Limitations in SELDI-TOF MS whole serum proteomic profiling with IMAC surface to specifically detect colorectal cancer

BACKGROUND

Surface enhanced laser desorption and ionization time-of-flight mass spectrometry (SELDI-TOF-MS) analysis on serum samples was reported to be able to detect colorectal cancer (CRC) from normal or control patients. We carried out a validation study of a SELDI-TOF MS approach with IMAC surface sample processing to identify CRC.

METHODS

A retrospective cohort of 338 serum samples including 154 CRCs, 67 control cancers and 117 non-cancerous conditions was profiled using SELDI-TOF-MS.

RESULTS

No CRC "specific" classifier was found. However, a classifier consisting of two protein peaks separates cancer from non-cancerous conditions with high accuracy.

CONCLUSION

In this study, the SELDI-TOF-MS-based protein expression profiling approach did not perform to identify CRC. However, this technique is promising in distinguishing patients with cancer from a non-cancerous population; it may be useful for monitoring recurrence of CRC after treatment.

Identification of tumor-associated autoantigens for the diagnosis of colorectal cancer in serum using high density protein microarrays

There is a mounting evidence of the existence of autoantibodies associated to cancer progression. Antibodies are the target of choice for serum screening because of their stability and suitability for sensitive immunoassays. By using commercial protein microarrays containing 8000 human proteins, we examined 20 sera from colorectal cancer (CRC) patients and healthy subjects to identify autoantibody patterns and associated antigens. Forty-three proteins were differentially recognized by tumoral and reference sera (p value <0.04) in the protein microarrays. Five immunoreactive antigens, PIM1, MAPKAPK3, STK4, SRC, and FGFR4, showed the highest prevalence in cancer samples, whereas ACVR2B was more abundant in normal sera. Three of them, PIM1, MAPKAPK3, and ACVR2B, were used for further validation. A significant increase in the expression level of these antigens on CRC cell lines and colonic mucosa was confirmed by immunoblotting and immunohistochemistry on tissue microarrays. A diagnostic ELISA based on the combination of MAPKAPK3 and ACVR2B proteins yielded specificity and sensitivity values of 73.9 and 83.3% (area under the curve, 0.85), respectively, for CRC discrimination after using an independent sample set containing 94 sera representative of different stages of progression and control subjects. In summary, these studies confirmed the presence of specific autoantibodies for CRC and revealed new individual markers of disease (PIM1, MAPKAPK3, and ACVR2B) with the potential to diagnose CRC with higher specificity and sensitivity than previously reported serum biomarkers.

Circulating vascular endothelial growth factor six months after primary surgery as a prognostic marker in patients with colorectal cancer

High preoperative circulating vascular endothelial growth factor (VEGF) is predictive of poor prognosis in patients with colorectal cancer (CRC). However, postoperative circulating VEGF has not yet been evaluated as a prognostic marker in CRC patients. In 318 consecutive patients who had undergone curative resection of primary CRC, the prognostic value of VEGF concentrations in plasma and serum obtained 6 months postoperatively was analysed and the results compared with the prognostic value of postoperative carcinoembryonic antigen (CEA) concentrations in matched serum samples. In univariate analyses, high serum and plasma VEGF ( > 533 pg/ml and > 112 pg/ml, respectively) had no significant (p = 0.17 and p = 0.13, respectively) impact on overall survival. On the contrary, high serum CEA ( > 5 ng/ ml) was significantly (p < 0.0001) correlated to a poor prognosis. Finally, in multivariate analyses, the combination of high serum CEA and high serum VEGF was significantly (hazard ratio 3.0, p = 0.02) associated with poor survival compared to high serum CEA and low serum VEGF. It is concluded that 6 months postoperatively serum CEA is a better prognostic marker than corresponding serum and plasma VEGF. However, high serum VEGF within high serum CEA was an even better predictor of overall survival than high serum CEA alone.

HERG1 gene expression as a specific tumor marker in colorectal tissues

INTRODUCTION

Colorectal carcinomas exhibit a frequent recurrence after curative surgery, which may partially be due to histopathologically inconspicuous minimal residual disease. Reliable markers for tumor cells in colorectal tissue are still missing. Therefore, in this study we compared the predictive value of the putative tumor markers carcinoembryonic antigen (CEA), cytokeratin-19 (CK19) and cytokeratin-20 (CK20) to that of a novel marker, the human ether-a-go-go-related gene (HERG1) K(+) channel, a suggested regulator of tumor cell proliferation.

MATERIALS AND METHODS

Using RT-PCR we studied HERG, CEA, CK19 and CK20 expression in colorectal carcinomas and non-carcinoma controls. HERG1 immunhistochemistry was performed in a total of 66 specimens, in colorectal carcinoma (n = 23), in matched histopathologically negative samples (n = 23) taken near the excision site from the same tumor patients and in healthy control biopsies (n = 20). In order to verify the relevance of HERG1 for tumor proliferation we studied the effect of HERG1 inhibition in the Colo-205 colon cancer carcinoma cell line using the MTT-assay.

RESULTS

HERG1 was expressed in all tumor samples regardless of their stage and in adenomas larger than 0.4 cm, but absent in small adenomas, sigmadiverticulitis specimen and healthy histopathologically negative samples, except for one which developed a tumor recurrence. In contrast, CEA, CK19 and CK20 were absent in some tumors. The selective HERG1 inhibitor E-4031 dose-dependently impaired tumor growth in the proliferation assays.

DISCUSSION

Our data indicate that HERG1, but not CEA, CK19 or CK20, is a highly sensitive and reliable tumor biomarker that may constitute a novel molecular target for tumor treatment.

High levels of tumor markers in pleural fluid correlate with poor survival in patients with adenocarcinomatous or squamous malignant effusions

BACKGROUND

The aim of this study was to determine whether several pleural fluid (PF) tumor markers, either alone or in combination, could be used to predict survival time of patients with malignant pleural effusion secondary to adenocarcinoma or squamous cell carcinoma.

METHODS

A total of 224 patients with confirmed metastatic pleural malignancies due to adenocarcinoma or squamous cell carcinoma were enrolled. PF tumor markers were determined either by electrochemiluminescence immunoassay (CEA, CA 15-3, CYFRA 21-1) or microparticle enzyme immunoassay (CA 125) technologies. Cutoff points that predicted death during the first month after diagnoses, with a specificity of 60%, were selected for each marker, using receiver operating characteristic analysis.

RESULTS

In patients with adenocarcinomatous or squamous malignant effusion, the combination of PF CA 125>or=1000 U/mL and CYFRA 21-1>or=100 ng/mL predicted a lower survival (4 vs. 11.7 months, p=0.03; and 0.3 vs. 8.4 months, p=0.003 respectively). This tumor marker combination remained as an independent predictor of poor outcome when adjusted for age and tumor type.

CONCLUSION

High PF tumor marker levels identify a subgroup of patients with a shorter median survival.

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.

Proteomics identification of desmin as a potential oncofetal diagnostic and prognostic biomarker in colorectal cancer

Colorectal cancer (CRC) is the third most common cancer worldwide and has poor prognosis. To identify the oncofetal proteins involved in CRC carcinogenesis, differentially expressed proteins among fetal colorectal tissues, CRC, and the paired tumor-adjacent normal colorectal tissues were investigated by a two-dimensional gel electrophoresis and MALDI-TOF/TOF-based proteomics approach. 42 protein spots were differentially expressed among these tissues, and 22 proteins were identified by MS analysis. Desmin and zinc finger protein 829 were found to be elevated in CRC tissue and fetal colorectal tissue compared with normal colorectal tissue. The elevated expression of desmin in CRC tissue and different developmental stages of fetus colon was confirmed by RT-PCR and Western blot analysis. Immunohistochemical analysis showed that the elevated expression of desmin was correlated with the severity and differentiation of CRC and decreased survival rate of CRC patients. Finally by developing a highly sensitive immunoassay, desmin could be detected in human serum and was significantly elevated in CRC patients compared with healthy volunteers. We propose that desmin be considered a potential oncofetal serum tumor marker for CRC that may have significance in the detection of patients with CRC.

