Non-metastatic Colorectal Cancer Research Articles

Aspirin as Colorectal Cancer Adjuvant Therapy

Men and women who were diagnosed with colorectal cancer and began regular use of aspirin had a lower risk of overall and colorectal-specific cancer mortality compared to patients not using aspirin, according to a study in the August 12, 2009, issue of JAMA. Numerous prospective, observational studies have demonstrated that regular aspirin use is associated with a lower risk of colorectal adenoma or cancer. Data indicate that aspirin is likely, at least in part, to prevent colorectal neoplasia through inhibition of cyclooxygenase-2 (COX-2), which promotes inflammation and cell proliferation, and is overexpressed in the majority of human colorectal cancers. However, the influence of aspirin on survival after a diagnosis of colorectal cancer has remained unknown. Andrew T. Chan, MD, MPH, of Massachusetts General Hospital and Harvard Medical School, Boston, and his colleagues studied the association between aspirin use and survival among 1,279 men and women with nonmetastatic (stage I, II, and III) colorectal cancer who were participating in 2 large, prospective, cohort studies (Nurses' Health Study and the Health Professionals Follow-up Study) that were initiated (in 1980 and 1986, respectively) before cancer diagnosis and followed through June 1, 2008. For participants who were alive through the end of follow-up, the median time of follow-up from the date of diagnosis was 11.8 years. There were 193 total deaths (35%) and 81 colorectal cancer-specific deaths (15%) among 549 participants who regularly used aspirin after a diagnosis of colorectal cancer, compared with 287 (39%) total and 141 (19%) colorectal cancer-specific deaths among 730 participants who did not use aspirin. For the entire cohort, the overall 5-year survival was 88% for participants who used aspirin compared with 83% for those who did not. The corresponding 10-year survival rates were 74% and 69%. Regular aspirin use after diagnosis was associated with a significant reduction in risk of colorectal cancer-specific death and a reduction in overall mortality. Compared with nonusers, regular aspirin use after diagnosis was associated with a 29% lower risk for colorectal-specific mortality and a 21% lower risk for overall mortality. Because the prognosis among stage I participants is generally favorable, the researchers also examined the influence of aspirin use among those diagnosed with stage II or III disease and observed similar results. Among the 719 participants who did not use aspirin before diagnosis, initiation postdiagnosis was associated with a 47% lower risk for colorectal cancer-specific mortality and a 32% lower risk of overall mortality. In contrast, among participants who were using aspirin before diagnosis, continuation of aspirin use postdiagnosis was not associated with a significant reduction in colorectal cancer-specific survival or overall survival. Among participants with tumors that expressed COX-2, regular aspirin use after diagnosis was associated with a 61% lower risk of colorectal cancer-specific death and a 38% lower risk of overall mortality, whereas postdiagnosis aspirin use was not associated with lower risk of either colorectal cancer-specific or overall mortality for those with COX-2–negative tumors. “This supports the hypothesis that COX-2–positive tumors may be relatively sensitive to the anticancer effect of aspirin, whereas COX-2–negative tumors may be relatively aspirin-resistant. Moreover, it potentially explains the observation that the benefit of postdiagnosis aspirin use on patient survival was not apparent among patients who used aspirin prior to cancer diagnosis,” the researchers note. Based on these results, the authors suggest that aspirin may influence the biology of established colorectal tumors in addition to preventing their occurrence. “Our data also highlight the potential for using COX-2 or related markers to tailor aspirin use among patients with newly diagnosed colorectal cancer.”

Colorectal cancer survival following adjuvant chemotherapy with weekly i.v. fluorouracil 425 mg/m2 and folinic acid 50mg

