Prognostic relevance of immunohistochemically detected lymph node micrometastasis in patients with gastric carcinoma

TUMOR MARKERS EXPRESSION LEVELS IN GASTRIC CANCER PATIENT'S PERIPHERAL BLOOD BY RT-PCR ASSESSMENT

BACKGROUND

Hematological recurrence is the second most frequent cause of failure in the treatment of gastric cancer. The detection of circulating tumor markers in peripheral blood by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) method may be a useful tool to predict recurrence and determine the patient's prognosis. However, no consensus has been reached regarding the association between the tumor markers level in peripheral blood and its impact on patient survival.

AIMS

To evaluate the expression of the circulating tumor markers CK20 and MUC1 in peripheral blood samples from patients with gastric cancer by qRT-PCR, and to verify the association of their expression levels with clinicopathological characteristics and survival.

METHODS

A total of 31 patients with gastric adenocarcinoma were prospectively included in this study. CK20 and MUC1 expression levels were analyzed from peripheral blood by the qRT-PCR technique.

RESULTS

There was no statistically significant (p>0.05) association between CK20 expression levels and clinical, pathological, and surgical features. Higher MUC1 expression levels were associated with female patients (p=0.01). There was a correlation between both gene levels (R=0.81, p<0.001), and CK20 level and tumor size (R=0.39, p=0.034).

CONCLUSIONS

CK20 and MUC1 expression levels could be assessed by qRT-PCR from total peripheral blood samples of patients with gastric cancer. CK20 levels were correlated to MUC1 levels as well as to tumor size. There was no difference in disease-free survival and overall survival regarding both genetic markers expression in this series.

Impact of Removal of Lymph Nodes on Survival in Stage I-III Gastric Signet-Ring Cell Cancer: The More, the Better?

BACKGROUND

There is an ongoing debate over the prognostic value of the number of examined lymph nodes (ELNs) in cases of gastric signet-ring cell cancer (GSRCC). In this study, we sought to evaluate the correlation between the number of ELNs and the prognosis of GSRCC and identify the optimal number of ELNs.

METHODS

A total of 1020 patients diagnosed with GSRCC between 2011 and 2018 in the National Cancer Center database were identified. Clinicopathological characteristics were retrospectively collected, and optimal cutoff values of ELNs were calculated by using X-tile. The impact of different ELNs on overall survival (OS) was compared by using Kaplan-Meier curves. We used univariate and multivariate Cox and subgroup analyses to explore the relationship between ELNs and OS. Furthermore, nonlinear correlations were investigated by using restricted cubic splines (RCSs).

RESULTS

X-tile showed that the optimal cutoff value of ELNs was 22. The 5-year OS was higher for patients with ELNs > 22 (vs. ELNs ≤ 22, 66.9% vs. 74.9%, P = 0.026). Multivariate Cox analyses showed that high ELNs were associated with superior OS (hazard ratio = 0.56, 95% confidence interval 0.43-0.74, P < 0.001). In subgroup analyses, the significant association between tumor size > 4 cm, and TNM III stage was still observed. The RCS regression model showed a U-shaped dose-response nonlinear relationship between ELNs and OS; the inflection point, as well as the lowest risk points, corresponded to 44-52 ELNs.

CONCLUSIONS

A U-shaped, nonlinear correlation with inflection points of 44-52 ELNs between ELNs and prognosis in GSRCC was identified.

Negative Lymph Node Is an Independent Prognostic Factor for Stage III Gastric Cancer Patients After Curative Gastrectomy: A Surveillance, Epidemiology, and End Results-Based Study

BACKGROUND

Negative lymph node (NLN)' s prognostic impact on stage III gastric cancer (GC) patients after curative gastrectomy has not been rigorously studied. We aimed to explore the relationship between NLNs count and outcomes of stage III GC patients.

METHODS

We retrospectively investigated stage III gastric cancer cases between 2008 and 2018 from Surveillance, Epidemiology, and End Results (SEER) database. Variables were compared by chi2 test. Kaplan-Meier methods and COX proportional hazard models were used to ascertain independent prognostic factors. Survival differences among the subgroups were analyzed to assess the effects of NLN count on overall survival (OS) in stage III GC patients.

RESULTS

2373 patients with curative gastrectomy for stage III GC were identified. Univariate analysis demonstrated that NLNs count >14 was associated better 5-year OS (43.7% VS 23.1%, P< .001) comparing with the NLNs count ≤ 14. Subgroup analysis showed that the NLNs count could predict survival in both node-negative and node-positive patients. Multivariate analysis revealed NLNs count is an independent prognostic factor.

CONCLUSIONS

The NLNs count is an independent prognostic factor for survival in stage III gastric cancer patients after curative gastrectomy and should be recommended for clinical applications.

The Influence of Group No.8p Lymph Node Dissection on the Prognosis of Advanced Gastric Cancer

BACKGROUND

Controversy over whether No.8p lymph nodes (LNs) involvement is distant or regional metastasis remains, and the possible inclusion of No.8p LNs in D2 lymphadenectomy is unclear.

AIM

This work aimed to investigate the effect of No.8p LN dissection on the prognosis of patients with different LN metastases in advanced gastric cancer (GC).

METHODS

A retrospective case-control study was used to collect 1149 cases of radical gastrectomy from July 2003 to April 2013. The patients were divided into the No.8a group (303 cases) and the No.8a + 8p group (846 cases) according to whether No.8p LN dissection was performed. The effect of No.8p LN dissection on the prognosis of patients with different total number of LN metastasis was analyzed.

RESULTS

Both No.8p positive and No.8p dissection were independent prognostic factors in patients with advanced GC. The 5-year overall survival rate (OS) of the positive No.8p group was 13.0%, and that of the negative No.8p group was 66.6%; the difference was significant (P < 0.05). In the group where the total number of LN metastasis was 3-15, the OS of patients with positive No.8p was significantly lower than that of the negative group (P < 0.05). The 5-year OS of the No.8a + 8p dissection group was 65.4%, and that of the No.8a dissection group was 55.5%; the difference was significant (P < 0.05). In the group where the total number of LN metastasis was 0-2, the No.8a + 8p dissection group had significantly higher OS than the No.8a dissection group (P < 0.05).

CONCLUSION

For patients with advanced GC, No.8p LN metastasis indicates a poor prognosis. LN dissection in the No.8a + 8p group may further improve the prognosis of some patients, especially when the total number of LN metastasis is 0-2.

Clinical Application of Indocyanine Green Fluorescence Technology in Laparoscopic Radical Gastrectomy

Background

This study aimed to observe the application and evaluate the feasibility and safety of indocyanine green (ICG) fluorescence technology in laparoscopic radical gastrectomy (LRG).

Methods

Patients who underwent LRG & D2 lymphadenectomy at Qilu Hospital of Shandong University were included between January 2018 and August 2019. According to whether endoscopic injection of ICG was performed, patients were assigned to the ICG group (n=107) and the control group (n=88). The clinicopathologic features, retrieved lymph nodes, postoperative recovery, and follow-up data were compared between the two groups.

Results

Baseline characteristics are comparable. The ICG group had a significantly larger number of lymph nodes retrieved (49.55 ± 12.72 vs. 44.44 ± 10.20, P<0.05), shorter total operation time (min) (198.22 ± 13.14 vs. 202.50 ± 9.91, P<0.05), shorter dissection time (min) (90.90 ± 5.34 vs. 93.74 ± 5.35, P<0.05) and less blood loss (ml) (27.51 ± 12.83 vs. 32.02 ± 17.99, P<0.05). The median follow-up time was 29.0 months (range 1.5-43.8 months), and there was no significant difference between the ICG group and the control group in 2-year OS (87.8% vs. 82.9%, P>0.05) or DFS (86.0% vs. 80.7%, P>0.05).

Conclusions

ICG fluorescence technology in laparoscopic radical gastrectomy has advantages in LN dissection, operation time, and intraoperative blood loss. The 2-year OS and 2-year DFS rates between the two groups were comparable. In conclusion, ICG fluorescence technology is feasible and safe.

Prognostic impact of lymph node micrometastasis in patients with gastric cancer

PURPOSE

The clinical significance of lymph node micrometastasis (LNMM) remains controversial in gastric cancer (GC). In this study, we investigated the prognostic impact of LNMM in patients with GC.

METHODS

A total of 624 patients with pathologically lymph node metastasis-negative (pN0) and N1 status (pN1) who underwent gastrectomy between 2004 and 2018 were enrolled in this retrospective study. The diameter of tumor cell clusters in metastatic lymph nodes was measured in 120 patients with pN1 GC.

