Postoperative staging of gastric carcinoma. A comparison between the UICC stage classification and the 12th edition of the Japanese General Rules for Gastric Cancer Study

Gastric cancer: factors affecting survival

BACKGROUND AND AIM

The present multicenter, retrospective study aimed at determining the factors affecting survival in patients who were operated on due to gastric cancer (GC).

PATIENTS AND METHODS

The data of 234 patients, who underwent elective surgery due to GC were retrospectively analyzed. The demographic characteristics, tumor localization and diameter, type of resection and lymph node dissection, experience of the operating surgeon (senior or junior), tumor grade, pT stage, number of lymph nodes harvested, number of lymph nodes with and without metastasis, tumor stage and survival data were recorded.

RESULTS

Survival was better a tumor diameter <4 cm, lower localization, experience of the operating surgeon (senior), without metastatic lymph nodes, tumor grade and decreased invasion depth (p < .05). There was no statistically significant difference between D1 LND and D2 LND with respect to survival (p = .793). Mortality was higher and survival was lower in patients with metastatic lymph nodes (p = .001). A number of harvested lymph nodes of 16 or more increased mortality (p = .003). Also, as disease stage increased, there was a decrease in survival and increase in mortality rates (p = .001).

CONCLUSIONS

Survival outcomes in resectable GCs are affected by the experience of the surgeon and patient-related factors at the time of surgery, including tumor size, T stage, and presence of metastatic lymph nodes.

PROGNOSTIC VALUE OF CARCINOEMBRYONIC ANTIGEN LEVELS IN TRANSOPERATIVE PERITONEAL LAVAGE IN PATIENTS WITH GASTRIC CANCER

Background:

The carcinoembryonic antigen level in peritoneal lavage has been showing to be a reliable prognostic factor in gastric cancer.

Aim:

To identify any association between carcinoembryonic antigen level in peritoneal lavage, in gastric cancer patients, with mortality, peritoneal recurrence, tumor relapse or other prognostic factors.

Methods:

In total, 30 patients (22 men, 8 women; median age 66 years) with resectable gastric cancer (mainly stage III and IV) were studied. Carcinoembryonic antigen level in peritoneal lavage was detected at operation by immunocytochemical method and a level over 210 ng/g of protein was considered as positive.

Results:

There were detected 10 positive cases (33.3%) of plCEA levels. These levels were associated with mortality, RR: 2.1 (p=0.018); peritoneal recurrence, OR: 9.0 (p=0.015); and relapse or gastric cancer progression, OR: 27.0 (p=0.001).

Conclusion:

Increased levels of plCEA fairly predicts mortality, peritoneal recurrence tumor relapse or cancer progression.

Assessment of Hyperthermic Intraperitoneal Chemotherapy to Eradicate Intraperitoneal Free Cancer Cells

OBJECTIVE: To assess the effect of hyperthermic intraperitoneal chemotherapy (HIPEC) to eradicate intraperitoneal free cancer cells and to explore the feasibility of cytological cure for peritoneal carcinomatosis (PC). METHODS: The peritoneal lavage fluid (or ascites) from 50 PC patients was collected before and after intraoperative HIPEC, respectively, for conventional cytology test, and conventional and real-time quantitative reverse transcript polymerase chain reaction detecting carcinoembryonic antigen (CEA) mRNA and cytokeratin-20 (CK20) mRNA. The blood samples 3 days before and 7 days after intraoperative HIPEC were also collected for detecting the serum tumor markers, including CEA, carbohydrate antigen (CA) 125, and CA19-9. RESULTS: The positive rate of conventional cytology test before HIPEC versus after HIPEC was100.0% versus 22.0% (P = .000). The positive rates of CEA mRNA and CK20 mRNA before HIPEC versus after HIPEC were 100.0% versus 86.0% (P = .012) and 100.0% versus 96.0% (P = .495), respectively. Moreover, after HIPEC, 18 (36.0%) patients had a decline in CEA mRNA (P = .000), and 17 (34.0%) patients had a decline in CK20 mRNA (P = .000). The positive rates of serum CEA, CA125, and CA199 before HIPEC versus after HIPEC were 52.0% versus 28.0% (P = .014), 52.0% versus 44.0% (P = .423), and 40.0% versus 28.0% (P = .205), respectively. CONCLUSION: HIPEC could effectively eradicate intraperitoneal free cancer cells and partially achieve cytological cure for PC.