e15089 Background: Adjuvant chemotherapy for colorectal cancer (CRC) using fluorouracil (5FU) and folinic acid (FA) has been proven effective and the QUASAR trial showed that a weekly administration schedule was as effective as, and less toxic than, the same daily doses delivered over 5 days every 4 weeks (the “Mayo regimen”). However the 5FU dose used (370 mg/m2) was lower than in some trials and a higher 5FU dose was considered desirable if tolerated. We therefore implemented a weekly regimen using 5FU 425 mg/m2 and DL-folinic acid 50mg in 2001 and retrospectively evaluated its efficacy and tolerability. Methods: Patients with non-metastatic CRC at assessment by medical oncologists in this institution between 2001 and 2004 were included in the analysis. Data was gathered on patient characteristics, duration of adjuvant chemotherapy and survival. Actuarial survival was calculated using the Kaplan-Meier method. Results: 417 patients (pts) were seen: 181 females, 236 males; median age 67 yrs (24–89); 291 with colon cancer, 126 with rectal cancer; 1 stage 1; 100 stage 2, 316 stage 3. Median follow-up was 6.2 years. 210 pts with colon cancer received adjuvant weekly 5FU/FA (32 stage 2, 178 stage 3) as did 58 pts with rectal cancer (50 of whom also received concurrent chemoradiation). 75% of pts with colon cancer received all 30 planned doses and 59% of rectal cancer pts received all 20 planned doses. 3 year survival for all pts treated with this regimen was 83.0% and for the subgroups with colon and rectal cancer it was 82.4% and 84.5% respectively. For stage 2 and 3 colon cancer pts treated with this regimen 3 year survival was 87.9% and 76.0% respectively; for stage III rectal cancer pts it was 84.1%. Conclusions: These outcomes compare favorably on indirect comparison with results from the QUASAR trial (which reported 3 year survival of 70.6%) and suggest that using a higher 5FU dose in this regimen is tolerable and may be advantageous. No significant financial relationships to disclose.

Long-term supportive treatment with fermented mistletoe (viscum album L.) extract in primary nonmetastatic colorectal cancer: Best time to start with for optimal effectiveness

e15099 Background: Safety and efficacy of fermented mistletoe extract (Iscador, ISC) in supportive care of post-surgical patients with primary colorectal cancer as compared to a parallel control group without ISC. Question: Is supportive ISC most effective when started before, during, or after radio- and/or chemotherapy? Methods: In a comparative, multicenter, non-interventional cohort study with parallel groups ISC was applied additionally to conventional adjuvant chemo- and/or radiotherapy (conv-th). The control group was treated with conv-th only. Unselected, standardized, anonymized data from medical records (1993–2002) meeting the eligibility criteria were followed until last visit or death. The pre-specified endpoints were the incidence of adverse drug reactions (ADR) caused by conv-th, and disease-free survival (DFS) in relation to start of ISC therapy before, during or after conv-th. All endpoints were adjusted to confounders. Results: 804 eligible patients (429 ISC and 375 control) from 26 centers were evaluated. ISC started mostly during conv-th (72.9%), and sometimes before (9.0%) or after (18.1%) conv-th. ISC dose was escalated from 0.01mg to 20mg as s.c. injection, 2–3 times weekly. The median follow-up time was 58 (ISC) vs. 51 months and median ISC duration was 52 months. The adjusted relative ADR risk was significantly lower in the ISC groups as compared to control: odds ratio, OR (95% CI) = 0.46 (0.28–0.77), p=0.003. The best results were found in patients where ISC started in parallel to conv-th. Analysis of DFS in the ISC subgroups is presently ongoing. ISC was well tolerated in all subgroups. Conclusions: The results show reliable safety and clinically relevant beneficial effects of ISC treatment, at best if applied in parallel to conv-th. [Table: see text]

Impact of patient age on quality of care in the treatment of colorectal cancer: Results from the Florida Initiative for Quality Cancer Care (FIQCC)

6548 Background: The quality of colorectal cancer (CRC) treatment has been suggested to vary by age, with older patients receiving poorer quality care. As part of a state-wide quality improvement effort, the FIQCC developed and implemented methods to assess the quality of care of several cancers among practices across the state of Florida. The current report focuses on the variability of adherence to CRC quality indicators for treatment and surveillance by patient age. Methods: Medical chart reviews were conducted of all patients first seen by a medical oncologist for CRC in 2006 at one of the 10 FIQCC sites (2 academic/8 community). Abstractors were trained and periodically monitored. Abstraction focused on assessing adherence to quality indicators consistent with evidence-, consensus-, and regulatory-based guidelines. Variability in adherence across age quartiles was evaluated using a Fisher's exact test. Of the 475 patients whose charts were reviewed, 53% were male, 80% were diagnosed with colon cancer and the median age was 65 years (range 27 to 92 years). Results: Adherence was consistently (p values>.05) high across all age quartiles for presence of chemotherapy flow sheets (85%-93%), assessment of body-surface area (98%-100%) and performance of complete colon evaluation within 12 months of surgery (87%-89%). Moderate-to-low adherence was consistent by age for performance of CEA test before (74%-84%) or in the 6 months after (75%-82%) surgery/chemotherapy, and documentation of planned chemotherapy dose (51%-59%). Adherence decreased with increasing age for documentation of discussion/referral for chemotherapy in non-metastatic CRC cases (100%, 99%, 93%, and 89%; p = 0.001), but was consistently adhered to for all ages among metastatic cases (100%). The documentation of consent for patients treated with chemotherapy also varied by age-quartile (63%. 57%, 79%, and 73%; p = 0.02). Conclusions: Overall quality of CRC treatment was not consistent across the broad spectrum of patient age. Our data suggest age related disparity in the recommendation for adjuvant chemotherapy. Efforts should be made to understand the reasons for these differences and to improve and standardize the quality of CRC care for patients across all age groups. No significant financial relationships to disclose.

