastasis.

METHODS

This is a prospective study of patients undergoing curative surgery for GBC from 1 March 2013 to 30 April 2015, at our institute. All lymph nodes were examined with hematoxylin and eosin and immunohistochemistry against CK7. The incidence of lymph node and its relation to other clinicopathological parameters, recurrence, and survival was evaluated.

RESULTS

Out of 589 lymph nodes retrieved from 40 patients, metastasis was seen in 13 (2.20%) nodes from 8 (20%) patients and micrometastasis in 4 (0.68%) nodes from 3 (7.5%) patients. Micrometastases were absent in pT1 tumors (0/10 in pT1 vs. 3/30 in pT2-4) and more common in patients with nodal metastasis (13% vs. 6%). Though the presence of micrometastasis would have upstaged the disease, it did not statistically relate to clinicopathological parameters, recurrence, and survival.

CONCLUSIONS

Incidence of lymph node micrometastasis in GBC was low and did not correlate with other clinicopathological parameters, recurrence, and survival.

Molecularly determined total tumour load in lymph nodes of stage I-II colon cancer patients correlates with high-risk factors. A multicentre prospective study

Stage I–II (pN0) colorectal cancer patients are surgically treated although up to 25 % will eventually die from disease recurrence. Lymph node (LN) status is an independent prognostic factor in colorectal cancer (CRC), and molecular tumour detection in LN of early-stage CRC patients is associated with an increased risk of disease recurrence and poor survival. This prospective multicentre study aimed to determine the relationship between LN molecular tumour burden and conventional high-risk factors in stage I–II colon cancer patients. A total of 1940 LN from 149 pathologically assessed pN0 colon cancer patients were analysed for the amount of tumour cytokeratin 19 (CK19) messenger RNA (mRNA) with the quantitative reverse transcription loop-mediated isothermal amplification molecular assay One-Step Nucleic Acid Amplification. Patient’s total tumour load (TTL) resulted from the sum of all CK19 mRNA tumour copies/μL of each positive LN from the colectomy specimen. A median of 15 LN were procured per case (IQR 12;20). Molecular positivity correlated with high-grade (p < 0.01), mucinous/signet ring type (p = 0.017), male gender (p = 0.02), number of collected LN (p = 0.012) and total LN weight per case (p < 0.01). The TTL was related to pT stage (p = 0.01) and tumour size (p < 0.01) in low-grade tumours. Multivariate logistic regression showed independent correlation of molecular positivity with gender, tumour grade and number of fresh LN [AUC = 0.71 (95 % CI = 0.62–0.79)]. Our results show that lymph node CK19 mRNA detection correlates with classical high-risk factors in stage I–II colon cancer patients. Total tumour load is a quantitative and objective measure that may help to better stage early colon cancer patients.

Clinical impact of minimal cancer cell detection in various colorectal cancer specimens

Detection of cancer cells using molecular targets is achieved by combining immunochemical reactions with gene amplification techniques. This enables the detection of cancer cells in specimens that are traditionally determined to be cancer-free. These improvements in detection can lead to prognoses that are different from those derived by conventional pathological staging. Survival is worse when cancer cells are detected in regional lymph nodes compared to when the nodes are cancer-free. Furthermore, the circulating tumor cell (CTC) count increases as the cancer progresses. Consequently, there is a correlation between CTC count and prognosis. However, large-scale prospective studies are required to confirm this. The development of more convenient and cost-effective analysis techniques will facilitate the practical application of these findings.

Prognostic significance of EpCAM-positive disseminated tumor cells in rectal cancer patients with stage I disease

Here we evaluated the prevalence and prognostic impact of epithelial cell adhesion molecule (EpCAM)-positive disseminated tumor cells (DTCs) in stage I rectal cancer. Further we tested the association of these single tumor cells or small tumor cell groups with the extent of peritumoral lymphangiogenesis. A total of 845 regional lymph nodes (LN) of 44 patients classified as negative on conventional histopathology were retrospectively reanalyzed with immunohistochemistry (IHC) using the monoclonal antibody Ber-Ep4 directed against EpCAM for the detection of DTCs. The degree of lymphangiogenesis in the primary tumors was assessed by IHC of the primary tumor tissue using the monoclonal antibody D2-40, which reacts with the lymphatic endothelium. The IHC results were correlated with clinico-pathologic parameters and clinical follow-up data. EpCAM-positive DTCs in LNs were detected in 8 (18.2%) of the 44 patients. During a median follow-up of 59 months, 3 (37.5%) of the 8 patients with EpCAM-positive DTCs relapsed, whereas none of the DTC-negative patients developed tumor recurrence (P=0.004). Survival analysis revealed a significant effect of the prevalence of DTCs on overall survival (P=0.0009) and on recurrence-free survival (P=0.0001). Finally, the prevalence of EpCAM-positive DTCs in perirectal LNs was significantly correlated with a high density of peritumoral lymphatic vessels (P=0.015). Our results show that DTCs may occur in stage I of rectal cancer and are associated with poor prognosis. Their occurrence seems to be linked to a high density of newly formed lymphatic vessel at the primary tumor site. According to our data, patients with DTCs in their LN might benefit from adjuvant therapy.

An optimal mRNA marker for OSNA (One-step nucleic acid amplification) based lymph node metastasis detection in colorectal cancer patients

BACKGROUND

We previously reported that the one-step nucleic acid amplification assay is effective for lymph node metastasis detection in breast cancer patients. This paper describes the identification of CK19 mRNA as an optimal marker and its cut-off value for use in the detection of one-step nucleic acid amplification-based lymph node metastasis in colorectal cancer patients.

METHODS

Candidate mRNA markers selected from the genome-wide expressed sequence tag database were evaluated by quantitative RT-PCR using a mixture of metastasis-positive and another mixture of metastasis-negative lymph nodes (n = 5 each), followed by quantitative RT-PCR using metastasis-positive and -negative lymph nodes (n = 10 each) from 20 patients. The one-step nucleic acid amplification assay for mRNA markers selected above was examined using 28 positive lymph nodes from 19 patients and 38 negative lymph nodes from the 11 pN0 patients.

RESULTS

Quantitative RT-PCR analyses of the 98 mRNAs selected from the genome-wide expressed sequence tag database and the subsequent quantitative RT-PCR analyses of the nine mRNAs selected above indicated that CK19 and CEA mRNAs have the highest capability for distinguishing between positive and negative lymph nodes. CK19, CEA and CK20 mRNAs were evaluated by the one-step nucleic acid amplification assay. An area under a receiver-operating-characteristic curve for CK19 mRNA (0.999) was slightly larger than that for CEA mRNA (0.946; P = 0.062) and significantly larger that than for CK20 mRNA (0.875; P = 0.006).

CONCLUSION

We found that CK19 mRNA has the best diagnostic performance and its cut-off value for discriminating positive from negative lymph nodes can be set in the range of 75-500 copies/µl with 96.4% sensitivity and 100% specificity.

Isolated tumor cells in regional lymph nodes as relapse predictors in stage I and II colorectal cancer

PURPOSE

Lymph node (LN) involvement is the most important prognostic factor in colorectal cancer (CRC), and pN-positive status identifies patients who require adjuvant chemotherapy. Approximately 15% to 20% of patients without nodal metastases (pN0) develop recurrent disease. In this study, we tested the prognostic significance of isolated tumor cells (ITCs) in LNs of patients with pN0 CRC (stages I and II).

PATIENTS AND METHODS

ITCs in LNs regional to CRC were assessed in 312 consecutive patients with pN0 CRC who were followed up clinically and/or endoscopically for at least 6 months after surgery (mean, 67 months; median, 64 months; range, 8 to 102 months). LNs were dissected from gross surgical specimens according to a standardized protocol (with a mean of 17 LNs per patient; range, five to 107 LNs). In all, 5,313 pN0 LNs were collected and assessed by using cytokeratin immunostaining in two serial histology sections from each LN, which amounting to a total of 10,626 specimens. The correlation between ITC status and cancer recurrence was tested by using univariate and multivariate statistics.

RESULTS

ITCs were documented in 185 of 312 patients (59%). CRC relapsed in 31 of 312 patients (10%), and 25 of 31 recurrences (81%) were documented among ITC-positive patients. CRC recurrence rates among ITC-positive and ITC-negative patients were 14% (25 of 185 patients) and 4.7% (six of 127 patients), respectively. In both univariate and multivariate analyses, ITC status was the only variable significantly associated with cancer relapse (Cox model; hazard ratio, 3.00; 95% CI, 1.23 to 7.32; P = .013).

