Survival predictors in patients with node-negative gastric carcinoma

miR-126: An indicator of poor prognosis and recurrence in histologically lymph node-negative gastric cancer

BACKGROUND

Few biomarkers are available for the prediction of prognosis and recurrence in lymph node (LN)-negative gastric cancer (GC) currently. miR-126 functions as a tumor suppressor in GC, however, its clinical significance in LN-negative GC remains unknown.

AIM

To investigate the associations of tissue miR-126 level with the clinicopathological characteristics and clinical outcome of LN-negative GC patients.

METHODS

Quantitative real-time polymerase chain reaction was performed to examine the tissue miR-126 level in 315 LN-negative GC patients who underwent curative gastrectomy with D2 lymphadenectomy. The associations of tissue miR-126 level with clinicopathological characteristics and clinical outcome were evaluated.

RESULTS

Compared with matched adjacent non-tumor tissues, miR-126 expression was significantly down-regulated in tumor tissues. A reduced tissue miR-126 level statistically correlated with aggressive clinicopathological characteristics, including larger tumor size, deeper local invasion, and poorer prognosis. Notably, multivariate analysis identified advanced T stage and low miR-126 level as independent predictors of the unfavorable prognosis and recurrence of LN-negative GC.

CONCLUSIONS

These results indicate for the first time that advanced T stage and low miR-126 level are predictors of unfavorable prognosis and recurrence in LN-negative GC patients. These parameters should be taken into account to stratify patients for adjuvant therapy and close follow-up.

Influence of Prognostic Factors for Recurrence of Adenocarcinoma of the Stomach

Introduction:

Gastric cancer is the second most important neoplasm in the world. Surgical resection is the treatment of choice for gastric cancer, and recognized by the International Union against Cancer (International Union Against Cancer – UICC) TNM classification of the parameters of the tumor and lymph node. Prognostic factors related to characteristics of the tumor by histopathologic findings have an impact on the planning of the operation. According to the results of most studies it is possible to predict survival and recurrence based on histological type and TNM classification of tumors on the one hand and the surgical procedure on the other.

Aim:

The aim of the research was to analyze prognostic factors that influenced the frequency of recurrence in gastric surgery patients.

Patients and methods:

The five year study covered a population of 100 treated patients of adenocarcinoma of the stomach at the Department of Surgery, University Clinical Center Tuzla. The first group were characteristics of tumors in patients with gastric adenocarcinoma. Lymphadenectomy and splenectomy, types of surgery were the second group of prognostic factors.

Results:

Histological type and TNM stage of tumor as prognostic factors had a significant impact on local tumor recurrence. The type of surgery had no statistically significant value for tumor recurrence (p = 0.7520).

Conclusion:

Statistical analysis of prognostic factors related to histopathologic characteristics of tumors and the type of surgery gave the results that had an impact on recurrence in gastric surgery patients. The most important prognostic factors were TNM stage of tumor and histological type of tumor that influenced the incidence of recurrence.

Recurrence in node-negative advanced gastric cancer: Novel findings from an in-depth pathological analysis of prognostic factors from a multicentric series

AIM

To analyze the clinicopathological characteristics of patients with both node-negative gastric carcinoma and diagnosis of recurrence during follow-up.

METHODS

We enrolled 41 patients treated with curative gastrectomy for pT2-4aN0 gastric carcinoma between 1992 and 2010, who developed recurrence (Group 1). We retrospectively selected this group from the prospectively collected database of 4 centers belonging to the Italian Research Group for Gastric Cancer, and compared them with 437 pT2-4aN0 patients without recurrence (Group 2). We analyzed lymphatic embolization, microvascular infiltration, perineural infiltration, and immunohistochemical determination of p53, Ki67, and HER2 in Group 1 and in a subgroup of Group 2 (Group 2bis) of 41 cases matched with Group 1 according to demographic and pathological characteristics.