T1558 Circulationg Tumor Cells in Portal Venous Blood of Patients with Non-Metastatic Colorectal Cancer: Preliminary Results

T1558 Circulationg Tumor Cells in Portal Venous Blood of Patients with Non-Metastatic Colorectal Cancer: Preliminary Results

Multiplexed Cell Signaling Analysis of Metastatic and Nonmetastatic Colorectal Cancer Reveals COX2-EGFR Signaling Activation as a Potential Prognostic Pathway Biomarker

The identification of prognostic determinants of colorectal cancer (CRC), including prediction of occult metastasis, is of urgent consideration, based on the tremendous differences in outcome and survival between patients who present with metastasis or develop metastasis versus those patients with organ-confined or nonrecurrent disease. Currently, a great deal of attention has been focused on using gene expression profiles of tumor specimens as a launch point for prognostic biomarker discovery. In our study, we chose to focus on functional protein-based pathway biomarkers as a new information archive because it is these proteins that form the functional signaling networks that control cell growth, motility, apoptosis, survival, and differentiation. We used reverse-phase protein microarray analysis of laser capture microdissected CRC tumor specimens to profile broad cell signaling pathways from patients who presented with liver metastasis versus patients who remained recurrence free after follow-up. Our results indicate that members of the EGFR and COX2 signaling pathways appear differentially activated in the primary tumors of patients with synchronous metastatic disease. If validated in larger study sets, this pathway defect might be useful as a prognostic clinical tool as well as a guide to potential therapeutic intervention strategies that target occult disease and/or preventative measure.

Comparative Analysis of Vascular Endothelial Growth Factor-A, C, D Expression in Colorectal Cancer with Liver Metastasis

Purpose: We aimed to investigate the correlations between expressions of angiogenic cytokines VEGF-A, C, D of primary colorectal cancer and liver metastasis. Methods: We examined paraffin-embedded primary colorectal cancer tissue from 45 patients who had liver resection due to colorectal liver metastasis (metastasis group) and 37 patients who had surgical resection due to colorectal cancer only (control group). In the control group, local recurrence and distant metastasis had not occurred. Immunohistochemical staining for VEGF-A, C and D was performed. We analysed the correlations between expression of VEGF-A, C and D in primary colorectal cancer tissues and clinicopathologic parameters. Results: VEGF-A expressions of primary colorectal carcinoma were not different between the two groups. VEGF-C was more frequently expressed in the metastasis group (P=0.008) but VEGF-D was more expressed in the control group (P=0.003). Patients with VEGF-C negative and VEGF-D positive expression were predominant in the control group (P=0.020). Tumor location, T stage, lymph node metastasis and tumor differentiation were not related with the expressions of VEGF-A, C, D but only preoperative CEA was positively correlated with VEGF-A and C expression. Conclusion: Expressions of VEGF-C in primary tumor were more frequent in metastatic colorectal cancer and expressions of VEGF-D were more frequent in nonmetastatic colorectal cancer. More large-scale prospective studies for VEGF-C and D expression in colorectal cancer are necessary.

