Serum carcinoembryonic antigen levels and proliferating cell nuclear antigen labeling index for patients with colorectal carcinoma. Correlation with tumor progression and survival

Septin4 promotes cell death in human colon cancer cells by interacting with BAX

Septin4 is a tumor suppressor protein that promotes cell programmed death in various cell types through specifically antagonizing XIAP (X linked inhibitor of apoptosis), little is known its other novel binding partner and role in colorectal cancer. In this study, we found that Septin4 significantly expressed lower in human colon cancer when compared to peri-tumor benign cells, and its low expression was significantly associated with worse prognostic outcomes. Furthermore, Septin4 participated in DOX-induced colon cancer cell death in vitro. Septin4-overexpressing colon cancer cells displayed augmented apoptotic cell death and ROS production. Additionally, Septin4-knockdown cells revealed a resistance of DOX-induced cell death and reduced ROS production. Importantly, we first identified that BAX is a novel Septin4 binding partner and the interaction is enhanced under DOX treatment. Finally, Septin4-knockdown promoted colon cells growth in vivo. These observations suggest that Septin4 as an essential molecule contribute to the occurrence and development of human colon cancer and provide new technical approaches for targeted treatment of this disease.

The prognostic value of proliferating cell nuclear antigen expression in colorectal cancer: A meta-analysis

BACKGROUND

A number of studies have attempted to determine the prognostic significance of proliferating cell nuclear antigen (PCNA) in patients with colorectal cancer (CRC), but the reports are controversial and inconsistent. Thus, we conducted a meta-analysis to clarify the value of PCNA in CRC prognosis.

METHODS

A systematic search of relevant studies was performed in 4 electronic databases including PubMed, Cochrane Library, Embase, and Web of Science until February 2018. Hazard ratios (HRs) combined with 95% confidence intervals (95% CIs) were used to evaluate the relationship of PCNA expression with overall survival (OS), cancer-specific survival (CSS), and disease-free survival (DFS).

RESULTS

A total of 1372 CRC patients in 14 studies were identified eventually in our meta-analysis. The pooled HRs demonstrated that CRC patients with high PCNA expression was significantly correlated with poor OS (HR = 1.81; 95% CI: 1.51-2.17; P = .000), CSS (HR = 1.99; 95% CI: 1.04-3.79; P = .037); but not significantly with DFS (HR = 2.48; 95% CI: 0.98-6.26; P = .055). Sensitivity analysis showed the pooled HRs for OS, CSS, and DFS were stable when the included studies were removed one by one.

CONCLUSION

Our meta-analysis suggested that high PCNA expression was associated with poor prognosis, and it could serve as a reliable and prognostic biomarker in CRC patients. More large-scale studies are needed to further support the conclusion.

Clinical Value of CXCL5 for Determining of Colorectal Cancer

Background:

Several studies indicate that chemokines play important roles in colorectal mucosal immunity.The chemokine CXCL5 which is expressed by epithelial cells within colorectal mucosa is a promoter of cell proliferation, migration and invasion, is a novel serum prognostic marker in patients with colorectal cancer. The purpose of this study was to investigate whether serum and tissue CXCL5 levels is altered in colorectal carcinomas (CRC) compared to colonic adenoma and normal mucosa. It also aimed to compare colon adenoma and colorectal cancer for blood CXCL5 and CEA levels, their sensitivity, and specificity.

Methods:

CXCL5 expression was assessed with immunohistochemistry staining in biopsy samples taken during colonoscopy in 22 colonic adenomas, 23 colorectal carcinomas and 23 normal colonic tissue samples. Also all patients’ serum CXCL5 and CEA levels were measured. This stduy was prospective observational study.

Results:

The number of cases who were stained positive with immunohistochemistry was found to be higher in the group with CRC. When compared with the other groups, both levels of serum CXCL5 and CEA were significantly high in the group CRC. Sensitivity and specificity of serum CXCL5 were found to be low as a result of the ROC analysis.

Conclusion:

Although the level of CXCL5 is high in CRC, its level in serum is not significant enough to support the early diagnosis of the disease.

