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.     

Fecal M2-pyruvate kinase (M2-PK): a novel marker of intestinal inflammation

BACKGROUND: Surrogate markers of bowel inflammation are increasingly being recognized as important, not only as markers of disease activity in inflammatory bowel disease (IBD) but also to differentiate irritable bowel syndrome (IBS) from IBD. The dimeric M2-isoform of pyruvate kinase (M2-PK) has been reported to be elevated in fecal specimens from colorectal cancer (CA) patients, but its role in IBD is unknown. This study investigated the usefulness of fecal M2-PK in cohorts of patients with IBD, IBS, and CA. METHODS: Stool samples were obtained for calprotectin and M2-PK measurements in patients with previously diagnosed IBD or new patients being investigated for lower gastrointestinal (GI) symptoms in a UK university hospital. Other investigations were performed as directed by the investigating physician and patients with known IBD were assessed for disease activity by a physician global assessment, Harvey-Bradshaw index (HBI), or endoscopic grading. RESULTS: Fecal M2-PK and calprotectin measurements were obtained for 148 patients: 50 with ulcerative colitis (UC); 31 with Crohn's disease (CD), 43 with irritable bowel syndrome/functional bowel disorders (IBS); 7 with colorectal CA, and 17 with miscellaneous conditions (excluded from the analysis). Median M2-PK values (U/mL) were significantly elevated in UC: 20.0 (95% confidence interval [CI] 5.4-69.0, P < 0.0001), CD: 24.3 (95% CI 6.4-44.0, P < 0.0001), and CA: 7.0 (95% CI 4.3-88.0, P < 0.0006) compared to IBS: 0.1 (95% CI 0.0-3.2). There was a strong linear correlation of M2-PK with calprotectin levels. A predetermined cutoff level of 3.7 U/mL for a normal M2-PK test produced a sensitivity, specificity, and positive predictive value (PPV) of 73%, 74%, and 89%, respectively, for organic disease. Furthermore, M2-PK levels were significantly elevated in active, compared to inactive, disease for CD (30 versus 0.55 U/mL, P < 0.005) and UC (40 versus 1.2 U/mL, P = 0.006), respectively. CONCLUSIONS: Fecal M2-PK is elevated in IBD as well as in CA patients and is a sensitive and relatively specific marker for organic GI pathology, with a PPV of 89%. Furthermore, it appears to be a potentially valuable, noninvasive marker of disease activity in IBD.     

肿瘤M2型丙酮酸激酶在非小细胞肺癌疗效监测中的应用价值

目的研究非小细胞肺癌手术前后血清肿瘤M2型丙酮酸激酶(tumor M2-PK)的应用价值。方法用酶联免疫吸附试验(ELISA)检测56例不同分期的非小细胞肺癌患者手术前后的Tu M2-PK含量的变化并进行分析。结果非小细胞肺癌患者血浆中Tu M2-PK明显高于正常人(P<0.01);非小细胞肺癌患者手术切除和不完全切除血浆中Tu M2-PK均明显低于手术前,无论手术前后,手术切除组血浆Tu M2-PK均显著低于不完全切除组(P<0.01);TNMⅢ期者明显高于Ⅰ、Ⅱ期,有淋巴结转移者显著高于无转移者(P<0.01);而非小细胞肺癌患者的性别、年龄对血浆Tu M2-PK影响无明显差别(P>0.05)。结论血浆Tu M2-PK可成为非小细胞肺癌患者病情监测及预后评估的有效指标。     

Tumor marker M2-pyruvate-kinase in differential diagnosis of chronic pancreatitis and pancreatic cancer

BACKGROUND/AIMS: This study addresses the possibility of very difficult differential diagnosis of pancreatic cancer and chronic pancreatitis, especially in cases where pancreatic cancer appears in the course of chronic pancreatitis. A combination of graphical methods and pancreatic biopsy targeted with endosonography seems to be the most precise diagnostic technique. Even negative findings for this procedure cannot exclude the risk of existing tumor and is additionally an invasive technique. Therefore there are different conditions that have to be fulfilled to allow use of both endoscopic and bioptic instruments (biopsy with biopsy needle). Tumor markers of blood serum are used in the practice, but this use seems to be limited by the sensitivity, which is on the level of 60-70% in average. METHODOLOGY: The authors examined M2-pyruvate-kinase concentration in their group, which included patients with chronic pancreatitis, different grading of pancreatic cancer as well as patients with pancreatic cancer which appeared in the course of chronic pancreatitis. M2-pyruvate-kinase was used as a marker of tumor hyperplasia as it is present in higher concentration in tumors of gastrointestinal tract. RESULTS: The authors observed important growth in advanced forms of pancreatic tumor compared to patients with chronic pancreatitis. M2-PK was increased in a similar way in patients with pancreatic cancer in the course of chronic pancreatitis. The results led to the conclusion that evaluation of M2-PK concentration helps differentiating between pancreatic cancer and chronic pancreatitis, especially in cases where morphological changes of the gland have focal character and are imitating pancreatic cancer.     