Elevated preoperative serum carcinoembrionic antigen level may be an effective indicator for needing adjuvant chemotherapy after potentially curative resection of stage II colon cancer

BACKGROUND

To determine the prognostic factors and to rationalize adjuvant therapy, the clinicopathologic data of patients with a stage II colon cancer were analyzed retrospectively.

PATIENTS AND METHODS

A total of 392 patients underwent potentially curative resection at the Kurume University Hospital between 1982 and 2005. Postoperative adjuvant chemotherapy using oral fluoropyrimidines was administered in 163 patients, and the other 229 patients underwent surgery alone. Univariate and multivariate analyses for prognostic factors were carried out.

RESULTS

Invasive type in gross features, elevated preoperative CEA level, and surgery alone were each an independently significant factor for shorter relapse-free survival, and tumor size <50 mm, invasive type in gross features, elevated preoperative CEA level, and surgery alone were each an independently significant factor for shorter overall survival. The relapse-free survival rate and overall survival rate in the patients who received postoperative adjuvant chemotherapy were significantly higher than those in the patients treated with surgery alone even after stratifying to the preoperative CEA level.

CONCLUSION

Patients with an elevated preoperative CEA may be candidates for adjuvant chemotherapy after curative resection in stage II colon cancer. These findings warrant clinical trials to test out the efficacy of adjuvant chemotherapy in stage II colon cancer with an elevated preoperative CEA.

Persistent high postoperative carcinoembryonic antigen in colorectal cancer patients--is it important?

INTRODUCTION

Evaluation of pre- and postoperative serum CEA levels together has seldom been assessed for the prognosis of colorectal cancer (CRC).

OBJECTIVE

To concurrently evaluate pre- and postoperative CEA as factors of relapse and survival.

METHODS

The study consisted of 114 patients who had undergone surgery from February 2002 to June 2006 for CRC. All patients were classified into four groups according to their pre- and postoperative CEA levels. Data obtained for clinicopathologic parameters, lymph node metastasis, stage, recurrence, and CEA levels were analyzed to determine their association with survival. Multivariate analysis by the Cox proportional hazard regression model was performed to identify the independent prognostic factors associated with survival.

RESULTS

Postoperative serum CEA levels remained high in Group 3 (n = 32). Nineteen patients (59.3%) demonstrated a detectable cause for persistent high CEA levels, while the reasons for those in the other thirteen patients (40.6%) remained obscure. Abnormal preoperative CEA levels significantly correlated with the depth of tumor invasion, lymph node metastasis, TNM stage, and recurrence (p < 0.05). Abnormal postoperative CEA levels were significantly related to the depth of tumor invasion, TNM stage, and postoperative relapse (p<0.05). Patients in Group 3 demonstrated the worst survival rate. Abnormal postoperative CEA levels, lymph node metastasis, and location of the tumor were independent prognostic factors for survival.

CONCLUSION

The survival of patients with high postoperative CEA levels due to unknown reasons may be extended if they are exhaustively tested with sensitive diagnostic methods and treated at an early stage.

Affinity analysis for biomolecular interactions based on magneto-optical relaxation measurements

Magneto-optical relaxation measurements of magnetically labelled biomolecules are a promising tool for immunometric analyses. Carcinoembryonic antigen (CEA) and its polyclonal and monoclonal antibodies (anti-CEA) were utilized as a model system for affinity analysis of the interaction between antibody and antigen. For this purpose antibodies were coupled with magnetic nanoparticles (MNPs). Aggregation of these antibody sensors due to interactions with the CEA was observed subsequently by measuring the relaxation time of the birefringence of a transmitted laser beam that occurs in a pulsed magnetic field. A kinetic model of chain-like aggregation developed for these purposes enables the rapid and simple calculation of the kinetic parameters of the underlying protein interaction. From the known antigen concentration and the increase in particle size during the interaction we are able to estimate the unknown parameters with standard methods for the statistical description of stepwise polymerization. This novel affinity analysis was successfully applied for the antigen-antibody interaction described herein and can be applied to other biomolecular interactions. First efforts have been made to establish magneto-optical relaxation measurements in body fluids.

National Academy of Clinical Biochemistry Laboratory Medicine Practice Guidelines for Use of Tumor Markers in Testicular, Prostate, Colorectal, Breast, and Ovarian Cancers

Background: Updated National Academy of Clinical Biochemistry (NACB) Laboratory Medicine Practice Guidelines for the use of tumor markers in the clinic have been developed.

Methods: Published reports relevant to use of tumor markers for 5 cancer sites—testicular, prostate, colorectal, breast, and ovarian—were critically reviewed.

Results: For testicular cancer, α-fetoprotein, human chorionic gonadotropin, and lactate dehydrogenase are recommended for diagnosis/case finding, staging, prognosis determination, recurrence detection, and therapy monitoring. α-Fetoprotein is also recommended for differential diagnosis of nonseminomatous and seminomatous germ cell tumors. Prostate-specific antigen (PSA) is not recommended for prostate cancer screening, but may be used for detecting disease recurrence and monitoring therapy. Free PSA measurement data are useful for distinguishing malignant from benign prostatic disease when total PSA is &lt;10 μg/L. In colorectal cancer, carcinoembryonic antigen is recommended (with some caveats) for prognosis determination, postoperative surveillance, and therapy monitoring in advanced disease. Fecal occult blood testing may be used for screening asymptomatic adults 50 years or older. For breast cancer, estrogen and progesterone receptors are mandatory for predicting response to hormone therapy, human epidermal growth factor receptor-2 measurement is mandatory for predicting response to trastuzumab, and urokinase plasminogen activator/plasminogen activator inhibitor 1 may be used for determining prognosis in lymph node–negative patients. CA15-3/BR27–29 or carcinoembryonic antigen may be used for therapy monitoring in advanced disease. CA125 is recommended (with transvaginal ultrasound) for early detection of ovarian cancer in women at high risk for this disease. CA125 is also recommended for differential diagnosis of suspicious pelvic masses in postmenopausal women, as well as for detection of recurrence, monitoring of therapy, and determination of prognosis in women with ovarian cancer.

Conclusions: Implementation of these recommendations should encourage optimal use of tumor markers.

A personalized approach to cancer treatment: how biomarkers can help

BACKGROUND

The present approach to cancer treatment is often referred to as "trial and error" or "one size fits all." This practice is inefficient and frequently results in inappropriate therapy and treatment-related toxicity. In contrast, personalized treatment has the potential to increase efficacy and decrease toxicity.

CONTENT

We reviewed the literature relevant to prognostic, predictive, and toxicity-related markers in cancer, with particular attention to systematic reviews, prospective randomized trials, and guidelines issued by expert panels. To achieve personalized treatment for cancer, we need markers for determining prognosis, predicting response to therapy, and predicting severe toxicity related to treatment. Among the best-validated prognostic markers currently available are serum concentrations of alpha-fetoprotein (AFP), human chorionic gonadotropin (hCG), and lactate dehydrogenase (LDH) for patients with nonseminoma germ cell tumors and tissue concentrations of both urokinase plasminogen activator and plasminogen activator inhibitor 1 (PAI-1) for breast cancer patients. Clinically useful therapy predictive markers are estrogen and progesterone receptors to select patients with breast cancer for treatment with endocrine therapy and human epidermal growth factor receptor 2 (HER-2) to select breast cancer patients for treatment with trastuzumab (Herceptin). Markers available for identifying drug-induced adverse reactions include thiopurine methyltransferase (TPMT) to predict toxicity from thiopurines in the treatment of acute lymphoblastic leukemia and uridine diphosphate glucuronyltransferase to predict toxicity from irinotecan in the treatment of colorectal cancer.

