Effect of lymph node micrometastases on prognosis of gastric carcinoma

AIM： To evaluate the relationship between lymph node micrometastases and prognosis of patients with gastric carcinoma and to evaluate the significance of the new assessment of nodal status in determining the pN categories in the 5th edition of the UICC TNM classification.METHODS： A total of 850 lymph nodes from 30 patients with gastric carcinoma who underwent gastrectomy with lymphadenectomy were assessed by reverse transcription polymerase chain reaction assay in addition to histologic examination. Cytokeratin-20 gene marker was used in this assay.RESULTS： Routine examination by HE staining confirmed metastasis in 233 lymph nodes from 20 patients. All these 233 lymph nodes were oltokeratin-20 positive. Moreover, lymph node micrometastases were detected in an additional 67 lymph nodes in 12 of these 20 patients. Lymph node micrometastases were also detected in t0 lymph nodes from 2 of 10 patients who had no obvious metastases identified by HE staining. Totally, lymph node micrometastases were identified by the reverse transcription polymerase chain reaction assay in 77 （12.5%） lymph nodes from 14 （46.7%） patients with gastric carcinoma. Of 27 patients who underwent curative resection, 7 （25.9%） were up-staged （from Ⅰ B stage to Ⅱ stage in 1 patient, from IB stage to ⅢA stage in 1 patient, from Ⅱ stage to ⅢA stage in 1 patient, from ⅢA stage to ⅢB stage in 1 patient, from ⅢA stage to Ⅳ stage in 1 patient, from ⅢB stage to Ⅳ stage in 2 patients）. In a median follow-up of 32 （range 8-36） too, Kaplan-Meier survival analysis showed significant improvements in median survival （22.86 ± 3.17 mo, 95% CI： 16.64-29.08 mo vs 18.00 ± 7.4 mo, 95% CI： 3.33-32.67 mo） of patients with negative lymph node micrometastases over patients with positive lymph node micrometastases （log-rank, P 〈 0.05）.CONCLUSION： Lymph node micrometastases have a significant impact on the current staging system of gastric carcinoma, and are significant risk factors for prognosis of patients with gastric carcinoma.

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

The 7th TNM classification clearly states that micro-metastases 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 micrometas-tases are detected by non-morphological techniques(e.g.,ow cytometry,reverse-transcriptase polymerase chain reaction) should still be classif ied as N0 or M0.In gastric cancer patients,micrometastases have been de-tected in lymph nodes,the peritoneal cavity and bone marrow.However,the clinical implications and/or their prognostic signif icance are still a matter of debate.Cur-rent literature suggests that lymph node micrometasta-ses 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 ex-amination should be obligatorily performed in pT3 or pT4 tumors.A positive cytology classif ies 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.Gas-tric 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 meth-odological problems are overcome in the future,specif ic target therapies may be designed for specif ic groups of patients.

The detection of micrometastases in the peripheral blood of patients with breast cancer for hSBEM mRNA and CD44V6 mRNA

