The importance of neural invasion (NI) as a prognostic factor in diffuse invasive gastric cancer

Neural Invasion is an Independent Prognostic Factor in Young and Lymph Node Negative Gastric Cancer Patients Underwent Curative Gastrectomy

BACKGROUND

The prognostic significance of neural invasion (NI) in gastric cancer (GC) has not been established. This study is to investigate the characteristic and prognostic value of NI in GC.

METHODS

592 patients who had undergone gastrectomy for GC were retrospectively analyzed. NI was defined when cancer cells infiltrated into the perineurium or neural fascicles by hematoxylin and eosin staining of surgical specimens. NI and the other clinical factors were analyzed.

RESULTS

NI was detected in 270 of the 592 patients. NI was associated with tumor size, site, depth of invasion, lymph node metastasis, TNM stage, D dissection, tumor differentiation, Lauren classification, and blood vessel invasion. NI was associated with the overall survival. Multivariate analysis indicated that NI was not an independent prognostic factor for total patients, while NI independently predicted prognosis for age < 60 and lymph node metastasis negative patients by subgroup analysis. Concomitant existence of NI with tumor size ≥3cm, TNM stage III, or diffused Lauren classification independently predicted prognosis.

CONCLUSIONS

The frequency of NI is high in GC patients and increases with disease progression. NI is related to poor survival in GC patients who underwent curative gastrectomy and provides independent prognostic value for young and lymph node metastasis negative patients.

The Impact of Nerve Involvement on the Prognosis of Gastric Cancer Patients with Curative Gastrectomy: An International Multicenter Analysis

Background

Several studies have been conducted to investigate the association between the presence of perineural invasion (PNI) and overall survival (OS) of gastric cancer (GC) patients who underwent curative resection, but no consensus has been reached. This study is aimed at determining the prognostic significance of PNI in gastric cancer. Study Design. The data of 2969 patients with gastric cancer and who had undergone curative gastrectomy from 2006 to 2010 in two high-volume hospitals of China and Korea were retrospectively analyzed. PNI positivity was identified when carcinoma cells were found to infiltrate into the perineurium or neural fascicles. The relationships between PNI and other clinicopathological factors were evaluated, and survival analyses were performed.

Results

The presence of PNI was detected in 1055 of the 2969 patients (35.5%). Nationality, age, tumor location, size of tumor, differentiation of the tumor, pT stage, pN stage, lymphatic invasion, and vascular invasion had been associated with PNI positivity. The mean survival time of patients with and without PNI was 62.5 months and 87.3 months, respectively (P < 0.001). However, the presence of PNI was not an independent prognostic factor for gastric cancer, except for patients in stage III (P = 0.037, hazard ratio: 1.21, 95% confidence interval: 1.01-1.44).

Conclusion

PNI occurs frequently in patients with gastric cancer, and the incidence of PNI increases with the staging of the tumor. The presence of PNI can provide additional information in predicting the survival outcome for those with stage III tumors.

Presence of cancer cells in the periarterial tissues of patients with advanced gastric cancer

Lymphadenectomy with gastrectomy is considered a curative surgical treatment for gastric cancer. Periarterial connective tissue-preserving lymphadenectomy has become a common procedure following developments in laparoscopic surgery. However, the presence of cancer cells in the periarterial tissue, including neural invasion, has not been examined. In the present study, the periarterial tissues from the vessel roots of the left gastric artery (LGA) and right gastroepiploic artery (RGEA) after gastrectomy were evaluated for the presence of cancer cells. The study included 28 consecutive patients who underwent gastrectomy for gastric cancer. The vessel roots of the RGEA and LGA were obtained from surgically resected specimens and examined by two independent pathologists to determine the presence of cancer cells in the periarterial tissues. The collected specimens included 23 RGEA roots and 26 LGA roots from 28 patients. In 8 cases of early gastric cancer, no cancer cells were indicated in the periarterial tissues. By contrast, cancer cells, including neural invasion in 2 cases, were identified in the periarterial tissues from the roots of examined gastric arteries in 3/20 (15%) cases of advanced gastric cancer. Notably, all 3 cases featured multiple regional lymph node (LN) metastases. Cancer cells were detected in the perivascular tissue of the major gastric arteries from cases with advanced gastric cancer with LN metastases, suggesting the requirement for oncologic evaluation to ensure adequate vascular tissue margins and an adequate periarterial layer during lymphadenectomy.

