Clinical significance of skip metastasis in patients with gastric cancer

Value of Computed Tomography Scan for Detecting Lymph Node Metastasis in Early Esophageal Squamous Cell Carcinoma

BACKGROUND

The necessity of computed tomography (CT) scan for detecting potential lymph node metastasis (LNM) in early esophageal squamous cell carcinoma (ESCC) before endoscopic and surgical treatments is under debate.

METHODS

Patients with histologically proven ESCC limited to the mucosa or submucosa were examined retrospectively. Diagnostic performance of CT for detecting LNM was analyzed by comparing original CT reports with pathology reports. The sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) were calculated.

RESULTS

A total of 625 patients from three tertiary referral hospitals were included. The rate of pathologically confirmed LNM was 12.5%. Based on original CT reports, the sensitivity, specificity, accuracy, PPV, and NPV of CT to determine LNM in T1 ESCC were 41.0%, 83.2%, 77.9%, 25.8%, and 90.8% respectively. For mucosal cancers (T1a), these parameters were 50.0%, 81.7%, 80.9%, 6.8%, and 98.4%, respectively. For submucosal cancers (T1b), they were 40.0%, 85.0%, 75.0%, 43.0%, and 83.3%, respectively. Additionally, the diagnostic performance of CT for LNM was relatively better for ESCC in the lower esophagus. Pathologically, 69.2% of patients with LNM did not exhibit lymphovascular invasion (LVI), and the sensitivity of CT for recognizing LNM in these patients (33.3%) was lower than those with LVI (58.3%).

CONCLUSIONS

Computed tomography can detect nearly half of the LNM cases in early ESCC with high specificity. The performance of CT further improved in LNM cases with LVI. Therefore, we conclude that routine preoperative CT for the assessment of potential LNM risk in patients with early ESCC is necessary.

Development and validation of a novel staging system integrating the number and location of lymph nodes for gastric adenocarcinoma

Background

Evidence suggests that the anatomic extent of metastatic lymph nodes (MLNs) affects prognosis, as proposed by alternative staging systems. The aim of this study was to establish a new staging system based on the number of perigastric (PMLN) and extra-perigastric (EMLN) MLNs.

Methods

Data from a Chinese cohort of 1090 patients who had undergone curative gastrectomy with D2 or D2 plus lymphadenectomy for gastric cancer were retrospectively analysed. A Japanese validation cohort (n = 826) was included. Based on the Cox proportional hazards model, the regression coefficients of PMLN and EMLN were used to calculate modified MLN (MMLN). Prognostic performance of the staging systems was evaluated.

Results

PMLN and EMLN were independent prognostic factors in multivariate analysis (coefficients: 0.044, 0.115; all P < 0.001). MMLN was calculated as follows: MMLN = PMLN + 2.6 × EMLN. The MMLN staging system showed superior prognostic performance (C-index: 0.751 in the Chinese cohort; 0.748 in the Japanese cohort) compared with the five published LN staging systems when MMLN numbers were grouped as follows: MMLN0 (0), MMLN1 (1–4), MMLN2 (5–8), MMLN3 (9–20), and MMLN4 (>20).

Discussion

The MMLN staging system is suitable for assessing overall survival among patients undergoing curative gastrectomy with D2 or D2 plus lymphadenectomy.

Should the left gastric artery lymph node be considered as the predictive lymph node for extra-gastric lymph node metastases?

BACKGROUND

To validate the prognostic impacts of the left gastric artery lymph node (No. 7 LN) metastasis and investigate whether the No. 7 LN metastasis should be considered as the predictive LN for extra-gastric LN metastases.

METHODS

Between January 2003 and December 2011, a total of 1,586 patients who underwent R0 gastrectomy were retrospected. Patients with LN metastases were divided into three groups: (I) patients with only peri-gastric LN metastases (peri-gastric group); (II) patients with peri-gastric and only No. 7 LN metastases (No. 7 group); and (III) patients with other extra-gastric LN metastases (extra-gastric group). Propensity score matching (PSM) was adopted to accurately evaluate prognoses of all patients after surgery.

RESULTS

Of 1,586 patients, 235 (14.82%) were pathologically identified to present with the No. 7 LN metastases. Patients with the No. 7 LN metastases presented the significantly lower survival rate both before and after adjustment by pTNM stage, compared to those without the No. 7 LN metastases. Patients in the No. 7 group were identified to present the significant lower survival rate than those in the peri-gastric group, and to present the similar median overall survival (OS) to those in the extra-gastric group. In addition, patients with extra-gastric LN except No. 7 LN metastases failed to show any superiority of survival outcomes, compared with those with extra-gastric LN metastases including the No. 7 LN metastasis.