CONCLUSIONS

Validated prognostic, predictive, and toxicity markers should help cancer treatment move from the current trial-and-error approach to more personalized treatment.

Tumor marker utility and prognostic relevance of cathepsin B, cathepsin L, urokinase-type plasminogen activator, plasminogen activator inhibitor type-1, CEA and CA 19-9 in colorectal cancer

BACKGROUND

Cathepsin B and L (CATB, CATL), urokinase-type plasminogen activator (uPA) and its inhibitor PAI-1 play an important role in colorectal cancer invasion. The tumor marker utility and prognostic relevance of these proteases have not been evaluated in the same experimental setting and compared with that of CEA and CA-19-9.

METHODS

Protease, CEA and CA 19-9 serum or plasma levels were determined in 56 patients with colorectal cancer, 25 patients with ulcerative colitis, 26 patients with colorectal adenomas and 35 tumor-free control patients. Protease, CEA, CA 19-9 levels have been determined by ELISA and electrochemiluminescence immunoassay, respectively; their sensitivity, specificity, diagnostic accuracy have been calculated and correlated with clinicopathological staging.

RESULTS

The protease antigen levels were significantly higher in colorectal cancer compared with other groups. Sensitivity of PAI-1 (94%), CATB (82%), uPA (69%), CATL (41%) were higher than those of CEA or CA 19-9 (30% and 18%, respectively). PAI-1, CATB and uPA demonstrated a better accuracy than CEA or CA 19-9. A combination of PAI-1 with CATB or uPA exhibited the highest sensitivity value (98%). High CATB, PAI-1, CEA and CA 19-9 levels correlated with advanced Dukes stages. CATB (P = 0.0004), CATL (P = 0.02), PAI-1 (P = 0.01) and CA 19-9 (P = 0.004) had a significant prognostic impact. PAI-1 (P = 0.001), CATB (P = 0.04) and CA 19-9 (P = 0.02) proved as independent prognostic variables.

CONCLUSION

At the time of clinical detection proteases are more sensitive indicators for colorectal cancer than the commonly used tumor markers. Determinations of CATB, CATL and PAI-1 have a major prognostic impact in patients with colorectal cancer.

Detection of Colorectal Cancer by Serum and Tissue Protein Profiling: A Prospective Study in a Population at Risk

Colorectal cancer (CRC) is the second most common cause of cancer-related death in Europe and its prognosis is largely dependent on stage at diagnosis. Currently, there are no suitable tumour markers for early detection of CRC. In a retrospective study we previously found discriminative CRC serum protein profiles with surface enhanced laser desorption ionisation—time of flight mass spectrometry (SELDI-TOF MS). We now aimed at prospective validation of these profiles. Additionally, we assessed their applicability for follow-up after surgery and investigated tissue protein profiles of patients with CRC and adenomatous polyps (AP). Serum and tissue samples were collected from patients without known malignancy with an indication for colonoscopy and patients with AP and CRC during colonoscopy. Serum samples of controls (CON; n = 359), patients with AP (n = 177) and CRC (n = 73), as well as tissue samples from AP (n = 52) and CRC (n = 47) were analysed as described previously. Peak intensities were compared by non-parametric testing. Discriminative power of differentially expressed proteins was assessed with support vector machines (SVM). We confirmed the decreased serum levels of apolipoprotein C-1 in CRC in the current population. No differences were observed between CON and AP. Apolipoprotein C-I levels did not change significantly within 1 month post-surgery, although a gradual return to normal levels was observed. Several proteins differed between AP and CRC tissue, among which a peak with similar mass as apolipoprotein C-1. This peak was increased in CRC compared to AP. Although we prospectively validated the serum decrease of apolipoprotein C-1 in CRC, serum protein profiles did not yield SVM classifiers with suitable sensitivity and specificity for classification of our patient groups.

Pre- and postoperative levels in serum of mannan-binding lectin associated serine protease-2 -a prognostic marker in colorectal cancer

Mannan-binding lectin-associated serine protease-2 (MASP-2) is the initiating enzyme of the lectin pathway of complement activation. High preoperative serum levels of MASP-2 are associated with recurrence and poor survival in patients with colorectal cancer (CRC). In this study we investigate the prognostic role of MASP-2 in patients curatively resected for primary CRC. Serum concentrations of MASP-2 were determined in 281 patients prior to surgery and 7 months postoperatively using a time-resolved immunofluorometric assay. End points were recurrent cancer and death within a median follow-up time of 7.9 years. The correlation between pre- and postoperative levels was 0.49. High postoperative levels of MASP-2 were significantly associated with poor survival [p = 0.04; hazard ratio (HR) = 1.35; 95% confidence interval (CI), 1.02-1.80] and recurrence (p = 0.01, HR = 1.6, 95% CI, 1.1-1.6). The inclusion of age, gender, tumor localization, and Dukes stage in multivariate analysis demonstrated that high MASP-2 levels were independently predictive of survival (p = 0.01; HR = 1.5, 95% CI, 1.1-2.0) and recurrence (p = 0.01, HR = 1.6; 95% CI, 1.1-2.4). Combining pre- and postoperative MASP-2 levels did not improve the prediction of survival/recurrence. High postoperative levels of MASP-2 are associated with poor prognosis in patients curatively resected for CRC. A change of the MASP-2 level from preoperative levels was not, per se, predictive of recurrent disease or survival.

Soluble intercellular adhesion molecule-1 as a prognostic marker for stage II colorectal cancer patients

BACKGROUND

Soluble intercellular adhesion molecule-1 (sICAM-1) represents a circulating form of ICAM-1 that is constitutively expressed or is inducible, which localizes to the cell surfaces of different cell lines and is related to the metastatic potential of cancer cells. The aim of the present study was to determine the relationships between the preoperative serum concentration of sICAM-1 and clinicopathological features, established tumor markers and prognosis, in colorectal cancer patients.

METHODS

One hundred and thirty-eight patients with histologically proven colorectal cancer and 40 normal volunteers were included in this trial. Preoperative serum was collected, and sICAM-1 levels were assayed using a commercially available enzyme-linked immunosorbent assay kit.

RESULTS

The mean sICAM-1 level in patients was significantly higher than that in controls, and increased with disease progression. The prognosis of patients with an elevated sICAM-1 level was significantly worse than that of patients with a normal sICAM-1 level. In a Cox multivariate analysis, the strongest prognostic factor in all patients was distant metastasis followed by sICAM-1 level, while in patients with stage II classification, the strongest prognostic factor was serum level of sICAM-1. The prognosis of stage II patients positive for sICAM-1 was comparable to that of stage III patients.

CONCLUSIONS

Preoperative sICAM-1 level is an independent prognostic marker for stage II colorectal cancer. Measuring serum sICAM-1 may provide valuable information, especially for stage II patients, when selecting appropriate candidates for adjuvant chemotherapy.

Enhanced detection of cholangiocarcinoma with serum trypsinogen-2 in patients with severe bile duct strictures

BACKGROUND/AIMS

Primary sclerosing cholangitis (PSC) is associated with a high risk of cholangiocarcinoma. Our aim was to evaluate the diagnostic value of trypsinogen-1, trypsinogen-2, tumour-associated trypsin inhibitor, human chorionic gonadotropin beta and trypsin-2-alpha(1)-antitrypsin for cholangiocarcinoma and to compare them with CA19-9 and CEA.