CONCLUSION

In patients with pN0 CRC, cancer relapse was significantly associated with ITCs in regional LNs. ITCs should be considered among the clinicobiologic variables that identify high-risk patients who can benefit from adjuvant chemotherapy.

Immunohistochemical assessment of lymphovascular invasion in stage I colorectal carcinoma: prognostic relevance and correlation with nodal micrometastases

Several studies have suggested that the presence of occult nodal metastases (micrometastases) is related to adverse clinical course in stage I colorectal carcinoma. Herein we analyzed the correlation between nodal micrometastases and lymphovascular invasion (LVI) or lymphatic vessel density (LVD) in a series of stage I colorectal carcinomas; the cohort included cases characterized or not characterized by disease progression during the follow-up. In these cases, LVI and LVD were evidenced through the immunohistochemical detection of the specific marker for lymphatic vessels, D2-40. LVI was significantly more frequent in colorectal carcinomas characterized by the presence of micrometastases (P<0.0001), high peritumoral LVD (P<0.0001), and disease progression (P<0.0001). The analysis for progression risk indicated that nodal micrometastases and LVI were significant, negative, independent prognostic parameters associated with shorter disease-free survival of stage I colorectal cancer (P=0.0001; P=0.0242). In conclusion, in this study we demonstrated for the first time that LVI is significantly associated with nodal occult metastases in stage I colorectal carcinoma. In the light of its significant, independent, prognostic value in this neoplasia, the detection of LVI may represent a faster and cheaper tool compared with the time-consuming evaluation of micrometastases to select high-risk patients who may benefit from adjuvant systemic treatment. Furthermore, the assessment of LVI may be applied to establish the likelihood of nodal involvement from carcinomas treated with conservative local excision techniques, which provide no regional nodes for histologic examination.

Molecular detection of tumor cells in regional lymph nodes is associated with disease recurrence and poor survival in node-negative colorectal cancer: a systematic review and meta-analysis

PURPOSE

Up to 25% of patients with node-negative colorectal cancer (CRC) on conventional histopathologic analysis ultimately die of recurrent disease. We performed a systematic review with meta-analyses to clarify whether molecular detection of isolated tumor cells or micrometastases in regional lymph nodes indicates high risk of disease recurrence and poor survival in node-negative CRC.

METHODS

The following databases were searched in August 2011 to identify studies on the prognostic significance of molecular tumor-cell detection in regional lymph nodes of node-negative CRC: MEDLINE, BIOSIS, Science Citation Index, EMBASE, CCMed, and publisher databases. We extracted hazard ratios (HRs) and associated 95% CIs from the identified studies and performed random-effects model meta-analyses on overall survival, disease-specific survival, and disease-free survival.

RESULTS

A total of 39 studies with a cumulative sample size of 4,087 patients were included. Immunohistochemistry, reverse transcriptase polymerase chain reaction, and both techniques were applied in 30, seven, and two studies, respectively. Thirteen studies were graded with low risk of bias. Meta-analyses revealed that molecular tumor-cell detection in regional lymph nodes was associated with poor overall survival (HR, 2.20; 95% CI, 1.43 to 3.40), disease-specific survival (HR, 3.37; 95% CI, 2.31 to 4.93), and disease-free survival (HR, 2.24; 95% CI, 1.57-3.20). Subgroup analyses showed the prognostic significance of molecular tumor-cell detection of being independent of the applied detection method, molecular target, and number of retrieved lymph nodes.

CONCLUSION

Molecular detection of occult disease in regional lymph nodes is associated with an increased risk of disease recurrence and poor survival in patients with node-negative CRC.

Lymph node micrometastasis and survival of patients with Stage I (Dukes' A) colorectal carcinoma

OBJECTIVE

Although patients with Stage I colorectal cancer show an excellent prognosis, a few of them die of metastatic disease. In this subgroup of individuals, the search of occult metastasis might reveal that early dissemination of tumor cells could be the cause of cancer progression.

MATERIAL AND METHODS

Through a Cancer Registry, we selected all patients with Stage I disease who died of metastatic tumor; a total of 32 patients were identified and in 25 of them paraffin-embedded material was available. The group was matched to 70 Stage I patients with favorable prognosis (controls). In cases and controls resected lymph nodes were cut, and micrometastases were searched using pan-cytokeratin antibodies.

RESULTS

Micrometastases were detected in 18 of 25 (72%) Stage I patients who died of the disease, while they were almost absent among controls (1 of 70, p < 0.001 by χ(2) test). Vascular invasion and tumor budding were more frequent among Stage I patients with an unfavorable prognosis than in controls. By regression analyses, micrometastases (HR 12.3, CI 4.8-32) and vascular invasion (HR 3.5, CI 1.4-8.5) maintained an independent association with prognosis (cancer-specific survival).

CONCLUSION

Micrometastasis in the lymph nodes can be revealed in the majority of patients with early colorectal cancer who die of tumor progression, while they appear extremely rare in Stage I individuals with good prognosis. The selection of patients through histology (vascular invasion) and search of occult metastatic cells might represent a way to identify individuals who might benefit from adjuvant chemotherapy.

Impact on Prognosis of Lymph Node Micrometastasis and Isolated Tumor Cells in Stage II Colorectal Cancer

Purpose

Even though the importance of micrometastases (MMS) and isolated tumor cells (ITC) has been brought up by many physicians, its impact on the prognosis in stage II colorectal cancer is uncertain. In this research, we tried to investigate the clinical features of MMS and ITC and to prove any correlation with prognosis.

Methods

The research pool was 124 colorectal cancer patients who underwent a curative resection from April 2005 to November 2009. A total of 2,379 lymph nodes (LNs) were examined, and all retrieved LNs were evaluated by immunohistochemical staining with anti-cytokeratin antibody panel. Clinicopathologic parameters and survival rates were compared based on the presence of MMS or ITC and on the micrometastatic lymph node ratio (mmLNR), which is defined as the number of micrometastatic LNs divided by the number of retrieved LNs.

Results

Out of 124 patients (26.6%) 33 were found to have MMS or ITC. There were no significant differences in clinicopathologic features, such as gender, tumor location and size, depth of invasion, histologic grade, except for age (P = 0.04). The three-year disease-free survival rate for the MMS or ITC positive group was 85.7%, and that for MMS and ITC negative group was 92.8% (P = 0.209). The three-year disease-free survival rate for the mmLNR > 0.25 group was 73.3%, and that for the mmLNR ≤ 0.25 group was 92.9% (P = 0.03).

Conclusion

The presence of MMS or ITC was not closely correlated to the prognosis. However, mmLNR is thought to be a valuable marker of prognosis in cases of stage II colorectal cancer.

Entire-volume serial histological examination for detection of micrometastases in lymph nodes of colorectal cancers

The purpose of this study was to accurately detect lymph-node micrometastases, i.e., metastatic cancer foci that have a size between 2.0 and 0.2 mm, in nodes excised from colorectal cancer (CRC) patients, and to determine how frequently micrometastases might be missed when standard histological examination procedures are used. A total of 311 lymph nodes were removed and examined from 90 patients with Stage I to IV CRC. The number of slices of histology sections ranged from 6 to 75 per node (average = 25.5; SD = 11.1), which provided a total of 7,943 slices. Lymph nodes were examined in their entire volume at every 50-μm and 100-μm intervals for nodes smaller and larger than 5 mm respectively. The total number of thin sections examined in each node and the number of thin sections where metastatic foci were present were counted. The number of thin sections with metastatic foci and the total number of slices was determined for each node. In addition, the presence or absence of metastatic foci in the "central" slice was determined. Micrometastases were found in 12/311 (3.9%) of all lymph nodes. In the 12 lymph nodes with micrometastases, the rate of metastatic slices over all slices was 39.4% (range = 6.3 to 81.3%; SD = 25.8%) In the central slice of each node, micrometastases were present only in 6 of 12 lymph nodes (50%); accordingly, they were not present in the central slice for half the micrometastatic nodes. These 6 nodes represented 1.9% of the 311 nodes and 11.1% of the 54 metastatic nodes. This study suggests that a significant fraction of micrometastases can be missed by traditional singleslice sectioning; half of the micrometastases would have been overlooked in our data set of 311 nodes.