Combined preoperative concentrations of CEA, CA 19-9, and 72-4 for predicting outcomes in patients with gastric cancer after curative resection

In many cancers, prognostic factors are useful for identifying high-risk patients and in individualizing treatment. We sought to determine whether a combination of tumor markers (CTM) would improve prognostic accuracy in patients with gastric cancer (GC). The CTM score, which is derived from serum concentrations of carcinoembryonic antigen (CEA), carbohydrate antigen 19-9 (CA 19-9), and carbohydrate antigen 72-4 (CA 72-4), was tested retrospectively in 1134 patients with GC undergoing curative resection between October 2000 and December 2012. The CTM score was 2 for patients with two or three elevated markers, 1 for those with one elevated marker, and 0 for those no elevated markers. Overall survival (OS) in patients with CTM scores 0, 1, and 2 was 61.8%, 31.4%, and 15.1%, respectively (P<.001). The CTM score independently predicted OS on multivariate analysis (HR, 1.95; 95% CI, 1.73 to 2.21; P<.001). Moreover, the area under the receiver operating characteristics curve of the CTM score (0.67; 95% CI, 0.64 to 0.70) was higher than the values of any individual marker (0.63, 0.57, 0.57; P<.001 for all comparisons). The CTM score independently predicted postoperative survival in GC, and it may have better clinical utility than individual tumor markers for identifying high-risk patients with GC.

Use of a combination of CEA and tumor budding to identify high-risk patients with stage II colon cancer

BACKGROUND

High-risk patients with stage II colon cancer may benefit from adjuvant chemotherapy, but identifying this patient population can be difficult. We assessed the prognosis value for predicting tumor progression in patients with stage II colon cancer, of a panel of 2 biomarkers for colon cancer: tumor budding and preoperative carcinoembryonic antigen (CEA).

METHODS

Consecutive patients (N = 134) with stage II colon cancer who underwent curative surgery from 2000 to 2007 were included. Multivariate analysis was used to evaluate the association of CEA and tumor budding grade with 5-year disease-free survival (DFS). The prognostic accuracy of CEA, tumor budding grade and the combination of both (CEA-budding panel) was determined.

RESULTS

The study found that both CEA and tumor budding grade were associated with 5-year DFS. The prognostic accuracy for disease progression was higher for the CEA-budding panel (82.1%) than either CEA (70.9%) or tumor budding grade (72.4%) alone.

CONCLUSIONS

The findings indicate that the combination of CEA levels and tumor budding grade has greater prognostic value for identifying patients with stage II colon cancer who are at high-risk for disease progression, than either marker alone.

Clinical significance of carcinoembryonic antigen in peritoneal lavage from patients with gastric cancer

BACKGROUND

Peritoneal carcinomatosis is the most common pattern of recurrence of gastric cancer, and it is important to identify patients at high risk for recurrence. Although the carcinoembryonic antigen level in peritoneal lavage (pCEA) was reported to be a useful biomarker to predict peritoneal recurrence in a small series, its clinical significance has not been fully validated. We evaluated the clinical significance of pCEA in a large cohort of patients with gastric cancer.

METHODS

We prospectively analyzed the pCEA level in 597 patients with histologically proven gastric cancer who underwent laparotomy.

RESULTS

A significant relationship was demonstrated between the value of pCEA and clinicopathologic features, such as the peritoneal lavage cytology, peritoneal metastasis, the depth of tumor invasion, and the lymph node metastasis. The cutoff value was set at 100 ng/g of protein, and 134 of the 462 patients who underwent curative surgery had positive pCEA findings. The overall and the intraperitoneal-recurrence-related survival of patients positive for pCEA were significantly poorer than those of pCEA-negative patients. When we analyzed the patients with pathologic stage I through III gastric cancers separately, the pCEA-positive patients had poorer prognoses than the pCEA-negative patients who had stage III gastric cancer. In a univariate analysis, the tumor size, depth of tumor invasion, lymph node metastasis, histologic type, serum CEA (sCEA), and pCEA were found to affect the patients' outcomes, although a multivariate analysis found only the extent of lymph node metastasis to be an independent prognostic factor.