A meta-analysis of the diagnostic value of detecting K-ras mutation in pancreatic juice as a molecular marker for pancreatic cancer

BackgroundK-ras codon 12 mutation is one of the earliest genetic changes in the development of pancreatic cancer (PC) and accurate detection of K-ras mutations is gaining increasing attention in the field of molecular diagnosis.MethodsOriginal research articles which evaluated the diagnostic accuracy of K-ras mutation detection in PC were selected. Data were presented as forest plots and summary receiver operating characteristic curve analysis was used to summarize the overall test performance.ResultsWe assessed 16 studies from 15 published articles. The pooled sensitivity and specificity were 59% (95%CI: 54%–64%) and 87% (95%CI: 84%–89%), respectively. The pooled positive likelihood ratio and negative likelihood ratio were 4.13 (95%CI: 2.73–6.25) and 0.42 (95%CI: 0.32–0.56), respectively, and the pooled diagnostic odds ratio was 13.66 (95% CI: 7.25–25.74).ConclusionsOur results indicate that the analysis of K-ras mutations in pancreatic juice has a considerable diagnostic value in PC. Further studies with rigorous design, large sample size, and multi-regional co-operation are needed.     

Tumor angiogenesis as a prognostic predictor in pancreatic cancer

The purpose of this study was to evaluate the role of angiogenesis, proliferative activity (assessed by Ki-67 expression), p53 and ras-oncogene (H-ras) expression, and conventional clinicopathologic factors in predicting overall survival rates in patients with pancreatic ductal adenocarcinoma. We followed-up 22 patients with ductal adenocarcinoma of the pancreas for a median of 19 months (range, 2 to 44 months). Angiogenesis was quantitated as vascular surface density (VSD) and the number of vessels per mm² stroma (NVES) after microvessels were immunostained, using factor VIII-related antigen. p53, H-ras, and Ki-67 proteins were also determined immunohistochemically. VSD and NVES showed significant correlations with increased proliferative activity, poor tumor differentiation, and tumor size of 3 cm or more (P = 0.001, P = 0.013, and P = 0.047, respectively). The overall 2-year survival rate of 33.3% in patients with high VSD and NVES values was significantly worse than that of 66.6% estimated in patients with low microvessel count (log rank, 3.97; P = 0.046). In multivariate analysis using the Cox model, VSD was found to be an independent prognostic factor of survival (P = 0.039). H-ras and p53 expressions were not correlated with angiogenesis parameters. We conclude that, in pancreatic ductal adenocarcinoma, angiogenesis is closely related to tumor growth and patient survival.     

Fecal pancreatic elastase: a reproducible marker for severe exocrine pancreatic insufficiency

Background In order to apply fecal pancreatic elastase for follow-up of exocrine pancreatic function in chronic pancreatitis and cystic fibrosis, we examined the sensitivity, specificity, and long-term variability of a new polyclonal antibody-based enzyme-linked immunosorbent assay (ELISA). Methods Patients with definite chronic pancreatitis (n = 23), probable or possible chronic pancreatitis (n = 14), autoimmune pancreatitis (n = 7), or acute pancreatitis (n = 11), and 51 healthy subjects and 11 healthy infants participated in this study. Pancreatic function was graded as normal (n = 3), mild (n = 18), moderate (n = 9), or severe (n = 18) exocrine insufficiency on the basis of secretin tests. Fecal pancreatic elastase was measured by a new ELISA. Results Fecal pancreatic elastase concentration in control subjects varied widely, with a median of 478 μg/g. The specificity of this test was 90.2% with a cutoff value of >200 μg/g. The sensitivities were 60.9% for detecting definite chronic pancreatitis, 76.5% for calcifying pancreatitis, 71.4% for autoimmune pancreatitis, and 7.1% for probable or possible chronic pancreatitis. The sensitivities were 16.7% for mild, 12.5% for moderate, and 72.2% for severe exocrine pancreatic insufficiency. Forty patients were reexamined after a median interval of 347 days. The fecal pancreatic elastase levels between the first and second tests were not significantly different. Two infants, 4.5 and 5 months old, had abnormally low values, but after a median of 304 days all infants showed normal levels (median, 444 μg/g). Conclusions Fecal pancreatic elastase is a reproducible marker for severe exocrine pancreatic insufficiency. This test is valuable for longitudinal follow-up of exocrine pancreatic function.     