D1 versus D2 dissection in gastric carcinoma: Evaluation of postoperative mortality and complications

OBJECTIVE

Surgery is the only curative treatment for patients with gastric cancer. However, the extent of lymph node dissection is still debated. The aim of the study was to evaluate complications, postoperative length of hospital stay and postoperative mortality after D1 or D2 lymph node dissection for gastric cancer in a non-specialized hospital.

MATERIAL AND METHODS

All patients who underwent surgery for pathologically confirmed gastric cancer at our 3rd General Surgery Department, Ankara Numune Training Hospital between January 1999 and 2007 were retrospectively reviewed. A consecutive series of 71 gastric cancer patients was identified. D1 resection (level 1 lymphadenectomy) was compared with D2 resection (levels 1 and 2 lymphadenectomy).

RESULTS

The D2 group had higher postoperative mortality (16% vs. 8%; p<0.005) and morbidity (54% vs. 34%; p<0.005), and their postoperative length of stay was longer. Splenectomy did not have an effect on postoperative morbidity and mortality in either the D1 or the D2 group.

CONCLUSION

The D2 procedure was associated with significantly higher postoperative mortality, morbidity, and postoperative length of hospital stay.

The progression potential of peritoneal dissemination nodules from gastrointestinal tumors

It is necessary to examine the characteristics of the dissemination nodules to establish a therapeutic strategy for peritoneal dissemination from digestive malignancy. Ki-67 expression as a proliferation marker in peritoneal dissemination nodules was investigated. The subjects were 15 patients with gastrointestinal cancers who underwent resection of the primary tumor and disseminated nodules. The expression of Ki-67 in both primary tumor and peritoneal dissemination nodule from each patient was evaluated by immunohistochemistry. Ki-67 labeling index in the original tumor was higher than that in the disseminated nodule in 13 of 15 patients (P < 0.0001). The mean value of Ki-67 labeling index was 42.2% in the 15 original tumors and 18.7% in the 15 disseminated nodules. Proliferative activity in the disseminated nodules was lower than that in the primary tumors. Further examination about characteristics of cancer dissemination is needed to treat patients with peritoneal metastasis.

Survival Benefit of Adjuvant Radiation Therapy for Gastric Cancer following Gastrectomy and Extended Lymphadenectomy

Purpose. Although randomized trials suggest a survival benefit of adjuvant chemotherapy and radiation therapy (XRT) for gastric adenocarcinoma, its use in patients who undergo an extended lymphadenectomy is less clear. The purpose of this study was to determine if a survival benefit exists in gastric cancer patients who receive adjuvant XRT following resection with extended lymphadenectomy. Methods. The SEER registry was queried for records of patients with resected gastric adenocarcinoma from 1988 to 2007. Multivariable Cox regression models were used to assess independent prognostic factors affecting overall survival (OS) and disease-specific survival (DSS). Results. Of 15,060 patients identified, 3,208 (21%) received adjuvant XRT. Adjuvant XRT was independently associated with improved OS (HR 0.67, CI 0.64–0.71) and DSS (HR 0.69, CI 0.65–0.73) in stages IB through IV (M0). This OS and DSS benefit persisted regardless of the extent of lymphadenectomy. Furthermore, lymphadenectomy with >25 LN resected was associated with improved OS and DSS compared with <15 LN or 15–25 LN. Conclusion. This population-based study shows a survival benefit of adjuvant XRT following gastrectomy that persists in patients who have an extended lymphadenectomy. Furthermore, removal of >25 LNs results in improved OS and DSS compared with patients who have fewer LNs resected.

The herb medicine formula "Yang Wei Kang Liu" improves the survival of late stage gastric cancer patients and induces the apoptosis of human gastric cancer cell line through Fas/Fas ligand and Bax/Bcl-2 pathways

The herb medicine formula "Yang Wei Kang Liu" (YWKLF) has been used to inhibit the metastasis of human gastric cancer to prolong patient survival. In this study, we evaluated the effect of combination of chemotherapy with YWKLF on the survival of stage IV gastric cancer patients and the potential mechanisms of YWKLF by focusing on its capacity to activate apoptotic pathways in human gastric cancer cell line MGC-803. We found that combination of chemotherapy with oral administration of YWKLF significantly increased the survival of stage IV gastric cancer patients. In an approach of "serum pharmacology" in which sera were collected from rabbits orally administered with YWKLF and examined for their anti-tumor cell activity in vitro, we observed that sera from rabbits administered with YWKLF induced the apoptosis of MGC-803 cells by causing the loss of mitochondrial membrane potential, increasing the expression of Fas protein and Bax mRNA, as well as down-regulating Fas-L mRNA. Our results suggest that activation of major pro-apoptotic pathways may account for the anti-gastric cancer activity of YWKLF, which may provide a basis for isolation and identification of more highly effective anti-cancer components.