Objective： Successful treatment of breast cancer greatly depends on the early detection of its metastasis, therefore a sensitive and specific biomarker for detecting dissemination of the cancer cells will help to achieve this goal. This study was to evaluate the prognostic significance of human small breast epithelial mucin （hSBEM） and CD44V6 in breast cancer. Methods： The expressions of hSBEM mRNA and CD44V6 mRNA were detected with nested reverse transcription polymerase chain reaction （nested RT-PCR） in 67 samples of breast cancer and adjacent normal breast tissue, 16 samples of breast benign lesions tissue, and 67 specimens of peripheral blood from patients with breast cancer, 16 specimens of benign breast lesions, 20 specimens of healthy volunteers, and 25 （each five cases） other carcinomas tissue samples, including those of gastric carcinoma, colorectal carcinoma, esophageal carcinoma, lung carcinoma, and ovary carcinoma, were analyzed for hSBEM mRNA expression by nested RT-PCR. Results： hSBEM mRNA expression was observed in 62/67 （92.54%） of breast cancer, 14/16 （87.50%） of breast benign lesions and 59/67 （88.05%） of normal breast tissue, with no significant differences between them （P 〉 0.05）. None of the samples from other cancer tissues were positive. In peripheral blood the expression of hSBEM mRNA was detected in 34/67 （50.75%） from patients with breast cancer, with significant increasing （P 〈 0.05） in the cases of metastatic disease （stage Ⅳ） and those with lymph node metastasis compared with localized disease （stage Ⅰ, Ⅱ and Ⅲ） and without lymph node metastasis, but its expression was not found in peripheral blood of patients with benign breast lesions or healthy volunteers. Although CD44V6 mRNA was significantly higher in breast cancer than in benign breast lesions tissue and normal breast tissue, its expression in peripheral blood show no significant difference （P 〉 0.05） in the patients with breast cancer （82.09%）, benign breast lesion （75.00%）, or healthy volunteers （70.00%）. The expressions of hSBEM mRNA and CD44V6 mRNA had no correlation with the age of the patients, size of primary tumor, histological type and estrogen or progestin receptor status （P 〉 0.05）. Conclusion： hSBEM mRNA, as assessed by nested RT-PCR, shows a mammary-specific and mammary-sensitive expression, and is a sensitive indicator of hematogeneous spread of breast cancer cell, while CD44V6 shows low sensitivity and specificity in detecting dissemination of breast cancer cell in peripheral blood, hSBEM mRNA is a promising molecular biomarker for detecting breast cancer micrometastases.

DETECTION OF MICROMETASTASES OF LUNG CANCER BY USING LUNX mRNA SPECIFIC REVERSE TRANSCRIPTION-POLYMERASE CHAIN REACTION

Objective: To detect of lung cancer micrometastases in peripheral blood and regional lymphatic nodes by using lunx mRNA specific reverse transcription-polymerase chain reaction (RT-PCR). Methods: RT-PCR was used to detect lunx mRNA in peripheral blood of 26 patients with lung cancer. We also detected 44 regional lymphatic nodes obtained from 25 patients with lung cancer who underwent curative lobectomy. All the 44 regional lymphatic nodes were also examined by histopathology. Micrometastatic tumor cells in the peripheral blood and regional lymphatic nodes were semiquantitatively determined with the ratio of lunx band intensity to the glyceraldehydes-3-phosphate dehydrogenase band intensity. Results: The positive detection rate of lunx mRNA in peripheral blood for non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC) patients were 60% (12/20) and 67% (4/6) respectively. 16 (36.4%) of regional lymphatic nodes from 44 lung cancer patients were positive by RT-PCR while 6 (13.6%) were positive by histopathology (x 2=6.06, P=0.014). However, no blood samples and lymphatic nodes from patients with benign pulmonary diseases or normal volunteers were positive for lunx mRNA. The positive detection rate of lunx mRNA in bone marrow of NSCLC amd SCLC patients were 65% (13/20) and 67% (4/6) respectively. Conclusion: RT-PCR amplification of lunx mRNA is an sensitive and specific means to detect early haematogenous and regional lymphatic nodes dissemination of cancer cells for patients with lung cancer.

Locoregional treatment of early breast cancer with isolated tumor cells or micrometastases on sentinel lymph node biopsy

The advent of sentinel lymph-node technique has led to a shift in lymph-node staging,due to the emergence of new entities namely micrometastases(p N1mi) and isolated tumor cells [p N0(i+)].The prognostic significance of this low positivity in axillary lymph nodes is currently debated,as is,therefore its management.This article provides updates evidence-based medicine data to take into account for treatment decision-making in this setting,discussing the locoregional treatment in p N0(i+) and p N1 mi patients(completion axillary dissection,axillary irradiation with or without regional nodes irradiation,or observation),according to systemic treatment,with the goal to help physicians in their daily practice.