Parathyroid hormone-related protein as a novel tumor marker in pancreatic adenocarcinoma

INTRODUCTION: Parathyroid hormone-related protein (PTHrP) can act as an oncoprotein to regulate the growth and proliferation of many common malignancies, including pancreatic cancer. Previous studies have shown that PTHrP is produced by human pancreatic cancer cell lines, can be shown in the cytoplasm and nucleus of paraffin-embedded pancreatic adenocarcinoma tumor specimens, and is secreted into the media of cultured pancreatic adenocarcinoma cells. We hypothesized that PTHrP could serve as a tumor-marker for growth of pancreatic cancer in vivo. AIM AND METHODOLOGY: To test this hypothesis, we used an orthotopic model developed in our laboratory of the PTHrP-producing human pancreatic cancer line, BxPC-3. This tumor was stably transduced with green fluorescence protein (GFP) to facilitate visualization of tumor growth and metastases. At early (5 weeks) and late (13 weeks) time points after surgical orthotopic implantation, serum PTHrP was measured and primary and metastatic tumor burden was determined for each mouse by assessing GFP expression. RESULTS: By 5 weeks after surgical orthotopic implantation (early group), the mean serum PTHrP level was 33.3 pg/mL. In contrast, by 13 weeks after surgical orthotopic implantation (late group), the mean serum PTHrP level increased to 158.5 pg/mL. These differences were highly significant (p < 0.001, Student t test). Numerous metastatic lesions were readily visualized by GFP in the late group. Serum PTHrP levels measured by immunoassay correlated with primary pancreatic tumor weights and serum calcium levels (p <0.01). PTHrP levels were not detectable (<21 pg/mL) in any of the 10 control mice with no tumor. Western blotting of BxPC-3-GFP tumor lysates confirmed the presence of PTHrP. BxPC-3-GFP tumor tissue stained with antibody to PTHrP. CONCLUSION: These results indicate that PTHrP can serve as a tumor marker in animal models of pancreatic cancer and may be a useful tumor marker for clinical pancreatic adenocarcinoma.     

Faecal pyruvate kinase isoenzyme type M2 for colorectal cancer screening: a meta-analysis

AIM: To present a critical discussion of the efficacy of the faecal pyruvate kinase isoenzyme type M2 (faecal M2-PK) test for colorectal cancer (CRC) screening based on the currently available studies.METHODS: A literature search in PubMed and Embase was conducted using the following search terms: fecal Tumor M2-PK, faecal Tumour M2-PK, fecal M2-PK, faecal M2-PK, fecal pyruvate kinase, faecal pyruvate kinase, pyruvate kinase stool and M2-PK stool.RESULTS: Stool samples from 704 patients with CRC and from 11 412 healthy subjects have been investigated for faecal M2-PK concentrations in seventeen independent studies. The mean faecal M2-PK sensitivity was 80.3%; the specificity was 95.2%. Four studies compared faecal M2-PK head-to-head with guaiac-based faecal occult blood test (gFOBT). Faecal M2-PK demonstrated a sensitivity of 81.1%, whereas the gFOBT detected only 36.9% of the CRCs. Eight independent studies investigated the sensitivity of faecal M2-PK for adenoma (n = 554), with the following sensitivities: adenoma < 1 cm in diameter: 25%; adenoma > 1 cm: 44%; adenoma of unspecified diameter: 51%. In a direct comparison with gFOBT of adenoma > 1 cm in diameter, 47% tested positive with the faecal M2-PK test, whereas the gFOBT detected only 27%.CONCLUSION: We recommend faecal M2-PK as a routine test for CRC screening. Faecal M2-PK closes a gap in clinical practice because it detects bleeding and non-bleeding tumors and adenoma with high sensitivity and specificity.     