Detailed examination of lymph nodes improves prognostication in colorectal cancer

Up to 30% of stage II patients with curatively resected colorectal cancer (CRC) will develop disease recurrence. We evaluated whether examination of lymph nodes by multilevel sectioning and immunohistochemical staining can improve prognostication. Lymph nodes (n = 780) from 36 CRC patients who had developed disease recurrence (cases) and 72 patients who showed no recurrence of disease for at least 5 years (controls) were analyzed. Sections of 4 levels at 200-microm interval were immunohistochemically stained for cytokeratin expression. The first level was analyzed by conventional and automated microscopy, and the 3 following levels were analyzed by automated microscopy for the presence of tumor cells. Overall, cases showed more micrometastases (3 patients) than controls (1 patient). Analysis of a second level led to the additional detection of 1 patient with micrometastases (case) and 1 patient with macrometastasis (case). Examining more levels only led to additional isolated tumor cells, which were equally divided between cases and controls. Likewise, automated microscopy resulted only in detection of additional isolated tumor cells when compared with conventional microscopy. In multivariate analysis, micrometastases [odds ratio (OR) 26.3, 95% confidence interval (CI) 1.9-364.8, p = 0.015], T4 stage (OR 4.8, 95% CI 1.4-16.7, p = 0.013) and number of lymph nodes (OR 0.9, 95% CI 0.8-1.0, p = 0.028) were independent predictors for disease recurrence. Lymph node analysis of 2 levels and immunohistochemical staining add to the detection of macrometastases and micrometastases in CRC. Micrometastases were found to be an independent predictor of disease recurrence. Isolated tumor cells were of no prognostic significance.

Predictors of occult nodal metastasis in colon cancer: results from a prospective multicenter trial

BACKGROUND

The relationship between primary colon cancer and occult nodal metastases (OMs) detected by cytokeratin immunohistochemistry (CK-IHC) is unknown. We sought to investigate the correlation of clinicopathologic features of colon cancer with OMs and to identify predictors of OM.

METHODS

Patients with colon cancer from 5 tertiary referral cancer centers enrolled in a prospective trial of staging had standard pathologic analysis performed on all resected lymph nodes (using hematoxylin and eosin staining [H&E]). Nodes negative on H&E underwent CK-IHC to detect OMs, which were defined as micrometastases (N1mic) or isolated tumor cells (N0i+). Patients who were negative on both H&E and CK-IHC were defined as node negative (NN), and those positive on H&E were node positive (NP). The relationships between tumor characteristics and OMs were analyzed using the Kruskal-Wallis and the Fisher exact test.

RESULTS

OMs were identified in 23.4% (25/107) of patients. No significant differences were found in demographics, tumor location, tumor size, and number of nodes examined between groups. Compared with the NN group, patients with OMs had more tumors that were T3/T4 (72% vs 57%; P < .001), had tumors of higher grade (28% vs 12%; P = .022), and had tumors with lymphovascular invasion (16% vs 3%; P < .001).

CONCLUSION

Adverse primary pathologic colon cancer characteristics correlate with OMs. In patients with negative nodes on H&E and stage T3/T4 colon cancer, lymphovascular invasion, or high tumor grade, consideration should be given to performing CK-IHC. The detection of OMs in this subset may influence decisions regarding adjuvant chemotherapy and risk stratification.

Total number of resected lymph nodes predicts survival in esophageal cancer

OBJECTIVE

Several population-based studies have shown that the total number of surgically removed lymph nodes is independently associated with overall and disease-free survival in a variety of gastrointestinal cancers. In this retrospective study, the impact of total nodal count on overall survival in esophageal cancer was examined using a single institution surgical database.

METHODS

We conducted a retrospective review of 264 patients with esophageal cancer treated by esophagectomy without neoadjuvant therapy between January 1988 and December 2006. The association between overall survival (the primary endpoint) and the total number of dissected lymph nodes was evaluated using multivariable Cox regression models.

RESULTS

When the total number of resected nodes was examined as a categorical variable based on quartiles (category 1: < or = 16, category 2: 17-25, category 3: 26-40, category 4: > 40) there was a reduced hazard of death with increasing number of examined nodes. Compared with those in category 1, the death hazard was reduced by 34% (P = 0.08), 48% (P = 0.001), and 49% (P = 0.001), respectively, for patients in categories 2, 3, and 4. For node negative patients a significantly reduced hazard was present only when more than 40 nodes were resected (HR = 0.23, P = 0.01). For node positive patients the death hazard was significantly reduced for those in all higher categories compared with those in category 1 (HR = 0.53, 0.39, 0.49; P = 0.03, 0.001, 0.02, respectively).

CONCLUSION

These data support the findings from population based studies in esophageal cancer and other gastrointestinal tumors, suggesting that a higher nodal count favorably influences survival.

Clinical significance of lymph node micrometastasis in stage I and II colon cancer

PURPOSE

A 25% rate of recurrence after performing complete resection in node-negative colon cancer patients suggests that their nodal staging is frequently suboptimal. Moreover, the value of occult cancer cells in tumor-free lymph nodes still remains uncertain. The authors evaluated the prognostic significance of the pathologic parameters, including the lymph node occult disease (micrometastases) detected by immunohistochemistry, in patients with node-negative colon cancer.

MATERIALS AND METHODS

The study included 160 patients with curatively resected stage I or II colon cancer and they were without rectal cancer. 2852 lymph nodes were re-examined by re-do hematoxylin and eosin (H-E) staining and immunohistochemical staining. The detection rates were compared with the clinicopathologic characteristics and with the cancer-specific survival.

RESULTS

Occult metastases were detected in 8 patients (5%). However, no clinicopathologic parameter was found to be correlated with the presence of micrometastasis. Twenty patients developed recurrence at a median follow-up of 45.7 months: 14 died of colon cancer and 9 died from noncancer-related causes. Univariate analysis showed that lymphatic invasion and the number of retrieved lymph nodes significantly influenced survival, and multivariate analysis revealed that the stage, the number of retrieved lymph nodes and lymphatic invasion were independently related to the prognosis.

CONCLUSIONS

Inadequate lymph node retrieval and lymphatic invasion were found to be associated with a poorer outcome for node-negative colon cancer patients. The presence of immunostained tumors cells in pN0 lymph nodes was found to have no significant effect on survival, but these tumor were identified by re-do H-E staining. Maximal attention should be paid to the total number of lymph nodes that are retrieved during surgery for colon cancer patients.

Detection of sentinel and non-sentinel lymph node micrometastases by complete serial sectioning and immunohistochemical analysis for gastric cancer

BACKGROUND

We investigated the presence and distribution of the sentinel and the non-sentinel node micrometastases using complete serial sectioning and immunohistochemical staining (IHC), to inspect whether lymph node micrometastases spread to the sentinel lymph nodes first.

METHODS

A total of 35 patients, who underwent gastrectomy with a sentinel lymph node biopsy for gastric cancer, were enrolled in this study. Total of 1028 lymph nodes of 35 patients having gastric cancer without metastasis of lymph node by permanent section with hematoxylin and eosin staining (H&E) were selected. There were 252 sentinel nodes and the other 776 were non-sentinel nodes. All nodes were sectioned serially and stained alternately with H&E and IHC. Lymph node micrometastases was defined as proving to be positive first either the IHC or the complete serial sectioning.

RESULTS

Micrometastases were detected in 4 (11%) of the 35 patients, 6 (0.58%) of 1028 nodes. Of these 4 patients, 3 had micrometastases exclusively in sentinel nodes, and the other had micrometastasis in both sentinel and non-sentinel nodes. There was no patient who had the micrometastases only in non-sentinel nodes.

CONCLUSION

These results support the concept that lymph node micrometastasis of gastric cancer spreads first to sentinel nodes.

The significances of lymph node micrometastasis and its correlation with E-cadherin expression in pT1-T3N0 gastric adenocarcinoma

BACKGROUND

Recently, micrometastasis (MM) in the lymph node in gastric cancer has been detected by cytokeratin immunostaining. However, clinical significance of MM and its relationship with reduced expression of E-cadherin in primary lesion have not been well studied.

METHODS

The 4,990 lymph nodes from 184 pT1~T3N0 patients from 1995 to 2000 at Korea University Hospital were immunostained with the anticytokeratin AE1/3 antibody for detection of micometastasis. The primary lesions were also immunostained for E-cadherin expression.

RESULTS

MM in the lymph node of gastric cancer was found in 131 (2.6%) of total dissected nodes, and 31 of 184 patients (16.8%) were shown to have MM. The MM was significantly correlated with the depth of invasion, tumor size, operation method, Lauren classification, lymphovascular invasion and loss of E-cadherin expression in primary tumor. On multivariate analysis, the independent risk factors for MM were the depth of invasion and loss of E-cadherin expression. The patients with MM had significantly lower 5-year overall and disease free survival rate than those without MM.