RESULTS

T4a stage and diffuse histotype were associated with recurrence in the group of pN0 patients. In-depth pathological analysis of two homogenous groups of pN0 patients, with and without recurrence during long-term follow-up (groups 1 and 2bis), revealed two striking patterns: lymphatic embolization and perineural infiltration (two parameters that pathologists can easily report), and p53 and Ki67, represent significant factors for recurrence.

CONCLUSION

The reported pathological features should be considered predictive factors for recurrence and could be useful to stratify node-negative gastric cancer patients for adjuvant treatment and tailored follow-up.

Prognostic Factors for Survival in Node-Negative Gastric Cancer Patients Who Underwent Curative Resection

BACKGROUND AND AIM

Lymph node involvement is the strongest prognostic factor for patients with gastric cancer; patients with node-negative gastric cancer present with better survival. However, some patients develop recurrent gastric cancer. The aim of this study was to review the clinicopathological characteristics and factors for prognosis in patients with node-negative gastric cancer who underwent curative resection.

METHODS

Between January 2004 and December 2015, the clinicopathological characteristics of 302 patients with node-negative gastric cancer who underwent curative gastrectomy in our hospital were retrospectively analyzed.

RESULTS

The 1-, 3-, and 5-year overall survival rates for patients with node-negative gastric cancer were 80.0%, 69.0%, and 63.0%, respectively. Univariate analysis showed that tumor size, histologic type, and depth of invasion had significant effects on survival (p < 0.05). Multivariate analysis showed that tumor size (hazard ratio: 1.83%, 95.0% confidence interval: 1.13-2.96, p = 0.014), histologic type (hazard ratio: 1.57%, 95.0% confidence interval: 1.01-2.44, p = 0.042), and depth of invasion (hazard ratio: 1.38%, 95.0% confidence interval: 1.14-1.67, p = 0.001) were independent prognostic factors.

CONCLUSION

Tumor size, histologic type, and depth of invasion are important prognostic factors in patients with node-negative gastric cancer. These parameters should be considered to stratify patients for therapy and follow-up strategies.

Prognostic significance of intraoperative macroscopic serosal invasion finding when it shows a discrepancy in pathologic result gastric cancer

Purpose

Depth of wall invasion is an important prognostic factor in patients with gastric cancer, whereas the prognostic significance of intraoperative macroscopic serosal invasion (mSE) findings remain unclear when they show a discrepancy in pathologic findings. This study, therefore, assessed the prognostic significance of mSE.

Methods

Data from cohort of 2,835 patients with resectable gastric cancer who underwent surgery between 1990 and 2010 were retrospectively reviewed.

Results

The overall accuracy of mSE and pathologic results was 83.4%. The accuracy of mSE was 75.5% in pT2. On the other hand, the accuracy of pT3 dropped to 24.5%. According to mSE findings (+/–), the 5-year disease-specific survival (DSS) rate differed significantly in patients with pT2 (+; 74.2% vs. –; 92.0%), pT3 (+; 76.7% vs. –; 91.8%) and pT4a (+; 51.3% vs. –; 72.8%) (P < 0.001 each), but not in patients with T1 tumor. Multivariate analysis showed that mSE findings (hazard ratio [HR], 2.275; 95% confidence interval [CI], 1.148–4.509), tumor depth (HR, 6.894; 95% CI, 2.325–20.437), nodal status (HR, 5.206; 95% CI, 2.298–11.791), distant metastasis (HR, 2.881; 95% CI, 1.388–6.209), radical resection (HR, 2.002; 95% CI, 1.017–3.940), and lymphatic invasion (HR, 2.713; 95% CI, 1.424–5.167) were independent predictors of 5-year DSS rate.

Conclusion

We observed considerable discrepancies between macroscopic and pathologic diagnosis of serosal invasion. However, macroscopic diagnosis of serosal invasion was independently prognostic of 5-year DSS. It suggests that because the pathologic results could not be perfect and the local inflammatory change with mSE(+) could affect survival, a combination of mSE(+/–) and pathologic depth may be predictive of prognosis in patients with gastric cancer.