Reduction of peritoneal carcinomatosis by intraperitoneal administration of phospholipids in rats

BACKGROUND

Intraperitoneal tumor cell attachment after resection of gastrointestinal cancer may lead to a developing of peritoneal carcinosis. Intraabdominal application of phospholipids shows a significant decrease of adhesion formation even in case of rising tumor cell concentration.

METHODS

In experiment A 2*106 colonic tumor cells (DHD/K12/Trb) were injected intraperitonely in female BD-IX-rats. A total of 30 rats were divided into three groups with treatments of phospholipids at 6% or 9% and the control group. In experiment B a total of 100 rats were divided into ten groups with treatments of phospholipids at 9% and the control group. A rising concentration of tumor cells (10,000, 50,000, 100,000, 250,000 and 500,000) were injected intraperitonely in female BD-IX-rats of the different groups. After 30 days, the extent of peritoneal carcinosis was determined by measuring the tumor volume, the area of attachment and the Peritoneal Cancer Index (PCI).

RESULTS

In experiment A, we found a significant reduction (control group: tumor volume: 12.0 +/- 4.9 ml; area of tumor adhesion: 2434.4 +/- 766 mm2; PCI 28.5 +/- 10.0) of peritoneal dissemination according to all evaluation methods after treatment with phospholipids 6% (tumor volume: 5.2 +/- 2.2 ml; area of tumor adhesion: 1106.8 +/- 689 mm2; PCI 19.0 +/- 5.0) and phospholipids 9% (tumor volume: 4.0 +/- 3.5 ml; area of tumor adhesion: 362.7 +/- 339 mm2; PCI 13.8 +/- 5.1). In experiment B we found a significant reduction of tumor volume in all different groups of rising tumor cell concentration compared to the control. As detected by the area of attachment we found a significant reduction in the subgroups 1*104, 25*104 and 50*104. The reduction in the other subgroups shows no significance. The PCI could be reduced significantly in all subgroups apart from 5*104.

CONCLUSION

In this animal study intraperitoneal application of phospholipids resulted in reduction of the extent of peritoneal carcinomatosis after intraperitoneal administration of free tumor cells. This effect was exceptionally noticed when the amount of intraperitoneal tumor cells was limited. Consequently, intraperitoneal administration of phospholipids might be effective in reducing peritoneal carcinomatosis after surgery of gastrointestinal tumors in humans.

Peritoneal lavage cytology and carcinoembryonic antigen determination in predicting peritoneal metastasis and prognosis of gastric cancer

AIM

To evaluate the role of peritoneal lavage cytology (PLC) and carcinoembryonic antigen (CEA) determination of peritoneal washes (pCEA) in predicting the peritoneal metastasis and prognosis after curative resection of gastric cancer.

METHODS

PLC and radioimmunoassay of CEA were performed in peritoneal washes from 64 patients with gastric cancer and 8 patients with benign diseases.

RESULTS

The positive rate of pCEA (40.6%) was significantly higher than that of PLC (23.4%) (P<0.05). The positive rates of PLC and pCEA correlated with the depth of tumor invasion and lymph node metastasis (P<0.05). pCEA was found to have a higher sensitivity and a lower false-positive rate in predicting peritoneal metastasis after curative resection of gastric cancer as compared to PLC. The 1-, 3-, and 5-year survival rates of patients with positive cytologic findings or positive pCEA results were significantly lower than those of patients with negative cytologic findings or negative pCEA results (P<0.05). Multivariate analysis indicated that pCEA was an independent prognostic factor for the survival of patients with gastric cancer.

CONCLUSION

Intraoperative pCEA is a more sensitive and reliable predictor of peritoneal metastasis as well as prognosis in patients with gastric cancer as compared to PLC method.