CONCLUSION

Lymph node MM in histologically node-negative gastric cancer was significantly correlated with poor 5-year survival rate. The determination of E-cadherin expression in primary gastric tumor may be useful in prediction of the MM.

The biologic significance of micrometastatic disease and sentinel lymph node technology on colorectal cancer

The sentinel lymph node (SLN) technique has practical applications in multiple solid tumors including colorectal carcinoma. Identifying the SLN(s) provides better staging of the regional lymphatics beyond standard H&E analysis. This additional information assists in predicting biology and may be useful in guiding adjuvant therapy. We postulate the era of sentinel node has ushered in a new generation of node-negative patients; patients that have an exceptionally favorable outcome when compared to historic controls.

Lymphoscintigraphic localization of sentinel node in early colorectal cancer: results of a monocentric study

BACKGROUND AND OBJECTIVES

Evaluation of the feasibility of the sentinel node technique in early colorectal neoplasms and its overall accuracy in predicting nodal metastases.

METHODS

Thirty-five patients with colon or rectal lesions or degenerate polyps not radically excised by endoscopy were included. Lymphatic mapping was performed with 99mTc labeled albumin colloid injected submucosally by an endoscopic route the afternoon before the surgical procedure. The day of the intervention, 2.5% patent blue V dye (S.A.L.F: Italy) was injected circumferentially around the tumor. A hand held gamma detecting probe (Scintiprobe m100, Pol-Hi-Tech, Italy) was employed to detect "hot" nodes, in vivo and ex vivo. All sentinel nodes were embedded separately for haematoxylin and eosin staining. No IHC or PCR techniques were employed.

RESULTS

Sentinel lymph nodes (SLN) were successfully identified in 35 out of 35 patients. Concordance between SLN and nodal status was observed in 32 out of 35 cases (91.4%); four patients (11.4%) were upstaged. Three skip nodal metastases were observed (false-negative rate: 8.5%).

CONCLUSIONS

The sentinel node technique with blue dye and radiotracer seems valuable in early colorectal cancers detected by screening programs: a good organization and a learning curve are needed, as further multicentric studies.

Prognostic impact of micrometastases in colon cancer: interim results of a prospective multicenter trial

OBJECTIVE

The 25% rate of recurrence after complete resection of stage II colon cancer (CC) suggests the presence of occult nodal metastases not identified by hematoxylin and eosin staining (H&E). Interim data from our ongoing prospective multicenter trial of sentinel node (SN) biopsy indicate a 29.6% rate of micrometastases (MM) identified by immunohistochemical staining (IHC) of H&E-negative SNs in CC. We hypothesized that these MM have prognostic importance.

METHODS

Between March 2001 and August 2006, 152 patients with resectable colorectal cancer were enrolled in the trial. IHC and quantitative RT-PCR (qRT) assay were performed on H&E-negative SNs. Results were correlated with disease-free survival.

RESULTS

The sensitivity of lymphatic mapping was significantly better in CC (75%) than rectal cancer (36%), P<0.05. Of 92 node-negative CC patients 7 (8%) were upstaged to N1 and 18 (22%) had IHC MM. Four patients negative by H&E and IHC were positive by qRT. At a mean follow-up of 25 months, 15 patients had died from noncancer-related causes, 12 had developed recurrence, 5 had died of CC (2 with macrometastases, 3 with MM), and 7 were alive with disease. The 12 recurrences included 4 patients with SN macrometastases and 6 with SN MM (2 by IHC, 4 by qRT). One of the 2 SN-negative recurrences had other positive lymph nodes by H&E. All patients with CC recurrences had a positive SN by either H&E/IHC or qRT. No CC patient with a negative SN by H&E and qRT has recurred (P=0.002).

CONCLUSION

This is the first prospective evaluation of the prognostic impact of MM in colorectal cancer. These results indicate that the detection of MM may be clinically relevant in CC and may improve the selection of patients for adjuvant systemic chemotherapy. Patients with CC who are node negative by cumulative detection methods (H&E/IHC and qRT) are likely to be cured by surgery alone.

Risk factors for occult lymph node metastasis of colorectal cancer invading the submucosa and indications for endoscopic mucosal resection

PURPOSE

Although risk factors for histologically overt lymph node metastasis in patients with early-stage colorectal cancer have been clarified, the risk factors for occult lymph node metastasis are not clear. This study was designed to clarify risk factors for lymph node metastasis, including occult metastasis, in patients with colorectal cancer invading the submucosa and to determine the criteria for endoscopic resection of early colorectal cancer.

METHODS

The risk factors for lymph node metastasis, including occult metastasis, were analyzed in 86 cases of surgically resected colorectal cancer invading the submucosa. The lymph nodes were assessed by immunohistochemistry with cytokeratin antibody CAM5.2.

RESULTS

The frequencies of overt and occult metastasis to the lymph nodes were 13 percent (11/86) and 13 percent (10/75), respectively. Multivariate analysis showed vascular invasion (P = 0.001) and tumor budding (P = 0.003) to be independent risk factors for lymph node metastasis, including occult metastasis. For tumors with submucosal invasion < or =1,000 microm, no lymph node metastasis was found. The frequencies of lymph node metastasis for tumors with submucosal invasion of 1,000 to 2,000 microm and >2,000 microm were 21 and 37 percent, respectively. In considering combinations of risk factors, there was no lymph node metastasis in tumors having neither vascular invasion nor tumor budding and submucosal invasion of < or =3,000 microm.

CONCLUSIONS

Vascular invasion, tumor budding, and the degree of submucosal invasion were significant risk factors for lymph node metastasis, including occult metastasis. These three factors can be used in combination to identify patients requiring additional surgery after endoscopic resection.

The impact of the largest metastasis size on nodal tumor burden in colorectal carcinomas: implications for the sentinel lymph node theory in cancers of the large intestine

BACKGROUND AND OBJECTIVES

Successful sentinel lymph node (SLN) biopsy has been reported in colorectal cancer (CRC), but its results are still controversial. The SLN theory suggests that there is an orderly spread from the primary tumor to the SLNs first, and from the SLNs to further nodes later. This study examines the influence of nodal metastasis size on further nodal involvement.

METHODS

CRC resection specimens with nodal metastasis have been evaluated for the maximum nodal metastasis size for a period of 5 years. All lymph nodes (LNs) were submitted to standard histological examination.

RESULTS

Two hundred thirty-five CRC specimens with a single invasive tumor were assessed. The mean numbers of LNs examined and involved were 18 and 4, respectively. The largest metastasis size ranged from 0.14 to 22.1 mm. There was a significant correlation between this parameter and the number or the ratio of LNs involved (Spearman's Rho: 0.517, and 0.382, respectively; P < 0.0001). A cluster analysis identified three relatively distinct groups of low, intermediate, and extensive nodal involvement.

CONCLUSIONS

The correlation of the largest metastasis size with the number and the ratio of involved nodes may be an indirect proof of the sequential spread from first echelon LNs to further nodes. However, the data suggest a more complex process: with increasing metastasis size, the number of involved nodes and its variability increase more than might be expected. This suggests a recruitment or cascade process, which becomes more unpredictable as nodal tumor burden increases.

Proliferative activity of micrometastases in the lymph nodes of patients with gastric cancer

BACKGROUND

Immunohistochemically detectable isolated tumour clusters (ITCs) with a diameter of less than 0.2 mm have been regarded as non-metastatic lesions, because of a lack of proliferative activity. This study investigated the proliferative activities of ITCs.

METHODS

Three hundred and eight patients with primary gastric cancer diagnosed as pN0 by routine histological examination were studied. All patients underwent curative resection. Sections of lymph nodes were stained by double-immunostaining methods using anti-cytokeratin and anti-Ki-67 antibody (MIB-1).

RESULTS

ITCs were detected in 77 nodes from 37 patients, designated as having pN0(i+) lesions. Seventy of 77 lymph nodes with ITCs were detected in the N1 station, and seven were found in the N2 station. Of 25 single isolated cancer cells, 12 showed positive labelling with MIB-1, and 49 of 52 ITCs with clusters of cancer cells had positive MIB-1 labelling (mean(s.d.) 46.6(30.1) per cent). Five of the 37 patients with ITCs (pN0(i+)) versus one of the 271 patients with no evidence of ITCs (pN0(i-)) died from recurrence. Patients with ITCs had a significantly worse prognosis than those without (P = 0.014).