Survival after Gastrectomy in Node-Negative Gastric Cancer: A Review and Meta-Analysis of Prognostic Factors

Background

Lymph node metastasis is one of the most important prognostic factors for survival of patients with gastric cancer (GC) after surgical resection. Nevertheless, a considerable number of patients have node-negative disease. We performed the present systematic review to evaluate survival and identify prognostic factors in node-negative GC patients undergoing curative intent resection.

Material/Methods

Relevant studies published between January 2000 and January 2015 were identified by searching the PubMed database and reviewed systematically. Summary relative risks (RR) and 95% confidence intervals (95% CI) were estimated using random-effects models.

Results

Thirty observational studies involving 12 504 patients were included in the review. Median 5-year overall survival was 84.3% (range, 53–96.3%). Pooled analysis showed that old age (RR, 1.26; 95%CI, 1.13–1.42), <D2 lymph node dissection (1.28; 1.05–1.55), larger tumor (1.18; 1.10–1.26), serosal invasion (2.03; 1.68–2.44), lymphatic invasion (1.25; 1.00–1.57), vascular invasion (1.67; 1.19–2.34), and lymphovascular invasion (1.93; 1.20–3.10) were significant association with decreased survival.

Conclusions

Surgical resection offers good overall survival for patients with node-negative GC. Tumor-related factors seem to have most prognostic significance.

Aberrant CCR4 expression is involved in tumor invasion of lymph node-negative human gastric cancer

Cellular chemotaxis is the best-known function of chemokine receptors which are closely linked with tumor metastasis. In fact, positive expression of chemokine receptors could also be identified even in some patients without metastatic tumors, while the clinical relevance of this data has not been fully established. Our studies were designed to clarify the CCR4 expression profiles and to explore its potential role in histologically node-negative (pN0) gastric cancer (GC). Immunohistochemistry (IHC) or immunohistofluorescence (IHF) analysis was performed on specimens obtained from 108 patients with pN0 GC. We found that CCR4 was aberrantly over-expressed inpN0 GC tissues, with different expression patterns on tumor cells and being associated with T-stage (P = 0.002). The matrigel in vitro invasion assay revealed that over-expression of CCR4 in GC cell lines significantly enhanced the invasive capacity of these cells. Results from real-time RT-PCR and gelatinzymography showed a significant increase in matrix metalloproteinase (MMP)-9 production induced by the forced expression of CCR4 in GC cell lines. Our data suggest that the aberrant CCR4 expression is involved in tumor invasion of pN0 GC and, conceivably, antagonists of CCR4 might be useful candidates for controlling early events in tumor progression.

Poor prognostic subgroup in T3N0 stage IIA gastric cancer, suggesting an indication for adjuvant chemotherapy

BACKGROUND

Adjuvant chemotherapy following curative gastrectomy is recommended for patients with pStage II or III, except pT3 (ss), N0 gastric cancer in Japan. This study aimed to detect the poor prognostic subgroup of T3N0 gastric cancer, suggesting an indication for adjuvant chemotherapy.

METHODS

Between 1999 and 2011, 116 patients with pStage IIA gastric cancer underwent curative gastrectomy. We reviewed their hospital records retrospectively.

RESULTS

The 5-year overall survival (OS) rates of patients with T1N2+T2N1 and T3N0 gastric cancer were 79% and 77%, respectively. Univariate and multivariate analyses revealed lymphatic invasion (LY+) to be an independent poor prognostic factor in T3N0 gastric cancer [P=0.004, HR 12.3 (95% CI: 2.07-112)]. The prognosis of patients with T3N0LY+ gastric cancer was significantly poorer than those with other pStage IIA gastric cancer (5-year OS; T3N0LY+ vs. other Stage IIA: 68% vs. 83%, P=0.043). The incidence of peritoneal recurrence was higher in patients with T3N0LY+ gastric cancer than in those with other Stage IIA gastric cancer (T3N0LY+ vs. other stage IIA: 9.0% vs. 2.8%, P=0.134).