RESULTS

Patients with lymph node tumors < 1500 μm in diameter (LNMM) had a significantly better prognosis than those with tumors ≥ 1500 μm in diameter (p = 0.012; log-rank test). Cox's proportional hazards model revealed that LNMM (p = 0.016), several dissected lymph nodes (p = 0.049), and the provision of adjuvant chemotherapy (p = 0.002) were independent prognostic factors for the overall survival of patients with pN1 GC. There was no significant difference in the overall survival between patients with LNMM who received chemotherapy and those who did not (p = 0.332).

CONCLUSIONS

LNMM is associated with a favorable prognosis and maybe an independent prognostic marker in patients with pN1 GC. LNMM in GC may be considered a factor preventing adjuvant chemotherapy.

Detection and prognostic significance of isolated tumor cells and micrometastases in pelvic lymph nodes of patients with early ovarian clear cell carcinoma

BACKGROUND/PURPOSE

Ovarian clear cell carcinoma (OCCC) accounts for approximately 18% of all epithelial ovarian malignancies in Taiwan and portends a poor prognosis. Here, we sought to investigate whether immunohistochemistry with an anti-pan-cytokeratin antibody cocktail (AE1/AE3) can be used as an adjunct to hematoxylin and eosin (H&E) staining for improving the detection of isolated tumor cells (ITCs) and micrometastasis to pelvic lymph nodes (LNs). We also assessed whether these lesions may predict disease recurrence.

METHODS

Pelvic lymphadenectomy specimens were obtained from 197 patients with stage 1 OCCC who had undergone surgery between 2000 and 2018 from Linkou and Kaohsiung Chang Gung Memorial Hospital. Immunohistochemical staining with AE1/AE3 was applied to a total of 1186 slides. Clusters of metastatic tumor cells, detected immunohistochemically, were classified as ITCs (clusters with diameters of ≤0.2 mm) or micrometastases (tumor cell clusters of >0.2 but ≤2.0 mm). We also assessed the diameter of metastases in patients with positive lymph nodes (stage IIIA1, n = 3, 7 positive nodes).

RESULTS

Clusters with a positive AE1/AE3 staining were identified in five (2.53%) of the 197 patients (ITCs, n = 3; micrometastasis, n = 2). Four patients had no evidence of disease recurrence but a patient recurred at follow-up. Metastatic foci of patients with stage IIIA1 disease were all >2.0 mm in size.

CONCLUSION

Immunohistochemical staining with AE1/AE3 can identify micrometastasis or ITCs in LNs missed on routine H&E staining. The role of micrometastasis in predicting recurrent OCCC and implementing on treatment strategies requires further investigation.

Occult Tumour Cells in Lymph Nodes from Gastric Cancer Patients: Should Isolated Tumour Cells Also Be Considered?

INTRODUCTION

Regional lymph node metastasis is an important prognostic factor for patients with gastric cancer. Occult tumour cells (OTCs), including either micrometastases (MMs) or isolated tumour cells (ITCs), may be a key factor in the development of cancer recurrence in pN0 patients.

AIMS

We aimed to determine the frequency and prognostic significance for disease recurrence of OTCs.

MATERIALS AND METHODS

This retrospective cohort study included all consecutive patients with pN0 gastric adenocarcinoma between January 2000 and December 2011 (n = 73). Immunohistochemistry using the pan-cytokeratin antibody AE1/AE3 was used to detect OTCs in 1257 isolated lymph nodes.

RESULTS

OTCs were identified in 30 patients (41%), including 20 cases with MMs (27%) and 10 cases with ITCs (14%). Disease recurrence and cancer-related death were observed in 24 (33%) and 20 patients (27%), respectively, and both were significantly associated with the detection of OTCs. A significant difference was also observed for the mean survival time between patients with OTCs and those without OTCs [100 vs 158 months (p = 0.015)]. The presence of OTCs was statistically significantly associated with the Lauren classification, tumour size and lymphatic permeation. Multivariate analyses revealed that only age, T stage and the presence of ITCs in lymph nodes were independent factors for recurrence. The presence of ITCs increased the risk for recurrence by 11.1-fold.

CONCLUSIONS

In a significant proportion of patients diagnosed as stage pN0, OTCs may be identified in lymph nodes if carefully searched for, which can negatively affect their prognosis. The presence of ITCs was found to be an independent factor for recurrence and after proper validation should be considered during lymph node assessment for prognosis definition.

Impact of multisection and immunohistochemistry in lymph node staging of Gastric Carcinoma - Case series

Gastric carcinoma (GC) locoregional recurrence may occur even in cases where the tumor has been completely resected, possibly due to lymph node (LN) micrometastases. It is estimated that in 10% to 30% of cases, LN micrometastases are not detected by a conventional method for histological assessment of LN metastases with hematoxylin-eosin (HE). A cross-sectional study assessed 51 patients with GC by histological evaluation of the LN micrometastases through LN multi sectioning associated with immunohistochemistry analysis with monoclonal antibodies AE1 and AE3. Total gastrectomy was performed in 51% of patients. The total number of resected LN nodes was 1698, with a mean number of resected LN of 33.3 ± 13.2 per surgical specimen, of which 187 had metastasis. After the application of LN multisection and immunohistochemistry, LN micrometastases were found in 45.1% of the cases. LN staging changed in 29.4%, and tumor staging changed in 23.5% of the cases. In patients initially staged as pN0, LN staging and tumor staging changed, both in 19.2% of the cases. In patients initially staged as pN1 or more, LN staging changed in 40.0% of them, and tumor staging changed in 28.0% of the cases. The accuracy of HE for the histological staging of LN tumoral involvement was 76%, which was considered insufficient for CG patients staging. Investigation of LN micrometastasis through LN multisection and immunohistochemistry should be performed, particularly in cases where the presence of blood and lymphatic vessel invasion has been identified after conventional histological analysis, as well as in patients with advanced GC.

Negative lymph node count as an independent prognostic factor in stage III patients after curative gastrectomy: A retrospective cohort study based on a multicenter database

OBJECTIVE

To examine the prognostic value of negative lymph node (NLN) count in stage III gastric cancer (GC) patients after curative gastrectomy.

METHODS

The clinicopathological data of 2942 stage III patients who underwent curative gastrectomy between 2001 and 2011 were analyzed. Only patients with ≥16 examined lymph nodes (ELNs) were included. After cut-point survival analysis, the 2942 patients were divided into three subgroups with NLN counts of 0, 1-9, and ≥10. Survival differences among the subgroups were analyzed to assess the effects of NLN count on stage migration and overall survival (OS) in stage III GC patients. Spearman's correlation coefficient was used to assess the relationships between the ELN count and the positive lymph node (PLN) count, the ELN count and the NLN count, and the NLN count and the PLN count.

RESULTS

Survival analyses revealed that the NLN count was significantly associated with OS (P = 0.001) and was an independent predictor (P < 0.01) of prognosis in stage III GC patients. Subgroup analysis showed that the prognostic evaluation accuracy was highest when the NLN count was ≥10 for stage III patients. Stage migrations were mainly detected in the following pathological tumor-node (pTN) subgroups: pT2N3a with 1-9 NLNs and pT2N3b with ≥10 NLNs, and pT3N3a with 1-9 NLNs and pT3N3b with ≥10 NLNs. NLN count was positively correlated with the ELN and the PLN counts for pT2N3 and pT3N3 stage GC patients (r = 0.694 and r = 0.881 for pT2N3 patients; r = 0.685 and r = 0.902 for pT3N3 patients, respectively; P < 0.001). These findings indicate that the NLN count may be a useful prognostic predictor in stage III GC patients.

CONCLUSIONS

The NLN count may improve the prognostic prediction efficiency of the tumor-node-metastasis (TNM) classification for GC, especially for stage III patients, and should be recommended for clinical applications.

Outcomes of Endoscopic Submucosal Dissection for Early Gastric Cancer with Undifferentiated-Type Histology: A Clinical Simulation Using a Non-Selected Surgical Cohort

Background/Aims

Outcomes of endoscopic submucosal dissection (ESD) for undifferentiated-type early gastric cancer (EGC) need to be further evaluated. We aimed to simulate the outcomes of ESD for undifferentiated-type EGC from a surgical database.

Methods

Among 802 patients who underwent gastrectomy with endoscopic biopsy for poorly differentiated adenocarcinoma (PD-type) or signet ring cell carcinoma (SRC-type), ESD candidates meeting the expanded indication (n=280) were selected by reviewing the endoscopic images. According to the surgical pathologic results, the outcomes of the ESD simulation were evaluated.