Possible involvement of RUNX3 silencing in the peritoneal metastases of gastric cancers

PURPOSE

Our previous results suggested that a lack of RUNX3 function contributed to human gastric carcinogenesis, but the role of RUNX3 in progression and metastasis remains unclear. We examined RUNX3 expression in clinical samples of peritoneal metastases in gastric cancers. Changes in metastatic potential were assessed in animal experiments using stable RUNX3 transfectants of gastric cancer cells. Finally, global expression changes were analyzed using a cDNA microarray.

EXPERIMENTAL DESIGN AND RESULTS

Significant down-regulation of RUNX3 through methylation on the promoter region was observed in primary tumors (75%) as well as in all clinical peritoneal metastases of gastric cancers (100%) compared with normal gastric mucosa. Stable transfection of RUNX3 inhibited cell proliferation slightly, and modest transforming growth factor-beta (TGF-beta)-induced antiproliferative and apoptotic effects were observed. Interestingly, it strongly inhibited peritoneal metastases of gastric cancers in animal model (P < 0.01). Furthermore, we did globally analyzed expression profiles of approximately 21,000 genes in parent cells and stable transfectant of RUNX3 using a cDNA microarray. Microarray analysis identified approximately 28 candidate genes under the possible downstream control of RUNX3, some of these genes were considered to be possibly involved in peritoneal metastases, which were related to signal transduction (vav3, TOLL-like receptor, MAPKK, MET, S1 00A1 1, and cathepsin E), apoptosis (caspase 9), immune responses (CD55 and TLR1O), and cell adhesion (sialyltransferase 1 and galectin 4). Some of the genes are involved in the TGF-beta signaling pathway.

CONCLUSION

These results indicate that silencing of RUNX3 affects expression of important genes involved in aspects of metastasis including cell adhesion, proliferation, apoptosis, and promoting the peritoneal metastasis of gastric cancer. Identification of such genes could suggest new therapeutic modalities and therapeutic targets.

Overexpression of dopa decarboxylase in peritoneal dissemination of gastric cancer and its potential as a novel marker for the detection of peritoneal micrometastases with real-time RT-PCR

We previously performed a global analysis of the gene expression of gastric cancer cell lines established from metastases to the peritoneal cavity with the cDNA microarray method, which made it possible to analyse the expression of approximately 21 168 genes for the identification of novel markers for the detection of micrometastases in the peritoneal cavity. One of the upregulated genes is dopa decarboxylase (DDC), which is responsible for the synthesis of the key neurotransmitters dopamine and serotonine. We have examined its potential as a novel marker for the detection of peritoneal micrometastases of gastric cancer.

DDC mRNA in the peritoneal wash from 112 gastric cancer patients was quantified for comparison of carcinoembryonic antigen (CEA) mRNA by means of real-time reverse transcriptase–polymerase chain reaction (RT–PCR) with a fluorescently labelled probe to predict peritoneal recurrence. The quantity of DDC and CEA correlated with wall penetration. Real-time RT–PCR could quantitate 10–10⁶ DDC-expressing gastric cancer cells per 10⁷ mesothelial cells. The cutoff value was set at the upper limit of the quantitative value for noncancer patients, and those above this cutoff value constituted the micrometastasis (MM+) group. Of 15 cases with peritoneal dissemination, 13 were MM+DDC (87% sensitivity), and one of 48 t1 cases was MM+ (98% specificity). DDC levels in peritoneal washes from patients with synchronous peritoneal metastases were more than 50 times higher than in those from patients without metastasis (P<0.01). For 15 cases of peritoneal dissemination (seven cases were cytologically positive), DDC was positive in 13 cases (87% sensitivity), but CEA failed to detect micrometastases in four cases (73% sensitivity), indicating that DDC is in some cases superior to CEA for the detection of peritoneal micrometastases of gastric cancer in terms of sensitivity as well as specificity, especially for poorly differentiated adenocarcinomas. A combination of CEA and DDC improved the accuracy of diagnosis up to 94%.

These results suggest that DDC is potentially a novel marker for peritoneal dissemination of gastric cancer and that quantitative RT–PCR of DDC is reliable and efficient for the selection of patients for adjuvant intraperitoneal chemotherapy to prevent peritoneal recurrence.