CONCLUSIONS

Lymphatic invasion was an independent poor prognostic factor in T3N0 gastric cancer. Adjuvant chemotherapy should be recommended to patients with T3N0LY+ gastric cancer.

Does tumor size improve the accuracy of prognostic predictions in node-negative gastric cancer (pT1-4aN0M0 stage)?

Background

The prognostic importance of tumor size in gastric cancer is unclear. This study investigated whether the inclusion of tumor size could improve prognostic accuracy in node-negative gastric cancer.

Methods

Clinical and pathological data of 492 patients with node-negative gastric cancer who underwent radical surgery in our department from January 1995 to December 2008 were analyzed. The prognostic accuracy of T stage was compared with that of T stage plus tumor size. The ability of tumor size to improve the 95% confidence interval (CI) of postoperative 5-year survival rate in gastric cancer patients was assessed. Different T stages plus tumor size were further analyzed to assess improvements in prognosis.

Results

Mean tumor size was 3.79±1.98 cm with a normal distribution. Multivariate analysis showed that tumor size and T stage were independent prognostic factors. Postoperative 5-year survival rate tended to decrease as tumor size increased in 1 cm increments. The addition of tumor size to T stage improved accuracy in predicting 5-year survival by 4.2% (P<0.05), as well as improving the 95% CI of postoperative 5-year survival rate by 3.2–5.1%. The addition of tumor size improved the predictive accuracy of postoperative 5-year survival rate by 3.9% (95% CI 70.4%–91.1%, P = 0.033) in patients with stage T3N0M0 tumors and by 6.5% (95% CI 68.7%–88.4%, P = 0.014) in patients with stage T4aN0M0 tumors.

Conclusions

Tumor size is an independent prognostic factor for survival in patients with node-negative gastric cancer, as well as improving prognostic accuracy in stage T3/4aN0M0 tumors.

Prognostic value of number of examined lymph nodes in patients with node-negative gastric cancer

AIM: To elucidate the potential impact of examined lymph nodes (eLNs) on long-term survival of node-negative gastric cancer patients after curative surgery.

METHODS: A total of 497 node-negative gastric cancer patients who underwent curative gastrectomy between January 2000 and December 2008 in our center were enrolled in this study. Patients were divided into 4 groups according to eLNs through cut-point analysis. Clinicopathological features were compared between ≤ 15 eLNs group and > 15 eLNs group and potential prognostic factors were analyzed. The Log-rank test was used to assess statistical differences between the groups. Independent prognostic factors were identified using the Cox proportional hazards regression model. Stratified analysis was performed to investigate the impact of eLNs on patient survival in each stage. Overall survival was also compared among the four groups. Finally, we explored the recurrent sites associated with eLNs.

RESULTS: Patients with eLNs > 15 had a better survival compared with those with eLNs ≤ 15 for the entire cohort. By the multivariate survival analysis, we found that the depth of invasion and the number of eLNs were the independent predictors of overall survival (OS) of patients with node-negative gastric cancer. According to the cut-point analysis, T2-T4 patients with 11-15 eLNs had a significantly longer mean OS than those with 4-10 eLNs or 1-3 eLNs. Patients with ≤ 15 eLNs were more likely to experience locoregional and peritoneal recurrence than those with > 15eLNs.

CONCLUSION: Number of eLNs could predict the prognosis of node-negative gastric cancer, and dissection of > 15 eLNs is recommended during lymphadenectomy so as to improve the long-term survival.

A New Subclassification of pT4 Gastric Cancers According to the Width of Serosal Invasion

OBJECTIVE

The purpose of this study was to propose a novel subclassification of pT4 gastric cancers according to the width of serosal changes and to investigate the validity and clinical utility of this subclassification as a predictor of prognosis.