Detection of micrometastases in sentinel lymph node of breast cancer

Objective： To study the best examination method of micrometastases in sentinel lymph node （SLN） of breast cancer and study the related factors with micrometastases. Methods： By step serial sectioning technique and immunohistochemistry, 121 SLNs and 44 tumors of 59 cases were examined. Results： Micrometastases was found in 17 SLNs （14%） of 14 （24%） cases. The more sections or examination methods, the more micrometastases were found. Micrometastases was related with the tumor size and the expression of c-erbB2, MMP-2 and VEGF. Conclusion： The best examination method is making sections at two levels with 100 pm interval and combination of HE staining and mucl immunohistochemistry. We can get the excellent detection/cost by this method. Micrometastases is a bad prognostic factor.

Detection of micrometastases in bone marrow and sentinel lymph nodes of breast cancer patients

To study the sensitivity and clinical significance of HE-staining,IHC and RT-PCR in detecting breast cancer micrometastases in bone marrow and sentinel lymph nodes （SLNs）. Methods ：After general anesthesia, all patients underwent bone marrow puncture and sentinel lymph node biopsy （SLNB） by 1% isosulfan blue, and then HE-staining,IHC and RT-PCR were used to detect micrometastases. Results：Of 62 patients with breast cancer whose axillary lymph nodes showed negative HE-staining results, 15 cases presented with positive RT-PCR and 9 cases showed positive IHC results positive in bone marrow micrometastases detection. PT-PCR and IHC showed good uniformity（kappa=0.6945）and there was significant difference in detective rate between these two methods （X2=4.1667,P = 0.0412）. In SLN samples, 13 showed positive RT-PCR results, while 7 showed positive IHC results. PT-PCR and IHC showed good uniformity （kappa=0.64.83）and significant difference was also found in detective rate between these two methods （X^2=4.1667 ,P = 0.0412）. Both bone marrow and SLN samples were RT-PCR positive in 3 cases, which indicated that bone marrow did not always accompany SLN micrometastases（X^2=0.067,P = 0.796）. Conclusion： Even if no axillary lymph node involvement or distant metastases are present in routine preoperative examination, micrometastases can still be detected in bone marrow or SLNs. Because the bone marrow micrometastases and axillary node micrometastses are not present simultaneously, combination test of multiple indicators will detect micrometastases more accurately.

DETECTION OF BREAST CANCER MICROMETASTASES IN BONE MARROW USING REVERSE-TRANSCRIPTASE CHAINREACTION AND SOUTHERN HYBRIDIZATION

Objective: The aim of this study was to detect micrometastases in bone marrow of primary breast cancer patients, and compare with other clinical parameters. Methods: Cytokeratin 19 (CK-19) gene mRNA expression was detected by reverse transcriptase-polymerase chain reaction (RT-PCR) and Southern blot hybridization. Human breast cancer cell line T47D was mixed with bone marrow cells in different proportions. The positive detection rate was compared among RT-PCR, Southern blotting and immunohistochemistry (IHC) methods. Results: Cytokeratin 19 gene was expressed in all 6 positive control samples while the expression was not seen in 8 negative control samples. In all 54 patients 14 cases were CK-19 positive (25.9%) by RT-PCR, another positive signal was obtained in 5/54 (9.3%) of bone marrow samples by Southern blotting. The total positive cases are 19/54 (35.2%). CK-19 IHC+ cells were detected at a dilution of one T47D cell in 5×104 bone marrow cells, while the sensitivity detected by PCR and Southern blot hybridization was at 1∶5×105 and 1∶1×106, respectively. This demonstrates that RT-PCR and Southern blotting was at least 20 times more sensitive than the IHC method. The micrometastases positive rate of the larger tumor size group (>5.0 cm) was significantly (P<0.05) greater than that of the smaller tumor size group (0–2.0 cm). Conclusion: detection of micrometastases in bone marrow by RT-PCR and Southern blotting, using CK-19 as a biological marker, is highly sensitive and it is a method to be used for anticipating the prognosis of breast cancer patients.