The role of surgery in the current treatment of gastric carcinoma

Surgery currently is the only curative option in the treatment of gastric cancer. For early gastric cancer, an endoscopic mucosal resection (EMR) is adequate for intramucosal cancer less than 2 cm in diameter without ulcer. For early cancers ineligible for EMR, limited surgical operation (proximal gastrectomy, segmental resection, and pylorus-preserving distal gastrectomy) can be recommended to reduce surgical risk and achieve improvements in quality of life without decreasing survival. Subtotal/total gastrectomy plus D2 lymph node dissection is the standard surgery for advanced gastric cancer in Japan. Pancreas-preserving total gastrectomy is recommended due to the reduced risk of pancreatic fistula and postoperative diabetes. Regarding extended surgery, results of a phase III study to evaluate the role of paraaortic node dissection will be analyzed in a few years' time after the accrual of more than 500 patients in a Japan Clinical Oncology Group (JCOG) study. For scirrhous gastric cancer, left upper abdominal exenteration appears to be associated with improved survival and should be tested in another controlled trial.

Effects of dietary, drinking, and smoking habits on the prognosis of gastric cancer

Although it has been clarified that dietary, drinking, and smoking habits contribute to the onset of gastric cancer, little is known about their impact on prognosis of gastric cancer. To examine this question, a prognostic analysis was conducted using data from Aichi Cancer Center Research Institute and Hospital. From January 1988 to December 1994, information on 877 gastric cancer patients (578 men and 299 women) regarding habitual smoking and drinking, food consumption, histological grade, and clinical stage of tumor as well as follow-up results were collected. Survival status of all patients was followed up until December 1998, and the survival function was estimated by the Kaplan-Meier method. Proportional hazard analysis was used to test the effect of each lifestyle item on gastric cancer death. After controlling for age, gender, histological grade, and stage of disease, hazard ratios (HR) were calculated. Values for consumption of raw vegetables [HR = 0.74, 95% confidence interval (CI) = 0.56-0.98], tofu (HR = 0.65, 95% CI = 0.42-0.99), and chicken meat (HR = 0.61, 95% CI = 0.39-0.95) more than three times per week demonstrated significantly decreased risk. However, the risk ratio was 2.53 (95% CI = 1.22-5.29) for habitual smokers, and an inverse dose-response relationship was also found between ever smoking and gastric cancer patient survival. Therefore, this study suggested that frequent intake of raw vegetables and tofu is favorable, whereas habitual smoking is an adverse prognostic factor for gastric cancer. Our study implies that an improvement of survival of Japanese gastric cancer might be achieved by lifestyle improvement.

Polymerase chain reaction for detection of carcinoembryonic antigen-expressing tumor cells on milky spots of the greater omentum in gastric cancer patients: a pilot study

Our recent studies indicate that omental milky spots are frequently involved in the early stage of peritoneal cancer dissemination. We have used carcinoembryonic antigen (CEA)-specific RT-PCR for omental milky spots to predict peritoneal recurrence in gastric cancer patients. CEA mRNA was found to be positive in both 10 peritoneal washes and 16 greater omenta of 30 gastric cancer patients, including all 6 patients who showed positive results for both cytology and RT-PCR of peritoneal wash and omentum. Three of the 6 cases with positive RT-PCR in the greater omentum but not in the peritoneal wash showed recurrence of peritoneal carcinomatosa within 2 years after operation. Micrometastasis on omental milky spots was histologically confirmed in 6 of 30 gastric cancer cases. Non-specific band was detected only in the omentum of 1 case of 15 benign disease (7%), but not in peritoneal washes (0%), probably due to weak expression of CEA in mesothelial cells. Our results show that CEA-specific RT-PCR targeting micro-metastases on omental milky spots is more sensitive than targeting the peritoneal wash or conventional cytology, and suggest that this method is useful for the prediction of peritoneal recurrence in gastric cancer patients.