METHODS

The study consisted of 84 patients with either PSC or cholangiocarcinoma or both referred for liver transplantation or other liver surgery. The serum concentrations were determined by time-resolved immunofluorometric assays.

RESULTS

Forty-six patients were transplanted due to PSC; in 3 of the explanted livers cholangiocarcinoma was found incidentally. All transplanted patients had severe biliary strictures together with cirrhosis or pre-cirrhosis. Twenty-nine of 38 patients with cholangiocarcinoma were candidates for intervention. In all, 8 patients had both PSC and cholangiocarcinoma. Receiver-operating characteristics curve analysis showed that serum trypsinogen-2 had the highest accuracy in differentiating between cholangiocarcinoma and PSC. The area under the curve (AUC) value was 0.804 for trypsinogen-2 and 0.613 for CA19-9. Serum trypsinogen-2 also showed the highest accuracy for differentiation between PSC and PSC with simultaneous cholangiocarcinoma with an AUC value of 0.759.

CONCLUSIONS

Our results suggest that serum trypsinogen-2 is a most useful marker for diagnosing patients with cholangiocarcinoma, and it is superior to serum CA19-9 and CEA.

Survival stratification panel of colorectal carcinoma with combined expression of carcinoembryonic antigen, matrix metalloproteinases-2, and p27 kip1

PURPOSE

The prognosis varies greatly in colorectal carcinoma patients, even in the same stage. We examined the association between the expression of matrix metalloproteinases-2, carcinoembryonic antigen, p27 kip1, and clinicopathologic features in patients with colorectal carcinoma to identify a possible panel of tumor markers in predicting prognosis of colorectal carcinoma.

METHODS

The expressions of three individual markers in 127 colorectal carcinoma cases were analyzed by immunohistochemistry method. Univariate and multivariate analysis were performed to analyze the expression with the disease-free survival time in colorectal carcinoma.

RESULTS

High expression of matrix metalloproteinases-2, carcinoembryonic antigen, and low expression of p27 kip1 were related to poor prognosis in univariate analysis (P = 0.0002; P < 0.0001; P = 0.0008). The expression of matrix metalloproteinases-2, carcinoembryonic antigen, p27 kip1, and tumor differentiation were independent prognostic factors for disease-free survival by Cox regression analysis. The coexpression panel of matrix metalloproteinases-2, carcinoembryonic antigen, and p27 kip had significant prognostic value in all patients (P AB = 0.0103; P(BC) = 0.0068; P CD = 0.0117). Multivariate analysis with Cox regression reveals that coexpression of matrix metalloproteinases-2, carcinoembryonic antigen, and p27 kip1 were independent prognostic factors as tumor differentiation in colorectal carcinoma. In different stages, coexpression tumor markers functioned in Stages II and III but not in the 19 cases of Stage I. The reason might be the number of patients was too small.

CONCLUSIONS

The results of this study provided further evidence that the combination of tumor markers of matrix metalloproteinases-2, carcinoembryonic antigen, and p27 kip1 was more informative than any single tumor marker alone for the disease-free survival stratification of colorectal carcinoma. Coexpression of matrix metalloproteinases-2, carcinoembryonic antigen, and p27 kip1 might be a useful survival stratification panel for clinical management.

Tumour markers in colorectal cancer: European Group on Tumour Markers (EGTM) guidelines for clinical use

The aim of this article is to present updated guidelines for the use of serum, tissue and faecal markers in colorectal cancer (CRC). Lack of specificity and sensitivity preclude the use of all existing serum markers for the early detection of CRC. For patients with stage II or stage III CRC who may be candidates for either liver resection or systemic treatment should recurrence develop, CEA should be measured every 2-3 months for at least 3 years after diagnosis. Insufficient evidence exists to recommend routine use of tissue factors such as thymidylate synthase, microsatellite instability (MSI), p53, K-ras and deleted in colon cancer (DCC) for either determining prognosis or predicting response to therapy in patients with CRC. Microsatellite instability, however, may be used as a pre-screen for patients with suspected hereditary non-polyposis colorectal cancer. Faecal occult blood testing but not faecal DNA markers may be used to screen asymptomatic subjects 50 years or older for early CRC.

Role of tumor markers in patients with solid cancers: A critical review

The measurement of tumor markers is currently one of the most rapidly growing areas in laboratory medicine. Lack of sensitivity and specificity preclude the use of most existing markers for the early detection of malignancy. For patients with diagnosed malignancy, however, markers are potentially useful in determining prognosis, predicting therapeutic response, maintaining surveillance following curative surgery and monitoring therapy in advanced disease. Clinically useful markers include CEA in the surveillance of patients with diagnosed colorectal cancer, AFP and HCG in the management of patients with non-seminomatous germ cell tumors, HCG in the management of patients with trophoblastic disease, CA 125 for monitoring therapy in patients with ovarian cancer, estrogen receptors for predicting response to hormone therapy in breast cancer and HER-2 for the identification of women with breast cancer likely to respond to trastuzumab (Herceptin). Although widely used, the impact of PSA screening in reducing mortality from prostate cancer remains to be shown.

Diagnostic accuracy of serum-carcinoembryonic antigen in recurrent colorectal cancer: a receiver operating characteristic curve analysis

BACKGROUND

Serial measurements of carcinoembryonic antigen (CEA) are frequently used in the follow-up after colorectal cancer (CRC), but its usefulness remains debatable. Choosing the appropriate cut-off point is crucial to the diagnostic accuracy (DA) of continuous test variables. Receiver operating characteristic curve (ROC) analysis is the appropriate statistical method for this purpose, but has not been applied in previous studies.

METHODS

One hundred ninety-four consecutive patients surgically treated with curative intent for CRC between July 1996 and June 1999 had systematic follow-up for five years. Follow-up included imaging, coloscopy and serial CEA measurements. Complete data including CEA measurements were available from 153 patients. ROC analysis of CEA was done with regard to detection of recurrent disease.

RESULTS

Depending on the chosen cut-off value of CEA, DA varied widely within the normal range (CEA <or=10 U/ml). CEA >4 U/ml provided the highest sensitivity (0.78) and specificity (0.91), compared to a sensitivity and specificity at the upper normal range (CEA = 10 U/ml) of 0.51 and 0.99, respectively. Thirty-three patients (24%) developed recurrence. Among 11 (5%) asymptomatic patients diagnosed by elevated CEA levels, only two patients (1.5%) were amenable to secondary curative surgery. A threefold increase of CEA in an individual patient had the same DA as the best cut-off value (>4 U/ml).

CONCLUSIONS

Diagnostic accuracy of CEA in follow-up after curative surgery for CRC is influenced by the chosen cut-off value. A threefold increase of CEA may indicate recurrent disease. The value of serial measurement of CEA was limited.

Targeting serum antibody for cancer diagnosis: a focus on colorectal cancer

The ability of the immune system to magnify the appearance of disease by generating relatively large amounts of antibody in response to small amounts of disease makes it a natural biosensor, and serum antibodies have emerged as promising biomarkers for the detection of cancer. This review summarizes recent progress in targeting serum antibodies for cancer diagnosis, with a particular focus on colorectal cancer (CRC). Several serum antibodies have been detected at increased levels in CRC patients, including p53, carcinoembryonic antigen, Ras, topoisomerase II-alpha, histone deacetylase 3 and 5, ubiquitin C-terminal hydrolase L3, tropomyosin and cyclin B1. As each antibody is only present in a limited proportion of patients (usually < 40%), a combination of serum antibodies that defines the 'immunological signature' of cancer needs to be developed. High-throughput methods to identify new serum antibodies for cancer diagnosis are also reviewed.