CONCLUSION

The pCEA level is a useful biomarker to predict gastric cancer-related death. Moreover, the pCEA level may be useful to identify a cohort of patients with gastric cancer who need more intensive adjuvant chemotherapy to improve their prognoses.

The influence of metastatic site on the expression of CEA and cellular localization of β-catenin in colorectal cancer

BACKGROUND AND AIM

The usefulness of carcinoembryonic antigen (CEA) in the diagnosis and prognosis of colorectal cancer (CRC) is unclear. The aim was to analyze changes in the expression of CEA during CRC progression and metastasis, so as to determine the influence of tumor metastatic organ on the CEA expression by CRC cells.

METHODS

The human biopsies of adenocarcinomas in colon and CRC liver and lung metastases were analyzed by immunohistochemistry for the expression of CEA. Expression of E-cadherin and β-catenin was also analyzed to localize the CRC neoplastic glands in metastatic tissues.

RESULTS

The CRC neoplastic glands in colon and liver expressed significantly higher amount of CEA compared with crypts in normal colon. In contrast, CRC neoplastic glands formed in lung expressed low CEA level. However, CEA expression was high in areas of tumor necrosis in lung. E-cadherin and β-catenin were cell membrane-bound in normal crypts and CRC neoplastic glands in colon and liver. Although these two proteins were also cell membrane-bound in a majority of CRC neoplastic glands in lungs, a significant proportion of these expressed β-catenin in the nucleus, which lacked either E-cadherin or β-catenin at the cell membrane.

CONCLUSION

Our findings indicate that lung microenvironment is unique in that it suppresses the expression of CEA by CRC cells forming neoplastic glands. In addition, lung microenvironment promotes nuclear localization of β-catenin, suggesting that the Wnt signaling pathway is relatively active highly in CRC metastasized to lung, when compared with liver or colon.

Clinical significance of serial serum carcinoembryonic antigen values for treating rectal cancer with preoperative chemoradiotherapy

Purpose

Preoperative chemoradiotherapy is now widely accepted to treat rectal cancer; however, the prognosis for rectal cancer patients during and after chemoradiotherapy must be determined. The aim of this study was to evaluate the serial serum carcinoembryonic antigen (s-CEA) samples in patients with rectal cancer who underwent radical surgery after concurrent chemoradiotherapy (CRT).

Methods

This study evaluated 236 patients with rectal cancer who received preoperative CRT followed by curative surgery between June 2005 and June 2010. We measured the patient's s-CEA levels pre-CRT, post-CRT and post-surgery. Patients were classified into four groups according to their s-CEA concentrations (group 1, high, high, high; group 2, high, high, normal; group 3, high, normal, normal; group 4, normal, normal, normal). We analyzed the clinicopathologic factors and the outcomes among these groups.

Results

Of the 236 patients, 12 were in group 1, 31 were in group 2, 67 were in group 3, and 126 were in group 4. The 3-year disease-free survival rate in group 1 was poorer than those in group 3 (P = 0.007) and group 4 (P < 0.001). In a univariate analysis, type of surgery, clinical N stage, pathologic T or N stage, lymphovascular invasion, perineural invasion, and CEA group were prognostic factors. A multivariate analysis revealed that type of surgery, pathologic T stage, and lymphovascular invasion were independent prognostic factors; however, no statistical significance was associated with the CEA group.

Conclusion

High pre-CRT, post-CRT, and post-surgery s-CEA levels in patients with rectal cancer were associated with high rates of systemic recurrence and poor survival. Therefore, patients with sustained high s-CEA levels during CRT require careful monitoring after surgery.

Prognostic value of pretreatment carcinoembryonic antigen after definitive radiotherapy with or without concurrent chemotherapy for squamous cell carcinoma of the uterine cervix

PURPOSE

To evaluate whether pretreatment carcinoembryonic antigen (CEA) levels have a prognostic role in patients after definitive radiotherapy for squamous cell carcinoma (SCC) of the uterine cervix.