Neural Invasion is a Significant Contributor to Peritoneal Recurrence in Signet Ring Cell Gastric Carcinoma

BACKGROUND

Gastric signet ring cell carcinoma (SRC) has shown a favorable outcome in early stages but has a worse prognosis than non-SRC in advanced stages. However, the cause for this stage-dependent prognostic impact has not been determined. This study aimed to compare clinicopathologic features and recurrence patterns between gastric SRC and non-SRC in a cohort of Eastern patients.

METHODS

This study reviewed the prospectively collected data of 764 patients undergoing curative resection for gastric cancer from 2005 to 2008. The demographics, clinicopathologic characteristics, disease-specific survival (DSS) rate, and recurrence-free survival (RFS) rate of the patients were analyzed.

RESULTS

The SRC patients (n = 176) had a worse prognosis than the non-SRC patients (n = 588), especially in stages T3 and T4. Peritoneal recurrence and the incidence of neural invasion (NI) were significantly increased in the SRC patients, albeit only in stages T3 and T4. In the T3 and T4 patients with NI, peritoneal recurrence occurred more frequently in SRC than in non-SRC (28.7% vs. 13.7%; p = 0.001), but not in the T3 and T4 patients without NI. Only in the patients with NI, SRC led to a significantly shorter DSS (67.6 vs. 90.7 months; p = 0.008) and RFS (67.1 vs. 80.3 months; p = 0.036) than non-SRC.

CONCLUSIONS

This report is the first to present the relationship between NI and peritoneal recurrence as the cause of stage-dependent prognoses for SRC. A better understanding of NI may lend insight into cancer spread and recurrence, especially in gastric SRC.

Reevaluating significance of perineural invasion in gastric cancer based on double immunohistochemical staining

CONTEXT

In gastric cancer, the significance of perineural invasion remains controversial. Detecting perineural invasion with hematoxylin-eosin staining often leads to misdiagnosis. Labeling nerves by immunohistochemistry greatly assists perineural invasion detection, but it might also be misdiagnosed, because scattered cancer cells are difficult to recognize.

OBJECTIVE

To reevaluate the significance of perineural invasion in gastric cancer by double immunohistochemical staining that labels both nerves and cancer cells, and to examine agreements on perineural invasion detection between double immunohistochemical staining and single immunochemical staining (to label nerves) or hematoxylin-eosin staining.

DESIGN

We evaluated perineural invasion in 160 cases of gastric cancer with double immunohistochemical staining, single immunochemical staining, and hematoxylin-eosin staining, respectively; then we investigated the prognostic significance of perineural invasion.

RESULTS

Perineural invasion was detected in 65.0% (104 of 160), 38.1% (61 of 160), and 56.9% (91 of 160) of cases with double immunohistochemical staining, hematoxylin-eosin staining, and single immunohistochemical staining, respectively. Agreement was low between double staining and hematoxylin-eosin staining (κ = .34), and most false reports occurred in diffuse gastric cancer. Agreement between single immunochemical staining and double staining was good (κ = .67), but it declined in diffuse gastric cancer (κ = .28). Perineural invasion was closely associated with other clinicopathologic variables. Although perineural invasion-positive patients had a worse outcome than perineural invasion-negative patients, it was not an independent prognostic factor (P = .11; hazard ratio, 0.637; 95% confidence interval, 0.366-1.110).