Results

Among the candidates, 104 (37.1%) were PD-type and 176 (62.9%) were SRC-type. The curative resection (CR) rate was 42.1%. Among the patients with CR, three patients (2.5%) showed lymph node metastasis (LNM). Three EGCs with CR and LNM were mucosal cancers ≥1.0 cm in size. The CR rate was higher in the SRC-type than in the PD-type (48.3% vs 31.7%, respectively, p=0.007). In the SRC-type, the CR rate was increased, with a smaller size criterion for the ESD indication, but was similar between the 1.0 cm and 0.6 cm criteria (63.3% and 63.6%, respectively), whereas the CR rate was below 50% in all of the different tumor size criteria (2.0 to 0.6 cm) in the PD-type.

Conclusions

In undifferentiated-type EGC, ESD should be considered in selected patients with tumor sizes ＜1 cm and SRC histology.

The effect of perigastric lipolymphatic tissue grouping by surgeon on the number of pathologic sampled lymph nodes after radical gastrectomy

To analyze the impact of perigastric lipolymphatic tissue grouping by the surgeon on the number of pathologic sampled lymph nodes and to explore the appropriate lymph node delivery process.The authors collected the medical records of gastric cancer patients who were hospitalized in Wuhan Union Hospital during the period January 2016 to January 2018. The authors selected 126 patients and divided them into experimental group and control group, 63 cases in each group. Samples of standard complete gastrectomy or distal gastrectomy +D2 lymph node dissection was performed. In experimental group, the fresh en bloc specimen was treated by the surgeon before the formalin fixation. The perigastric lipolymphatic tissue was divided into the lymph node grouping according to JSGC guideline III. Then the stomach and each group of lipolymphatic tissue were fixed and then transferred to the pathologic department, then the lymph nodes were harvested by the pathological technician. In control group, the whole en bloc specimen was fixed with formalin and then lymph nodes were detected by palpation and thin slice inspection, and then harvested by the pathological technician. The lymph node acquisition was compared in 2 groups.The total number of lymph nodes in experimental group is 2611, the number of negative lymph nodes is 2273; the total number of lymph nodes in control group is 1643, the number of negative lymph nodes is 1351; the comparison difference in 2 groups was statistical sense (P < .01); patients with lymph node which reach 25 pieces/person of experimental group could reach a ratio of 90.1%, and that is 47.6% in the control group, the comparison difference in 2 groups was statistical sense (P < .01), the number of positive lymph nodes did not increase significantly compared with the control group, and there was no statistical significance in the 2 groups.Dissecting the perigastric lipolymphatic tissue into lymph node groups by the surgeon might improve the total number of lymph node harvested by the pathological technician, and increase the rate of cases with >25 lymph nodes. Our results also implicated that, when the routing harvested lymph nodes were more than 20, the increasing number by perigastric lipolymphatic tissue grouping might result from more negative lymph nodes detected and might not result in stage migrating.

Effect of total number of harvested lymph nodes on survival outcomes after curative resection for gastric adenocarcinoma: findings from an eastern high-volume gastric cancer center

BACKGROUND

Greater lymph node retrieval in gastric cancer improves staging accuracy and may improve survival from increased clearance of nodal micrometastasis. This retrospective cohort study investigated if more lymph nodes removed in gastric cancer increases survival and if such effect is stage-specific due to differential risks of nodal micrometastasis and systemic disease.

METHODS

The prospectively collected database of curatively resected gastric cancer patients in National Cancer Center, South Korea between 2000 and 2009 was reviewed. Disease-free survival (DFS) and overall survival (OS) for all patients and for each stage according to number of lymph nodes examined (1-30, 31-45, > 45) were analyzed.

RESULTS

Of 4049 patients, 96.6% and 98.4% underwent D2 (perigastric and extragastric) lymphadenectomy and had ≥ 15 lymph nodes examined. Mean number of nodes examined was 43. Five-year OS & DFS rates were 83.3% and 80.7%. Patients with > 45 nodes examined had significantly lower DFS (p = 0.002) and OS (p = 0.007) compared to those with 1-30 and 31-45 nodes. However, proportion of patients with > 45 nodes examined increased with stage (p = 0.0005). Per stage, there was no significant difference in DFS and OS according to number of nodes examined except for stage IIIA favoring more nodes (p = 0.018 and p = 0.044, respectively). Similar trend was seen in stage IIB. Number of examined nodes positively correlated with number of pathologic nodes for all patients (r = 0.144, p < .001) but not for stage IIB and IIIA. Number of nodes examined was a significant survival predictor in stage IIIA.

CONCLUSION

Greater lymph node harvest showed improved survival in intermediate-stage gastric cancer.

Acquisition of histologic diversity contributes to not only invasiveness but also lymph node metastasis in early gastric cancer

BACKGROUND

As more endoscopic resections are performed in early gastric cancer, the pretreatment prediction of lymph node metastasis (LNM) becomes more important. Some tumor characteristics including histologic type, invasion depth, ulceration, size, and lymphovascular invasion have been used to determine the endoscopic resectability of early gastric cancer; however, a more detailed analysis between clinicopathologic factors and lymph node metastasis is needed.

METHODS

We analyzed the correlation between the clinicopathological findings and LNM with 310 cases of early gastric cancer by dividing invasion depths in detail.

RESULTS

LNM occurred in 3.2% and 16.2% of the T1a and T1b tumors, respectively. LNM was associated with invasion depth (p=0.002) and lymphatic (p<0.001) and perineural (p=0.013) invasion. Among them, lymphatic invasion was the most powerful factor associated with LNM and significantly constant in T1a and T1b. The rate of LNM increased gradually as the tumor invaded deeper, and invasion of the muscularis mucosae layer was associated with an increased mixed adenocarcinoma incidence, suggesting that histologic diversity was associated with tumor invasiveness.

CONCLUSIONS

We demonstrated that lymphatic invasion was the most important and powerful parameter for LNM in early gastric cancers. In addition, tumor invasiveness into the muscularis mucosae was accompanied by tumor histologic diversity.

N staging: the role of the pathologist

Gastric cancer is the second cause of cancer-related mortality worldwide. Metastases, including lymph nodes ones, heavily influence the prognosis of this disease. The pathological detection of positive lymph nodes is pivotal for an optimal prognostication and clinical management of affected individuals. Several factors influence the pathological investigation of surgical specimens, ultimately affecting the number of retrieved lymph nodes and, with it, the reliability of N staging. The pathologist plays a central role in optimizing this process. Factors influencing lymph node retrieval and analysis will be herein reviewed, together with the procedures adopted for an optimal pathological analysis of lymph nodes in gastric cancer.

DETECTION OF OCCULT LYMPH NODE TUMOR CELLS IN NODE-NEGATIVE GASTRIC CANCER PATIENTS

BACKGROUND

The presence of lymph nodes metastasis is one of the most important prognostic indicators in gastric cancer. The micrometastases have been studied as prognostic factor in gastric cancer, which are related to decrease overall survival and increased risk of recurrence. However, their identification is limited by conventional methodology, since they can be overlooked after routine staining.

AIM

To investigate the presence of occult tumor cells using cytokeratin (CK) AE1/AE3 immunostaining in gastric cancer patients histologically lymph node negative (pN0) by H&E.

METHODS

Forty patients (T1-T4N0) submitted to a potentially curative gastrectomy with D2 lymphadenectomy were evaluated. The results for metastases, micrometastases and isolated tumor cells were also associated to clinicopathological characteristics and their impact on stage grouping. Tumor deposits within lymph nodes were defined according to the tumor-node-metastases guidelines (7th TNM).

RESULTS

A total of 1439 lymph nodes were obtained (~36 per patient). Tumor cells were detected by immunohistochemistry in 24 lymph nodes from 12 patients (30%). Neoplasic cells were detected as a single or cluster tumor cells. Tumor (p=0.002), venous (p=0.016), lymphatic (p=0.006) and perineural invasions (p=0.04), as well as peritumoral lymphocytic response (p=0.012) were correlated to CK-positive immunostaining tumor cells in originally negative lymph nodes by H&E. The histologic stage of two patients was upstaged from stage IB to stage IIA. Four of the 28 CK-negative patients (14.3%) and three among 12 CK-positive patients (25%) had disease recurrence (p=0.65).

CONCLUSION

The CK-immunostaining is an effective method for detecting occult tumor cells in lymph nodes and may be recommended to precisely determine tumor stage. It may be useful as supplement to H&E routine to provide better pathological staging.