METHODS AND MATERIALS

A retrospective study of 550 patients was performed. The SCC antigen (SCC-Ag) and CEA levels were regarded as elevated when they were ≥2 and ≥5 ng/mL, respectively. A total of 208 patients underwent concurrent chemoradiotherapy (CCRT). The Kaplan-Meier method was used to calculate the distant metastasis (DM), local failure (LF), disease-free survival (DFS), and overall survival (OS) rates. Multivariate analysis was performed using the Cox proportional hazards model. The hazard ratio (HR) with 95% confidence interval (CI) was evaluated for the risk of a poor prognosis.

RESULTS

Compared with the patients with normal CEA/SCC-Ag levels, CEA levels ≥10 ng/mL but without elevated SCC-Ag levels was an independent factor for LF (HR, 51.81; 95% CI, 11.51-233.23; p < .001), DM (HR, 6.04; 95% CI, 1.58-23.01; p = .008), DFS (HR, 10.17; 95% CI, 3.18-32.56; p < .001), and OS (HR, 5.75; 95% CI, 1.82-18.18; p = .003) after RT alone. However, no significant role for CEA was noted in patients with SCC-Ag levels ≥2 ng/mL. In patients undergoing CCRT, a CEA level ≥10 ng/mL was an independent factor for LF (HR, 2.50; 95% CI, 1.01-6.21; p = .047), DM (HR, 3.41; 95% CI, 1.56-7.46; p = .002), DFS (HR, 2.73; 95% CI, 1.39-5.36; p = .003), and OS (HR, 3.93; 95% CI 1.99-7.75; p < .001). A SCC-Ag level of ≥40 ng/mL was another prognostic factor for DM, DFS, and OS in patients undergoing not only CCRT, but also RT alone. The 5-year OS rate for CCRT patients with CEA <10 ng/mL and ≥10 ng/mL was 75.3% and 35.8%, respectively (p < .001). CCRT was an independent factor for better OS (HR, 0.69; 95% CI, 0.50-0.97; p = .034).

CONCLUSION

Pretreatment CEA levels in patients with SCC of the uterine cervix provide complementary information for predicting LF, DM, DFS, and OS, except for in patients with abnormal SCC-Ag levels before RT alone. More aggressive therapy might be advisable for patients with CEA levels of ≥10 ng/mL.

Preoperative carcinoembryonic antigen level as an independent prognostic factor in potentially curative colon cancer

OBJECTIVE

We evaluated the prognostic value of the preoperative serum carcinoembryonic antigen (CEA) level in patients with colon cancer.

METHODS

We reviewed 474 patients who underwent potentially curative resection for nonmetastatic colon cancer. Patients were categorized into two groups according to the preoperative serum CEA level: low CEA (<5 ng/ml) and high CEA (>or=5 ng/ml) groups.

RESULTS

During the median 45-month follow-up period, the 5-year overall and disease-free survival rates for patients with a low CEA level were 81.7% and 82.4%, respectively, which were significantly higher than the rates for those with a high CEA level (69.9%; P = 0.011 and 70.6%; P = 0.002, respectively). A multivariate analysis revealed that a preoperative serum CEA level was a significant independent prognostic factor for both overall survival (P = 0.021) and disease-free survival (P = 0.026). Both the overall and disease-free survival rates in patients with stage II tumors differed significantly between the low and high CEA groups, whereas the rates did not different between those with stage I and III tumors.

CONCLUSIONS

Preoperative serum CEA is a reliable predictor of recurrence and survival after curative surgery in patients with colon cancer, particularly in those classified as having stage II disease.

Cytoreductive surgery plus intraperitoneal chemohyperthermia in patients with colorectal cancer at high risk for local-regional recurrence

This article was written to define the situations in which early second-look surgery with a combined treatment should be indicated in patients at high risk of developing peritoneal carcinomatosis (PC). Through a review of the literature, this is a definition of the second-look concept and of the different groups of patients at risk, in different situations (after resection of the primary, after initial cytoreductive surgery plus hyperthermic intraperitoneal chemotherapy, and after the discovery of isolated carcinoembryonic antigen elevation or isolated peritoneal uptake on positron emission tomography scan). Systematic second-look surgery for early treatment of asymptomatic PC is probably beneficial in patients presenting a high risk of developing PC after resection of their primary. The benefit seems considerably lower for the other groups of high-risk patients.

