warfarin and Colorectal-Neoplasms

Endoscopic removal of colorectal adenoma is considered an effective treatment for reducing the mortality rates associated with colorectal cancer. Warfarin, a type of anticoagulant, is widely used for the treatment and prevention of thromboembolism; however, bleeding may increase with its administration after polypectomy. In recent times, a high incidence of bleeding after endoscopic polypectomy has been reported in patients receiving heparin bridge therapy. However, previous studies have not compared the bleeding rate after endoscopic colorectal polypectomy between patients who continued with anticoagulant therapy and those who received heparin bridge therapy. We hypothesised that endoscopic colorectal polypectomy under the novel treatment with continuous warfarin is not inferior to endoscopic colorectal polypectomy under standard treatment with heparin bridge therapy with respect to the rate of postoperative bleeding. This study aims to compare the efficacy of endoscopic colorectal polypectomy with continuous warfarin administration and endoscopic colorectal polypectomy with heparin bridge therapy with respect to the rate of postoperative bleeding.. We will conduct a prospective multicentre randomised controlled non-inferiority trial of two parallel groups. We will compare patients scheduled to undergo colorectal polypectomy under anticoagulant therapy with warfarin. There will be 2 groups, namely, a standard treatment group (heparin bridge therapy) and the experimental treatment group (continued anticoagulant therapy). The primary outcome measure is the rate of postoperative bleeding. On the contrary, the secondary outcomes include the rate of cumulative bleeding, rate of overt haemorrhage (that does not qualify for the definition of haemorrhage after endoscopic polypectomy), incidence of haemorrhage requiring haemostasis during endoscopic polypectomy, intraoperative bleeding during endoscopic colorectal polypectomy requiring angiography, abdominal surgery and/or blood transfusion, total rate of bleeding, risk factors for postoperative bleeding, length of hospital stay, incidence of thromboembolism, prothrombin time-international ratio (PT-INR) 28 days after the surgery, and incidence of serious adverse events.. The results of this randomised controlled trial will provide valuable information for the standardisation of management of anticoagulants in patients scheduled to undergo colorectal polypectomy.. UMIN-CTR UMIN000023720 . Registered on 22 August 2016.

Topics: Anticoagulants; Colorectal Neoplasms; Heparin; Humans; Multicenter Studies as Topic; Postoperative Hemorrhage; Prospective Studies; Randomized Controlled Trials as Topic; Warfarin

The bleeding risk after cold snare polypectomy in anticoagulated patients is not known.. To compare the bleeding risk after cold snare polypectomy or conventional polypectomy for small colorectal polyps in anticoagulated patients.. Prospective randomized controlled study.. Municipal hospital in Japan.. Anticoagulated patients with colorectal polyps up to 10 mm in diameter were enrolled. Patients were randomized to polypectomy with either cold snare technique (Cold group) or conventional polypectomy (Conventional group) without discontinuation of warfarin. The primary outcome measure was delayed bleeding (ie, requiring endoscopic intervention within 2 weeks after polypectomy). Secondary outcome measures were immediate bleeding and retrieval rate of colorectal polyps.. Seventy patients were randomized (159 polyps): Cold group (n = 35, 78 polyps) and Conventional group (n = 35; 81 polyps). The patients' demographic characteristics including international normalized ratio and the number, size, and shape of polyps removed were similar between the 2 techniques. Immediate bleeding during the procedure was more common with conventional polypectomy (23% [8/35]) compared with cold polypectomy (5.7% [2/35]) (P = .042). No delayed bleeding occurred in the Cold group, whereas 5 patients (14%) required endoscopic hemostasis in the Conventional group (P = .027). Complete polyp retrieval rates were identical (94% [73/78] vs 93% [75/81]). The presence of histologically demonstrated injured arteries in the submucosal layer with cold snare was significantly less than with conventional snare (22% vs 39%, P = .023).. Small sample size, single-center study.. Delayed bleeding requiring hemostasis occurred significantly less commonly after cold snare polypectomy than conventional polypectomy despite continuation of anticoagulants. Cold snare polypectomy is preferred for removal of small colorectal polyps in anticoagulated patients. (. NCT 01553565.).