DETECTION AND SIGNIFICANCE OF LYMPH NODE MICROMETASTASES IN PATIENTS WITH NODE-NEGATIVE GASTRIC CARCINOMA

Objective: To study micrometastases in lymph nodes from patients with node-negative gastric carcinoma by routine histologic examination and discuss their prognostic significance and the relationship between micrometastases and each of the clinicopathologic factors. Methods: A total of 1245 perigastric lymph nodes from 105 patients with node-negative gastric carcinoma was immunohisto-chemically detected using a monoclonal antibody against low molecular weight cytokeratin AE1. The characteristics of the micrometastases, their related factors and effect on patients’ survival after surgery were analysed and tested with statistical methods. Results: Micrometastases were observed in 81 lymph nodes (6.5%) of 31 patients (29.5%). The incidence of lymph node micrometastases was significantly higher in the diffuse type (41.5%) than in the intestinal type gastric carcinoma (17.6%,P<0.01,x 2test). In addition, the presence of micrometastases was closely correlated with the size and invasion depth of the primary tumor, but had no relation to patient’s age, sex and the location of primary tumor. The patients with micrometastases had significantly worse prognosis shown by Log-rank test. Their five-year survival rate after surgery was 61.29%; for those without micrometastases the rate was 82.43%,P=0.0116. When the number of patient’s lymph nodes with micrometastases was three or more, the five-year survival rate of these patients was much lower (41.67%,P=0.0012). Conclusion: The detection of lymph node micrometastases is necessary to more accurately determine the prognosis and clinical staging of patients with node-negative gastric carcinoma by routine histologic examination. The presence of micrometastases may be regarded as one of the clues in adjuvant therapy of those patients.

COMBINED DETECTION OF BREAST CANCER MICROMETASTASES IN THE LYMPH NODES AND BONE MARROW USING REVERSETRANSCRIPTASE CHAIN REACTION AND SOUTHERN HYBRIDIZATION

Objective: The presence of lymph nodes and bone marrow micrometastases of patients with breast carcinoma by immunohistochemistry (IHC) methods has been strongly correlated to early recurrence and shorter overall survival. The aim of this study was to detect micrometastases in matched sample pairs of lymph nodes and the bone marrow of primary breast cancer patients using a more sensitive method, and compare with other clinical parameters. Methods: Cytokeratin 19 (CK-19) gene mRNA expression was detected by reverse transcriptase-polymerase chain reaction (RT-PCR) and Southern blot hybridization. Human breast cancer cell line T47D was mixed with bone marrow cells at different proportions. The positive detection rate was compared among RT-PCR, Southern blotting and IHC methods. Results: Cytokeratin 19 gene was expressed in all 6 positive control samples, while the expression wasn’t seen in 18 negative control samples. CK-19 IHC positive cells were detected at a dilution of one T47D cell in 5×105 bone marrow cells, while the sensitivity detected by PCR and Southern blot hybridization was at 1:5×104 and 1:106, respectively. In the samples from the 35 patients, we found CK-19 positive cells in 2 cases (5.7%) by IHC. CK-19 gene expression signal was detected in 14/35 (40%) by RT-PCR, and 17/35 (48.6%) by southern blotting. Four cases were micrometastases positive both in lymph node and bone marrow (11.4%). There was no correlation between CK-19 detection and other clinical parameters. Conclusion: combined detection of micrometastases in lymph node and bone marrow by RT-PCR and Southern blotting, using CK-19 as a biological marker, is a highly sensitive method for breast cancer.

Correlativity of lymph node micrometastases detection in follicular carcinoma of thyroid in different risk groups

Objective:The aim of this study was to explore the relationship between follicular carcinoma of thyroid in different risk groups and lymph node micrometastases.Methods:The keratin-19 of negative neck lymph nodes in 83 cases in routine pathological examination,was detected by SP immunohistochemistry using keratin-19 monoclonal antibody to confirm lymph node micrometastases.All of cases are divided into high risk group,middle risk group and low risk group according to factors related prognosis,the relationship between lymph node micrometastases and different risk groups and follow-up visit documents were analyzed.Results:Fifty-eight neck lymph nodes in 16 cases of 83 cases(19.3%) showed positive lymph node micrometastases,and incidence of lymph node micrometastases was 4/39 in low risk group,5/32 in middle risk group and 7/12 in high risk group,respectively.it showed remarkable difference during 3 groups(P < 0.001).Nine patients in 16 cases with positive lymph node micrometastases showed local recurrence and distant metastases,6 patients in 67 cases with negative lymph node micrometastases showed same result(P < 0.001).Conclusion:Lymph node micrometastases in follicular thyroid carcinoma closely correlated to factors related to prognosis.The detection of lymph node micrometastases can directly assistant postoperative treatment and prognosis evaluation to some extent for follicular thyroid carcinoma.