Methylation of serum DNA is an independent prognostic marker in colorectal cancer

PURPOSE

Aberrant CpG island hypermethylation is a feature of a subgroup of colorectal cancers, which can be detected in the serum of affected patients. This study was designed to identify methylation targets with prognostic significance in the serum of patients with colorectal cancer.

EXPERIMENTAL DESIGN

In a gene evaluation set consisting of sera from 24 patients with local colorectal cancers, 14 with metastasized disease, and 20 healthy controls, the genes HPP1/TPEF, HLTF, and hMLH1 were identified as potential serum DNA methylation markers. These genes were further analyzed in a test set of sera of 104 patients with colorectal cancer.

RESULTS

Methylation of HLTF, HPP1/TPEF, and hMLH1 was found to be significantly correlated with tumor size, and methylation of HLTF and HPP1/TPEF was significantly associated with metastatic disease and tumor stage. Moreover, methylation of HPP1/TPEF was also associated with serum carcinoembryonic antigen. The prognostic relevance of methylation of these genes was tested in pretherapeutic sera of 77 patients with known follow-up. Patients with methylation of HPP1/TPEF or HLTF were found to have unfavorable prognosis (P = 0.001 and 0.008). In contrast, serum methylation of hMLH1 was not associated with a higher risk of death. Multivariate analysis showed methylated HPP1 and/or HLTF serum DNA to be independently associated with poor outcome and a relative risk of death of 3.4 (95% confidence interval, 1.4-8.1; P = 0.007).

CONCLUSIONS

These data show that the methylation status of specific genes in the serum of patients with colorectal cancer has the potential to become a pretherapeutic predictor of outcome.

Tumour M2-pyruvate kinase: a gastrointestinal cancer marker

BACKGROUND

Gastrointestinal cancer tumour markers are valuable in the detection of recurrence following resection or in monitoring response to chemotherapy. CEA, CA19-9, CA-50 and CA72-4 are currently available but are nonspecific and have a low sensitivity. 'Tumour M2-pyruvate kinase' was described by Eigenbrodt around 1985. In cancers the active tetrameric form of the M2 isoenzyme of pyruvate kinase converted to an inactive dimeric form by direct interaction with oncoproteins to channel glucose carbons into DNA synthesis. This review summarizes the current knowledge of this unique tumour marker with regard to its biochemistry, assay and potential use as a diagnostic and screening tool in gastrointestinal cancer.

METHODS

A literature search was conducted for entries from 1980 to 2005 using PubMed and NeLH databases using tumour M2-pyruvate kinase, faecal tumour M2-pyruvate kinase, tumour metabolism, tumour markers and carcinoembryonic antigen as keywords. A total of 56 references relevant to tumour M2-pyruvate kinase were retrieved. Eighteen references were clinical studies involving plasma/faecal tumour M2-pyruvate kinase and gastrointestinal cancer. The remaining 38 references were clinical/nonclinical trials and reviews on tumour metabolism and plasma/faecal tumour M2-pyruvate kinase assay. Seven of the 18 clinical studies involved faecal M2-pyruvate kinase. Three of the 11 plasma tumour M2-pyruvate kinase studies were non-English language and were excluded. The sensitivity, specificity, positive predictive and negative predictive value for plasma/serum tumour M2-pyruvate kinase in the detection of gastrointestinal cancer was determined for each of the remaining eight studies. Data for gastrointestinal cancer M2-pyruvate kinase were compared with other gastrointestinal cancer markers. Data from three of the eight studies using a diagnostic cut-off value of 15 U/ml for ethylenediaminetetraacetic acid (EDTA) plasma tumour M2-pyruvate kinase were analysed together as a small meta-analysis.

RESULTS

At a diagnostic cut-off value of 15 U/ml for tumour M2-pyruvate kinase in EDTA plasma the sensitivity, specificity, positive predictive and negative predictive value was 57.3, 89, 85.7 and 64.8%, respectively, for colorectal cancers, 62.1, 89, 88 and 64%, respectively, for gastric/oesophageal cancers and 72.5, 89, 58 and 94%, respectively, for pancreatic cancers. As a faecal marker for colorectal cancers, faecal tumour M2-pyruvate kinase has a sensitivity of 73-92% at a cut-off value of 4 U/ml as against 50% sensitivity for Guaiac faecal test.

CONCLUSION

Circulating tumour M2-pyruvate kinase is more commonly elevated in oesophageal, gastric and colorectal cancer patients than conventional tumour markers. Faecal M2-pyruvate kinase is a sensitive marker of colorectal cancer. The clinical role of tumour M2-pyruvate kinase in gastrointestinal cancer management should be investigated in large-scale clinical trials.

Survivin: a promising tumor biomarker

Survivin is a 16.5 kDa protein overexpressed in almost all malignancies but rarely detected in normal differentiated adult tissues. Functionally, survivin has been shown to inhibit apoptosis, promote cell proliferation and enhance angiogenesis. Consistent with its role in these processes, survivin has been shown to play a key role in cancer progression. Because of the large difference in expression between normal and malignant tissue and its causal role in cancer progression, survivin is currently undergoing intensive investigation as a potential tumor marker. Emerging data suggests that measurement of survivin can aid the early diagnosis of bladder cancer, determine prognosis in multiple cancer types and predict response to diverse anti-cancer therapies. These preliminary findings on the diagnostic, prognostic and predictive potential of survivin should now be confirmed in large prospective trials. Furthermore, assays for the measurement of survivin should be simplified, standardized and evaluated in external quality assurance schemes.

Multivariate analysis of prognostic determinants for colorectal cancer patients with high preoperative serum CEA levels: prognostic value of postoperative serum CEA levels

High preoperative serum carcinoembryonic antigen (CEA) levels have been well investigated and found to be associated with poor prognosis in patients with colorectal cancer (CRC). However, it has been observed that the outcome varies after curative resection, along with postoperative serum CEA levels; some patients continue to have high postoperative serum CEA levels while postoperative CEA levels return to normal in others. The purpose of this study was to determine the prognostic significance of postoperative serum CEA levels in CRC patients with high preoperative serum CEA levels. Between January 2002 and December 2004, 423 CRC patients underwent operation in our hospital; 181 (42.8%) had high preoperative serum CEA levels and were enrolled in this study. Among the 181 patients, 165 patients had curative resection; the remaining 16 had stage IV disease, so they underwent palliative surgery and were subsequently excluded from analysis. Pre- and postoperative serum CEA levels were measured and analyzed. All patients had curative resection and were divided into two groups according to postoperative serum CEA levels: one group comprised patients with postoperative serum CEA > or = 5 ng/mL (n = 80) and the other group comprised patients with postoperative serum CEA levels < 5 ng/mL (n = 85). Postoperative serum CEA levels were significantly related to location of primary tumors (p = 0.042), lymph node metastases (p = 0.009), TNM stage (p = 0.001), and postoperative relapse (p = 0.004). The results of multivariate analysis showed that both lymph node metastases and high postoperative serum CEA levels (> or = 5 ng/mL) were independent prognostic factors for CRC patients after curative resection. Postoperative serum CEA levels can be a single independent prognostic determinant in CRC patients with high preoperative serum CEA levels. Intensive follow-up and adjuvant therapy may be necessary in CRC patients who continue to have high postoperative serum CEA levels even after curative resection.

Combined measurement of hepatocyte growth factor and carcinoembryonic antigen as a prognostic marker for patients with dukes a and B colorectal cancer: results of a five-year study

PURPOSE

There is no marker capable of differentiating patients with Dukes A and B colorectal cancer with aggressive diseases from those with indolent diseases. We evaluated the results of five years of actuarial survival data to determine whether serial monitoring of serum hepatocyte growth factor could provide prognostic information on these patients.