CONCLUSIONS

Double immunohistochemical staining could improve accuracy of perineural invasion detection in gastric cancer, particularly in the diffuse type. Moreover, perineural invasion predicts a poor outcome in gastric cancer, but it cannot provide more information than traditional clinicopathologic variables.

Poor prognostic factors in patients with stage I gastric cancer according to the seventh edition TNM classification: a comparative analysis of three subgroups

BACKGROUND AND OBJECTIVES

The purpose of this study was to investigate the prognosis of stage I gastric cancer and to compare clinicopathologic characteristics by subgroup.

METHODS

Between January 2000 and December 2006, 384 patients with gastric cancer were reclassified as stage I according to the seventh edition classification. A comparative analysis was performed between three subgroups. Univariate and multivariate analyses were conducted.

RESULTS

The 5-year overall survival rates in T1N0, T1N1, and T2N0 were 98.8%, 94.1%, 91.1%, respectively (P = 0.009). In patients with T2N0 gastric cancer, tumors in the upper third and larger tumors were more common than in patients with T1N0 and T1N1 gastric cancer (P < 0.001). In patients with T1N1 and T2N0 gastric cancer, the presence of lymphatic and/or blood vessel invasion (LBVI) and perineural invasion (PNI) were more common than in patients with T1N0 gastric cancer (P < 0.001). Univariate analysis showed tumor stage, depth of invasion, LBVI, and PNI were significant prognostic factors. However, multivariate analysis demonstrated that only tumor stage, LBVI, and PNI were significant variables.

CONCLUSIONS

Survival data support the accuracy of new TNM classification for stage I gastric cancer. Tumor stage, the presence of LBVI and PNI are important independent prognostic factors in stage I gastric cancer.

Prognostic significance of perineural invasion in patients with gastric cancer who underwent curative resection

BACKGROUND

The prognostic significance of perineural invasion (PNI) in gastric cancer has been previously investigated in a few studies, but had not reached a consensus. The aim of this study was to determine the prognostic value of PNI in patients with gastric cancer who underwent curative resection.

MATERIALS AND METHODS

We retrospectively analyzed 238 patients who had undergone curative gastrectomy. Paraffin sections of surgical specimens from all patients were stained with hematoxylin and eosin. PNI was defined when carcinoma cells infiltrated into the perineurium or neural fascicles. PNI and the other prognostic factors were evaluated by univariate and multivariate analysis.

RESULTS

PNI was detected as positive in 180 of the 238 patients (75.6%). pT stage, tumor size, lymph node metastasis, clinical stage, tumor differentiation, Borrmann classification, histological type, lymphatic vessel invasion, and blood vessel invasion were closely associated with the presence of PNI. The PNI-positive tumors had significantly larger size and more lymph node metastasis than the PNI-negative tumors (P = .001 and P < .001, respectively). The median survival of the PNI-positive patients was significantly worse than that of the PNI-negative patients (28.1 vs. 64.9 months, P = .001). Multivariate analysis indicated that the positivity of PNI was an independent prognostic factor (P = .02, hazard ratio [HR]: 2.75; 95% confidence interval [95% CI]:1.12-3.13) as were classical clinicopathological features.

CONCLUSION

Our results showed that the frequency of PNI was high in patients with gastric cancer who underwent curative gastrectomy and the proportion of PNI positivity increased with progression and clinical stage of disease. PNI may be useful in detecting patients who had poor prognosis after curative resection in gastric cancer.