Clinical effects of apatinib mesylate for treatment of multiple brain micrometastases:Two case reports

BACKGROUND Apatinib is a small-molecule multitargeted tyrosine kinase inhibitor.Apatinib has demonstrated encouraging antitumor activities.This study aimed to observe the efficacy and safety of apatinib for the treatment of multiple brain micrometastases.CASE SUMMARY We report two patients with multiple brain micrometastases after failure of second-line treatment.Both patients had extracerebral metastases.When the patients took 250 mg/d apatinib orally,the intracerebral lesions disappeared.The extracerebral lesions were partially alleviated.Both patients had a progressionfree survival of more than 12 mo and were still stable.The safety was good.The main adverse events(AEs)were mild hypertension and proteinuria,which could be controlled.CONCLUSION Apatinib has clear efficacy and good tolerance in patients with multiple brain micrometastases after failure of second-line treatment.

Routine modified D2 lymphadenectomy performance in pT1-T2N0 gastric cancer

AIM： To evaluate routine modified D2 lymphadenectomy in gastric cancer, based on immunohistochemicaUy detected skip micrometastases in level 11 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 11 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 Ⅰ A to Ⅰ B in one patient and from stage Ⅰ B 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.

Early stage colon cancer

Evidence has now accumulated that colonoscopy and removal of polyps,especially during screening and surveillance programs,is effective in overall risk reduction for colon cancer.After resection of malignant pedunculated colon polyps or early stage colon cancers,long-term repeated surveillance programs can also lead to detection and removal of asymptomatic high risk advanced adenomas and new early stage metachronous cancers.Early stage colon cancer can be defined as disease that appears to have been completely resected with no subsequent evidence of involvement of adjacent organs,lymph nodes or distant sites.This differs from the clinical setting of an apparent"curative"resection later pathologically upstaged following detection of malignant cells extending into adjacent organs,peritoneum,lymph nodes or other distant sites,including liver.This highly selected early stage colon cancer group remains at high risk for subsequent colon polyps and metachronous colon cancer.Precise staging is important,not only for assessing the need for adjuvant chemotherapy,but also for patient selection for continued surveillance.With advanced stages of colon cancer and a more guarded outlook,repeated surveillance should be limited.In future,novel imaging technologies(e.g.,confocal endomicroscopy),coupled with increased pathological recognition of high risk markers for lymph node involvement(e.g.,"tumor budding")should lead to improved staging and clinical care.

Micrometastasis in surrounding liver and the minimal length of resection margin of primary liver cancer