Detection of cervical lymph node micrometastasis and isolated tumor cells in oral squamous cell carcinoma using immunohistochemistry and serial sectioning

INTRODUCTION

Oral squamous cell carcinoma (OSCC) comprises one of the largest subsets of cancers with a tendency for regional metastasis. Nodal status is a key prognostic indicator in patients with OSCC, particularly with N0 neck. Occult metastasis in the form of micrometastasis (MM) and isolated tumor cells (ITCs), often goes undetected by routine hematoxylin and eosin (H&E) examination using 1-2 sections for analysis. This limitation could be overcome by combining serial sectioning (SS) with immunohistochemistry (IHC) for the detection of MM and ITC. Pan-cytokeratin (pan-CK) (AE1/AE3) is particularly a useful marker to detect these deposits as their presence has resulted in varied interpretations and different applications of the tumor-node-metastasis system.

OBJECTIVES

The objective of the study was to identify a suitable method for detecting MM and ITC in lymph nodes (LNs) of OSCC by combining SS and IHC and to compare it with conventional H&E staining.

MATERIALS AND METHODS

This laboratory-based, prospective study was conducted on 133 LNs harnessed from ten patients treated with radical neck dissection for primary OSCC. The LNs were subjected to SS at 100 μm intervals. The sections were stained with routine H&E staining, pan-CK and analyzed for MM and ITC according to criteria laid by Hermanek et al.

STATISTICAL ANALYSIS

The obtained data were subjected to statistical analysis using Chi-square test.

RESULTS

The application of combination of SS and IHC using pan-CK (AE1/AE3) in our study revealed the presence of MM and ITC in 2.25% of the LNs diagnosed as negative on routine H&E examination. The detection of these occult metastatic deposits resulted in upstaging of 33.33% of the patients.

CONCLUSION

In the view of crucial role of occult LN metastasis in prognosis and survival of OSCC patients with N0 neck, diagnostic tools such as IHC staining, particularly with pan-CK (AE1/AE3), combined with SS should be preferred over conventional methods as they result in upstaging, thus sparing the low-risk patients the morbidity of unnecessary treatment.

Occult Tumor Cells in Lymph Nodes of Patients with Gastric Cancer: A Systematic Review on Their Prevalence and Predictive Role

BACKGROUND AND AIMS

The presence of lymph node (LN) metastasis is a key prognostic factor for gastric adenocarcinoma. However, even among patients without LN metastasis (N0), recurrence may occur. In some of these cases, occult tumor cells (OTC) are thought to play an important role. We aimed to determine the prevalence of OTC and its clinical relevance.

METHODS

We conducted a systematic review of studies in English published until September 2013 that addressed OTC prevalence and/or its clinical relevance. The studies were retrieved from the MEDLINE database.

RESULTS

We included 42 studies. The most frequently used methods for detecting OTC were immunohistochemical examination (IHC) and/or polymerase chain reaction (PCR) with a wide range of markers. Using IHC for OTC detection, in patients and in LN, the prevalence varied from 9 to 88% and 0.4 to 42%, respectively. With PCR, it ranged from 17 to 46% in patients, and from 3 to 33% in LN. In the studies assessing the predictive role of OTC in gastric cancer recurrence (n=24), 8 studies found no statistical association, while 18 concluded that OTC presence was associated with poorer prognosis. However, only 6 studies presented a significantly different 5-year survival rate between patients with and without LN micrometastasis.

CONCLUSIONS

OTC seems to occur in gastric cancer patients with a variable prevalence, depending on the definition, methods and setting. The majority of the retrieved studies (75%) evaluating the predictive role of OTC conclude that its presence is associated with a worse prognosis.

Endoscopic submucosal dissection for undifferentiated-type early gastric cancer: do we have enough data to support this?

Although endoscopic submucosal dissection (ESD) is now accepted for treatment of early gastric cancers (EGC) with negligible risk of lymph node (LN) metastasis, ESD for intramucosal undifferentiated type EGC without ulceration and with diameter ≤ 2 cm is regarded as an investigational treatment according to the Japanese gastric cancer treatment guidelines. This consideration was largely based on the analysis of surgically resected EGCs that contained undifferentiated type EGCs; however, results from several institutes showed some discrepancies in sample size and incidence of LN metastasis. Recently, some reports about the safety and efficacy of ESD for undifferentiated type EGC meeting the expanded criteria have been published. Nonetheless, only limited data are available regarding long-term outcomes of ESD for EGC with undifferentiated histology so far. At the same time, endoscopists cannot ignore the patients' desire to guarantee quality of life after the relatively non-invasive endoscopic treatment when compared to conventional surgery. To satisfy the needs of patients and provide solid evidence to support ESD for undifferentiated EGC, we need more delicate tools to predict undetected LN metastasis and more data that can reveal predictive factors for LN metastasis.

Current status and scope of lymph node micrometastasis in gastric cancer

Recently, lymph node micrometastasis has been evaluated for its prognostic value in gastric cancer. Lymph node micrometastasis cannot be detected via a usual pathologic examination, but it can be detected by using some other techniques including immunohistochemistry and reverse transcription-polymerase chain reaction assay. With the development of such diagnostic techniques, the detection rate of lymph node micrometastasis is constantly increasing. Although the prognostic value of lymph node micrometastasis remains debatable, its clinical impact is apparently remarkable in both early and advanced gastric cancer. At present, studies on the prognostic value of lymph node micrometastasis are evolving to overcome its current limitations and extend the scope of its application.

Gastric carcinoma: stage migration by immunohistochemically detected lymph node micrometastases

BACKGROUND

Immunohistochemically detected micrometastases of the regional lymph nodes in previously pN0-classified gastric cancer have been incorporated in the TNM staging system. This study aims to determine the incidence of such micrometastases in gastric carcinoma and to investigate their impact on stage grouping and prognosis.

METHODS

Ninety-five patients with gastric carcinoma classified as pN0 by conventional histological examination were enrolled. All patients underwent gastric resection with regional lymphadenectomy between 2006 and 2010. A total of 2018 lymph nodes was obtained (median, 20 Lymph nodes) and immunohistostained with anti-pan cytokeratin antibody (KL1).

RESULTS

Micrometastases were detected in regional lymph nodes by immunohistostaining in 16 out of all 95 patients. Fourteen patients were upstaged by micrometastasis-positive regional lymph nodes. Three patients demonstrated lymph nodes with isolated tumor cells alone. A significantly higher incidence of micrometastases was observed in patients with diffuse histologic type (p = 0.007) and total gastrectomy (p = 0.007). When isolated tumor cells were also regarded as lymph node involvement, the recurrence rate was significantly higher for node-positive than for node-negative patients and for those younger than 70 years (33.3 and 6.7 %, respectively; p = 0.026; n = 39). Overall survival analysis revealed no significant difference between micrometastasis-positive and micrometastasis-negative patients.

CONCLUSION

Immunohistostaining of regional lymph nodes in node-negative gastric carcinoma patients leads to an increased detection of micrometastases with significant implications for the staging system. Although no impact on survival time was shown, the higher recurrence rate for node-positive patients younger than 70 years indicates a prognostic value of immunohistochemically detectable micrometastases.

Should lymph node micrometastasis be considered in node staging for gastric cancer?: the significance of lymph node micrometastasis in gastric cancer

BACKGROUND

In TNM staging system, lymph node staging is based on the number of metastatic lymph nodes in gastric cancer and micrometastasis is not considered. Several reports proposed the importance of lymph node micrometastasis as the causative factor for recurrence and poor survival, but it remains controversial among researchers.

METHODS

A total of 482 gastric cancer patients who underwent curative resection from 2004 to 2010 at Korea University Medical Center Ansan Hospital, South Korea were prospectively enrolled. For detecting lymph node micrometastasis, immunohistochemical staining with anti-cytokeratin antibody (CAM 5.2) was performed on negative lymph nodes by hematoxylin-eosin (H-E) staining. Survival differences were compared between conventional node staging and new node staging that took micrometastasis into consideration. Also, the prognostic value of lymph node micrometastasis was investigated in multivariate analysis.

RESULTS

A total of 156 patients (32.4%) showed lymph node micrometastasis. Overall, the micrometastatic group had more advanced tumor and lymph node stage, lymphovascular cancer cell invasion, a higher rate of recurrence, and poor survival. Furthermore, when the cumulative numbers of macro- and micrometastatic lymph nodes were calculated together, the discriminative power of survival difference between each node stage became more stratified. Also, multivariate analysis using Cox's proportional hazards model demonstrated perineural invasion, pathologic T stage, dissected lymph nodes, macro- and micrometastatic lymph nodes are independent prognostic factors.

CONCLUSIONS

Lymph node micrometastasis was clinically significant as a risk factor for recurrent gastric cancer. Lymph node micrometastasis should be considered when estimating TNM stage for determining prognosis and the best treatment strategy.

Prognostic value of the lymph node ratio in stage III gastric cancer patients undergoing radical resection

OBJECTIVE

The aim of this study was to investigate the prognostic value of metastatic lymph node ratio (LNR) in patients having radical resection for stage III gastric cancer.