Pancreatic amylase as a tumour marker for pancreatic cancer

Pancreatic cancer was induced in male Sprague-Dawley rats by 7,12-dimethylbenz(a)anthracene. Pancreatic amylase has been purified from normal as well as treated rats after 2, 3 and 4 months of exposure to the carcinogen. The level of pancreatic amylase in rats with pancreatic carcinoma was significantly decreased (L.S.D.-5.25). Purified enzyme was then subjected to disc gel electrophoresis. Both normal and treated rats gave the same electrophoretic pattern (three bands: two major, and one minor). Therefore, there was no isoenzyme component in pancreatic extracts of rats bearing pancreatic cancer that could be held to be peculiar for pancreatic cancer. Histological findings showed a decrease in zymogen content together with its total absence in some areas of malignant cells. The data obtained suggested that the original carcinogenic events were associated with a decrease in amylase initial activity, and did not involve alteration in gene expression related to amylase biosynthesis.     

Tumor type M2 pyruvate kinase expression in gastric cancer,colorectal cancer and controls

AIM: Tumor formation is generally linked to an expansionof glycolytic phosphometabolite pools and aerobic glycolyticflux rates.To achieve this,tumor cells generally overexpressa special glycolytic isoenzyme,termed pyruvate kinase typeM_2.The present study was designed to evaluate the useof a new tumor marker,tumor M_2-PK,in discriminatinggastrointestinal cancer patients from healthy controls,andto compare with the reference tumor markers CEA andCA72-4.METHODS: The concentration of tumor M2-PK in body fluidscould be quantitatively determined by a commerciallyavailable enzyme-linked immunosorbent assay (ELISA)-kit(ScheBo(?) Tech,Giessen,Germany).By using this kit,thetumor M_2-PK concentration was measured in EDTA-plasmaof 108 patients.For the healthy blood donors a cut-offvalue of 15 U/mL was evaluated,which corresponded to90% specificity.Overall 108 patients were included in thisstudy,54 patients had a histological confirmed gastriccancer,54 patients colorectal cancer,and 20 healthyvolunteers served as controls.RESULTS: The cut-off value to discriminate patients fromcontrols was established at 15 U/mL for tumor M_2-PK.Themean tumor M_2-PK concentration of gastric cancer was26.937 U/mL.According to the TNM stage system,the meantumor M_2-PK concentration of stage Ⅰ was 16.324 U/mL,ofstage Ⅱ 15.290 U/mL,of stage Ⅲ 30.289 U/mL,of stage Ⅳ127.31 U/mL,of non-metastasis 12.854 U/mL and of metastasis35.711 U/mL.The mean Tumor M_2-PK concentration ofcolorectal cancer was 30.588 U/mL.According to the Dukesstage system,the mean tumor M_2-PK concentration ofDukes A was 16.638 U/mL,of Dukes B 22.070 U/mL,andof Dukes C 48.024 U/mL,of non-metastasis 19.501 U/mL,ofmetastasis 49.437 U/mE The mean tumor M_2-PK concentrationallowed a significant discrimination of colorectal cancers(30.588 U/mL) from controls (10.965 U/mL) (P<0.01),andgastric cancer (26.937 U/mL) from controls (10.965 U/mL)(P<0.05).The overall sensitivity of tumor M_2-PK for colorectalcancer was 68.52%,while that of CEA was 43.12%.Ingastric cancer,tumor M_2-PK showed a high sensitivity of50.47%,while CA72-4 showed a sensitivity of 35.37%. CONCLUSION: Tumor M_2-PK has a higher sensitivity thanmarkers CEA and CA72-4,and is a valuable tumor markerfor the detection of gastrointestinal cancer.     