Insulin, the Insulin-Like Growth Factor Axis, and Mortality in Patients With Nonmetastatic Colorectal Cancer

Obesity, sedentary lifestyle, and Western dietary pattern have been linked to increased risk of cancer recurrence and mortality among patients with surgically resected colorectal cancer. Excess energy balance leads to increased circulating insulin and depressed levels of circulating insulin-like growth factor binding protein (IGFBP) -1, which promote cancer cell growth in preclinical models. Among 373 patients diagnosed with nonmetastatic colorectal cancer between 1991 and 2004, we performed a prospective observational study nested within two large US cohorts to evaluate the association between mortality and prediagnosis circulating C-peptide (a marker of insulin secretion), IGFBP-1, insulin-like growth factor-I (IGF-I), and IGFBP-3. Compared with patients in the bottom quartile, patients in the top quartile of plasma C-peptide had an age-adjusted hazard ratio (HR) for death of 1.87 (95% CI, 1.04 to 3.36; P = .03 for trend), whereas those in the top quartile of circulating IGFBP-1 had a significant reduction in mortality (HR = 0.48; 95% CI, 0.28 to 0.84; P = .02 for trend). Little change in these estimates was noted after adjusting for other covariates known or suspected to influence survival. No associations were noted between mortality and IGF-I or IGFBP-3, which are two components of the IGF axis not closely correlated with lifestyle factors. Among patients with surgically resected colorectal cancer, higher levels of prediagnosis plasma C-peptide and lower levels of prediagnosis plasma IGFBP-1 were associated with increased mortality. Circulating insulin and IGFBP-1 are potential mediators of the association between lifestyle factors and mortality after colorectal cancer resection.

Long-Term Outcomes for Laparoscopic Versus Open Resection of Nonmetastatic Colorectal Cancer

Skepticism prevails over the role of minimally invasive surgery in the treatment of colorectal cancer. Long-term data on the safety and efficacy of this technique remain scarce. A nonrandomized, prospective comparison of laparoscopic colorectal cancer surgery (LS) with open surgery (OS) was undertaken to evaluate long-term survival. A total of 233 patients with nonmetastatic colorectal cancer underwent either a laparoscopic (n = 116) or an open (n = 117) potentially curative resection. Almost all patients between July 1996 and December 2002 were randomized within two consecutive trials; however, prior to this, a significant proportion of patients received open surgery. The primary endpoints were overall survival, disease-free survival, and cumulative disease recurrence. Analysis was by intention to treat. Median follow-up was 40 months for the LS group and 58 months for the OS group. No statistically significant difference was found between the LS and OS groups regarding overall survival (P = 0.603 for colon cancer and P = 0.841 for rectal cancer), disease-free survival (P = 0.684 for colon cancer and P = 0.625 for rectal cancer), and overall recurrence (P = 0.383 for colon cancer and P = 0.166 for rectal cancer). Cumulative recurrence rate in colon cancer favors OS (P = 0.018). In rectal cancer, this did not differ between the two treatment modalities (P = 0.965). Tumor resection margins and lymph node harvest were similar in the two surgery groups. Perioperative mortality in the LS group was also no different from the OS group (P = 0.644 for 30-day mortality and P = 0.692 for in-hospital mortality). Long-term survival data support LS as a safe, effective alternative to conventional surgery for treating potentially curative colorectal cancer. However, the higher cumulative recurrence associated with LS in the colonic cancer group needs further research into its underlying cause.

Local recurrence after curative resection in patients with colon and rectal cancers

There are a range of rates and a number of prognostic factors associated with the local recurrence of colorectal cancer after curative resection. The aim of this study was to identify the potential prognostic factors of local recurrence in patients with colon and rectal cancers. A retrospective review of 1,838 patients who underwent curative resection of non-metastatic colorectal cancer was conducted. The patients were treated between 1994 and 2004, and had a minimum follow-up of 3 years. There were 994 patients with colon cancer and 844 patients with rectal cancer. The median duration of follow-up was 60.9 +/- 24.5 months. With respect to colon cancer, the local recurrence rate was 6.1% (61 patients). With respect to rectal cancer, 95 patients had a local recurrence (11.3%), the rate of which was statistically greater than the local recurrence rate for colon cancer (p < 0.001). The overall recurrence rate was 16.4% (301 patients), and the local recurrence rate, with or without systemic metastases, was 8.5% (156 patients). Local recurrences occurred within 2 and 3 years in 59.9% and 82.4% of the patients, respectively. In patients with colon and rectal cancer, the pathologic T stage (p = 0.044 and p = 0.034, respectively), pathologic N stage (p = 0.001 and p < 0.001, respectively), and lymphovascular invasion (p = 0.013 and p = 0.004, respectively) were adverse risk factors for local recurrence. The level of the anastomosis from the anal verge was an additional prognostic factor (p = 0.007) in patients with rectal cancer. Compulsive follow-up care of patients with colon and rectal cancers is needed for 3 years after curative resection, especially in patients who have adverse risk factors for local recurrence.