Carcinoembryonic Antigen in the Staging and Follow-up of Patients with Colorectal Cancer

CEA is a complex glycoprotein produced by 90% of colorectal cancers and contributes to the malignant characteristics of a tumor. It can be measured in serum quantitatively, and its level in plasma can be useful as a marker of disease. Because of its lack of sensitivity in the early stages of colorectal cancer, CEA measurement is an unsuitable modality for population screening. An elevated preoperative CEA is a poor prognostic sign and correlates with reduced overall survival after surgical resection of colorectal carcinoma. A failure of the CEA to return to normal levels after surgical resection is indicative of inadequate resection of occult systemic disease. Frequent monitoring of CEA postoperatively may allow identification of patients with metastatic disease for whom surgical resection or other localized therapy might be potentially beneficial. To identify this group, serial CEA measurement appears to be more effective than clinical evaluation or any other diagnostic modality, although its sensitivity for detecting recurrent disease is not as high for locoregional or pulmonary metastases as it is for liver metastases. Several studies have shown that a small percentage of patients followed postoperatively with CEA monitoring and who undergo CEA-directed salvage surgery for metastatic disease will be alive and disease-free 5 years after surgery. Furthermore, CEA levels after salvage surgery do appear to predict survival in patients undergoing resection of liver or pulmonary metastases. However, several authors argue that CEA surveillance is not cost-effective in terms of lives saved. In support of this argument, there is no clear difference in survival after resection of metastatic disease with curative intent between patients in whom the second-look surgery was performed on the basis of elevated CEA levels and those with other laboratory or imaging abnormalities. There is also no clear consensus on the frequency or duration of CEA monitoring, although the ASCO guidelines currently recommend every 2-3 months for at least 2 years after diagnosis. In the follow-up of patients undergoing palliative therapy, the CEA level correlates well with response, and CEA is indicative of not only response but may also identify patients with stable disease for whom there is also a demonstrated benefit in survival and symptom relief with combination chemotherapy. More recently, scintigraphic imaging after administration of radiolabeled antibodies afforded an important radionuclide technique that adds clinically significant information in assessing the extent and location of disease in patients with colorectal cancer above and beyond or complementary to conventional imaging modalities. Immunotherapy based on CEA is a rapidly advancing area of clinical research demonstrating antibody and T-cell responses.

Prognostic value of carcinoembryonic antigen distribution in tumor tissue of colorectal carcinoma