CONCLUSION

ITCs have a high proliferative activity and may have the potential to evolve into established lymph node metastasis.

Sentinel lymph node mapping in colon cancer: current status

BACKGROUND

The primary role of sentinel lymph node (SLN) mapping in colon cancer is to increase the accuracy of nodal staging by identifying those lymph nodes with the greatest potential for harbouring metastatic disease. Ultrastaging techniques aim to identify the otherwise undetected metastases. Until now, no consensus exists as to the most optimal procedure in patients with colon cancer.

METHODS

A systematic literature search on the value of different SLN mapping techniques in patients with colon cancer was performed using the electronic search engine PubMed. Prospective studies published before 1 December 2005 were included and further articles were selected by cross-referencing. The results of different techniques using either blue dye or radiocolloid, were investigated.

RESULTS

The literature search yielded 17 relevant articles. SLN mapping using blue dye was described in 15 studies. Two studies reported the results of SLN mapping using a combination of blue dye and radiocolloid. The reported results on identification rate varied between 71 and 100%. Accuracy rates were between 78 and 100%, sensitivity rates between 25 and 100% and true upstaging rates between 0 and 26%. The results were not affected by the addition of radiocolloid to blue dye.

CONCLUSIONS

Sentinel lymph node mapping in patients with colon cancer remains an experimental procedure with varying results. Further evaluation may lead to a standardized technique that offers the potential for significant upstaging of stage II patients. This may have important implications as to tailor adjuvant chemotherapeutic regimens in these patients.

Does immunostaining effectively upstage colorectal cancer by identifying micrometastatic nodal disease?

PURPOSE

Measure the association between the incidence of primary tumor staining and the identification of mediastinal lymph node (MLN) using cytokeratins, NM23, DCC-positive tumors, and vascular endothelial growth factor (VEGF) expression in T(2) and T(3)/N(0) colorectal cancers. The impact of MLN on both recurrence and survival was assessed.

MATERIALS AND METHODS

There were 153 CORC patients (T(2), T(3)/N(0)) selected from a prospectively accrued database. All patients had been staged by routine histopathology after a curative resection and no patients received adjuvant chemotherapy. The primary tumors (PT) were assessed with a panel of immunohistochemical stains (cytokeratin, DCC, Nm23, and VEGF). If the PT was positive, the regional nodes were assessed with that marker(s). For any positive tumor marker, all lymph nodes (LNs, mean of 12.6+/-4.2) were stained for this marker.

RESULTS

Patient age ranged from 38 to 86 years with a mean age of 61.56+/-25.56 years. Mean follow-up was 72.1+/-32.4 months. Recurrence rate of the whole group was 19/153 (12.4%) and the mean time to recurrence was 37.6+/-23.6 months (15 to 77 months). Crude mortality was 39.9%, while the cancer specific mortality was 11.2% after the whole follow-up period. The relationship between PT staining and MLNs was: cytokeratin-PT 143 (93.5%)/MLN 9 (6.3%); NM23-PT 51 (33.3%)/MLN 3 (5.9%); DCC-PT 79 (53%)/MLN 3 (3.8%); and VEGF-PT 72 (47%)/MLN 4 (5.6%). Nineteen (12.4%) patients experienced tumor recurrence. No correlation exist between PT and/or MLN staining and either recurrence or survival. No patient with MLN with any stain experienced a recurrence. There was no advantage to using an individual stain or all four stains.

CONCLUSION

Immunohistochemical stains for PT and focused analysis of regional nodes did not improve prediction of survival or recurrence. Sentinel LN evaluation and the provision of adjuvant chemotherapy in node-negative patients should be questioned and not be utilized outside of a research protocol.

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.

The prognostic effect of micrometastases in previously staged lymph node negative (N0) colorectal carcinoma: a meta-analysis

BACKGROUND

The prognostic relevance of lymphatic micrometastases in colorectal carcinoma is unclear. To determine the prognostic significance of micrometastases in colorectal cancer, a meta-analysis was performed on all studies, which reported 3-year disease-free survival (DFS) and overall survival (OS).

METHODS

Published studies selected for meta-analysis contained sufficient data from which to extrapolate estimates of 3-year DFS and/or OS. From 1991-2003, 25 studies re-examined N0 lymph nodes by serial sectioning and immunohistochemical (IHC) staining or reverse transcriptase-polymerase chain reaction (RT-PCR) assay. Eight studies (566 patients) with IHC detected micrometastases and three (173 patients) with RT-PCR micrometastases were used to determine DFS and OS. Weighted estimates of 3-year survival were combined across studies within each group, and the combined survival estimates were compared across groups using a binomial test.

RESULTS

Micrometastases were identified in all IHC studies; upstaging, including N1, N1mi and N0(i+), was achieved in 32% (179/566 patients). All RT-PCR studies identified micrometastases; upstaging to N0(mol+) was achieved in 37% (64/173 patients). There was a statistically significant difference in 3-year OS between RT-PCR positive N0(mol+) patients (77.8%) and those for whom micrometastases were not detected (96.6%) (P < .001).

CONCLUSION

The prognostic value of micrometastases detected retrospectively by RT-PCR is significant in AJCC stage II colorectal patients. Studies utilizing RT-PCR performed a more complete nodal analysis when compared to studies using IHC techniques. RT-PCR may also be more specific for the detection of clinically relevant micrometastases compared to IHC detected cytokeratins. Prospective studies are needed to evaluate the potential benefit of systemic chemotherapy in patients with molecular metastases.

Incidence and prognostic significance of occult tumor cells in lymph nodes from patients with stage IIA colorectal carcinoma

Approximately 30% of patients with lymph node (LN)-negative colorectal carcinoma (CRC) die of tumor recurrence, which can be related to the presence of tumor cells in LNs not detected by conventional histopathologic analysis. However, the prognostic significance of occult cancer cells still remains uncertain. We evaluated the incidence and the prognostic significance of occult cancer cells in LNs from 395 consecutive patients with curatively resected stage IIA CRC using immunohistochemistry for cytokeratin 20. Immunostained tumor cells were categorized as micrometastases (MCMs) or isolated tumor cells (ITCs) according to the American Joint Committee on Cancer criteria. The detection rates were compared with the clinicopathologic characteristics of the patients and with cancer-specific survival. The median follow-up time was 128 months. Micrometastases were detected in 39 patients (9.9%), whereas ITCs were found in 112 (28.4%), for an overall frequency of 38.2%. None of the clinicopathologic parameters examined was correlated with the presence of occult cancer cells. Patients with ITCs and those with negative LNs showed a similar survival rate (77.7% and 78.3%, respectively), whereas patients with MCMs had a lower survival rate (64.1%). At the univariate analysis, MCMs, tumor growth pattern, extent of tumor spread, and Crohn's-like lymphoid reaction influenced the survival rate significantly. Nevertheless, at the multivariate analysis, only the pattern of tumor growth and the extent of tumor spread were independent prognostic factors. The detection of immunostained tumor cells in the LNs of patients with stage IIA CRC occurs relatively frequently but has no significant effect on prognosis.

Impact of disseminated tumor cells in gastrointestinal cancer

The detection of epithelial cells by sensitive immunological and molecular methods in blood, lymph nodes or bone marrow of gastrointestinal cancer patients may open a new approach to clinical metastasis research. The phenotypic and genomic characterization of these cells is of great value in the prediction of the further course of the disease and the monitoring of response to treatment. In addition, the role of ultrastaging in blood, lymph nodes and bone marrow of cancer patients for the indication of multimodal therapy is discussed in this review. The impact of prognostic or predictive factors for new treatment protocols in patients with gastrointestinal cancer was evaluated as well as the correlation with clinical factors.

The importance of accurate pathological assessment of lymph node involvement in colorectal cancer

This review presents an up-to-date analysis of the importance of accurate pathological lymph node staging in colorectal cancer. Lymph node staging is reliant on the technique of the surgeon and the pathologist as well as methods employed in the histopathology laboratory, and is vital for determining appropriate therapy. The significance of micrometastatic nodal disease is evaluated and new techniques for pathological evaluation are discussed. Recommendations for evaluation of lymph node status in colorectal cancer are provided based on current scientific evidence, and standardization of pathological dissection and laboratory handling is advocated.