Isolated Tumor Cells and Circulating CK20 mRNA in pN0 Colorectal Cancer Patients

Micrometastases in lymph nodes and blood may provide important prognostic information. In this study, cytokeratin 20 (CK20) positive cells in lymph nodes and circulating CK20 mRNA were studied using 57 paraffin-embedded lymph node specimens and blood from 24 patients with pN0 colorectal cancer (CRC), respectively. Results showed that 29 out of 56 (52%) lymph node specimens had CK20-positive cells (range: 1-35). Follow-up of the patients for 12 months indicated that 4 patients (7%) had CRC metastases to liver, lung, and bone. In addition, 8 out of 24 (33%) samples had at least 2-fold circulating CK20 mRNA expression higher than the pooled normal sample. This study provides evidence that CK20-positive cells were found in the lymph nodes and differentially expressed circulating CK20 mRNA was also detected in the blood from patients with pN0 CRC. Long-term follow-up is necessary to study their prognostic use in patients with non-metastatic CRC.

Tenascin‐W, a new marker of cancer stroma, is elevated in sera of colon and breast cancer patients

Tenascins are extracellular matrix proteins present during the development of organisms as well as in pathological conditions. Tenascin-W, the fourth and last member of the tenascin family remains the least well-characterized one. Our study aimed to evaluate the potential significance of tenascin-W as cancer biomarker by monitoring its presence in the serum of colorectal and breast cancer patients and its expression in colorectal tumor tissues. To measure serum tenascin-W levels, a sensitive sandwich-ELISA was established. Mean tenascin-W concentration in sera of patients with nonmetastatic colorectal cancer at time of diagnosis was highly increased compared to that of healthy volunteers. A similar tendency was observed for tenascin-C in the same patient cohort. However, the increase was much more striking for tenascin-W. We also detected elevated tenascin-W levels in sera of breast cancer patients. Furthermore, we could show a prominent expression of tenascin-W in extracts from colorectal tumor tissues by immunoblot analysis, whereas tenascin-W was not detectable in the corresponding normal colon mucosa. To confirm the western blot results, we performed immunohistochemistry of frozen sections of the same patients as well as of an additional, independently chosen collection of colorectal cancer tissues. In all cases, similarly to tenascin-C, tenascin-W was detected in the tumor stroma. Our results reveal a clear association between elevated levels of tenascin-W and the presence of cancer. These results warrant further studies to evaluate the potential value of serum and tissue tenascin-W levels as diagnostic, prognostic or monitoring biomarker in colorectal, breast and possibly other solid cancers.

Coagulation factor levels in non-metastatic colorectal cancer patients.

To determine the plasma concentrations of several coagulation factors and C4b-binding protein (C4BP) in a group of patients with non-metastatic colorectal cancer in order to investigate some aspects of cancer-acquired thrombophilia. Plasma fibrinogen, FII, FV, FVII, FVIII, FIX, FX, FXI and FXII activity levels and C4BP concentrations were determined in 73 patients with non-metastatic colorectal cancer (48 colon and 25 rectum) and in 67 matched control subjects. No one in either group had had previous thrombotic events. Mean plasma concentrations of fibrinogen (functional and antigen), FVIII, FIX, FV and C4BP were significantly higher in colorectal cancer patients than in control subjects, while FVII and FXII levels were significantly decreased. Several correlations were found between the increased coagulation factors and C4BP concentrations, while FVII was highly correlated with FXII. In colorectal cancer patients high plasma fibrinogen, FVIII and FIX levels might represent further risk factors for venous thrombotic complications in the immediate post-surgery period, while decreased FVII and FXII concentrations may be an index of intravascular coagulation activation, still in a subclinical phase.

Coagulation Factor Levels in Non-Metastatic Colorectal Cancer Patients

There is evidence that high plasma levels of factor (F) VIII, FIX, FXI and fibrinogen are independent risk factors for venous thromboembolism. To determine the plasma concentrations of several coagulation factors and C4b-binding protein (C4BP) in a group of patients with non-metastatic colorectal cancer in order to investigate some aspects of cancer-acquired thrombophilia. Plasma fibrinogen, FII, FV, FVII, FVIII, FIX, FX, FXI and FXII activity levels and C4BP concentrations were determined in 73 patients with non-metastatic colorectal cancer (48 colon and 25 rectum) and in 67 matched control subjects. No one in either group had had previous thrombotic events. Mean plasma concentrations of fibrinogen (functional and antigen), FVIII, FIX, FV and C4BP were significantly higher in colorectal cancer patients than in control subjects, while FVII and FXII levels were significantly decreased. Several correlations were found between the increased coagulation factors and C4BP concentrations, while FVII was highly correlated with FXII. In colorectal cancer patients high plasma fibrinogen, FVIII and FIX levels might represent further risk factors for venous thrombotic complications in the immediate post-surgery period, while decreased FVII and FXII concentrations may be an index of intravascular coagulation activation, still in a subclinical phase.