METHODS

A total of 365 patients with stage III gastric cancer who underwent radical resection between 2002 and 2008 at Tianjin Medical University Cancer Institute and Hospital were analyzed. The cut-point survival analysis was adopted to determine the appropriate cutoffs for LNR. Kaplan-Meier survival curves and log-rank tests were used for the survival analysis.

RESULTS

By cut-point survival analysis, the LNR staging system was generated using 0.25 and 0.50 as the cutoff values. Pearson's correlation test revealed that the LNR was related with metastatic lymph nodes but not related with total harvested lymph nodes. Cox regression analysis showed that depth of invasion and LNR were the independent predictors of survival (p<0.05). There was a significant difference in survival between each pN stages classified by the LNR staging, however no significant difference was found in survival rate between each LNR stages classified by the pN staging.

CONCLUSIONS

The LNR is an independent prognostic factor for survival in stage III gastric cancer and is superior to the pN category in TNM staging. It may be considered as a prognostic variable in future staging system.

Endoscopic submucosal dissection for undifferentiated-type early gastric cancer: Do we have enough data to support this?

Although endoscopic submucosal dissection (ESD) is now accepted for treatment of early gastric cancers (EGC) with negligible risk of lymph node (LN) metastasis, ESD for intramucosal undifferentiated type EGC without ulceration and with diameter ≤ 2 cm is regarded as an investigational treatment according to the Japanese gastric cancer treatment guidelines. This consideration was largely based on the analysis of surgically resected EGCs that contained undifferentiated type EGCs; however, results from several institutes showed some discrepancies in sample size and incidence of LN metastasis. Recently, some reports about the safety and efficacy of ESD for undifferentiated type EGC meeting the expanded criteria have been published. Nonetheless, only limited data are available regarding long-term outcomes of ESD for EGC with undifferentiated histology so far. At the same time, endoscopists cannot ignore the patients’ desire to guarantee quality of life after the relatively non-invasive endoscopic treatment when compared to conventional surgery. To satisfy the needs of patients and provide solid evidence to support ESD for undifferentiated EGC, we need more delicate tools to predict undetected LN metastasis and more data that can reveal predictive factors for LN metastasis.

Prediction of risk factors for lymph node metastasis in early gastric cancer

AIM: To explore risk factors for lymph node metastases in early gastric cancer (EGC) and to confirm the appropriate range of lymph node dissection.

METHODS: A total of 202 patients with EGC who underwent curative gastrectomy with lymphadenectomy in the Department of Surgery, Xinhua Hospital and Ruijin Hospital of Shanghai Jiaotong University Medical School between November 2003 and July 2009, were retrospectively reviewed. Both the surgical procedure and the extent of lymph node dissection were based on the recommendations of the Japanese gastric cancer treatment guidelines. The macroscopic type was classified as elevated (type I or IIa), flat (IIb), or depressed (IIc or III). Histopathologically, papillary and tubular adenocarcinomas were grouped together as differentiated adenocarcinomas, and poorly differentiated and signet-ring cell adenocarcinomas were regarded as undifferentiated adenocarcinomas. Univariate and multivariate analyses of lymph node metastases and patient and tumor characteristics were undertaken.

RESULTS: The lymph node metastases rate in patients with EGC was 14.4%. Among these, the rate for mucosal cancer was 5.4%, and 8.9% for submucosal cancer. Univariate analysis showed an obvious correlation between lymph node metastases and tumor location, depth of invasion, morphological classification and venous invasion (χ² = 122.901, P = 0.001; χ² = 7.14, P = 0.008; χ² = 79.523, P = 0.001; χ² = 8.687, P = 0.003, respectively). In patients with submucosal cancers, the lymph node metastases rate in patients with venous invasion (60%, 3/5) was higher than in those without invasion (20%, 15/75) (χ² = 4.301, P = 0.038). Multivariate logistic regression analysis revealed that the depth of invasion was the only independent risk factor for lymph node metastases in EGC [P = 0.018, Exp (B) = 2.744]. Among the patients with lymph node metastases, 29 cases (14.4%) were at N1, seven cases were at N2 (3.5%), and two cases were at N3 (1.0%). Univariate analysis of variance revealed a close relationship between the depth of invasion and lymph node metastases at pN₁ (P = 0.008).

CONCLUSION: The depth of invasion was the only independent risk factor for lymph node metastases. Risk factors for metastases should be considered when choosing surgery for EGC.

Comparison of immunohistology using pan-CK and EMA in the diagnosis of lymph node metastasis of gastric cancer, particularly micrometastasis and isolated tumor cells

The aim of this study was to identify a suitable method for detecting lymph node metastasis of gastric cancer (GCA) by hematoxylin and eosin (HE) and immunohistochemical (IHC) staining. We investigated lymph node metastasis using pan-cytokeratin (CK) and epithelial membrane antigen (EMA) IHC staining in a total of 1,422 lymph nodes from 100 patients who underwent radical gastrectomy between 2007 and 2009. Of 700 intestinal and 722 diffuse type GCA lymph nodes, the metastasis rates were significantly different when using conventional HE staining only or HE supplemented with IHC (P<0.01). The metastasis rate of the intestinal type was 31.71% using HE staining, 35.71% with HE and pan-CK, 35.57% with HE and EMA and 35.71% with combination examinations of all three. The false-positive rate was zero with pan-CK, 12.67% with EMA and 18.57% with all three. The metastasis rate of the diffuse type was 27.70% using HE staining, 36.01% with HE and pan-CK, 35.04% with HE and EMA and 36.01% with all three. The false-positive rate was zero with pan-CK, 7.58% with EMA and 11.86% with all three. For both types, the true-positive and -negative rates of pan-CK were higher than those of EMA. IHC staining is unnecessary if lymph node metastasis is detected in HE staining. If HE staining does not reveal metastasis, pan-CK staining should be performed for further diagnosis.

Does immunohistochemical staining have a clinical impact in early gastric cancer conducted endoscopic submucosal dissection?

AIM: To evaluate clinicopathologic parameters and the clinical significance related lymphovascular invasion (LVI) by immunohistochemical staining (IHCS) in endoscopic submucosal dissection (ESD).

METHODS: Between May 2005 and May 2010, a total of 348 lesions from 321 patients (mean age 63 ± 10 years, men 74.6%) with early gastric cancer (EGC) who met indication criteria after ESD were analyzed retrospectively. The 348 lesions were divided into the absolute (n = 100, differentiated mucosal cancer without ulcer ≤ 20 mm) and expanded (n = 248) indication groups after ESD. The 248 lesions were divided into four subgroups according to the expanded ESD indication. The presence of LVI was determined by factor VIII-related antigen and D2-40 assessment. We compared LVI IHCS-negative group with LVI IHCS-positive in each group.

RESULTS: LVI by hematoxylin-eosin staining (HES) and IHCS were all negative in the absolute group, while was observed in only the expanded groups. The positive rate of LVI by IHCS was higher than that of LVI by HES (n = 1, 0.4% vs n = 11, 4.4%, P = 0.044). LVI IHCS-positivity was observed when the cancer invaded to the mucosa 3 (M3) or submucosa 1 (SM1) levels, with a predominance of 63.6% in the subgroup that included only SM1 cancer (P < 0.01). In a univariate analysis, M3 or SM1 invasion by the tumor was significantly associated with a higher rate of LVI by IHCS, but no factor was significant in a multivariate analysis. There were no cases of tumor recurrence or metastasis during the median 26 mo follow-up.

CONCLUSION: EGCs of the absolute group are immunohistochemically stable. The presence of LVI may be carefully examined by IHCS in an ESD expanded indication group with an invasion depth of M3 or greater.

Detection and clinical significance of lymph node micrometastasis in gastric cardia adenocarcinoma

OBJECTIVES

Lymph node micro metastasis was investigated in gastric cardia adenocarcinoma (GCA) patients without lymph node metastasis on routine pathological examination. The relationship between micrometastasis and clinicopathological features was also evaluated.

METHODS

A total of 349 lymph nodes were obtained from 45 patients with GCA. Micrometastases were detected by immunohistochemical staining for the markers cytokeratin 19 (CK19) and CD44 variant 6 (CD44v6).

RESULTS

A total of 33 lymph nodes (9.5%) from 15 patients (33.3%) were positive for CK19. Of these, 27 lymph nodes (7.7%) from 12 patients (26.7%) were also positive for CD44v6. Micrometastasis was significantly related to depth of tumour invasion and Lauren classification (intestinal or diffuse). The recurrence rate was significantly higher and 2-year survival rate significantly lower in patients with than in those without lymph node micrometastasis, showing the necessity of detecting micrometastasis in GCA patients who test negative for lymph node metastasis on routine examination.