High prevalence of isolated tumour cells in regional lymph nodes from pN0 colorectal cancer

BACKGROUND

The prevalence of isolated tumour cells (ITCs) in regional lymph nodes from colorectal cancer (CRC) is controversial and has never been prospectively assessed in large groups of consecutive patients. pN0 early-relapsing CRC can be explained by lymph node-ITC.

AIM

To assess the prevalence of ITCs in regional lymph nodes from 309 consecutive patients with pN0M0 (pathological (p)-tumour-node-metastasis (TNM) staging system) CRCs.

PATIENTS AND METHODS

ITCs were assessed by immunohistochemistry (MNF116 monoclonal antibody (1:100); Dako, Glostrup, Denmark) in two serial histological sections obtained from 5016 mesenteric lymph nodes from 309 patients with pN0 CRCs (mean number of lymph nodes per patient = 16.2; p-TNM stage 0, n = 25; p-TNM stage I, n = 123; and p-TNM stage II (A+B), n = 161). Tumour histology, vascular cancer invasion and pathological stage were also recorded.

RESULTS

ITCs were detected in the regional lymph nodes of 156 of 309 (50.5%) patients with CRC, mostly in nodes located within 3 cm from the neoplasia. ITC status correlated with (a) tumour p-TNM stage (Pearson's chi(2): p<0; ordered logistic regression: odds ratio (OR) = 4.6; 95% confidence interval (CI) = 2.88 to 7.33; p<0) and (b) pT value (Pearson's chi(2): p = 0; ordered logistic regression: OR = 4.9; 95% CI = 3.1 to 7.7; p<0). By multivariate analysis, including p-TNM stage, vascular invasion and ITC status, both stage (OR = 5.1; 95% CI = 2.9 to 8.9; p<0) and vascular invasion (OR = 4.2; 95% CI = 1.94 to 8.98; p<0) were found to be independent variables associated with ITC+ lymph nodes.

CONCLUSION

More than 50% of pN0-CRC patients have ITCs in the mesenteric lymph nodes. ITC status is significantly correlated with cancer stage and vascular cancer invasion. The clinicopathological effect of ITC remains to be prospectively evaluated.

Isolated tumor cells in lymph nodes are not a prognostic marker for patients with stage I and stage II colorectal cancer

BACKGROUND AND OBJECTIVES

Lymph node metastasis is an important prognostic factor for colorectal cancer (CRC). The relationship between isolated tumor cells (ITC) in lymph nodes and the prognosis is controversial. The aim of this study is to evaluate the prognostic importance of ITC in lymph nodes from patients with stage I and II CRC.

METHODS

We examined all the lymph nodes obtained during surgery from 121 consecutive patients with stage I and II CRC after a curative resection in 1999 by using monoclonal antibody against cytokeratin (MNF116). Clinicopathologic data and follow-up information were obtained from all patients. The mean follow up duration was 57 months.

RESULTS

ITC were found in 50% (60/121) of the patients. The mean number of examined lymph node was 19.3 +/- 9.4. The presence of ITC was not related to clinicopathologic factors such as age, sex, location of tumor, tumor size, tumor depth, differentiation, lymphovascular invasion, and the preoperative CEA level, except for the tumor gross type (P = 0.002). There were no statistically significant differences for the recurrence rate (10/60 = 16.7% and 9/61 = 14.8%, respectively), and disease-free survival (P = 0.809) between the ITC positive group and ITC negative group.

CONCLUSIONS

The presence of ITC detected by immunohistochemical staining does not have an influence on the prognosis of patients with stage I and II CRC.

Prognostic relevance of occult tumour cells in lymph nodes in colorectal cancer

AIMS

Presently, in Europe the treatment of node-negative colorectal cancer (CRC) patients consists of surgical resection of the primary tumour without adjuvant systemic therapy. However, up to 30% of these patients will develop disease recurrence. These high-risk patients are possibly identified by occult tumour cell (OTC) assessment in lymph nodes. In this paper, studies on the clinical relevance of OTC in lymph nodes are reviewed.

METHODS

A literature search was conducted in the National Library of Medicine by using the keywords colonic, rectal, colorectal, neoplasm, adenocarcinoma, cancer, lymph node, polymerase chain reaction, mRNA, immunohistochemistry, micrometastases and isolated tumour cells. Additional articles were identified by cross-referencing from papers retrieved in the initial search.

RESULTS

The upstaging percentages through OTC assessment and the prognostic relevance of OTC in lymph nodes vary among studies, which is related to differences in techniques used to detect OTC.

CONCLUSIONS

We conclude that OTC examination techniques should be standardized to illuminate whether OTC in lymph nodes can reliably identify high-risk node-negative patients.

Is there any role for sentinel node mapping in colorectal cancer staging? Personal experience and review of the literature

BACKGROUND

We explored the role of lymphatic mapping and sentinel lymphadenectomy (originally described for melanoma and breast cancer) in colon cancer. Pathologic techniques can successfully identify micrometastatic disease in lymph nodes, but they are not suitable for clinical routine use. We evaluated the role of sentinel node (SN) mapping in refining the staging of colorectal cancer.

METHODS

A total of 56 open colorectal resections were performed, and Patent Blue V dye was injected under the serosa surrounding the tumor immediately after opening the abdomen. SNs were analysed by immunohistochemistry to find micrometastatic disease. A literature search for the role of SNs in colorectal cancer was also performed.

RESULTS

We identified the SN in 100% of patients, with a mean of 2.02 SNs/patient (range 1-5). After immunohistochemical staining, we could upstage 21 out of 56 patients (37.5%), and we observed 10.7% false negative SNs (6/56 patients). Fewer than half of the articles described false negative rates of <15%, and most articles showed an upstaging rate of >5% of patients. These differences are probably the result of different sensitivities of the methods used in identifying the lymph node micrometastases.

CONCLUSIONS

SN mapping is an easy and cost-effective technique that holds promise and warrants further investigations.

Lymph node micrometastasis in stage II distal rectal cancer following neoadjuvant chemoradiation therapy

OBJECTIVE

The objective was to determine the presence and frequency of micrometastasis in lymph nodes of patients with rectal cancer treated by preoperative chemoradiation followed by curative resection.

PATIENTS AND METHODS

All 56 patients included were treated with 5-FU and leucovorin plus 5,040 cGy, followed by radical surgery and were diagnosed with stage II distal rectal adenocarcinoma after complete pathological examination (ypT3-4N0M0). Immunohistochemistry was assessed with cytokeratin monoclonal antibody AE1/AE3. Three 4-microm paraffin sections were obtained from each lymph node, cut at 50 microm apart from each other. The results were reviewed by two independent pathologists.

RESULTS

Mean number of lymph nodes was 9.6 per patient. Four patients (7%) and seven lymph nodes (1.35%) were positive for micrometastasis. Three patients had pT3 and one a pT4 tumor. One of the patients had positive micrometastasis and the presence of mucinous deposits. One other patient had mucinous deposits without any micrometastasis. All four patients are alive with no evidence of recurrent disease. Fourteen patients negative for micrometastasis had recurrent disease (25%), eight systemic (14.7%) and six locoregional (10.3%). There were two cancer-related deaths. The mean follow-up period was 39 months.

CONCLUSION

Patients with rectal cancer treated by preoperative chemoradiation showed a surprisingly low rate of micrometastasis detection (7%), even in high-risk patients (T3 and T4 tumors). Lymph node micrometastasis was not associated with decreased overall or disease-free survival. The identification of mucinous deposits on lymph nodes with no viable tumor cells may be direct evidence of lymph node downstaging. The downstaging effect of preoperative chemoradiation therapy may be significant in reducing even micrometastasis detection in low rectal cancer managed by this treatment strategy.

Detection and clinical implications of minimal residual disease in gastro-intestinal cancer

INTRODUCTION

Metastatic dissemination is an important factor for the prognosis of patients with gastro-intestinal cancer. Exact staging is crucial to determine appropriate multimodal therapeutic strategies. At present, the sensitivity of routinely performed diagnostic techniques is suboptimal for the detection of minimal residual disease (MRD) and occult metastases since the number of disseminated tumour cells (DTCs) is mostly marginal. To amend the verification of DTCs, immunohistochemical and molecular methods were applied to retrieve epithelial cell-specific proteins in non-epithelial tissue of different body compartments or fluids. Many groups have eagerly focussed on the identification of new markers and novel tests, yet specificity and sensitivity of these methods as well as robustness in the clinical setting are frequently missing.

MATERIALS AND METHODS

This review critically evaluates the prognostic impact of MRD in patients with pancreatic, colorectal and gastric cancer by outlining those studies showing diagnostic results of DTC detection in lymph nodes, bone marrow, venous blood and peritoneal lavage, some of which present novel strategies.

