***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: INTRODUCTION This study evaluated the prognostic role of vascular epidermal growth factor ( VEGF ) , thymidylate synthase ( TS ) , topoisomerase I ( Topo-I ) , topoisomerase IIalpha ( Topo-IIalpha ) and E-cadherin ( E-cadh ) tumor expression , in patients with resectable gastric cancer , who were treated postoperatively with the docetaxel/irinotecan combination .  PATIENTS AND METHODS Forty-five patients with resectable gastric cancer were treated with 6 cycles of docetaxel 30 mg/m2 and irinotecan 110 m/m2 on day 1 and d8 every 21 days . All specimens were examined by using immunohistochemistry ( IHC ) for the expression of VEGF , TS , Topo-I , Topo-IIalpha and E-cadh . RESULTS Positivity for TS was significantly correlated with age and for VEGF with diffuse histological type and good PS . No significant correlation was observed among Topo-I , Topo-IIalpha and E-cadh positivity with any of the clinicopathological parameters studied . Median overall survival ( OS ) was 31.7 , and disease-free survival ( DFS ) 26 months , respectively . None of the above-investigated molecular markers were significantly associated with OS and DFS . Finally , according to the univariate analysis for survival , only advanced stages ( III , IV ) of the disease implied risk of death , mainly due to lymph node involvement and , to a lesser extent , tumor size . None of the studied molecular markers were found to be independent prognostic markers . CONCLUSION These results should be interpreted very cautiously , due to the limited number of patients studied , as well as the limitations of the IHC technique Objective To evaluate the correlation between serum vascular endothelial growth factor ( VEGF ) level and the clinicopathologic features in patients with hepatocellular carcinoma ( HCC ) . Summary Background Data VEGF is an important angiogenic factor regulating tumor angiogenesis . A high serum VEGF level has been shown to be associated with tumor progression and metastasis in several human cancers , but its significance in HCC is unclear . The correlation between serum VEGF level and tumor pathologic features in patients with HCC has not been studied before . Methods Preoperative serum sample s and tumor specimens were prospect ively collected in 100 patients undergoing resection of HCC .  Serum VEGF level  was measured by enzyme-linked immunosorbent assay , and tumor VEGF expression was assessed by immunohistochemical study . Histopathologic examination was performed by a pathologist without prior knowledge of the serum VEGF level or tumor VEGF expression . Results Preoperative serum VEGF levels ranged from 15 to 1,789 pg/mL ( median 269 ) . When serum VEGF levels were compared between groups categorized by different clinicopathologic variables , significant correlation was found between a high serum VEGF level and absence of tumor capsule , presence of intrahepatic metastasis , presence of microscopic venous invasion , and advanced stage . There was a positive correlation between the serum VEGF level and tumor expression of VEGF as well as platelet count . When the 75th percentile serum VEGF level ( 500 pg/mL ) was used as a cutoff level , the frequency of venous invasion in patients with a high serum VEGF level was significantly greater compared with patients with a low serum VEGF level . By multivariate analysis , a serum VEGF level of more than 500 pg/mL and tumor size more than 5 cm were independent preoperative factors predictive of microscopic venous invasion . During a median follow-up of 11.6 months , 48 % of patients with a serum VEGF level of more than 500 pg/mL and 27 % of those with a serum VEGF level of 500 pg/mL or less developed postoperative recurrence . Conclusions These results show that a high preoperative serum VEGF level is a predictor of microscopic venous invasion in HCC , suggesting that the serum VEGF level may be useful as a biologic marker of tumor invasiveness and a prognostic factor in HCC Vascular endothelial growth factor ( VEGF ) is an important regulator of angiogenesis and vascular permeability . Increased serum VEGF concentrations ( S-VEGF ) have been found in patients with various types of human cancer , including cancer of the lung . However , the clinical and prognostic significance of S-VEGF in cancer is unknown . We measured S-VEGF , using enzyme-linked immunosorbent assay , in sera taken from 68 untreated patients with small-cell lung cancer ( SCLC ) at the time of diagnosis . The patients were treated with 6 cycles of cisplatin and etoposide , and were r and omly assigned to receive recombinant interferon , leukocyte interferon or neither .  S-VEGF ranged from 70 to 1738 pg/ml ( mean , 527 pg/ml ) . The patients who achieved partial or complete response to treatment had lower pre-treatment S-VEGF than the non-responding patients ( p = 0.0083 , Mann-Whitney test ) . High ( > 527 pg/ml ) S-VEGF was associated with poor survival ( p = 0.012 , Log Rank Test ) , and all 3-year survivors had lower than mean pre-treatment S-VEGF . In a multivariate analysis , S-VEGF and stage were the only independent prognostic factors , and the estimated 3-year survival of the patients with limited stage disease and low pretreatment S-VEGF ( n = 17 , 25 % of all patients ) was 41 % ( p = 0.0055 , log rank test ) . These data show that high pretreatment S-VEGF is associated with poor response to treatment and unfavourable survival in patients with SCLC treated with combination chemotherapy with or without interferon Despite years of research and hundreds of reports on tumor markers in oncology , the number of markers that have emerged as clinical ly useful is pitifully small . Often initially reported studies of a marker show great promise , but subsequent studies on the same or related markers yield inconsistent conclusions or st and in direct contradiction to the promising results . It is imperative that we attempt to underst and the reasons why multiple studies of the same marker lead to differing conclusions . A variety of method ological problems have been cited to explain these discrepancies . Unfortunately , many tumor marker studies have not been reported in a rigorous fashion , and published articles often lack sufficient information to allow adequate assessment of the quality of the study or the generalizability of study results . The development of guidelines for the reporting of tumor marker studies  was a major recommendation of the National Cancer Institute – European Organisation for Research and Treatment of Cancer ( NCI – EORTC ) First International Meeting on Cancer Diagnostics in 2000 . As for the successful CONSORT initiative for r and omized trials and for the STARD statement for diagnostic studies , we suggest guidelines to provide relevant information about the study design , preplanned hypotheses , patient and specimen characteristics , assay methods , and statistical analysis methods . In addition , the guidelines provide helpful suggestions on how to present data and important elements to include in discussion s. The goal of these guidelines is to encourage transparent and complete reporting so that the relevant information will be available to others to help them to judge the usefulness of the data and underst and the context in which the conclusions apply 
    Output:
    
Positive expression of tissue VEGF , circulating VEGF , VEGF-C and VEGF-D were all associated with poor prognosis in resected gastric cancer .
However , VEGF demonstrated no significant prognostic value for non-Asian population s. Circulating VEGF may be better than tissue VEGF in predicting prognosis