AIM： To describe the distribution of micrometastases in the surrounding liver of patients with primary liver cancer （PLC）, and to describe the minimal length of resection margin （RM） for hepatectomy. METHODS： From November 2001 to March 2003, 120 histologically verfied PLC patients without macroscopic tumor thrombi or macrosatellites or extrahepatic metastases underwent curative hepatectomy. Six hundreds and twenty-nine routine pathological sections from these patients were re-examined retrospectively by light microscopy. In the prospective study, curative hepatectomy was performed from November 2001 to March 2003 for 76 histologically verfied PLC patients without definite macroscopic tumor thrombi or macrosatellites or extrahepatic metastases in preoperative imaging. Six hundreds and forty-five pathological sections from these patients were examined by light microscopy. The resected liver specimens were minutely examined to measure the resection margin and to detect the number of daughter tumor nodules, dominant lesions, and macroscopic tumor thrombi inside the lumens of the major venous system. The paraffin sections were microscopically examined to detect the microsatellites, microscopic tumor thrombi, fibrosis tumor capsules, as well as capsule invasion and the distance of histological spread of the micrometastases. RESULTS： In the retrospective study, 70 micrometastases were found in surrounding liver in 26 of the 120 cases （21.7%）. The farthest distance of histological micrometastasis was 3.5 mm, 5.3 mm and 6.0 mm in 95%, 99% and 100% cases, respectively. Macroscopic tumor thrornbi or rnacrosatellites were observed in 18 of 76 cases, and 149 rnicrometastases were found in the surrounding live in 25 （43.1%） of 58 cases with no macroscopic tumor thrombi. The farthest distance of histological micrometastasis was 4.5 mm, 5.5 mm and 6.0 mm in 95%, 99% and 100% cases, respectively. Two hundred and sixty-seven rnicrometastases were found in surrounding liver in 14 （77.8%） out of 18 cases with macroscopic tumor thrombi or macrosatellites. The farthest distance of histological micrometastasis was 18.5 mm, 18.5 mm and 19.0 mm in 95%, 99% and 100% cases, respectively. CONCLUSION： The required minimal length of RM is 5.5 mm and 6 mm respectively to achieve 99% and 100% rnicrometastasis clearance in surrounding liver of PLC patients without macroscopic tumor thrornbi or rnacrosatellites, and should be greater than 18.5 mm to obtain 99% rnicrometastasis clearance in surrounding liver of patients with macroscopic tumor thrornbi or rnacrosatellites.

Prognostic relevance of minimal residual disease in colorectal cancer

Presence of occult minimal residual disease in patients with colorectal cancer(CRC)has a strong prognostic impact on survival.Minimal residual disease plays a major role in disease relapse and formation of metastases in CRC.Analysis of circulating tumor cells(CTC)in the blood is increasingly used in clinical practice for disease monitoring of CRC patients.In this review article the role of CTC,disseminated tumor cells(DTC)in the bone marrow and micrometastases and isolated tumor cells(ITC)in the lymph nodes will be discussed,including literature published until September 2013.Occult disease is a strong prognostic marker for patient survival in CRC and defined by the presence of CTC in the blood,DTC in the bone marrow and/or micrometastases and ITC in the lymph nodes.Minimal residual disease could be used in the future to identify patient groups at risk,who might benefit from individualized treatment options.

Strong prognostic value of nodal and bone marrow micro-involvement in patients with pancreatic ductal carcinoma receiving no adjuvant chemotherapy

AIM： To study the prognostic value of adjuvant chemotherapy in patients with pancreatic, ductal adenocarcinoma. METHODS： Lymph nodes from 106 patients with resectable pancreatic ductal adenocarcinoma were systematically sampled. A total of 318 lymph nodes classified histopathologically as tumor-free were examined using sensitive immunohistochemical assays. Forty-three （41%） of the 106 patients were staged as pT1/2, 63 （59%） as pT3/4, 51 （48%） as pNo, and 55 （52%） as pN1. The study population included 59 （56%） patients exhibiting G1/2, and 47 （44%） patients with G3 tumors. Patients received no adjuvant chemoor radiation therapy and were followed up for a median of 12 （range： 3.5 to 139） mo.RESULTS： Immunostaining with Ber-EP4 revealed nodal microinvolvement in lymph nodes classified as ＂tumor free＂ by conventional histopathology in 73 （69%） out of the 106 patients. Twenty-nine （57%） of 51 patients staged histopathologically as pNo had nodal microinvolvement. The five-year survival probability for pN0-patients was 54% for those without nodal microinvolvement and 0% for those with nodal microinvolvement. Cox-regression modeling revealed the independent prognostic effect of nodal microinvolvement on recurrence-free （relative risk 2.92, P = 0.005） and overall （relative risk 2.49, P = 0.009） survival. CONCLUSION： The study reveals strong and independent prognostic significance of nodal microinvolvement in patients with pancreatic ductal adenocarcinoma who have received no adjuvant therapy. The addition of immunohistochemical findings to histopathology reports stratification of patients with may help to improve risk pancreatic cancer.