CONTEXT: Carcinoembryonic antigen (CEA) can be detected in colorectal tumor tissue but its role in the survival of patients remains controversial. OBJECTIVE: To characterize the expression of tissue CEA using immunohistochemical staining in colorectal tumors and to analyze the relationship between this finding and preoperative plasmatic level of CEA, morphologic features and survival of patients operated with curative intent for colorectal carcinoma. METHOD: Forty-seven patients were included in the study: 18 (38.3%) males and 29 (61.7%) females, with a mean age of 67.8 ± 9.7 years (37 to 84 years). Immediately before laparotomy, pre-operative serum levels of CEA were obtained where normal levels were considered <2.5 ng/mL for non-smokers, and <5.0 ng/mL for smokers. CEA immunohistochemical studies were carried out using anti-human CEA monoclonal mouse antibody. The expression of immunostaining for each neoplasia was classified according to the pattern of CEA tissular distribution into apical or cytoplasmic. The variables considered for the statistical analysis were plasmatic preoperative CEA level, location of the lesion within the large intestine, lesion diameter, lymph node involvement, Duke's classification, vein invasion, grade of cellular differentiation, survival and pattern of CEA tissular distribution. The statistical models utilized were Spearman's correlation and the Mann-Whitney, Kruskal-Wallis and Student t tests. Patients' survival was analyzed using the Kaplan-Meier method. RESULTS: The mean preoperative CEA value was 15.4 ± 5.5 ng/mL (0.2 to 92.1 ng/mL). The neoplasm was located in the colon in 29 (61.7%) and in the rectum in 18 (38.3%) patients. Eight (17.0%) patients were classified as Duke's stage A, 22 (46.8%) as stage B and 17 (36.2%) as stage C. On immunohistochemical studies, the pattern of CEA tissular distribution was apical in 33 (70.2%) patients and cytoplasmic in 14 (29.8%) patients. Patients with apical patterns presented a mean sera CEA level of 15.5 ± 6.5 ng/mL while those with cytoplasmic pattern attained a mean sera CEA level of 15.1 ± 7.3 ng/mL, with no significant difference between these values (P = 0.35). Apical distribution of CEA occurred in 6 (12.8%) Duke A, 18 (38.2%) Duke B and 9 (12.2%) Duke C patients, while cytoplasmic CEA tissular distribution was observed in 2 (4.2%) Duke A, 3 (6.4%) Duke B and 9 (19.1%) Duke C patients. Patients with Duke B neoplasms presented significantly more apical CEA tissular distribution patterns (P = 0.049) than subjects with cytoplasmic CEA tissular patterns. The apical CEA tissular distribution pattern in neoplasms was significantly more frequent in neoplasms with no lymph node compromise compared to the cytoplasmic pattern (P = 0.50). However, no significant differences were seen between apical and cytoplasmic CEA tissular distribution patterns in terms of colon or rectal site (P = 0.21), lesion diameter across greatest axis (P = 0.19), vein invasion (P = 0.13) or degree of cellular differentiation (P = 0.19). Of the 47 patients operated, 33 (70.2%) survived for more than 5 years where mean survival was 31.1 ± 5.6 months. Survival between patients with apical and cytoplasmic CEA tissular distribution showed no significant difference (P = 0.38). CONCLUSIONS: Although the apical distribution pattern of CEA was significantly more frequent in more advanced stages of Duke's classification, the CEA tissular distribution presented no relationship with serum CEA levels, morphological features of the neoplasm or survival of patients undergoing curative colorectal carcinoma resection.

Prognostic value of preoperative CEA, CA 19-9, CA 72-4, and AFP levels in gastric cancer

INTRODUCTION

Recent research has suggested that serum tumor markers can give valuable prognostic information in gastric cancer. In this study, we examined the relationship between preoperative serum carcinoembryonic antigen (CEA), carbohydrate antigen (CA) 19-9, CA 72-4, and alfa fetoprotein (AFP) levels on clinicopathologic significance in gastric cancer patients.

METHODS

Preoperative plasma levels of CEA, CA 19-9, CA 72-4, and AFP were retrospectively examined in 95 patients who underwent surgical resection for gastric cancer, and the prognostic value of the tumour markers were estimated.

RESULTS

The percentage of CA 19-9, CA 72-4, CEA, and AFP-positive cases were 41%, 32.6%, 24.2%, and 8.4%, respectively. CEA was more frequently positive in the patients with liver metastases (P=0.02). CA 19-9 was more frequently positive in patients with lymph node (P=0.005), peritoneal (P=0.01), and serosal (P=0.03) involvement. CA 72-4 was more frequently positive in patients with lymph node (P=0.01), peritoneal (P=0.03), and liver (P=0.01) involvement. Low 3-year cumulative survival was associated significantly with elevated serum levels of CEA (P=0.001), CA 19-9 (P=0.001), CA 72-4 (P=0.001), and AFP (P=0.01). In multivariate analysis, age, tumor stage, and CA 72-4 were the only independent prognostic factors. Being positive for CA 72-4 was associated with a 3.8-fold higher risk of death (95% confidence intervals: 1.3, 10.9).

CONCLUSION

Our results suggest that high preoperative serum levels of CA 72-4 in gastric cancer patients are associated with a higher risk of death due to gastric cancer.