Detection of telomerase activity in peritoneal lavage fluid from patients with gastric cancer using immunomagnetic beads

Cytologic examination of peritoneal lavage fluid is a useful predictor of peritoneal recurrence in gastric cancer. However, this technique is not overly sensitive and requires special abilities in the cytologist. In this study, telomerase activity was used to detect free cancer cells in peritoneal lavage fluid from patients with gastric cancer. In the first part, 12 lavage-fluid samples obtained from 12 patients with gastric cancer were analysed using the conventional telomeric repeat amplification protocol (TRAP) assay. Three of five patients with early gastric cancer had positive telomerase activity. These false-positive results may have been due to lymphocyte contamination. Furthermore, polymerase chain reaction inhibitors were also detected in the lavage-fluid samples. Therefore, we developed a novel method for elimination of haematopoietic cell and Taq polymerase inhibitors to increase the accuracy of the TRAP assay using immunomagnetic beads, which bind to most normal and neoplastic human epithelial cells. Telomerase activity was found in 10 of 20 (50%) lavage-fluid samples from patients with serosal or subserosal invasion. Cytologic examination was positive in nine of 20 (45%) samples. Both the telomerase activity and cytology were negative in all 14 patients without serosal or subserosal invasion. These results suggest that the TRAP assay combined with immunomagnetic beads might be useful for detection of free cancer cells in the peritoneal space in gastric cancer without the aid of an experienced cytologist.

The number of metastatic lymph nodes: a promising prognostic determinant for gastric carcinoma in the latest edition of the TNM classification

BACKGROUND

The number of metastatic regional lymph nodes determines the new pN categories in the 5th edition of the TNM classification.

STUDY DESIGN

Our retrospective study was conducted to compare the new method of defining lymph node status with the conventional classification, consisting of the anatomic extent of lymph node metastases, a well-established prognostic factor. The study was based on clinical data for 493 patients with gastric carcinomas who underwent potentially curative operations and had histologically confirmed nodal metastases. These patients were stratified into 1) n categories according to the Japanese Classification of Gastric Carcinoma, 2) the new pN categories, and 3) the pN categories determined by the number of metastatic perigastric nodes resected by standard D1 gastrectomy. Survival data were analyzed for each group.

RESULTS

The number of metastatic nodes after D2 lymphadenectomy reflected prognosis well and was shown by multivariate analysis to be a strong independent prognostic factor. When the classification was performed limited to the metastatic perigastric nodes, stage migration was evident, but the variable remained competent as a prognostic indicator.

CONCLUSIONS

The number of metastatic nodes is a promising determinant in the new international stage classification.

Evaluation of a new staging system by the Japanese Research Society for Gastric Cancer

The feasibility of the new classification of stage grouping by the Japanese Research Society for Gastric Cancer was evaluated. During the 22-year period between January 1975 and December 1996, a total of 1294 patients with primary gastric cancer underwent laparotomy at the Department of Surgery, Chiba University; 1222 had their lesions removed during the gastrectomy and 72 remained nonresected. Cases of direct operative death totaled 17 (1.3%). Five hundred patients (38.6%) died of a relapse of the original cancer and 42 (3.2%) died of other diseases within the followup period. Six patients (0.5%) were lost during the followup. The 5-year cumulative patient survival rates of the seven stages of the new stage grouping were distinctly proportional, and the differences were also statistically significant except between stages IIIb and IVa. The two major revised points in the new stage grouping, new classification of the depth of cancer invasion, and new stage grouping by a mosaic combination of the degree of invasion and lymph node metastasis were thus found to be reasonable based on the actuarial 5-year survival rates of the subgroups in the same stage. The present study also showed that the classification of stage IV still requires further discussion.

Lymph node status assessment for gastric carcinoma: is the number of metastatic lymph nodes really practical as a parameter for N categories in the TNM Classification? Tumor Node Metastasis

BACKGROUND AND OBJECTIVES

The anatomical extent of nodal metastasis has been replaced by the number of metastatic nodes as a key indicator of prognosis (pN categories) in the fifth edition of Tumor Node Metastasis Classification for gastric carcinoma by the International Union Against Cancer. The rate of metastatic nodes among all the nodes harvested is also a good prognostic factor. The object of this study is to evaluate which of the three parameters for the assessment of nodal status is the most appropriate for use in the stage classification.

METHODS

Retrospective survival analyses were performed in 656 consecutive patients with advanced gastric carcinoma who underwent D2 lymphadenectomy and for whom histopathologic data of more than 20 lymph nodes were available.

RESULTS

Although all three systems served well to classify the patients into distinct groups in terms of survival curves, stratification by the number of metastatic nodes was vulnerable to stage migration because of differences in the number of lymph nodes harvested. Such stage migration was not evident for the other two parameters.

CONCLUSIONS

Lymph node metastatic rate can be recommended as an internationally applicable parameter for lymph node involvement of gastric carcinoma.