Determining of metastatic lymph node ratio in patients who underwent D2 dissection for gastric cancer

The purpose of this study was to determine outcome of the ratio of metastatic lymph nodes to the total number of dissected lymph nodes (MLR) in patients with gastric cancer. We retrospectively analyzed 111 patients who underwent D(2) lymph node dissection. The prognostic factors including UICC/AJCC TNM classification and MLR were evaluated by univariate and multivariate analysis. The MLR was significantly higher in patients with a larger tumor, lymphatic vessel invasion, blood vessel invasion and perineural invasion, and advanced stage. Moreover, the MLR was significantly associated with the depth of invasion and the number of lymph node metastasis. The univariate analysis revealed for overall survival (OS) that stage of disease, lymphatic vessel invasion, blood vessel invasion, perineural invasion, lymph node metastasis (UICC/AJCC pN stage) and MLR were relevant prognostic indicators. Furthermore, both UICC/AJCC pN stage and MLR were detected as prognostic factor by multivariate analysis, as was perineural invasion. Our results indicated that MLR and UICC/AJCC pN staging system were important prognostic factors for OS of patients with D(2) lymph node dissection in gastric cancer in a multivariate analysis. MLR may be useful for evaluating the status of lymph node metastasis in gastric cancer.

The effect of perineural invasion on overall survival in patients with gastric carcinoma

AIMS

The availability of different treatment options for gastric carcinoma has reopened the question of correct definition of high-risk categories, which may help in identifying patients with high risk for poor prognosis who would benefit more from adjuvant therapy after operation. Perineural invasion (PNI) seems to provide useful information for management. Therefore, we examined the effect of PNI on overall survival (OS) in patients with gastric carcinoma and the association between PNI and other clinical and pathological factors.

PATIENTS AND METHODS

A total of 1,632 patients with gastric carcinoma from 2000 to 2005 were analyzed retrospectively. Paraffin sections of surgical specimens from all patients who underwent gastric resection were stained with laminin. If carcinoma cells infiltrated into the perineurium or neural fascicles, PNI was assessed as positive. Survival analysis was done in 1,372 patients with T1-T4 tumors who underwent curative resection.

RESULT

PNI was positive in 518 of the 1,632 patients (31.7%). The size of tumors, T stage, differentiation of tumor, and clinical stage were significantly related to PNI positivity. The proportion of large tumors was significantly higher in PNI-positive patients than in PNI-negative patients (P < 0.01). As the depth of gastric mural invasion or clinical stage increased, the positive rate of PNI also increased. The OS of the PNI-positive patients was significantly shorter than that of the PNI-negative patients in the univariate analysis (P < 0.01). At multivariate Cox proportional hazards model of OS analysis, the positivity of PNI appeared to be an independent prognostic factor for OS (hazards ratio [HR] = 3.23, 95%CI = 2.6-8.11, P < 0.01), which was also influenced by tumor differentiation, T stage, and clinical stage (P < 0.01).

CONCLUSION

Our results suggested that the incidence of PNI was high in gastric carcinoma and that it corresponded to the progression of disease. It could provide additional information for identifying patients who are at high risk for poor prognosis. PNI can be a candidate for a new kind of prognostic parameters.

Lymphatic, blood vessel and perineural invasion identifies early-stage high-risk radically resected gastric cancer patients

The availability of different treatment options for radically resectable gastric cancer reopened the question of treatment selection and correct definition of high-risk categories. Lymphatic, blood vessel and perineural invasion (LBVI/PNI) seem to possess the necessary potential to provide useful information for the clinical management of this disease. Seven hundred and thirty-four patients with advanced gastric cancer who underwent curative gastrectomy were analysed according to the presence of LBVI/PNI. Patients were divided into two groups: group A for patients with LBVI/PNI (189 patients 26%) and group B for patients without LBVI/PNI (545 patients, 74%). The disease-free survival (DFS) for patients in group A was 32.1 months, whereas it was not reached for patients in group B (P=0.0001); the median overall survival was 45.5 months for patients in group A, whereas it was not reached for patients in group B (P=0.0001). At multivariate analysis, the presence of LBVI/PNI appeared an independent prognostic factor for DFS and OS. Our results were confirmed in subgroup analysis, separately considering stage I and early gastric cancer patients with and without LBVI/PNI. Taken together, our findings suggest the importance of LBVI/PNI in gastric cancer as it may provide additional information for identifying patients at high risk, who may be candidates for further medical treatment after or before surgery.