Carcinoembryonic antigen antibody inhibits lung metastasis and augments chemotherapy in a human colonic carcinoma xenograft

PURPOSE

In addition to its use as a blood marker for many carcinomas, elevated expression of carcinoembryonic antigen (CEA, CD66e, CEACAM5) has been implicated in various biological aspects of neoplasia, especially tumor cell adhesion, metastasis, the blocking of cellular immune mechanisms, and having antiapoptosis functions. However, it is not known if treatment with anti-CEA antibodies can affect tumor metastasis or alter the effects of cytotoxic drugs.

METHODS

In vitro, human colon cancer cell lines were treated with anti-CEA MAb IgG1, hMN-14 (labetuzumab), to assess direct effects on proliferation, as well as antibody-dependent cellular cytotoxicity (ADCC), and complement-dependent cytotoxicity (CDC). In vivo studies were undertaken in nude mice bearing s.c. (local growth) or i.v. (metastatic model) GW-39 and LS174T human colon cancer grafts, to evaluate the MAb alone and in combination with either CPT-11 or 5-fluorouracil (5FU).

RESULTS

In vitro, labetuzumab did not induce apoptosis, nor did it affect tumor cell proliferation directly or by CDC, but it did inhibit tumor cell proliferation by ADCC. In vivo, labetuzumab did not increase median survival in the GW-39 metastatic model unless the mice were pretreated with GM-CSF to increase their peripheral WBC counts; GM-CSF alone was ineffective. Also, if GW-39 tumors were pretreated with IFN-gamma to up-regulate CEA expression threefold prior to i.v. injection, labetuzumab significantly increased median survival of the mice. When nude mice received labetuzumab with CPT-11 or 5FU, median survival increased significantly as compared to the drug or antibody alone.

CONCLUSIONS

Labetuzumab, a CEA-specific MAb, induces effector-cell function in vitro against CEA-positive colonic tumor cells, and also inhibits growth of lung metastasis when CEA expression is up-regulated or if peripheral WBCs are increased. The MAb also shows chemosensitizing properties.

Analysis of key cell-cycle checkpoint proteins in colorectal tumours

Aberrations in the components of cell-cycle checkpoints are a common feature of many tumours and several have been shown to have prognostic significance in colorectal cancer. In this study, seven components of cell-cycle control [cyclin D1, retinoblastoma (pRb), p21, p27, p16, p53, and proliferating cell nuclear antigen (PCNA)] were examined in a large series of well-characterized colorectal adenocarcinomas using immunohistochemistry to ascertain co-regulation and influence on survival. The majority (92%) of the tumours had abnormal staining of > or =2 cell-cycle control factors. Expression of cyclin D1 protein was correlated with both p21 (p<0.001) and p27 (p=0.033), suggesting co-regulation of these proteins in colorectal tumours. Only cyclin D1 (p=0.048) and p53 (p=0.025) were directly associated with PCNA levels, suggesting a more important role in the proliferative capacity of tumour cells. Significant associations between cell cycle-related proteins and clinicopathological data were observed: cyclin D1 and p53 proteins were correlated with patient age (p=0.042 and p<0.001, respectively) and p53 (p=0.01) and p21 (p=0.024) proteins were associated with tumour site. Expression of cyclin D1 protein was the only protein examined that was related to improved outcome in these patients (p=0.0266), but it was not an independent predictor of survival. These results suggest that loss of control of cell-cycle checkpoints is a common occurrence in colorectal tumours and may be an important therapeutic target.