Antiphospholipid Antibodies and Acute-Phase Response in Non-Metastatic Colorectal Cancer Patients

Aim To investigate the plasma levels and prevalence of the most common antiphospholipid antibodies, as well as their relationships with several plasma markers of inflammation, in order to characterize some aspects of cancer thrombophilia. Materials and methods Eighty-three cancer patients with non-metastatic colorectal solid tumors and 94 control subjects were tested for the presence of IgG/IgM/IgA anti-cardiolipin and anti-β2-glycoprotein I antibodies and of several acute-phase reactants, i.e., fibrinogen, factor VIII:C and C4b-binding protein. Results In cancer patients the plasma levels of the acute-phase reactants and the IgA/IgG anti-cardiolipin and IgA anti-β2-glycoprotein I antibodies were significantly higher; the acute-phase reactants were significantly correlated with anti-cardiolipin antibodies; the prevalence of antiphospholipid antibodies was not significantly higher. Conclusions In patients with non-metastatic colorectal cancer the acute-phase response is associated with antiphospholipid generation. This could represent a further pathogenetic mechanism for the short-term post-surgery thrombotic complications of patients with colorectal cancer.

Antiphospholipid antibodies and acute-phase response in non-metastatic colorectal cancer patients.

To investigate the plasma levels and prevalence of the most common antiphospholipid antibodies, as well as their relationships with several plasma markers of inflammation, in order to characterize some aspects of cancer thrombophilia. Eighty-three cancer patients with non-metastatic colorectal solid tumors and 94 control subjects were tested for the presence of IgG/IgM/IgA anti-cardiolipin and anti-Beta2-glycoprotein I antibodies and of several acutephase reactants, i.e., fibrinogen, factor VIII:C and C4b-binding protein. In cancer patients the plasma levels of the acute-phase reactants and the IgA/IgG anti-cardiolipin and IgA anti-Beta2- glycoprotein I antibodies were significantly higher; the acute-phase reactants were significantly correlated with anti-cardiolipin antibodies; the prevalence of antiphospholipid antibodies was not significantly higher. In patients with non-metastatic colorectal cancer the acute-phase response is associated with antiphospholipid generation. This could represent a further pathogenetic mechanism for the short-term post-surgery thrombotic complications of patients with colorectal cancer.

Increased Plasma Superoxide Radical in Patients with Non-Metastatic Colorectal Cancer.

BackgroundSeveral studies have investigated the potential role of oxidative stress in the evolution of colorectal cancer. In most of these studies, oxidative stress was assessed indirectly by measurements of indices like lipid peroxidation, protein oxidation or antioxidant status. The present study was undertaken to directly assess systemic oxidative stress by measuring plasma superoxide radical (O2-·) in patients with non-metastatic colorectal cancer.MethodsTwelve patients (6 males and 6 females) with a recent diagnosis of colorectal cancer and no signs of metastases and 12 healthy volunteers matched for age and gender were enrolled in the study. O2-· levels in plasma were assessed by application of a new ultra-sensitive fluorescent assay. Also lipid peroxidation levels in plasma were measured as thiobarbituric acid reactive species (TBARS).ResultsIn the plasma fraction of whole blood, there was a significant increase (47%) of O2-· levels in colorectal carcinoma patients as compared to healthy volunteers (P < 0.001). In fractionated plasma, no O2-· was detected in both groups. Plasma TBARS levels were increased by 81% in colorectal carcinoma patients as compared to controls (P < 0.001).ConclusionsThese data show that colorectal cancer, even at early (non-metastatic) stages, induces systemic oxidative stress as evidenced by increased O2·- levels measured in plasma. Given the important role of oxidative stress in carcinogenesis and the fact that O2·- is considered its primary parameter, our findings if confirmed in larger studies might establish the potential validity of O2·- as a new biomarker for colorectal cancer.