CONCLUSION

The analysed data concerning MRD in gastro-intestinal cancers reveal that results are undesirably heterogeneous. From a critical point of view, many clinical studies missed their chance because of small cohort size; moreover, methodological standardisation is generally lacking. On the other hand, the very encouraging results achieved so far, together with the comprehensive analyses of a few research groups, foster the prediction that DTC/MRD issues will soon expand the standard TNM classification.

Detection of lymph nodes micrometastases in Dukes’ A and B colorectal cancer using anti-cytokeratin antibodies AE1/AE3

AIM: To detect lymph nodes micrometastases and analyze its correlation with clinicopathological parameters in Dukes’ A and B colorectal cancer patients.

METHODS: One hundred and fourteen patients with colorectal cancer (Dukes’ A 16; Dukes’ B 98) undergoing curative operation without histological lymph nodes metastases were studied between 2001 and 2003. A total of 2 481 lymph nodes were analyzed using monoclonal cytokeratin antibody AE1/AE3 (DAKO, Carpinteria, CA) for immunohist-ochemistry.

RESULTS: In total, 33 (29%) patients were positive for cancer cell by immunohistochemistry. In 31 (94%) patients of them positive nodes showed single tumor cell or small groups of tumor cells; and tumor deposits measuring 0.2 and 0.37 mm in diameter in another 2 (6%) patients. Micrometastases were mainly located in the subcapsular sinus or paracortical sinus. There was no correlation between the positive lymph nodes and gender, age, tumor site, tumor size, histological type, histological grade, invasion depth, Dukes’ staging and microsatellite instability (P>0.05).

CONCLUSION: Our findings suggest that immunohist-ochemical technique using monoclonal cytokeratin antibody AE1/AE3 may be a sensitive and reliable method for detecting lymph nodes micrometastases in Dukes’ A and B colorectal cancer. The clinical significance of lymph nodes microme-tastases is still not confirmed.

Prognostic value of nodal micrometastases in patients with cancer of the gastro-oesophageal junction

AIMS

Aim of this study was to examine the presence and the prognostic impact of immunohistochemically identified nodal micrometastases in patients with gastro-oesophageal junction (GEJ) carcinomas.

METHODS

Between January 1988 and December 2000, 148 patients underwent a radical (R0) resection with a two-field lymphadenectomy for a GEJ carcinoma. Specimens of 60 patients in whom conventional haematoxylin and eosin (H & E) examination did not demonstrate lymph-node metastases (pN0) were available for immunohistochemical (IHC) analysis using antibodies AE1/AE3 directed against cytokeratins. Paraffin embedded material of all retrieved lymph nodes in these patients were serially sectioned and analysed by one pathologist after H & E examination for the presence of micrometastases by IHC.

RESULTS

In 60 resection specimens initially staged as pN0 a total of 524 lymph nodes were available for IHC analyses. Micrometastases were detected in 126 out of 524 lymph nodes (24%), corresponding with 18 of the 60 patients (30%) who were upstaged by this technique. Compared with the pN0 group, the disease free survival (DFS) was significantly lower in patients with nodal involvement at IHC (p<0.001). Survival of patients with IHC identified micrometastatic disease was comparable to those with H & E positive lymph nodes.

CONCLUSIONS

Micrometastases in regional nodes were detected by cytokeratin-specific IHC in 30% of radical resected GEJ tumours without overt nodal involvement. Their presence conveys a worse prognosis with a significant reduced DFS, suggesting that the finding of micrometastases should be included in the staging system.

Adjuvant therapy for stage II colon cancer: an elephant in the living room?

At present, standard adjuvant treatment for patients with stage III colon cancer after surgical resection is represented by 6 months of chemotherapy based on 5-fluorouracil/leucovorin regimens. Even elderly patients enjoy the benefit of chemotherapy in terms of superior overall survival with no detrimental effects on quality of life. More questionable is the role of adjuvant chemotherapy for stage II colon cancer patients, the standard of care for whom is surgical resection alone. Although a majority of patients will be cured with resection, a significant minority will ultimately relapse, suggesting the need to identify patients who may benefit from adjuvant therapy. Putative prognostic markers for stage II patients, as well as the state-of-the-art of the adjuvant treatment in this setting, are reviewed in this paper.

[Optimization of staging in colon cancer using sentinel lymph node biopsy]

Routine determination of the nodal status in colon cancer is strongly dependent on the individual quality and technique of histopathological assessment and surgical lymph node dissection. We evaluated whether sentinel lymph node biopsy (SLNB) could contribute to an improvement in staging. At least one SLN (median n=2) was detected (detection rate 84%) in each of 38 of 45 patients with primary colon cancer. Ten of these 38 were found to have lymph node metastases by HE staining (26%), six of them in the SLN. Nine of the 28 patients that were initially nodal-negative by HE revealed one micrometastasis and eight cases of isolated tumor cells by immunohistochemical (IHC) staining (32% upstaging response). Including the IHC-positive cases, 19 of the 38 patients were nodal-positive (50%), 15 of them with tumor-infiltrated SLN (overall sensitivity of SLNB 79%). Using the dye method, SLNB is clinically practicable and leads in the majority of the patients to the detection of SLN. The selective, intensified histopathological assessment of SLN identifies small tumor cell deposits in a relevant percentage of patients with little and clinically practicable effort.

Lymphatic staging in colorectal cancer: pathologic, molecular, and sentinel node techniques

PURPOSE

Accurate staging in colorectal cancer is important to predict prognosis and identify patients who could benefit from adjuvant therapy. Patients with lymphatic metastasis, Stage III/Dukes C, are generally treated with adjuvant chemotherapy. Still, patients without lymphatic metastasis do have relapse as high as 27 percent in five years in Dukes B2. It is hypothesized that these patients have occult (micro)metastasis in their lymph nodes. If these (micro)metastasis can be identified, these patients might benefit from adjuvant therapy. We reviewed the literature on procedures to improve lymph node staging.

METHODS

An extensive literature search was performed in PubMed (www.pubmed.com). Using the reference lists, more articles were found.

RESULTS

We found 30 articles about sentinel node in colorectal cancer describing original series. Some groups reported several studies including the same patients. We reported their largest studies. For all other techniques, we only included key articles.

CONCLUSIONS

Many techniques to improve staging have been described. The finding of occult (micro)metastasis is of prognostic significance in most studies. The sentinel node technique has been recently described for use in colorectal cancer. Although it seems clear that this technique has prognostic potential, it is not yet been shown in a follow-up study. Furthermore, the finding of occult (micro)metastasis in any technique used has not been shown to be clinically significant. Whether to treat patients with adjuvant therapy if occult (micro)metastasis are found needs to be proven in future studies.

Sentinel lymph node mapping for adenocarcinoma of the colon does not improve staging accuracy

PURPOSE

This study was designed to: determine the efficacy of sentinel lymph node mapping in patients with intraperitoneal colon cancer; and create an algorithm to predict potential survival benefit by using best-case estimates in favor of sentinel node mapping and lymph node ultraprocessing techniques.

METHODS

Forty-one patients with intraperitoneal colon cancer undergoing colectomy with curative intent were studied prospectively. After mobilization of the colon and mesentery, 1 to 2 ml of isosulfan blue dye was injected subserosally around the tumor. The first several nodes highlighted with blue dye were identified as sentinel nodes. Additional nodes were identified by the pathologist in routine fashion by manual dissection of the mesentery. All nodes were processed in routine fashion by bivalving and hematoxylin and eosin staining. To create an algorithm to predict potential survival benefit of sentinel node mapping and lymph node ultraprocessing techniques, assumptions were made using data from the literature. All bias was directed toward success of the techniques.

RESULTS

Three of 41 patients (7 percent) did not undergo injection of dye and were excluded from further analysis. Stage of disease in the remaining 38 patients was: I, n = 10 (26 percent); II, n = 15 (39 percent); III, n = 11 (29 percent); IV, n = 2 (5 percent). At least one sentinel node was identified in 30 of 38 patients (79 percent). The median number of sentinel nodes identified was two (range, 1-3). Median total nodal retrieval was 14 (range, 7-45). All nodes were negative in 26 of 38 patients (68 percent). Sentinel nodes and nonsentinel nodes were positive in 2 of 38 patients (5 percent). Sentinel nodes were the only positive nodes in 1 of 38 patients (3 percent). Sentinel nodes were negative and nonsentinel nodes were positive in 9 of 38 patients (24 percent). Thus, sentinel node mapping would have potentially benefited only 3 percent, and failed to accurately identify nodal metastases in 24 percent of the patients in our study. To create a survival benefit algorithm, we assumed the following: combined fraction of Stage I and II disease (0.5); fraction understaged by bivalving and hematoxylin and eosin staining that would have occult positive nodes by more sophisticated analysis (0.15); fraction of occult positive nodes detected by sentinel node mapping (0.9); and survival benefit from chemotherapy (0.33). Thus, the fraction of patients benefiting from sentinel lymph node mapping and lymph node ultraprocessing techniques would be 0.02 (2 percent).