Perfusion computed tomography in colorectal cancer:Protocols,clinical applications and emerging trends

Perfusion computed tomography (CT) has emerged as a novel functional imaging technique with gradually increasing importance in the management of colorectal cancer (CRC).By providing the functional tumor microvasculature,it also helps the assessment of therapeutic response of anti-angiogenic drugs as it may reflect tumor angiogenesis.Perfusion CT has been applied in clinical practice to delineate inflammatory or neoplastic lymph nodes irrespective of their size,identify micro-metastases and to predict metastases in advance of their development.It is of increasing significance for preoperative adjuvant therapies and avoidance of unnecessary interventions.Despite controversies regarding the techniques employed,its validity and reproducibility,it can be advantageous in the management of CRCs in which the prognosis is dependent on preoperative staging.With recent advances in the perfusion CT techniques,and incorporation to other modalities like positron emission tomography,perfusion CT will be a novel tool in the overall management of CRCs.This article aims at reviewing the existing clinical applications and recent advances of perfusion CT with a reference to future development in the management of CRCs.

AN IMMUNOHISTOCHEMICAL STUDY OF OCCULT MICRO- METASTASES IN REGIONAL LYMPH NODES OF 94 PATIENTS WITH STAGE I NON-SMALL CELL LUNG CARCINOMA

In the study, 739 regional lymph nodes from 94 patients with stage I non- small cell lung carcinoma (NSCLC) were studied by immunohistochemical techniques. These lymph nodes contained no metastatic tumor as assessed by conventional histopatholgy were recut. A series of consecutive sections from the original blocks were immunostained with poly-and monoclonal antibodies to cytokeratins, carcinoembryonic antigen (CEA), and human milk fat globulin membrane antigen (HMFG-2). Single tumor cells or small clusters of tumor cells, not visible on routine examination, were readily detected. The actual number of lymph nodes that contained occult tumor cells was 123 (16.6%) from 53 patients (56.4%). The majority of 102 immunostalned positive nodes were distributed in the hllar (29% ) and peribronchlal (25%) regions. Our data indicate that (1) a series of consecutive sections and immunohistochemistry may greatly Increase the diagnostic yield of occult micrometastases in lymph nodes; (2) the high incidence of occult metastases in NSCLC may be of Importance in relation to their rapid dissemination and high death rates; (3) the high frequencyof occult nodal metastases in NSCLC raises questions in regard to our presently used criteria for staging, prognosis and treatment of ostensibly stage I disease; and (4) perhaps dissections of hllar and peribronchlal nodes will have an Importantly clinical significance in prevention of wide dissemination of tumor cells.

Clinical pathology of nodal micrometasteses in non-small cell lung cancer

Objective： To explore whether the conventional pathologic stages of some non-small cell lung cancer （NSCLC） patients were underestimated. Methods： 195 lymph node samples were taken from 25 NSCLC patients during the operations. Firstly, each resulting tissue block was processed for routine paraffin embedding. Then the 6- 10 serial sections were chosen, each 5/am thick, from every paraffin block of the lymph node. Finally, the first and the second last sections of each lymph node were stained by hematoxylin eosin （HE）, and the other serial sections were used for the immunohistochemical （IHC） staining examination with the monoclonal antibody against cyokeratin 19. Results： With HE staining, 30 of the 195 regional lymph nodes revealed dominant nodal metastases, and none showed micrometastases. IHC staining was performed on 135 lymph nodes that were identified as free of metastases by HE staining, 31 showed micrometastases; none showed gross nodal metastases. There was a significant difference between HE staining staging and IHC staining staging （P〈0.05）. Conclusion： Conventional HE staining can accurately detect gross nodal metastases in the lymph nodes of NSCLC patients, but is unfit for detecting lymph nodal micrometastases. IHC staining analysis can significantly facilitate the detection of occult micrometastatic tumor cells in lymph nodes, and its assessment of nodal micrometastases can provide a refinement of TNM stage for NSCLC patients. Our results provide a rationale for extensive lymph nodes sampling