Proteome analysis of metastatic colorectal cancer cells recognized by the lectin Helix pomatia agglutinin (HPA)

The lectin from Helix pomatia (HPA) binds to adenocarcinomas with a metastatic phenotype but the glycoconjugates of cancer cells that bind to the lectin have yet to be characterized in detail. We used a model of metastatic (HT29) and nonmetastatic (SW480) human colorectal cancer cells and a proteomic approach to identify HPA binding glycoproteins. Cell membrane proteins purified by HPA affinity chromatography, were separated by 2-DE and analyzed by MS. Competitive inhibition experiments with N-acetylgalactosamine, N-acetylglucosamine, and sialic acid confirmed that HPA binding was via a glycan-mediated interaction. Western blot analysis showed that HPA binds to proteins not recognized by an antibody against blood group A epitope. The proteomic study showed the main HPA binding partners include integrin alphav/alpha6 and annexin A2/A4. These proteins were found complexed with microfilament proteins alpha and beta tubulin, actin, and cytokeratins 8 and 18. HPA also bound to Hsp70, Hsp90, TRAP-1, and tumor rejection factor 1. This study revealed that the prognostic utility of HPA lies in its ability to bind simultaneously to many glycoproteins involved in cell migration and signaling, in addition, the proteins recognized by HPA are glycosylated with structures distinct from the blood group A epitope.

Reduced expression of TLR4 is associated with the metastatic status of human colorectal cancer

Signaling mediating colorectal cancer (CRC) progression is incompletely understood. Previously, we identified lipopolysaccharide (LPS), an endotoxin of ubiquitously existing colonic bacteria, as a pivotal stimulus increasing the metastatic potential of human CRC. Since the ubiquitous colonic bacteria release large amounts of LPS this observation could be of enormous relevance for the progression of CRC. In this study we present data contributing to the elucidation of its mode of action. Since both receptors CD14 and TLR4 act as LPS mediators, we determined their expression in various CRC cell lines and in 115 non-metastatic, lymphogenous-metastatic and haematogenous-metastatic CRC specimens. Here we showed that CD14 was not expressed in normal colon epithelium, in non-metastatic and metastatic CRC. Furthermore, we showed that diverse CRC cell lines did not express CD14 under normal conditions and after LPS stimulation. Thus, CD14 can be ruled out as a mediator of LPS-induced signaling related to CRC progression. In contrast, we found that normal colon epithelium and CRC cell lines were positive for TLR4. Furthermore, both lymphogenous and haematogenous metastatic cases showed either loss of expression or strong downregulation of TLR4 as compared to normal tissue and to non-metastatic tumors. We found that LPS stimulation resulted in significant TLR4 upregulation in cells expressing lower constitutive TLR4 levels such as CaCo2, whereas no significant response to LPS was observed in cells characterized by relatively high amounts of constitutive TLR4. Our data suggest that TLR4 expression may be associated with mechanisms preventing CRC progression.

Serum matrix metalloproteinase 7 levels identifies poor prognosis advanced colorectal cancer patients

Metalloproteinase 7 (MMP-7) plays an important role in tumor growth, invasion and dissemination, and is secreted to the media. Because of the close implication of MMP-7 in cancer biology, we sought to define the prognostic significance of serum levels of MMP-7 in metastatic colorectal cancer (CRC) and explore its possible impact in the daily clinical practice. MMP-7 expression was determined by enzyme-linked immunoabsorbent assay. We assessed serum MMP-7 levels in 87 healthy controls, 96 patients with nonmetastatic CRC and 120 patients with advanced CRC. Clinical information was gathered from patient files. Cox proportional hazards model was used to assess survival. MMP-7 and the variables associated with prognosis were entered and a backward elimination method was employed to adjust the model. Inclusion criteria was p </= 0.05 and exclusion criteria was p >/= 0.10. Advanced CRC patients have a significant higher mean serum MMP-7 levels (13.4 ng/ml) than those in nonmetastatic CRC (5.5 ng/ml; p < 0.001) and healthy controls (4.2 ng/ml; p < 0.001). In metastatic patients, after adjusting for other prognostic variables, MMP-7 (entered as a continuous variable) is associated with decreased survival (HR 1.016, IC 95% 1.002-1.031). Serum MMP-7 levels are significantly elevated in patients with advanced CRC. In conclusion, MMP-7 is an independent prognostic factor for survival in advanced CRC. In our sample, the risk of death associated to MMP-7 increase is much higher than the risk of death associated to lactate dehydrogenase elevation.