METHODS

Blood samples of 147 colorectal cancer patients were obtained and the serum concentration of hepatocyte growth factor was measured.

RESULTS

Elevated serum hepatocyte growth factor levels were associated with stage progression. Although the overall positive rate of hepatocyte growth factor in the patients was the same as that of the carcinoembryonic antigen, the positive rate of hepatocyte growth factor in the Dukes A patients was two times higher than that of the carcinoembryonic antigen, and nearly 40 percent of the carcinoembryonic antigen-negative patients had a positive serum hepatocyte growth factor in the Dukes A and B classification. In this subgroup, patients with positive serum hepatocyte growth factor or carcinoembryonic antigen levels had a poorer prognosis, whereas positive serum hepatocyte growth factor level after surgery could predict disease recurrence.

CONCLUSIONS

A combination of serum hepatocyte growth factor and carcinoembryonic antigen tests might be useful for selecting patients with aggressive diseases in Dukes A and B classification.

Human neutrophil peptides 1, 2 and 3 are biochemical markers for metastatic colorectal cancer

Colorectal cancer (CRC) patients have increased levels of human neutrophil peptides 1-3 (HNP1-3) in tumour tissue and plasma. The aim is to study whether the amount of HNP1-3 in tumour and plasma from CRC patients correlate with Dukes' stages A-D. The amount of HNP1-3 in tumour tissue, normal colonic mucosa, and plasma was determined with mass spectrometry. Plasma levels of HNP1-3 were determined with enzyme-linked immuno-sorbent assay (ELISA). The amount of HNP1-3 determined with mass spectrometry was increased in tumours compared to normal colonic tissue in CRC patients in Dukes' stage A-D, whereas HNP1-3 in plasma was only elevated in Dukes' stage D compared to healthy individuals. HNP1-3 plasma concentration determined with ELISA was increased in Dukes' stages C and D, but not in A and B. It is concluded that HNP1-3 is a potential marker for prognostic assessment, surveillance of patients, and monitoring chemotherapy in CRC patients with advanced disease.

Carcinoembryonic antigen, alpha-fetoprotein, and prostate-specific antigen in the sera of industrial workers exposed to phenol, formaldehyde, urea, and mixed vapors

Exposure to certain industrial agents has been thought to have carcinogenic potential, both for employees who work closely with agents and for the general population that comes into contact with them. The objective of the present study is to evaluate the changes at the cellular level or at the level of cellular metabolism products present in the biological fluid, and to detect early stages of the carcinogenic process resulting from the exposure of industrial environmental hazards. Carcinoembryonic antigen (CEA), alpha-fetoproteins (AFP), and prostate-specific antigen (PSA) were measured in sera of workers (n = 51), who were divided into 4 groups: group I, workers exposed to phenol; group II, workers exposed to formaldehyde; group III, workers exposed to urea; and group IV, workers exposed to mixed vapor, plus a reference control healthy group (n = 15). The results showed that 75% of the workers exposed to phenol, 75% of the workers exposed to urea, 83.3% of workers exposed to formalin, and 92.3% of the workers exposed to mixed vapors had raised values of serum CEA (S-CEA) above normal value of the control group. Also, 23% of workers exposed to mixed vapors, 44% of workers exposed to formalin, 50% of workers exposed to phenol, and 62.5% of workers exposed to urea had raised values of serum AFP (S-AFP) above normal value of control group. Finally, 16.6% of workers exposed to phenol, 23% of workers exposed to mixed vapors, and 33.3% of workers exposed to formalin had raised values of serum PSA (S-PSA) above the normal value of control group; there were no raised values of S-PSA in workers exposed to urea. No significant difference was found in the activities of AST and ALT in group I, but a highly significant increase was found in the AST activities for groups II and IV and the ALT activities for groups III and IV. A significant difference was found in the activity of ALT in group II and in AST for group III. There was no significant difference in the levels of albumin in groups I, II, and III, whereas albumin levels were significantly decreased in group IV. No significant change was found in the level of urea and creatinine in all groups except for group III, where serum levels of creatinine were significantly decreased. From our findings, we concluded that S-CEA can be used as an important prognostic screening marker for early prediction for malignancy, and for management of workers with lung cancer who are exposed to the environmental hazards in industrial factories. Furthermore, S-AFP can be used also as a biomarker if it is carried out and correlated with S-CEA.

Statistically Integrated Metabonomic−Proteomic Studies on a Human Prostate Cancer Xenograft Model in Mice

A novel statistically integrated proteometabonomic method has been developed and applied to a human tumor xenograft mouse model of prostate cancer. Parallel 2D-DIGE proteomic and 1H NMR metabolic profile data were collected on blood plasma from mice implanted with a prostate cancer (PC-3) xenograft and from matched control animals. To interpret the xenograft-induced differences in plasma profiles, multivariate statistical algorithms including orthogonal projection to latent structure (OPLS) were applied to generate models characterizing the disease profile. Two approaches to integrating metabonomic data matrices are presented based on OPLS algorithms to provide a framework for generating models relating to the specific and common sources of variation in the metabolite concentrations and protein abundances that can be directly related to the disease model. Multiple correlations between metabolites and proteins were found, including associations between serotransferrin precursor and both tyrosine and 3-D-hydroxybutyrate. Additionally, a correlation between decreased concentration of tyrosine and increased presence of gelsolin was also observed. This approach can provide enhanced recovery of combination candidate biomarkers across multi-omic platforms, thus, enhancing understanding of in vivo model systems studied by multiple omic technologies.

Surgical approaches to cancer in patients who have inflammatory bowel disease

IBD clearly increases the risk for GI malignancies, especially CRC. The absolute number of patients that develops such malignancies is low compared with the overall cancer rate; however, younger age of onset, higher relative risk, unique clinical presentations, and problems with early diagnosis make this a serious complication of IBD. With the exception of patients with comorbid complications, such as primary sclerosing cholangitis, the prognosis is no worse for CRCs that arise as the result of IBD compared with those that arise sporadically. The prognosis remains poor for small bowel adenocarcinomas in patients who have CD, primarily because of their advanced stage at detection. Diligent surveillance is essential for early detection and treatment of IBD-related CRCs in patients with unresected colons, long-standing or extensive disease, and in those who have early-onset CD, although pundits still question whether it significantly affects prognosis and survival. Better surveillance techniques for small bowel dysplasia or malignancy in patients who have CD is needed, especially given the poor prognosis of these patients when advanced cancers are detected. Depending on the presentation and disease diagnosis, patients have several surgical treatment options and can expect good outcomes for all. When the appropriate surgical technique is used in patients who have colon or rectal cancer, along with adjuvant chemotherapy when appropriate, prognosis and function is good; however, the experience of the surgeon can affect the prognosis for IBD-related GI cancers. Surgical therapy is based not only on general oncologic principles, but also on the surgery that is appropriate for the IBD diagnosis. Resection of the mesentery and lymphadenectomy should be performed according to oncologic principles. Postoperative survival for IBD-related CRC is good, and diligent surveillance and follow-up are critical to the patient's overall prognosis.