CONCLUSIONS

The No. 7 LN metastases had the crucial survival implications. Nevertheless, the No. 7 LN failed to be considered as the predictive LN for the extra-gastric LN metastases in gastric cancer (GC).

Clinical significance of skip lymph-node metastasis in pN1 gastric-cancer patients after curative surgery

BACKGROUND

In addition to the stepwise manner of lymph-node metastasis from the primary tumour, the skip lymph-node metastasis (SLNM) was identified as a low-incidence metastasis of gastric cancer (GC). So far, both the mechanism and outcome of SLNM have not been elucidated completely. The purpose of this study was to analyse the clinical significance and the potential mechanism of SLNM in GC patients who had lymph-node metastasis.

METHODS

Clinicopathological data and follow-up information of 505 GC patients who had lymph-node metastasis were analysed to demonstrate the significance of SLNM in evaluating the prognostic outcome. According to the pathological results, all GC patients who had lymph-node metastasis were categorized into three groups: patients with the perigastric lymph-node metastasis, patients with the perigastric and extragastric lymph-node metastasis and patients with SLNM.Results: Among the 505 GC patients who had lymph-node metastasis, 24 (4.8%) had pathologically identified SLNM. The location of lymph-node metastasis was not significantly associated with 5-year survival rate and overall survival (OS) (P = 0.194). The stratified survival analysis results showed that the status of SLNM was significantly associated with the OS in patients with pN1 GC (P = 0.001). The median OS was significantly shorter in 19 pN1 GC patients with SLNM than in 100 patients with perigastric lymph-node metastasis (P < 0.001). The case-control matched logistic regression analysis results showed that tumour size (P = 0.002) was the only clinicopathological factor that may predict SLNM in pN1 GC patients undergoing curative surgery. Among the 19 pN1 GC patients with SLNM, 17 (89.5%) had metastatic lymph nodes along the common hepatic artery, around the celiac artery or in the hepatoduodenal ligament.

CONCLUSIONS

SLNM may be considered a potentially practicable indicator for prognosis among various subgroups of pN1 GC patients.

Lymph nodes around the posterior gastric artery: their existence, frequency, and clinical implications

PURPOSE

The lymphatic flow along the posterior gastric artery (PGA) is considered of possible clinical importance in terms of lymphatic metastasis; however, little is known about the lymph nodes (LNs) around this artery. The purpose of this study was to establish if LNs exist around the PGA and to evaluate their clinical implications.

METHODS

We examined the tissues surrounding the PGA from 21 cadavers to search for LNs. We also investigated the patterns of lymphatic metastases in patients who underwent surgery for gastric neoplasms at our institute to detect their presence along the PGA.

RESULTS

The PGA was identified in 11 cadavers, and LNs around the PGA were detected microscopically in 2 of these. Lymphatic metastasis directly to the LNs at the splenic artery without any metastases was regarded as skip metastasis along the PGA. Skip metastasis was found in two of ten patients who underwent surgery for remnant gastric cancer.

CONCLUSIONS

The existence of LNs around the PGA was confirmed, and based on our findings, lymphatic metastasis through the PGA is possible in patients with remnant gastric cancer.

Anatomical location of metastatic lymph nodes: an indispensable prognostic factor for gastric cancer patients who underwent curative resection

BACKGROUND

Although the numeric-based lymph node (LN) staging was widely used in the worldwide, it did not represent the anatomical location of metastatic lymph nodes (MLNs) and not reflect extent of LN dissection. Therefore, in the present study, we investigated whether the anatomical location of MLNs was still necessary to evaluate the prognosis of node-positive gastric cancer (GC) patients.

METHODS

We reviewed 1451 GC patients who underwent radical gastrectomy in our institution between January 1986 and January 2008. All patients were reclassified into several groups according to the anatomical location of MLNs and the number of MLNs. The prognostic differences between different patient groups were compared and clinicopathologic features were analyzed.

RESULTS

In the present study, both anatomical location of MLNs and the number of MLNs were identified as the independent prognostic factors (p < .01). The patients with extraperigastric LN involvement showed a poorer prognosis compared with the perigastric-only group (p < .001). For the N1-N2 stage patients, the prognostic discrepancy was still observed among them when the anatomical location of MLNs was considered (p < .05). For the N3-stage patients, although the anatomical location of MLNs had no significant effect on the prognosis of these patients, the higher number of MLNs in the extraperigastric area was correlated with the unfavorable prognosis (p < .05).