METHODS

A total of 780 pT4 stage gastric cancer patients classified according to the 7th American Joint Committee on Cancer (AJCC) staging system were reviewed. Clinicopathologic features were compared between patients with narrow serosal changes (nSE), wide serosal changes (wSE) and invasions of adjacent structures (SI). Prognostic factors were evaluated by univariate and multivariate analyses. The 7th AJCC and novel pT4 subclassification were compared for prognostic performance using the linear trend chi-square test, likelihood ratio chi-square test, and Akaike information criterion (AIC) in the Cox regression analysis.

RESULTS

The appropriate serosa infiltrate cutoff value was 8 cm. Most of the evaluated clinicopathologic features significantly differed between nSE and SI cancers. Only 3 factors were significantly different between wSE and SI cancers. The 5-year survival rates for patients with the novel pT4a and pT4b cancers were 47.2% and 14.52%, respectively, while they were 41.66% and 16.34% for the 7th AJCC pT4a and pT4b cancers, respectively. The novel pT4 subclassification had better discriminatory ability, monotonicity of gradients, and homogeneity and had smaller AIC values compared with the 7th AJCC pT4.

CONCLUSIONS

It is reasonable to subclassify pT4 to pT4a (nSE) and pT4b (wSE/SI) because the novel pT4 subclassification had more potential to identify the different prognoses for patients with gastric cancer.

Risk factors for lymphatic and venous involvement in endoscopically resected gastric cancer

BACKGROUND

Lymphatic and venous involvement is a critical factor in the curability assessment of endoscopically resected gastric cancers; however, the risk factors for lymphatic and venous involvement in endoscopically resected gastric cancers remain unknown.

METHODS

To identify risk factors for lymphatic and venous involvement in endoscopically resected gastric cancers, we retrospectively reviewed a consecutive series of 1229 endoscopically resected gastric cancers in 1083 patients treated between January 2009 and December 2011.

RESULTS

Lymphatic and venous involvement was detected in 57 (4.6%) and 32 (2.6%) lesions, respectively. A multivariate analysis identified a larger tumor size, deeper invasion (submucosal invasion or deeper), and the presence of a papillary or an undifferentiated-type adenocarcinoma component as independent risk factors for lymphatic involvement. As for venous involvement, deeper invasion (≥500 μm submucosal invasion), a macroscopically elevated type, and the presence of an undifferentiated-type adenocarcinoma component were identified as independent risk factors.

CONCLUSIONS

The present study identified the independent risk factors for lymphatic and venous involvement in endoscopically resected gastric cancers. The recognition of these risk factors would help in the selection of lesions that may require a particularly careful histological evaluation.

Impact of lymphatic and/or blood vessel invasion in stage II gastric cancer

AIM: To determine the prognostic value of lymphatic and/or blood vessel invasion (LBVI) in patients with stage II gastric cancer.

METHODS: From January 2001 to December 2006, 487 patients with histologically confirmed primary gastric adenocarcinoma were diagnosed with stage II gastric cancer according to the new 7th edition American Joint Committee on Cancer stage classification at the Department of Gastric Cancer and Soft Tissue Surgery, Fudan University Shanghai Cancer Center. All patients underwent curative gastrectomy with standard lymph node (LN) dissection. Fifty-one patients who died in the postoperative period, due to various complications or other conditions, were excluded. Clinicopathological findings and clinical outcomes were analyzed. Patients were subdivided into four groups according to the status of LBVI and LN metastases. These four patient groups were characterized with regard to age, sex, tumor site, pT category, tumor grading and surgical procedure (subtotal resection vs total resection), and compared for 5-year overall survival by univariate and multivariate analysis.