Tumor angiogenesis predicts recurrence with normal serum carcinoembryonic antigen in advanced rectal carcinoma patients

Many studies have established the usefulness of serum carcinoembryonic antigen (CEA) oriented serial monitoring for predicting recurrence and prognosis; however, few studies have so far investigated serum CEA-negative recurrence. The aim of this study was to elucidate the nature of CEA-negative recurrence regarding tumor angiogenesis. Fifty-seven patients with T3/T4 rectal cancer were divided into the two groups according to the serum CEA status. Angiogenesis was defined as the intratumoral vessel count by immunohistochemical staining using CD31. The CD31 count was significantly higher in the recurrent patients in both groups and the ratio of nodal involvement was significantly higher in the recurrent patients of the CEA-negative group. Local recurrence mainly developed in the CEA-negative group; however, the CD31 count did not predict the sites of recurrence nor the relapse period in the both groups. A multivariate analysis showed a high CD31 count >26) to be a prognostic factor not only for recurrence but also for survival (P = 0.001, 0.043, respectively). These results suggest that a high degree of tumor angiogenesis in sections of T3/T4 rectal cancer may therefore be an important predictor for CEA-negative recurrence.

Immunohistochemical evaluation of thymidylate synthase in gastric carcinoma using a new polyclonal antibody: the clinical role of thymidylate synthase as a prognostic indicator and its therapeutic usefulness

BACKGROUND

Before this study was conducted, the clinical and therapeutic significance of immunohistochemical evaluation of thymidylate synthase (TS) in patients with gastric carcinoma had not yet been clarified.

METHODS

TS was immunohistochemically evaluated in 134 gastric carcinomas using anti-TS antibody. TS expression, 11 clinicopathologic variables, and survival were studied, and the correlations among them were investigated.

RESULTS

The groups with high and low TS levels consisted of 56 and 78 patients, respectively. Granular cytoplasmic staining patterns of tumor cells were produced by immunohistochemical staining of the gastric carcinoma tissues. The grade of TS staining was significantly correlated with three clinicopathologic variables: depth of invasion, peritoneal metastasis, and stage of the carcinoma (P < 0.05). A univariate analysis revealed that the 5-year survival was significantly better for the low TS group than for the high TS group (P < 0.05): 65.2% for the low TS group and 43.2% for the high TS group. The group with high grade TS staining who received chemotherapy because of the advanced stage of their disease had worse prognoses even if they received adjuvant chemotherapy. A multivariate analysis revealed that four variables (peritoneal metastasis, lymphatic invasion, liver metastasis, and TS staining grade) independently contributed to survival (P < 0.05). The hazard ratio for the group with low grade TS staining was 0.464 compared with the group with high grade staining.

CONCLUSIONS

The immunohistochemical evaluation of TS using this anti-TS antibody may be clinically and therapeutically useful in determining the prognosis of gastric carcinoma patients.

Evaluation of argyrophilic nucleolar organizer region and proliferating cell nuclear antigen in colorectal cancer

BACKGROUND AND OBJECTIVES

Information on cellular proliferation is gaining importance for predicting prognosis in several cancers. To clarify the clinicopathological significance of argyrophilic nucleolar organizer region (AgNOR), proliferating cell nuclear antigen (PCNA), and DNA ploidy pattern, we studied their correlations with clinicopathological factors in colorectal cancer.

METHODS

Fifty-two patients with colorectal cancer were examined by AgNOR staining, immunohistochemical study of PCNA expression, and DNA flow cytometry.

RESULTS

The AgNOR score and the PCNA labeling rate (PCNA LR) were significantly higher in patients with deep invasion (P = 0.0072, P = 0.0355), liver metastasis (P = 0.0022, P = 0.0001), and Dukes D classification (P = 0.0002, P = 0.0001) than in patients without these factors. In patients with high AgNOR score (>3.83) or with high PCNA LR (>48.8), prognosis was significantly worse (P = 0.0002, P = 0.0123) than in those with low AgNOR score (<3.83) or in those with low PCNA LR (<48.8), respectively. No significant association was observed between AgNOR score and PCNA LR. Combined analysis revealed that the survival curve for patients with high AgNOR score and high PCNA LR was significantly lower (P = 0.0156) than that for patients with high AgNOR score and low PCNA LR. There was no significant correlation between DNA ploidy pattern and clinicopathological findings.

CONCLUSIONS

PCNA LR and AgNOR score were correlated not only with local progression but also with metastasis. Their determination provided useful prognostic information, and these parameters are probably independent. Their simultaneous determination was useful for accurate evaluation of prognosis. The value of DNA ploidy pattern was uncertain.