Identification of PSME3 as a novel serum tumor marker for colorectal cancer by combining two-dimensional polyacrylamide gel electrophoresis with a strictly mass spectrometry-based approach for data analysis

The purpose of this study was to identify and validate novel serological protein biomarkers of human colorectal cancer (CRC). Proteins from matched CRC and adjacent normal tissue samples were resolved by two-dimensional gel electrophoresis. From each gel all spots were excised, and enveloped proteins were identified by MS. By comparison of the resulting protein profiles, dysregulated proteins can be identified. A list of all identified proteins and validation of five exemplarily selected proteins, elevated in CRC was reported previously (Roessler, M., Rollinger, W., Palme, S., Hagmann, M. L., Berndt, P., Engel, A. M., Schneidinger, B., Pfeffer, M., Andres, H., Karl, J., Bodenmuller, H., Ruschoff, J., Henkel, T., Rohr, G., Rossol, S., Rosch, W., Langen, H., Zolg, W., and Tacke, M. (2005) Identification of nicotinamide N-methyltransferase as a novel serum tumor marker for colorectal cancer. Clin. Cancer Res. 11, 6550-6557). Here we describe identification and initial validation of another potential marker protein for CRC. Comparison of tissue protein profiles revealed strong elevation of proteasome activator complex subunit 3 (PSME3) expression in CRC tissue. This dysregulation was not detectable based on the spot pattern. The PSME3-containing spot on tumor gels showed no visible difference to the corresponding spot on matched control gels. MS analysis revealed the presence of two proteins, PSME3 and annexin 4 (ANXA4) in one and the same spot on tumor gels, whereas the matched spot contained only one protein, ANXA4, on control gels. Therefore, dysregulation of PSME3 was masked by ANXA4 and could only be recognized by MS-based analysis but not by image analysis. To validate this finding, antibody to PSME3 was developed, and up-regulation in CRC was confirmed by Western blot analysis and immunohistochemistry. Finally by developing a highly sensitive immunoassay, PSME3 could be detected in human sera and was significantly elevated in CRC patients compared with healthy donors and patients with benign bowel disease. We propose that PSME3 be considered a novel serum tumor marker for CRC that may have significance in the detection and in the management of patients with this disease. Further studies are needed to fully assess the potential clinical value of this marker candidate.

Molecular prognostic markers in resectable colorectal liver metastases: a systematic review

BACKGROUND

Determination of prognosis in patients with resectable colorectal liver metastases (CLM) is desirable in order to improve case selection for surgery and tailor adjuvant treatment according to individual recurrence risk. Conventional clinicopathological factors lack the sensitivity to accurately achieve this goal. Consideration of tumour biology and the identification of molecular prognostic markers may allow more accurate risk stratification.

METHOD

This systematic review examines evidence from published manuscripts looking at molecular markers in resectable colorectal liver metastases and their correlation with disease recurrence and survival following hepatectomy.

RESULTS

Studies have yielded promising results in the search for prognostic molecular markers of CLM. Molecular biomarkers from varied aspects of tumour biology have been examined and a number of these, including proliferation indices, telomerase, thymidylate synthase, microvessel density and thrombospondin-1 appear to have prognostic utility in this context. Validation of other markers, notably p53, has been limited by a failure of methodologies to account for their biological complexity.

CONCLUSIONS

A biomarker-based approach may yield significant benefits through informed treatment of resectable metastatic colorectal malignancy. Standardised retrospective analyses are necessary to confirm preliminary findings and identify existing and novel markers for inclusion into prospective studies. Assessment and verification of multiple molecular markers in this manner may allow molecular profiling of metastases and tailoring of therapy according to the biological aggressiveness of individual tumours. The advent of genomic- and proteomic-based technologies will allow the simultaneous analysis of multiple molecular markers and the derivation of disease profiles associated with disease recurrence and poor survival.

Preoperative carcinoembryonic antigen and albumin in predicting survival in patients with colon and rectal carcinomas

OBJECTIVE

To examine the relationship between postoperative outcomes of colorectal carcinoma patients and preoperative serum carcinoembryonic antigen (CEA) and albumin (ALB) levels and evaluate if these levels can accurately predict outcomes and/or be factor indicating adjuvant chemotherapy.

BACKGROUND

CEA is a marker for colorectal carcinoma and its level usually increases before a distant metastasis is detected. Also, a low level of serum ALB is usually found in metastatic colorectal carcinoma patients.

STUDY

A retrospective cohort study of patients with colorectal carcinomas who were treated with curative surgery in Songklanagarind Hospital between 1998 and 2002.

RESULTS

One hundred seventy patients were identified with a median survival of 1131 days (range 71 to 2293 d) and with an overall 5-year survival rate of 54%. Patients were stratified using CEA at 5 ng/mL and an ALB level at 3.5 g/dL into 4 groups: (1) low CEA, high ALB; (2) low CEA, low ALB; (3) high CEA, high ALB; and (4) high CEA, low ALB. The 5-year survival rates for groups 1 to 4 were 66%, 63%, 46%, and 34%, respectively. There was statistically significant difference in 5-year survival between the well-differentiated tumor with low CEA and the poorly differentiated tumor with high CEA (P=0.0115). The high CEA patients who had the well-differentiated tumor had longer survival than those with a poorly differentiated tumor (P=0.0412).

CONCLUSIONS

A preoperative CEA level greater than or equal to 5 ng/mL and ALB level less than 3.5 g/dL predict a poor survival chance for colorectal carcinoma patients. In high CEA patients, tumor differentiated is an independent factor affecting survival.

Intensive follow-up after liver resection for colorectal liver metastases: results of combined serial tumour marker estimations and computed tomography of the chest and abdomen - a prospective study

The aim of the study was to prospectively evaluate an intensive follow-up programme using serial tumour marker estimations and contrast-enhanced computed tomography (CT) of the chest and abdomen in patients undergoing potentially curative resection of colorectal liver metastases. Seventy-six consecutive patients having undergone potentially curative resections of colorectal liver metastases in a single unit were followed up with a protocol of 3 monthly carcinoembryonic antigen and carbohydrate antigen 19-9 estimations and contrast-enhanced spiral CT of the chest, abdomen and pelvis for the first 2 years following surgery and 6 monthly thereafter. The median period of follow-up was 24 months (range 18-60). Recurrent tumour was classed as early if within 6 months of liver resection. Thirty-seven of the 76 patients (49%) developed recurrence on follow-up. Nineteen recurrences were in the liver alone (51%), 16 liver and extrahepatic (43%) and two extrahepatic alone (6%). Of the 19 patients with isolated liver recurrence, eight developed within 6 months of liver resection none of which were resectable. Of the 11 recurrences after 6 months, five (45%) were resectable. Of the 37 recurrences, CT indicated recurrence despite normal tumour markers in 19 patients. Tumour markers suggested recurrence before imaging in 12 and concurrently with imaging in 6. In the 12 patients who presented with elevated tumour markers before imaging, there was a median lag period of 3 months (range 1-21) in recurrence being detected on further serial imaging. Seventeen patients who developed recurrence had normal tumour markers before initial resection of their liver metastases. Of these 17, 10 (58%) had an elevation of tumour markers associated with recurrence. Over a median follow-up of 2 years following liver resection, the use of CT or tumour markers alone would have failed to demonstrate early recurrence in 12 and 18 patients respectively. A combination of tumour markers and CT detected significantly more (P < 0.05) recurrence than either modality alone. Tumour markers and CT should be used in combination in the follow-up of patients with resected colorectal liver metatases, including patients whose markers are normal at the time of initial liver resection.

Increased integrity of free circulating DNA in sera of patients with colorectal or periampullary cancer: direct quantitative PCR for ALU repeats

BACKGROUND

Cell-free DNA circulating in blood is a candidate biomarker for malignant tumors. Unlike uniformly truncated DNA released from apoptotic nondiseased cells, DNA released from dead cancer cells varies in size. We developed a novel method to measure the ratio of longer to shorter DNA fragments (DNA integrity) in serum as a potential biomarker for patients with colorectal cancer (CRC) or periampullary cancers (PACs).