RESULTS: The study was composed of 320 men and 116 women aged 58.9 ± 11.5 years (range: 23-88 years). The 5-year overall survival rates were 50.7% and the median survival time was 62 mo. Stage IIa cancer was observed in 334 patients, including 268 T3N0, 63 T2N1, and three T1N2, and stage IIb was observed in 102 patients, including 49 patients T3N1, 51 T2N2, one T1N3, and one T4aN0. The incidence of LBVI was 28.0% in stage II gastric cancer with 19.0% (51/269) and 42.5% (71/167) in LN-negative and LN-positive patients, respectively. In 218 patients (50.0%), there was neither a histopathologically detectable LBVI nor LN metastases (LBVI⁻/LN⁻, group I); in 51 patients (11.7%), LBVI with no evidence of LN metastases was detected (LBVI⁺/LN⁻, group II). In 167 patients (38.3%), LN metastases were found. Among those patients, LBVI was not determined in 96 patients (22.0%) (LBVI⁻/LN⁺, group III), and was determined in 71 patients (16.3%) (LBVI⁺/LN⁺, group IV). Correlation analysis showed that N category and the number of positive LNs were significantly associated with the presence of LBVI (P < 0.001). The overall 5-year survival was significantly longer in LN-negative patients compared with LN-positive patients (56.1% vs 42.3%, P = 0.015). There was a significant difference in the overall 5-year survival between LBVI-positive and LBVI-negative tumors (39.6% vs 54.8%, P = 0.006). Overall 5-year survival rates in each group were 58.8% (I), 45.8% (II), 45.7% (III) and 36.9% (IV), and there was a significant difference in overall survival between the four groups (P = 0.009). Multivariate analysis in stage II gastric cancer patients revealed that LBVI independently affected patient prognosis in LN-negative patients (P = 0.018) but not in LN-positive patients (P = 0.508).

CONCLUSION: In LN-negative stage II gastric cancer patients, LBVI is an additional independent prognostic marker, and may provide useful information to identify patients with poorer prognosis.

Prognostic factors in patients with node-negative gastric cancer: a single center experience from China

BACKGROUND AND OBJECTIVES

Lymph node metastasis was the most important prognostic factor in gastric cancer. Patients with node-negative gastric cancer presented better survival. However, some of them would die of the disease. The aim of this study was to evaluate the prognostic factors of patients with node-negative gastric cancer.

METHODS

From 1996 to 2007, 4,426 patients had undergone curative D2 gastrectomy for gastric cancer at the Fudan University Shanghai Cancer Center. Patients with node-negative gastric cancer who underwent curative D2 gastrectomy with more than 15 lymph nodes dissected were selected into this study. The prognostic value of pathological features was investigated.

RESULTS

This study included 234 patients with node-negative gastric cancer. The 5-year overall survival in these patients was 85 %. The factors correlating significantly with overall survival on univariate analysis included age (P = 0.016), depth of invasion (P = 0.000), tumor size (P = 0.013), tumor site (P = 0.000), histological grade (P = 0.009), lymphatic tumor emboli (P = 0.014), vascular tumor emboli (P = 0.005), and nervous invasion (P = 0.033). Multivariate analysis showed that lymphatic tumor emboli (hazard ratio (HR) = 7.270), vascular tumor emboli (HR = 3.010), and depth of invasion (HR = 2.735) were defined as independent prognostic factors.

CONCLUSION

Among patients with node-negative gastric cancer and higher risk for recurrence, the use of adjuvant therapies should be considered.

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.

Lymphangiogenesis in cancer: current perspectives

Although the lymphatic system has been initially described in the sixteenth century, basic research has been limited. Despite its importance for the maintenance of tissue fluid homeostasis and for the afferent immune response, research of the molecular mechanisms of lymphatic vessel formation and function has for a long time been hampered. One reason could be because of the difficulties of visibility due to the lack of lymphatic markers. But since the discovery of several molecules specifically expressed in lymphatic endothelial cells, a rediscovery of the lymphatic vasculature has taken place. New scientific insights has facilitated detailed analysis of the nature and organization of the lymphatic system in physiological and pathophysiological conditions, such as in chronic inflammation and metastatic cancer spread. Knowledge about the molecules that control lymphangiogenesis and tumor-associated lymphangiogenesis is now expanding, allowing better opportunities for the development of drugs interfering with the relevant signaling pathways. Advances in our understanding of the mechanisms have translated into a number of novel therapeutic studies.