CONCLUSIONS

Sentinel node mapping with isosulfan blue dye and routine processing of retrieved nodes does not improve staging accuracy in patients with intraperitoneal colon cancer. Even using best-case assumptions, the percentage of patients who would potentially benefit from sentinel lymph node mapping is small.

Prognostic evaluation and review of immunohistochemically detected disseminated tumor cells in peritumoral lymph nodes of patients with pN0 colorectal cancer

BACKGROUND

The value of immunohistochemical detection of disseminated tumor cells in histopathologically tumor-free lymph nodes (pN0) of patients with colorectal cancer is still of uncertain prognostic value. We therefore evaluated the immunohistochemical detection rates and their prognostic value comparing three different monoclonal antibodies.

METHODS

A total of 170 lymph nodes of 85 patients with curatively resected colorectal carcinoma at UICC stage I or II were evaluated for disseminated tumor cells. Frozen sections of each lymph node were immunohistochemically stained using three antibodies directed against CEA, CK20, and Ber-EP4. The detection rates were compared with histopathological tumor parameters and with the patient's survival. The median follow-up time was 86 months.

RESULTS

CEA-, CK20-, and Ber-EP4-positive disseminated tumor cells were identified microscopically in lymph nodes of 23 patients (27%), 24 patients (28%), and 23 patients (27%), respectively. In 18 patients (21%) disseminated tumor cells were found in consecutive sections and stained positive for all three monoclonal antibodies. The lymph nodes of 10 of 18 patients (56%), which developed tumor recurrence, contained CEA- and CK20-positive disseminated tumor cells. Ber-EP4-positive cells were present in lymph nodes of 9 of 18 patients (50%) with tumor recurrence. The 5-year overall survival of the 23 patients with CEA-positive disseminated tumor cells was 72% compared to 91% of the patients without immunohistochemical evidence of tumor cells (p<0.01). While the identification of CK20-positive tumor cells was also correlated significantly with a worse overall patient survival (p<0.01), the application of Ber-EP4 failed to reach significance (p=0.057). Multivariate analysis identified the tumor site (colon versus rectal cancer) (p<0.006) and the presence of CEA-positive disseminated tumor cells (p<0.03) as independent prognostic factors.

CONCLUSION

In colorectal carcinoma, the immunohistochemical detection of disseminated tumor cells in histopathologically pN0 peritumoral lymph nodes allows the identification of a subgroup with a significantly worse prognosis. Nevertheless, the prognostic value of immunohistochemically detected disseminated tumor cells remains controversial due to the nonuniform data in the literature.

Detection of occult tumour cells in lymph nodes of colorectal cancer patients using real-time quantitative RT-PCR for CEA and CK20 mRNAS

The purpose of our study was to develop specific, sensitive, objective assays for early detection of disseminated tumour cells in patients with colorectal cancer (CRC). Carcinoembryonic antigen (CEA) and cytokeratin 20 (CK20) were chosen as markers because they are selectively expressed in epithelial cells with maintained expression in CRC. Real-time quantitative RT-PCR assays with RNA copy standards were constructed. Regional lymph nodes were collected from patients with CRC (n = 51) and benign intestinal disease (n = 10). Results were compared to routine histopathology and anti-CEA immunohistochemistry. Lymph node levels of CEA and CK20 mRNA correlated strongly (p < 0.0001, r = 0.8). Lymph nodes from non-CRC patients had <0.01 CEA and <0.001 CK20 mRNA copies/18S rRNA unit. Lymph nodes from 3/6 Dukes' A, 17/26 Dukes' B, 10/10 Dukes' C and 7/9 Dukes' D patients had CEA mRNA levels above cut-off. Corresponding figures for CK20 mRNA were 3/6, 10/26, 9/10 and 5/9, respectively. CEA mRNA levels varied from 0.001 to 100 copies/18S rRNA unit in Dukes' A and B, and 50% of the Dukes' B patients had CEA mRNA levels within the range of Dukes' C patients. Three Dukes' B patients have died from CRC or developed distant metastases. All 3 had high CEA and CK20 mRNA levels. Determination of mRNA was superior to immunohistochemistry in showing CEA expression in lymph nodes. The present qRT-PCR assay for CEA mRNA seems to be a superior tool to identify individuals with disseminated tumour cells. Future extended studies will establish the clinically most relevant cut-off level.

Minimal residual disease assessment in sentinel nodes of breast and gastrointestinal cancer: a plea for standardization

Lymph node dissection plays an important role in staging and treatment of solid cancers. Sentinel node biopsy (SNB) has been introduced to minimize the extent of surgery and to enable assessment of minimal residual disease (MRD) without compromising accurate staging or survival. This review addresses the variation in technical aspects and outcome of SNB and MRD assessment in patients with breast and gastrointestinal cancer. Quality control leading to standardization of SNB and pathological examination will enable reliable comparison of studies, which is necessary for consensus of diagnostic and therapeutic strategies.

Presence of isolated tumour cells in mesenteric lymph nodes predicts poor prognosis in patients with stage II colon cancer

AIM

Most patients with stage I and stage II colon adenocarcinomas do not have disseminated disease, and the group is not offered adjuvant therapy. However, more than 30% of stage II colon adenocarcinoma patients get metastases to remote organs. Thus, it is important to identify patients in this group at risk of disease relapse.

PATIENTS AND METHODS

We have examined the prognostic value of isolated tumour cells (ITC) in mesenteric lymph nodes in a consecutive series of 156 colon carcinoma patients with stage II disease. Immunohistochemistry, using antibodies to cytokeratins, and morphology were used to identify presence of ITC.

RESULTS

ITC were detected in 59 (37.8%) patients. Presence of ITC in mesenteric lymph nodes was independently associated with reduced relative survival both in univariate (p=0.0199) and in a multivariate analysis (p=0.041).

CONCLUSION

The results strongly suggest that presence of ITC in mesenteric lymph nodes is associated with reduced relative survival in colon carcinoma patients stage II, and that detection of ITC may be important in treatment of these patients.

The prognostic significance of intranodal isolated tumor cells and micrometastases in patients with non-small cell carcinoma of the lung

OBJECTIVE

To study whether isolated tumor cells and micrometastases, as defined by the current American Joint Committee on Cancer criteria for extrapulmonary neoplasms, have prognostic value for patients with resected non-small cell carcinoma of the lung.

METHODS

Intrathoracic lymph nodes (n = 1063) from 60 patients with non-small cell carcinoma of the lung were studied for the presence of metastases with serial histologic sections and keratin immunostains. Metastases were classified as isolated tumor cells, pN1mi, pN1, pN2mi, and pN2. Isolated tumor cells were smaller than 0.2 mm, while pN1mi and pN2mi measured 0.2 mm to 2 mm. Survival analysis was performed, stratifying by nodal status and stage.

RESULTS

Isolated tumor cells were detected in 11 lymph nodes from 5 of 33 pN0 patients and in 9 pN1 and pN2 patients. The lymph nodes from 3 patients were reclassified as pN1mi. No pN2mi were detected. A survival model based on a stratification of the cohort into stages I to III was significant (chi-square = 7.426, df = 2, P =.024) but demonstrated considerable overlap between the survival curves of stage I and II patients. A model stratifying isolated tumor cells and pN1mi into stage I disease was significant (chi-square = 7.985, df = 2, P =.018) and showed no overlap between the survival curves of stage I and II patients. There were no significant survival function differences between patients with pN0, isolated tumor cells, and pN1mi.

CONCLUSIONS

Patients with non-small cell carcinoma of the lung with isolated tumor cells and pN1mi have similar survivals to those with pN0, consistent with the findings reported for breast cancer patients. Future larger studies of patients with non-small cell carcinoma of the lung are needed to confirm whether current American Joint Committee on Cancer staging criteria should be modified to include the pN1mi category.