Prognostic value and clinical implications of disseminated cancer cells in the peritoneal cavity detected by reverse transcriptase-polymerase chain reaction and cytology

Free cancer cells exfoliated from the cancer-invaded serosa contribute to peritoneal dissemination, the most frequent pattern of recurrence in gastric carcinoma patients. This study was designed to evaluate the prognostic relevance of such free cells in peritoneal washes detected by reverse transcriptase-polymerase chain reaction (RT-PCR) and cytology. RT-PCR analysis with primers specific for carcinoembryonic antigen and conventional cytologic examination by Papanicolaou staining were performed on peritoneal washes, collected at laparotomy from 148 gastric carcinoma patients. Prognostic analyses were performed with 1) death due to cancer recurrence and 2) peritoneal dissemination as endpoints. RT-PCR was found to be more sensitive than cytologic examination for detection of free cancer cells in the peritoneal washes, with a higher detection rate for each of the T categories in the tumor-node-metastasis (TNM) classification. Five patients with synchronous or recurrent peritoneal dissemination were found among 17 patients with positive RT-PCR and negative cytologic results. Both positive cytologic results and positive RT-PCR results had significant influences over the survival of patients with advanced gastric carcinomas (n = 75, p < .002). Detection of free cancer cells in peritoneal washes, most reliably by RT-PCR, is promising as a predictor of peritoneal dissemination in patients with gastric carcinoma.

Long-term survival of patients with stage IV gastric carcinoma

BACKGROUND

Survival of patients with Stage IV (based on general rules established by the Japanese Research Society for Gastric Cancer) gastric carcinoma often is unfavorable. Among patients with a poor prognosis, a few do survive > 5 years. The authors examined pathologic and biologic features of tumors of long term survivors.

METHODS

The authors analyzed data from 442 patients with Stage IV gastric carcinoma, including 20 surviving for > 5 years after gastrectomy (Group A) and 422 who died of gastric carcinoma within 5 years (Group B). Mutant p53 was immunohistochemically stained using the monoclonal antibody PAb1801. Proliferative activity was estimated by argyrophilic nuclear organizer region (AgNOR) staining and proliferating cell nuclear antigen (PCNA) staining.

RESULTS

Group A had smaller and more localized tumors than Group B (P < 0.05 and P < 0.01, respectively). Lymphatic or venous invasion and peritoneal dissemination were less frequent in Group A than in Group B (P < 0.01). Abnormalities of p53 expression were found in 3 of the 14 tumors in Group A (21%), a value significantly lower than the 58 of 118 tumors in Group B (49%; P < 0.05). AgNOR count and percentage of PCNA labeling were not significantly different between Groups A and B. A multivariate analysis showed that lymph node dissection, liver metastasis, gastric resection, venous invasion, and tumor size were independent prognostic factors.

CONCLUSIONS

Even in patients with Stage IV gastric carcinoma, radical gastrectomy and extensive lymph node dissection can lead to long term survival. The authors believe that combination analysis of pathologic features and p53 overexpression predict length of survival for patients with Stage IV gastric carcinoma.

Detection of carcinoembryonic antigen-expressing free tumor cells in peritoneal washes from patients with gastric carcinoma by polymerase chain reaction

Cytological examination of peritoneal washes is a useful predictor of peritoneal recurrence in gastric carcinoma patients. In the present study, even more sensitive detection of free cancer cells could be achieved through amplification of carcinoembryonic antigen (CEA) mRNA by means of the reverse transcriptase-polymerase chain reaction (RT-PCR). CEA was first confirmed to be present in all the gastric cancer cell lines examined, irrespective of the differentiation degree, and absent in blood and mesothelium, indicating the specificity of this approach for detection of carcinoma cells in peritoneal lavage fluid. In sensitivity tests, CEA RT-PCR proved to be capable of detecting 10 carcinoma cells per sample. Peritoneal washes of 15 of 48 gastric carcinoma patients, including all 10 patients with positive cytology results, proved positive for CEA mRNA. None of the 5 patients with benign disease was positive. Moreover, a close association with the depth of cancer invasion was established. The results indicate that the assay is more sensitive for detection of free carcinoma cells in the peritoneal cavity than conventional cytology. This is the first study to suggest the feasibility of the RT-PCR method for prediction of peritoneal recurrence in gastric cancer patients.