Tumor type M2 pyruvate kinase expression in gastric cancer, colorectal cancer and controls

AIM: Tumor formation is generally linked to an expansion of glycolytic phosphometabolite pools and aerobic glycolytic flux rates. To achieve this, tumor cells generally overexpress a special glycolytic isoenzyme, termed pyruvate kinase type M2. The present study was designed to evaluate the use of a new tumor marker, tumor M2-PK, in discriminating gastrointestinal cancer patients from healthy controls, and to compare with the reference tumor markers CEA and CA72-4. METHODS: The concentration of tumor M2-PK in body fluids could be quantitatively determined by a commercially available enzyme-linked immunosorbent assay (ELISA)-kit (ScheBo(R) Tech, Giessen, Germany). By using this kit, the tumor M2-PK concentration was measured in EDTA-plasma of 108 patients. For the healthy blood donors a cut-off value of 15 U/mL was evaluated, which corresponded to 90% specificity. Overall 108 patients were included in this study, 54 patients had a histological confirmed gastric cancer, 54 patients colorectal cancer, and 20 healthy volunteers served as controls. RESULTS: The cut-off value to discriminate patients from controls was established at 15 U/mL for tumor M2-PK. The mean tumor M2-PK concentration of gastric cancer was 26.937 U/mL. According to the TNM stage system, the mean tumor M2-PK concentration of stage I was 16.324 U/mL, of stage II 15.290 U/mL, of stage Ⅲ 30.289 U/mL, of stage IV 127.31 U/mL, of non-metastasis 12.854 U/mL and of metastasis 35.711 U/mL. The mean Tumor M2-PK concentration of colorectal cancer was 30.588 U/mL. According to the Dukes stage system, the mean tumor M2-PK concentration of Dukes A was 16.638 U/mL, of Dukes B 22.070 U/mL, and of Dukes C 48.024 U/mL, of non-metastasis 19.501 U/mL, of metastasis 49.437 U/mL. The mean tumor M2-PK conoentration allowed a significant discrimination of colorectal cancers(30.588 U/mL) from controls (10.965 U/mL) (P&lt;0.01), and gastric cancer (26.937 U/mL) from controls (10.965 U/mL)(P&lt;0.05). The overall sensitivity of tumor M2-PK for colorectal cancer was 68.52%, while that of CEA was 43.12%. In gastric cancer, tumor M2-PK showed a high sensitivity of 50.47%, while CA72-4 showed a sensitivity of 35.37%. CONCLUSION: Tumor M2-PK has a higher sensitivity than markers CEA and CA72-4, and is a valuable tumor marker for the detection of gastrointestinal cancer.     

Newly diagnosed type 2 diabetes may serve as a potential marker for pancreatic cancer

Pancreatic cancer has an extremely highly case fatality. Diabetes is a well‐established strong risk factor for pancreatic cancer. Compared with a nondiabetic population, we previously reported a 15‐ and 14‐fold greater risk for detecting pancreatic cancer during the first year after diagnosing diabetes in adult women and men, respectively, which dropped during the second year to 5.4‐fold and 3.5‐fold, respectively, and stabilized around 3‐fold for the rest of the 11‐year follow‐up in our historical cohort. The population attributable risk during the 11‐year period was 13.3% and 14.1% in prevalent diabetic women and men, respectively. This means that one out of about every 8 patients diagnosed with pancreatic cancer has been previously diagnosed with diabetes. The globally high prevalence of diabetes and the aggravating implications of a delayed pancreatic cancer diagnosis call for newly‐onset diabetes to be considered a potential marker for an underlying pancreatic cancer and addressed accordingly.     

肿瘤M2型丙酮酸激酶在结直肠癌粪便筛查中的临床价值

目的:评估一种新的肿瘤标志物—肿瘤M_2型丙酮酸激酶(Tumor M_2-PK)在结直肠癌粪便筛查中的诊断价值.方法:采集80例结直肠癌患者以及80例正常健康对照者的粪便,用酶结合免疫吸附测定(ELISA)法检测粪便中Tumor M_2-PK值,并进行比较分析.结果:结肠癌患者粪便中Tumor M_2-PK的整体水平(713.41μkat/L)显著高于健康人群(59.55μkat/L)(P<0.0001),其总体敏感性为77.5%,总体特异性为92.5%(正常值定为<166.7μkat/L).随着结肠癌的进展和转移,Tumor M_2-PK检测值随之升高,检测的敏感性也随之升高,11例Dukes A期患者的Tumor M_2-PK平均值为233.53μkat/L,敏感性为63.64%;37例Dukes B期患者为522.58μkat/L,敏感性为75.68%;25例Dukes C期患者为847.27μkat/L,敏感性为84%;7例Dukes D期患者为1998.04μkat/L敏感性为85.71%.结论:Tumor M_2-PK在粪便中的检测可以区别大部分的结肠患者和健康人群,且其敏感性明显高于粪便潜血实验,他将适用于人群普查和绝大多数有亚临床症状患者的早期诊断.