CONCLUSION

The anatomical location of MLNs was an important factor influencing the prognostic outcome of GC patients. To provide more accurate prognostic information for GC patients, the anatomical location of MLNs should not be ignored.

Sentinel Lymph Node Navigation Surgery for Early Gastric Cancer: Is It a Safe Procedure in Countries with Non-Endemic Gastric Cancer Levels? A Preliminary Experience

Purpose

Early diagnosis of gastric cancer is still the exception in Western countries. In the East, as in Japan and Korea, this disease is an endemic disorder. More conservative surgical procedures are frequently performed in early gastric cancer cases in these countries where sentinel lymph node navigation surgery is becoming a safe option for some patients. This study aims to evaluate preliminary outcomes of patients with early gastric cancer who underwent sentinel node navigation surgeries in Brazil, a country with non-endemic gastric cancer levels.

Materials and Methods

From September 2008 to March 2014, 14 out of 205 gastric cancer patients underwent sentinel lymph node navigation surgeries, which were performed using intraoperative, endoscopic, and peritumoral injection of patent blue dye.

Results

Antrectomies with Billroth I gastroduodenostomies were performed in seven patients with distal tumors. The other seven patients underwent wedge resections. Sentinel basin resections were performed in four patients, and lymphadenectomies were extended to stations 7, 8, and 9 in the other 10. Two patients received false-negative results from sentinel node biopsies, and one of those patients had micrometastasis. There was one postoperative death from liver failure in a cirrhotic patient. Another cirrhotic patient died after two years without recurrence of gastric cancer, also from liver failure. All other patients were followed-up for 13 to 79 months with no evidence of recurrence.

Conclusions

Sentinel lymph node navigation surgery appears to be a safe procedure in a country with non-endemic levels of gastric cancer.

Skip lymph node metastasis in gastric cancer: is it skipping or skipped?

BACKGROUND

Skip metastasis is the presence of a metastatic lymph node (LN) in an extraperigastric (EP) area without perigastric (PG) involvement. The mechanism and prognosis of skip metastasis are still unknown. The purpose of this study was to scrutinize the clinical significance of skip metastasis in gastric cancer.

METHODS

Data were reviewed from 6,025 patients who had undergone gastrectomy for primary gastric cancer. Patients were categorized as a PG-only group when the metastatic LNs were limited to only the PG area, as a PG + EP group if metastatic LNs extended to both the PG area and the EP area, and as a skip group if metastatic LNs were in the EP area but there were no metastatic LNs in the PG area.

RESULTS

After we had performed matching, the prognosis of the skip group was worse than that of the PG-only group (adjusted hazard ratio 1.69, 95% confidence interval 1.13-2.54) and was similar to that of the PG + EP group (adjusted hazard ratio: 1.54, 95% confidence interval 0.92-2.59). The number of retrieved LNs was less in the skip group than in the other groups, especially from the PG area (p < 0.001).

CONCLUSIONS

The prognosis of the skip group was worse than that of the PG-only group and was similar to that of the PG + EP group when the tumor stage was considered. It is difficult to conclude whether skip metastasis is real skipping of cancer cells or a result of inadequate LN sampling. Further evaluation of LNs in the PG area of the skip group could provide more clues for the mechanism of skip metastasis.

Clinical significance of skip lymph node metastasis in gastric cancer patients

PURPOSE

Given the recent increase in the incidence of early gastric cancer, there is greater interest in identifying a minimally invasive therapy. The purpose of this study was to analyze the patterns of lymph node metastasis in patients with gastric cancer and to elucidate the clinical significance of skip metastasis.

METHODS

We retrospectively analyzed patterns of lymph node metastasis (LNM) and clinicopathologic factors related to skip metastasis.

RESULTS

Among 2963 patients with gastric cancer, 997 patients (33.6%) were detected as having LNM, and 27 patients (2.7%) with skip metastasis were detected among 997 patients with LNM. Skip metastasis were detected more frequently in the elderly. Compared with the N1 group, the skip metastasis group showed lower frequency of vascular invasion, and compared with the stepwise N2 group, the skip metastasis group showed smaller tumor size and a significantly higher incidence of negative lymphatic, vascular, and perineural invasion.

CONCLUSIONS

Currently there is no way to predict N2 station LNM including skip metastasis, D2 LN dissection for gastric cancer is thought to be the appropriate treatment, even during early stage disease. Minimally invasive therapy should be performed cautiously in consideration of possible skip metastasis.