CONCLUSION

CK19 and CD44v6 were shown to be good markers for micrometastasis detection.

Lymph node, peritoneal and bone marrow micrometastases in gastric cancer: Their clinical significance

The 7th TNM classification clearly states that micrometastases detected by morphological techniques (HE stain and immunohistochemistry) should always be reported and calculated in the staging of the disease (pN1mi or M1), while patients in whom micrometastases are detected by non-morphological techniques (e.g., flow cytometry, reverse-transcriptase polymerase chain reaction) should still be classified as N0 or M0. In gastric cancer patients, micrometastases have been detected in lymph nodes, the peritoneal cavity and bone marrow. However, the clinical implications and/or their prognostic significance are still a matter of debate. Current literature suggests that lymph node micrometastases should be encountered for the loco-regional staging of the disease, while skip lymph node micrometastases should also be encountered in the total number of infiltrated lymph nodes. Peritoneal fluid cytology examination should be obligatorily performed in pT3 or pT4 tumors. A positive cytology classifies gastric cancer patients as stage IV. Although a curative resection is not precluded, these patients face an overall dismal prognosis. Whether patients with a positive cytology should be treated similarly to patients with macroscopic peritoneal recurrence should be evaluated further. Gastric cancer cells are detected with high incidence in the bone marrow. However, the published results make comparison of data between groups almost impossible due to severe methodological problems. If these methodological problems are overcome in the future, specific target therapies may be designed for specific groups of patients.

The clinical importance of micrometastases within the lymphatic system in patients after total gastrectomy

BACKGROUND

In spite of radical gastrectomy with resection of the lymphatic system, where no metastases are found during histopathological examination, about 30% of patients have relapse of the neoplastic process. This situation may be caused by micrometastases or isolated neoplastic cells in the lymphatic system which were not identified during a standard histopathological examination.

AIM

The aim of the study was to evaluate the clinical importance of micrometastases within the lymphatic system in patients with gastric cancer.

MATERIALS AND METHODS

A group of 20 patients treated for gastric cancer were subjected to retrospective analysis. Of all the patients who underwent surgery, a group with tumours classified as T1 or T2 was selected. No metastases within the lymphatic system were found in the standard evaluation - N0 mark. Paraffin-embedded blocks of lymph nodes were cut and new specimens were made, which were then stained again by means of immunohistochemistry. Antibodies against cytokeratin AE1/AE3 were used.

RESULTS

A total of 319 lymph nodes were assessed in 20 patients in an H + E examination. After the immunohistochemical examination, micrometastases within the lymphatic system were found in 4 (20%) patients and isolated neoplastic cells in other 4 (20%) patients.

CONCLUSION

On the basis of numerous publications and our own material, we think that the presence of micrometastases may be related to a worse prognosis. The clinical importance of micrometastases within the lymphatic system in patients after total gastrectomy.

Prognostic factors in patients with node-negative gastric cancer: an Indian experience

Background

The status of the regional nodes is the most important prognostic factor in gastric cancer. There are subgroups of patients with different prognosis even in node-negative patients of gastric cancer. The aim of this study is to analyze the factors influencing the prognosis in Indian patients with node-negative gastric cancer.

Methods

This was a retrospective analysis of patients who underwent radical gastrectomy in a tertiary cancer centre in India between1991 and 2007. The study group included only patients with histologically node-negative disease. Various clinical, pathological and treatment related factors in this group of patients were analyzed to determine their prognostic ability by univariate and multivariate analyses.

Results

Among the 417 patients who underwent gastrectomy during this period, 122 patients had node-negative disease. A major proportion of the patients had advanced gastric cancer. The 5-year overall survival and disease-free survival in all node-negative gastric cancer patients was 68.2% and 67.5% respectively. The overall recurrence rate in this group was 27.3%. On univariate analysis, the factors found to significantly influence the disease-free survival were the size, location and presence or absence of serosal invasion of the primary tumor. However, on multivariate analysis, only tumor size more than 3 cm and serosal invasion were found to be independently associated with an inferior survival.

Conclusion

Serosal invasion and primary tumor size more than 3 cm independently predict a poor outcome in patients with node-negative gastric cancer.

Effect of negative lymph node count on survival for gastric cancer after curative distal gastrectomy

AIMS

The aim of this study is to evaluate the long-term effect of negative lymph node (LN) counts on the prognosis after curative distal gastrectomy among gastric cancer patients.

METHODS

The study enrolled 634 patients with gastric cancer, who had undergone curative resection (R0) with distal gastrectomy from 1995 to 2004. Long-term surgical outcomes and relationships between the negative LN count and the 5-year survival rate were investigated.

RESULTS

The 5-year survival rate of the entire cohort was 57.6%. The number of metastasis negative LN was positively associated with the retrieved node according to the Pearson's correlation test (P < 0.001). Cox regression analysis showed the negative LN count was an independent predictor of survival (P < 0.05). Based on the statistical assumption the best fitting linear, linear regression showed a significant survival improvement based on increasing negative LN count for patients with stages I (P = 0.014), II (P = 0.011) and III (P = 0.003). The greatest survival differences were observed at cutoff value 10 negative LN counts for stage I, and 15 for stages II, III and IV.

CONCLUSION

Negative LN counts can reflect the extent of lymphadenectomy for gastric cancer after curative distal gastrectomy. The higher the negative LN count, the better the survival would be; the best long-term survival outcome was observed on the negative LN count more than 10 (stage I) or 15 (stages II, III, and IV).

One-step nucleic acid amplification (OSNA) for the application of sentinel node concept in gastric cancer

PURPOSE

This study was designed to apply safely the sentinel node navigation surgery (SNNS) to the malignancies, an accurate and prompt intraoperative diagnosis of SN is essential, and micrometastasis has been frequently missed by conventional frozen sections. Recently, a novel molecular-based rapid diagnosis for the lymph node (LN) metastases has been developed using (OSNA) in breast cancer, which takes approximately 30 min to obtain a final result. We evaluated the efficacy of OSNA in terms of the intraoperative diagnosis of LN metastasis in patients with gastric cancer.

METHODS

A total of 162 LNs dissected from 32 patients with gastric cancer was included in this study; 45 LNs were pathologically diagnosed as metastatic LNs and 117 LNs were negative. The LNs were bisected; halves were examined with H&E stain, and the opposite halves were subjected to OSNA analyses of CK19 mRNA. The CK19 mRNA expression was examined in the positive or negative metastatic LNs, and the correlation between the tumor volume and CK19 mRNA expression in the metastatic LNs was examined.

RESULTS

The CK19 mRNA expressions in the positive metastatic LNs were significantly higher than those of negative LNs. When 250 copies/μl was set as a cutoff value, the concordance rate was 94.4%, the sensitivity was 88.9%, and the specificity was 96.6%. The OSNA expression was significantly correlated with the estimated tumor volumes in the metastatic LNs.

CONCLUSIONS

The OSNA method is feasible and acceptable for detecting LN metastases in patients with gastric cancer. This should be applied for the intraoperative diagnosis in the SN-navigation surgery in gastric cancer.

Adverse prognosis of clustered-cell versus single-cell micrometastases in pN0 early gastric cancer

BACKGROUND AND OBJECTIVES

The clinical significance of lymph node micrometastasis (MM) for pN0 early gastric cancer is not well documented. The aim of this study is to clarify the risk factors of lymph node MM and the prognostic significance of the type of lymph node MM in patients with pN0 early gastric cancer.

METHODS

We investigated the lymph node MM with using an anticytokeratin immunohistochemical stain in 160 patients with pN0 early gastric cancer who underwent curative resection between 2000 and 2005.

RESULTS

We identified lymph node MM in 34 of 160 patients (21.3%), and in 84 of 1,656 lymph nodes (5.1%). MM occurred as single-cell type in 10 patients and as cell cluster type in 24 patients. MM was significantly associated with tumor size (P = 0.041) and lymphatic invasion (P = 0.008). The statistically significant prognostic factors affecting 5-year survival rates were depth of tumor invasion (P = 0.020), tumor size (P = 0.035), lymphatic invasion (P = 0.018), MM (P < 0.001), and type of MM (P < 0.001). Cox regression survival analysis revealed that the presence of MM, and particularly the cluster-type MM (P < 0.001), were independent prognostic factors in pN0 early gastric cancer patients.

CONCLUSIONS

The incidence of lymph node MM in patients with node negative early gastric cancer was 21.3%, and cancer cell cluster type of MM proved a primary independent prognostic factor for pN0 early gastric cancer patients.