Prognostic impact of lymphatic invasion in patients with node-negative gastric cancer

BACKGROUND AND OBJECTIVES

This study investigated the prognostic impact of lymphatic invasion on the outcome of patients with node-negative gastric cancer.

METHODS

A total of 828 patients with node-negative gastric cancer who underwent curative gastrectomy were reviewed retrospectively. The clinicopathological features and prognoses of patients with lymphatic invasion were compared to those of patients without such invasion.

RESULTS

The total rate of lymphatic invasion was 18.2% in node-negative gastric cancers, with a significant difference between early gastric cancers (9.8%) and advanced gastric cancers (49.2%). The presence of lymphatic invasion correlated significantly with tumor location, size and depth of tumor (P < 0.01). Lymphatic invasion was significantly associated with a poorer overall survival in node-negative gastric cancer patients on univariate analysis (P < 0.001) as well as multivariate analysis (P < 0.01).

CONCLUSIONS

Lymphatic invasion provides additional useful information that could be applied to identify patients at high risk for recurrence who might be candidates for adjuvant therapies in patients with node-negative gastric cancers.

Lymphatic vessel activation in cancer

Most cancerous lesions metastasize through the lymphatic system and the status of regional lymph nodes is the most important indicator of a patient's prognosis. The extent of lymph node involvement with cancer is also an important parameter used for determining treatment options. Although the importance of the lymphatic system for metastasis has been well recognized, traditionally, the lymphatic vessels have not been considered actively involved in the metastatic process. Recent evidence, however, indicates that the activation of the lymphatic system is an important factor in tumor progression to metastasis. Tumor lymphangiogenesis has been associated with increased propensity for metastasis, and lymphatic vessel density has emerged as another promising prognostic indicator. More recently, lymphangiogenesis in the sentinel lymph nodes has been shown to contribute to malignant progression. In addition to its role as a transport system for tumor cells, the lymphatic system may also be more actively involved in metastases by directly facilitating tumor cell recruitment into the lymphatic vessels. This review highlights recent advances in our understanding of the mechanisms by which lymphatic vessels participate in metastasis.

Tumor diameter as a prognostic factor in patients with gastric cancer

BACKGROUND

The aim of this study was to evaluate the prognostic value of tumor diameter in gastric cancer.

METHODS

The study group comprised a series of 1215 patients who underwent curative gastrectomy. The appropriate tumor diameter cutoff value was determined. Prognostic factors were evaluated by univariate and multivariate analyses.

RESULTS

The tumor diameter cutoff value was 100 mm. Multivariate analysis showed that tumor site, macroscopic appearance, tumor diameter, depth of invasion, and presence of lymph node metastasis independently affected prognosis in all patients. Multivariate analysis of patients with larger tumors identified depth of invasion as an independent prognostic factor. A comparison between patients with smaller and larger tumors showed marked differences in the survival of those with stage II, IIIA, and IIIB tumors. A comparison of clinicopathological factors between stage II and III patients revealed that tumors occupying the entire stomach, ill-defined, undifferentiated, and serosa-penetrating tumors, and peritoneal metastases were far more frequent in patients with larger tumors.

CONCLUSIONS

Tumor diameter in gastric cancer is a reliable prognostic factor that might be a candidate for use in the staging system. To improve outcomes for patients with tumors >/=100 mm in diameter, it is necessary to establish therapeutic strategies for peritoneal metastasis, particularly in stage II and III tumors.