METHODS

Sera from 32 patients with CRC (3 stage I, 14 stage II, 6 stage III, and 9 stage IV patients), 19 patients with PACs (2 stage I, 9 stage II, 1 stage III, and 7 stage IV patients), and 51 healthy volunteers were assessed by quantitative real-time PCR of ALU repeats (ALU-qPCR) with 2 sets of primers (115 and 247 bp) amplifying different lengths of DNA. We used serum directly as a template for ALU-qPCR without DNA purification. DNA integrity was determined as ratio of qPCR results of 247-bp ALU over 115-bp ALU.

RESULTS

ALU-qPCR had a detection limit of 0.01 pg of DNA. Eliminating DNA purification reduced technical artifacts and reagent/labor costs. Serum DNA integrity was significantly increased for stage I/II and III/IV CRC and stage I/II and III/IV PACs (P = 0.002, P = 0.006, P = 0.022, and P <0.0001, respectively). ROC curves for detecting CRC and PACs had areas under the curves of 0.78 and 0.80, respectively.

CONCLUSIONS

Direct ALU-qPCR is a robust, highly sensitive, and high-throughput method to measure serum DNA integrity. DNA integrity is a potential serum biomarker for detection and evaluation of CRC and PACs.

Preoperative plasma vascular endothelial growth factor but not nitrite is a useful complementary tumor marker in patients with colorectal cancer

PURPOSE

Vascular endothelial growth factor and nitric oxide are both related to tumor progression. This study was designed to measure preoperative plasma vascular endothelial growth factor and nitrite levels in patients with colorectal cancer to evaluate their clinical applications as tumor markers.

METHODS

In total, 279 patients with primary colorectal cancer and 20 patients with hemorrhoids (as a control) were included in this study. Plasma vascular endothelial growth factor was measured by quantitative, solid-phase, enzyme-linked immunosorbent assay (R&D Systems), whereas nitrite was measured by a high-performance liquid chromatographic method.

RESULTS

The vascular endothelial growth factor (mean, 220.6 pg/ml, P < 0.005) and nitrite (mean, 29.4 microM, P = 0.043) levels of patients with cancer were significantly higher than those of controls (mean vascular endothelial growth factor, 67 pg/ml; mean nitrite, 23 microM). Preoperative plasma vascular endothelial growth factor levels were positively correlated with tumor stage, T class, M class, and tumor size (Spearman correlation, P < 0.01), but were not associated with gender, N class, tumor location, histology type, or grade. There were no statistical differences in nitrite levels among different groups of patients with cancer. Higher vascular endothelial growth factor levels also were correlated with leukocytosis, elevated carcinoembryonic antigen, and a higher platelet count. The positive rates of vascular endothelial growth factor elevation (>148.6 pg/ml) compared with carcinoembryonic antigen elevation were 36.9 to 14.6 percent in Stage I, 60.9 to 33 percent in Stage II, 62.9 to 48.7 percent in Stage III, and 86 to 70.2 percent in Stage IV, respectively. The overall positive rate of vascular endothelial growth factor elevation also was higher than that of carcinoembryonic antigen elevation (63 percent for vascular endothelial growth factor vs. 42.5 percent for carcinoembryonic antigen, P = 0.016). More than one-half of the patients without carcinoembryonic antigen elevation still had elevated vascular endothelial growth factor levels. The combined assessment using vascular endothelial growth factor and carcinoembryonic antigen was superior to individual assessment using vascular endothelial growth factor or carcinoembryonic antigen. In node-negative tumor, the patients with vascular endothelial growth factor elevation had worse disease-free survival than those without vascular endothelial growth factor elevation (P = 0.0367). There was no association of vascular endothelial growth factor elevation with survival in patients with node-positive tumor.

CONCLUSIONS

Plasma vascular endothelial growth factor is a useful complementary tumor marker; however, synchronous measurement of white blood cells, platelets, and carcinoembryonic antigen is suggested in the clinical application of vascular endothelial growth factor to colorectal cancer.

Using the Cancer Rehabilitation Questionnaire in Patients with Colorectal Cancer

This article describes the development and testing of the Cancer Rehabilitation Questionnaire (CRQ) in patients with colorectal cancer. A descriptive, correlational survey was conducted in a sample of patients with colon or rectal cancer who received care at an outpatient cancer clinic at a large, northeastern U.S. academic medical center. Patients were identified from the Tumor Registry (N = 327) and received a mailed questionnaire. One hundred and three patients with colorectal cancer completed the demographic questionnaire, the CRQ developed by the investigators, and the Quality of Life Index (QLI). Significant differences were found between individuals with colon cancer and individuals with rectal cancer on the total CRQ (p < .005) and the physical, future orientation, and role-relationship subscales. For the QLI, significantly lower scores were reported on the family subscale for patients with rectal cancer in comparison with those with colon cancer. More attention to rehabilitation issues and quality of life is required across the trajectory of the cancer experience. With the increasing incidence of colorectal cancer, nurses in rehabilitation practice must address the issues affecting patients with this disease as they progress from diagnosis to treatment and rehabilitation.

Colorectal cancer follow-up in 2005

The main goal in monitoring patients after the treatment of colorectal cancer is to improve survival through the early identification and treatment of metastatic or locally recurrent disease. Although the results of several randomized, controlled trials have identified a survival benefit associated with careful follow-up, specific testing strategies to maximize survival while minimizing cost and patient inconvenience have not been identified. There is, therefore, great variability in the types, number, and frequency of tests ordered to follow these patients. This article reviews the level-I data avail-able regarding the efficacy of follow-up, the specific tests commonly used, and issues of costs and patient satisfaction, and provides a summary of the available societal guidelines concerning colorectal cancer follow-up.

Preoperative serum levels of the carcinoembryonic antigen in hereditary non-polyposis colorectal cancer compared to levels in sporadic colorectal cancer

BACKGROUND

Carcinoembryonic antigen (CEA) serves as the most widely used and most cost-effective tumor marker in colorectal cancer for almost 30 years. Recent publications about serum CEA levels are based on patient groups without definite differentiation between hereditary and non-hereditary forms of colorectal cancer.

PATIENTS AND METHODS

We compared preoperative CEA serum levels from 105 patients with hereditary non-polyposis colorectal cancer (HNPCC) and 107 patients with sporadic colorectal cancer including influences of age and Dukes stage. CEA values in cases of HNPCC were correlated to the findings of microsatellite analyses, mutation analyses of the MMR genes (MLH1, MSH2) and respective immunohistochemistries.

RESULTS

Thirty-three HNPCC patients (31%) and 37 patients with sporadic CRC (34%) revealed elevated CEA levels higher than 5 ng/ml. The mean preoperative CEA level in all Dukes stages of HNPCC patients was lower with 31.7 +/- 180 ng/ml than in sporadic colorectal cancer with 68.3 +/- 424 ng/ml, but without significance (p = 0.72). HNPCC tumors with signs of de-differentiation (G3 and G4) revealed significantly higher CEA values with 62.2 +/- 262 ng/ml in comparison to well-differentiated tumors (G1 and G2) with 5.0 +/- 9.6 ng/ml (p = 0.02). HNPCC patients with "classical characteristics" (high microsatellite instability (MSI), MMR gene mutation, loss of MMR protein expression) had lower preoperative CEA serum levels than those without equivalent genetic alterations, but without reaching statistical significance. CEA levels of HNPCC tumors increased significantly under occurrence of metastases with mean values of 170.3 +/- 343 (p < 0.02).

CONCLUSIONS

Normal preoperative serum CEA levels do not have the same validity for all colorectal cancer patients. Low CEA levels in HNPCC patients could occur due to well-differentiated tumors and should be considered more critically than in sporadic CRC patients. Further studies including comparison of postoperative CEA development are necessary to elucidate the importance of these results.