The prognostic significance of isolated tumor cells in the lymph nodes of gastric cancer patients

BACKGROUND

The clinical significance of isolated tumor cells (ITC) detected immunohistochemically in the lymph nodes of gastric cancer patients is controversial. The aim of this study was to examine the prognostic impact of ITC in patients with gastric cancer.

METHODS

The data of a total of 402 patients with pathological T2N0 and T2N1 gastric cancer who underwent gastrectomy with D2 lymph node dissection between 1984 and 1990 at four participant hospitals were analyzed. All resected lymph nodes were reexamined by serial sectioning with hematoxylin & eosin (H&E) staining, and evaluated by immunohistochemistry using antibody against cytokeratin (AE1/3). The prevalence and prognostic significance of ITC were investigated.

RESULTS

ITC were detected in 187 of the 402 (47%) patients. A multivariate analysis identified the nodal status, histological type, and tumor size as significant factors predictive of the presence/absence of ITC. The 5-year and 10-year overall survival rates of patients with vs those without ITC were 84.4% (95% confidence interval [CI], 79.1-89.0) and 70.4% (95% CI, 64.1-76.7) vs 83.9% (95% CI, 78.6-89.2) and 72.0% (95% CI, 65.4-78.5), respectively. The hazard ratio for death in patients with ITC as compared with those without ITC was 0.90 (95% CI, 0.64-1.26; P = 0.53).

CONCLUSIONS

The presence of ITC in the lymph nodes does not affect the prognosis of patients with gastric cancer who have undergone gastrectomy with D2 lymph node dissection.

Prognostic impact of metastatic lymph node ratio on gastric cancer after curative distal gastrectomy

AIM: To investigate the prognostic impact of metastatic lymph node ratio (rN) on gastric cancer after curative distal gastrectomy.

METHODS: A total of 634 gastric cancer patients who underwent curative resection (R0) of lymph nodes at distal gastrectomy in 1995-2004. Correlations between positive nodes and retrieved nodes, between rN and retrieved nodes, and between rN and negative lymph node (LN) count were analyzed respectively. Prognostic factors were identified by univariate and multivariate analyses. Staging accuracy of the pN category (5th UICC/TNM system) and the rN category was compared according to the survival rates of patients. A linear regression model was used to identify the relation between rN and 5-year survival rate of the patients.

RESULTS: The number of dissected LNs was related with metastatic LNs but not related with rN. Cox regression analysis showed that depth of invasion, pN and rN category were the independent predictors of survival (P < 0.05). There was a significant difference in survival between LN stages classified by the rN category or by the pN category (P < 0.05). However, no significant difference was found in survival rate between LN stages classified by the pN category or by the rN category (P > 0.05). Linear regression model showed a significant linear correlation between rN and the 5-year survival rate of gastric cancer patients (β = 0.862, P < 0.001). Pearson’s correlation test revealed that negative LN count was negatively correlated with rN (P < 0.001).

CONCLUSION: rN category is a better prognostic tool than the 5th UICC pN category for gastric cancer patients after curative distal gastrectomy. Increased negative LN count can reduce rN and improve the survival rate of gastric cancer patients.

Risk factors for lymph node metastasis from gastric cancers with submucosal invasion

BACKGROUND

Accurate prediction of the metastatic status of lymph nodes (LNs) is clinically important for selecting treatment strategies in patients with gastric cancer with submucosal invasion (GCSM). In this study, we determined the risk factors for lymph node metastasis (LNM), including micrometastasis, in patients with GCSM.

MATERIALS AND METHODS

A total of 5610 LNs dissected from 189 patients with GCSM who had undergone a standard gastrectomy were immunostained with CAM 5.2 monoclonal antibody to detect LN micrometastasis. Clinicopathological risk factors for lymph node metastasis (LNM), including micrometastasis, were determined.

RESULTS

LNM was detected in 216 LNs (107 macroscopic metastases, 72 micrometastases, and 37 isolated tumor cells) in 55 (29.1%) of the 189 patients with GCSM. A multivariate analysis revealed that a tumor size of more than 20 mm, a mixed- or undifferentiated-type histology, a vertical tumor invasion depth in the submucosal layer (VTIDSM) of more than 0.5 mm, and the presence of lymphatic vessel invasion (LVI) were independent risk factors for LNM. The incidences of LNM in patients with 0, 1, 2, 3, and 4 risk factors were 0, 4.5, 11.4, 36.1, and 52.9%, respectively. Among the patients with only 1 or 2 risk factors, all the metastatic lesions were located only in the first tier. On the other hand, LNM in the second tier was also detected in 24.5% of the patients with more than 3 risk factors.

CONCLUSIONS

Tumor size, histologic type, VTIDSM, and LVI are important risk factors for predicting the presence and extent of LNM in patients with GCSM.

Routine modified D2 lymphadenectomy performance in pT1-T2N0 gastric cancer

AIM: To evaluate routine modified D2 lymphadenectomy in gastric cancer, based on immunohistochemically detected skip micrometastases in level II lymph nodes.

METHODS: Among 95 gastric cancer patients who were routinely submitted to curative modified D2 lymphadenectomy, from January 2004 to December 2008, 32 were classified as pN0. All level I lymph nodes of these 32 patients were submitted to immunohistochemistry for micrometastases detection. Patients in whom micrometastases were detected in the level I lymph node stations (n = 4) were excluded from further analysis. The level II lymph nodes of the remaining 28 patients were studied immunohistochemically for micrometastases detection and constitute the material of the present study.

RESULTS: Skip micrometastases in the level II lymph nodes were detected in 14% (4 out of 28) of the patients. The incidence was further increased to 17% (4 out of 24) in the subgroup of T1-2 gastric cancer patients. All micrometastases were detected in the No. 7 lymph node station. Thus, the disease was upstaged from stage IA to IB in one patient and from stage IB to II in three patients.

CONCLUSION: In gastric cancer, true R0 resection may not be achieved without modified D2 lymphadenectomy. Until D2+/D3 lymphadenectomy becomes standard, modified D2 lymphadenectomy should be performed routinely.

The prognostic impact of isolated tumor cells in lymph nodes of T2N0 gastric cancer: comparison of American and Japanese gastric cancer patients

BACKGROUND

The clinical significance of immunohistochemically detected isolated tumor cells (ITC) in lymph nodes of gastric cancer patients is controversial. This study examined the prognostic impact of ITC on patients with early-stage gastric cancer in two large volume centers in the United States and Japan.

METHODS

Fifty-seven patients with T2N0M0 gastric carcinoma who underwent gastric resection between January 1987 and January 1997 at Memorial Sloan-Kettering Cancer Center (MSKCC) in New York and 107 patients resected at National Cancer Center Hospital (NCCH) in Tokyo between January 1984 and December 1990 were studied. The sections were newly prepared from each lymph node for immunohistochemical staining for cytokeratin. Lymph nodes and original specimens from MSKCC were examined by pathologists in NCCH. The prognostic significance of the presence of ITC in lymph nodes was investigated in patients of both institutions.

RESULTS

ITC were identified in 30 of 57 patients (52.6%) at MSKCC and in 38 of 107 patients (35.5%) at NCCH. In both institutions, there was no significant difference in the prognosis of the studied patients with or without ITC (P= .22, .86 respectively).

CONCLUSIONS

The presence of ITC detected by immunohistochemistry in the regional lymph nodes did not affect the prognosis of American and Japanese patients with T2N0M0 gastric carcinoma who underwent gastrectomy with D2 lymph node dissection.

Prognostic significance of occult lymph node micrometastasis in gastric cancer: a histochemical and immunohistochemical study based on 1997 UICC TNM and 1998 JGCA classifications

BACKGROUND: Micrometastasis is a single or a cluster of malignant cells inside the lymph node that are not detected by routine histopathological sections. Micrometastasis is related to poorer prognosis in many gastric cancer studies the real significance of these cells is still controversial. AIM: To evaluate if lymph node micrometastasis is a significant independent prognostic factor and important risk factor for recurrence in gastric cancer. METHODS: A total of 1290 lymph nodes from 28 patients with gastric cancer, since 1998 until 2003, treated by radical resection (D2 and modified D3 lymphadenectomies) were studied. Three sections per lymph node were stained by Hematoxilin-Eosin, histochemical (AB-PAS) and immunohistochemical (AE1-AE3) techniques. Kaplan-Meier's survival curves and Log-rank/Cox tests were used in order to compares lymph node micrometastasis positivity, depth (pT) and location of tumor in gastric wall, histologic type, lymphatic, vascular and perineural invasion, lymph node status (pN) and stage. RESULTS: There were worse prognosis and recurrence in patients with positive lymph node micrometastasis related to vascular and perineural invasions, advanced lymph node status and advanced stages. CONCLUSION: Lymph node micrometastasis seems to be a significant independent prognostic factor and important risk factor for recurrence in gastric cancer, in a context of radical D2 lymphadenectomy

Lymph node micrometastasis in node negative early gastric cancer

AIMS

The clinical significance of lymph node micrometastasis for histologically node negative gastric cancer is not well documented. This study was to assess the incidence and to clarify the risk factors of lymph node micrometastasis in patients with node negative early gastric cancer (EGC).