Lymph node metastasis in early gastric cancer

OBJECTIVE: to evaluate the incidence of lymph node metastasis in early gastric cancer, identifying risk factors for its development. METHODS: we conducted a prospective study of patients with gastric cancer admitted to the Section of the Esophago-Gastric Surgery of the Surgery of Service HUCFF-UFRJ, from January 2006 to May 2012. RESULTS: the rate of early gastric cancer was 16.3%. The incidence of nodal metastases was 30.8% and occurred more frequently in patients with tumors with involvement of the submucosa (42.9%), in those poorly differentiated (36.4%), in tumors larger than 2 cm (33.3%) and in type III ulcerated lesions (43.8%). CONCLUSION: the incidence of lymph node metastases in patients was very high and suggests that one should keep the radicality of resection in early gastric cancer, particularly in relation to D2 lymphadenectomy, recommended for advanced gastric cancer. Conservative resections, with lymphadenectomies smaller than D2, should be performed only in selected cases, well-studied as for the risk factors of lymph node metastasis. Despite the small number of cases did not permit to relate the rate of lymph node metastasis to the risk factors considered, we noted a strong tendency for the occurrence of these metastases in the poorly differentiated, type III, larger than 2 cm tumors, and in the Lauren diffuse types.

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.

Prognostic significance of lymph node station 7 for patients with gastric cancers underwent radical surgery

BACKGROUND

To investigate the validity of gastric cancers with nodes metastasis at Level II stations limited to No. 7 being classified as level-based n1 stage disease and the impact of this revision on lymph node staging.

METHODS

Clinicopathologic features and prognosis of 1,606 node positive gastric cancers were retrospectively reviewed. Four patient groups were classified according to the status of node involvement: Group A, 734 patients with node metastasis at Level I stations; Group B, 317 patients with nodes metastasis at Level II stations limited to No. 7; Group C, 501 patients with nodes metastasis at Level II stations besides No. 7; and Group D, 54 patients with nodes metastasis at Level III stations.

RESULTS

Although the extent of node metastasis for patients in Group B was more severe than that for patients in Group A, clinicopathologic features (especially pT stage) were not significantly different. Although overall survival for patients in Group B was significantly worse than that for patients in Group A, no significant differences in prognosis could be observed when stratified by pN or rN category. A revised level-based n category was established by considering cancers in Group B as level-based n1 stage disease. Multivariate analysis confirmed rN category and the revised level-based n category independently predicted patients' survival. A novel N category was established by combining rN category and the revised level-based n category. Further analysis revealed the novel N category had better homogeneity, discriminatory ability, and monotonicity of gradients than the other node categories, indicating the novel N system might be the most valuable node staging system for prognostic assessment.

CONCLUSION

It might be more suitable for cancers in Group B being classified as level-based n1 stage disease. And we recommend the anatomical location of metastatic lymph nodes also being considered in the categorization of lymph node metastasis.

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.

Outcome in relation to numbers of nodes harvested in lymph node-positive gastric cancer

AIMS

We conducted a retrospective case-control study to compare the prognostic differences of lymph node-positive gastric cancer patients between dissected lymph nodes (DLNs) <15 group and DLNs > or =15 group.

METHODS

A retrospective study of 323 lymph node-positive gastric patients who underwent potentially curative resection for gastric cancer was analyzed to identify the prognostic differences between DLNs <15 group and DLNs > or =15 group. Of these patients, 49 patients with <15 DLNs were matched with 147 patients with > or =15 DLNs according to gender, age, location of primary tumor, and type of gastrectomy.

RESULTS

Patients with n1 lymph node metastasis (according to JCGC), serosal involvement, ratio of positive lymph nodes less than 25%, or without adjuvant chemotherapy in > or =15 DLN group had comparatively longer median survival than patients with homologous clinicopathologic variables in <15 DLN group, respectively. Patients with n1 stage lymph node metastasis, serosal involvement, non-intestinal Lauren classification, or without adjuvant chemotherapy in <15 DLN group had higher recurrence rate than patients with homologous clinicopathologic variables in > or =15 DLN group, respectively. In addition, we demonstrated that patients with more than n1 stage lymph node metastasis in <15 DLN group had higher rate of peritoneal dissemination than those with more than n1 lymph node metastasis in > or =15 DLN group.

CONCLUSIONS

DNL > or =15 was an important factor to improve the prognosis of lymph node-positive gastric cancer patients after potential curative resection.