METHODS

We investigated the lymph node micrometastasis with using an anticytokeratin immunohistochemical stain in 90 patients with node negative EGC who underwent curative resection between 1991 and 2000.

RESULTS

Among 3526 nodes from 90 patients, there were 17 cytokeratin immunohistochemical stain positive nodes from nine patients. The incidence of micrometastasis was higher in patients with lymphatic invasion (p=0.012), venous invasion (p=0.026) and larger tumor (p=0.003). The independent risk factors for lymph node micrometastasis were lymphatic invasion (p=0.004, RR=22.915, 95% CI = 2.709 ~ 193.828) and tumor size (p=0.029, RR=1.493, 95% CI = 1.042 ~ 2.138). Although there were 10 deaths during the follow-up period of mean 67.6 months (1 month ~ 147 months), there was no death from a cancer recurrence.

CONCLUSIONS

The incidence of lymph node micrometastasis in patients with node negative early gastric cancer was 10%, and the independent risk factors for micrometastasis were lymphatic invasion and tumor size.

[Morphological tumor front grading and matrix metalloproteinases type I expression as a prognostic parameter of the presence of lymph node micrometastases in laryngeal carcinoma]

INTRODUCTION

Occult foci of neoplasm cells in lymph nodes (referred to as micrometastases) in various squamous cell carcinomas may be discovered by immunohistochemistry by using anti-CKs (cytokeratine filaments) policlonal antibodies which reactive with epithelial cells. Matrix metalloproteinases (MMPs) are proteolytic family enzymes represent a group of endopeptidases which are capable to degrading components of the extracellular matrix and have been implicated as playing an important role in cancer invasion and metastases. The purpose of this study was to analyze the morphological parameters and to investigate MT1-MMP expression in laryngeal carcinoma to relate the expression to CKs in pN0 lymph nodes.

MATERIALS AND METHODS

To presented the direct correlation between the morphological features of tumor front and the probability of micrometastases and prediction of prognosis we have analyzed 22 patients operated for squamous cell carcinoma of the larynx. The total score of TFG classification, tumor clinicomorphological features and grade of matrix metalloproteinase membrane type 1 staining in tumor front were analyzed to predict the presence of micrometastases and prognosis. Immunohistochemical methods with a panel of CKs antigens in lymph nodes and MT1-MMP expression in tumor tissue were performed.

RESULTS

Our study showed that the total morphologic score TFG is very useful in the prediction of micrometastases in patients with laryngeal squamous cell carcinoma. The statistical analysis has revealed a significant correlation between the total TFG score and the depth of invasion and the presence of micrometastases. Positive MT1-MMP expression in 68.2% cases was observed. There was no significant relationship for immunoexpression of MT1-MMP in examined group of patients with advanced laryngeal carcinoma and positive poliCKs stain in lymph nodes.

CONCLUSIONS

The results of study suggest that extended traditional pathologic evaluation by features from the TFG classification, especially the depth of invasion, could aid in diagnosis of micrometastases. The positive expression of poliCKs in the conventional pathological examination of pN0 lymph nodes appears to play an important role in determining prognosis in patients with carcinoma of the larynx.

Detection of micrometastases in sentinel node navigation surgery for gastric cancer

Although lymph node metastasis is one of the important prognostic factors for patients with gastric cancer, the clinical significance of micrometastasis remains controversial. In the 6th edition of the TMN classification, micrometastases were classified as micrometastasis (MM) and isolated tumor cells (ITC) according to its greatest dimension. The accurate diagnosis of micrometastases is required when considering less invasive surgery, especially in early stage of gastric cancer. Since generating useful information about micrometastases by conventional RT-PCR is time-consuming, this procedure is not useful for rapid diagnosis during surgery. Recently some new methods of genetic diagnosis have reduced the amount of time required to obtain information about micrometastases in lymph nodes to 30-40 min. Such methodology can be clinically applied during less invasive surgery. The sentinel node (SN) concept has recently been applied to gastric cancer and SN navigation surgery (SNNS) is ideal for reduction of lymphadenectomy in patients with early gastric cancer. However, we should think about some conditions to establish SN concept for gastric cancer: the particle size of radioisotope, relationship between metastatic area and RI uptake, and the diagnosis of micrometastases by various method such as histological examination, immunostaining and RT-PCR. Here, we described the current status of MM and ITC in the lymph nodes and the SN concept in gastric cancer.

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.

Genetic detection of free cancer cells in the peritoneal cavity of the patient with gastric cancer: present status and future perspectives

The purpose of this review is to examine the current status and future perspectives of the molecular analysis of peritoneal lavage fluid in patients with gastric cancer. During the past 10 years, the polymerase chain reaction (PCR) has been applied for the molecular detection of free cancer cells in the abdominal cavity of patients with gastric cancer, and its clinical significance in establishing the presence of peritoneal dissemination has been assessed by several groups especially in Japan. The majority of these studies have confirmed the predictive value of the molecular detection of peritoneal metastasis and recurrence using peritoneal lavage fluid. Based on these findings, since April 2006, the genetic diagnosis of body fluids has been included in the Japanese Government public health insurance program for patients with solid tumors. However, there are still many obstacles to overcome before the genetic diagnosis of micrometastasis can be considered a routine laboratory assay. Here we review the importance of the molecular detection of cancer cells in the abdominal cavity, and the molecular techniques used for such diagnosis; we also provide some clinical examples to illustrate the value of molecular diagnosis.

Clinicopathological features and medical management of early gastric cancer

BACKGROUND

The detection of early gastric carcinoma (EGC) has increased worldwide due to advances in endoscopic techniques and equipment. The aim of the current study was to compare the clinicopathological findings of patients with and without lymph node metastasis.

METHODS

A total of 440 cases of early gastric carcinoma in patients who underwent surgical procedures between 1981 and 2002 at Kochi Medical School were studied.

RESULTS

Lymph node metastasis was observed in 38 patients (8.6%) with EGC. Multivariate analysis identified 4 independent risk factors of lymph node metastasis: (1) submucosal invasion; (2) tumor diameter greater than 3.5 cm; (3) the presence of vascular invasion; and (4) the presence of lymphatic permeation.

CONCLUSION

For patients with tumor size between 1 cm and 3.5 cm we would recommend endoscopic resection initially, with a consideration for additional surgical resection if microscopic vascular invasion or lymphatic permeation is demonstrated.

Analysis of sentinel node involvement in gastric cancer

BACKGROUND & AIMS

Sentinel node navigation surgery (SNNS) is performed for patients with early gastric cancer. Because sentinel nodes (SNs) to gastric cancer exist but they have not been well-described, we attempted to validate the SN concept at the micrometastasis level.

METHODS

For 53 patients who underwent curative gastrectomy for T1/T2 (<4 cm) N0 gastric cancer, SNNS was performed with radioactive tin colloid and/or indocyanine green, and subsequent modified D1 lymphadenectomies were added. Whole formalin-fixed paraffin-embedded tissues of all resected lymph nodes from these patients were cut into 5-mum thick serial step sections at 85-mum intervals, and occult metastases were examined immunohistochemically.

RESULTS

Metastases were detected in 3 (1.5%) of 204 SNs and 3 (0.33%) of 901 non-SNs in pN0 cases and in 18 (46%) of 39 SNs and 3 (1.9%) of 158 non-SNs in pN1 cases. On a patient basis, metastases were detected in 4 (9%) of 46 pN0 patients, 2 (4%) each in SNs and non-SNs, and in 7 pN1 patients, of whom 7 and 4 had SN and non-SN metastases, respectively. The sensitivity, false-negative rate, and accuracy of SN identification by SNNS were 82%, 18%, and 96%, respectively, at the occult metastasis level. However, on the basis of the concept of the sentinel lymphatic station (SLS), which represents all lymphatic stations to which SNs belong, metastases were always limited to the lymph nodes in SLS in the 11 cases with metastases. Non-SN metastases occurred in 3 (60%) of 5 patients with SN metastases >2.0 mm in diameter but not in 4 patients with SN metastases </=2.0 mm in diameter.

CONCLUSIONS

The sentinel node concept held true at the occult metastasis level in 96% of patients with gastric cancer, and the accuracy of SNNS was elevated to 100% by introducing the concept of the sentinel lymphatic station. The size of SN metastasis was a predictive factor for metastasis beyond the sentinel node.