Topics: Adenoma; Aged; Aged, 80 and over; Anticoagulants; Arteries; Blood Loss, Surgical; Colon; Colonic Polyps; Colonoscopy; Colorectal Neoplasms; Female; Hemostasis, Endoscopic; Humans; International Normalized Ratio; Male; Middle Aged; Postoperative Hemorrhage; Rectum; Vascular System Injuries; Warfarin

Plasma warfarin and its R,S enantiomer concentrations, one-stage prothrombin times, and mean daily warfarin doses were analyzed in 196 patients given warfarin. These individuals were part of a controlled clinical trial that examined the effect of warfarin as an adjuvant to "standard" treatment in a variety of malignancies. Neither the plasma warfarin concentration nor the daily warfarin dose required to produce a given degree of prothrombin-time prolongation was influenced by age or body weight in these subjects. When the data were analyzed by performance status, we noted several variations of interest. Individuals with different tumor types demonstrated disparities in warfarin disposition. Patients with colorectal cancer, for example, required lower mean daily warfarin doses to achieve a given degree of one-stage prothrombin time prolongation. Analysis of warfarin enantiomers (R,S) in a selected group of patients demonstrated a lower-than-normal ratio (2:1) for the colorectal cancer group (1.42:1) because of an apparent decrease in the plasma R component. In contrast, patients with head and neck cancer demonstrated a ratio of 2.85:1, and the R component was elevated. Warfarin disposition and the effect of warfarin on vitamin K-dependent clotting factor production were altered in the patients with cancer reported in this study. The mechanisms for these alterations are complex and not completely understood.

Topics: Aging; Body Weight; Colorectal Neoplasms; Head and Neck Neoplasms; Humans; Neoplasms; Prospective Studies; Prothrombin Time; Psychomotor Performance; Stereoisomerism; United States; United States Department of Veterans Affairs; Warfarin

To clarify whether antithrombotic drugs affect diagnosis using the immunochemical faecal occult blood test -(iFOBT) of colorectal neoplasia.. Using the Japan Endoscopy Database from 8 centres between 2015 and 2017, we analyzed data about patients who were iFOBT positive and had received direct oral anticoagulants (DOAC), warfarin, aspirin or thienopyridine. One-to-one matching-analogue propensity score weighted analyses were performed to compare the positive predictive value (PPV) of all neoplasms, invasive and non-invasive colorectal cancers and adenomas between drug users and non-users. All neoplasms included invasive and non-invasive colorectal cancer, and adenomas.. We analyzed 197 DOAC users and 196 non-users, 153 warfarin users and 153 non-users, 408 aspirin users and 415 non-users, and 97 thienopyridine users and 97 non-users. No significant differences were observed in the PPV for all neoplasms (56.67 vs. 50.43%), invasive cancer (4.32 vs. 3.53%), non-invasive cancer (15.58 vs. 15.56%) or adenoma (53.13 vs. 48.09%) between the DOAC user and non-user groups. No significant differences were observed in the PPV for all neoplasia, invasive and non-invasive cancer, or adenoma between warfarin, aspirin and thienopyridine use and non-users.. DOAC, warfarin, aspirin and thienopyridine use did not decrease the PPVs of the iFOBT used to evaluate all colorectal neoplasia.

Topics: Adenoma; Administration, Oral; Aged; Aged, 80 and over; Anticoagulants; Aspirin; Case-Control Studies; Colonoscopy; Colorectal Neoplasms; False Positive Reactions; Feces; Female; Humans; Japan; Male; Mass Screening; Middle Aged; Occult Blood; Predictive Value of Tests; Prospective Studies; Pyridines; Retrospective Studies; Warfarin

The fecal immunochemical test (FIT) is the tool most frequently used for colorectal cancer (CRC) screening worldwide. It is unclear how the use of aspirin and oral anticoagulants in the screening population affects the diagnostic performance of FIT.. We performed a cross-sectional study in an ongoing CRC screening trial in Norway. Participants aged 50-74 years with a positive result from an FIT (>15 μg hemoglobin/g feces) and subsequent colonoscopy (reference standard) were included. Those who used regular aspirin, warfarin, or direct-acting oral anticoagulants (DOACs) were defined as users. Non-users were matched according to age, sex, screening center, and screening round. The primary outcomes were the positive predictive value (PPV) for CRC and advanced adenoma.. Among 4908 eligible participants, 1008 used aspirin, 147 used warfarin, 212 used DOACs, and 3541 were non-users. CRCs were found in 234 individuals and advanced adenomas in 1305 individuals. The PPV for CRC was 3.8% for aspirin users vs 6.4% for matched non-users (P = .006), The PPV for advanced adenoma in aspirin users was 27.2% vs 32.6% for matched non-users (P = .011). For DOAC, the PPV for CRC was 0.9% in users vs 6.8% in matched non-users (P = .001). The PPV for advanced adenoma in DOAC users was 20.5% vs 32.4% in matched non-users (P = .002). There was no significant difference in PPV for CRC or advanced adenoma in warfarin users compared to non-users.. In a large screening cohort in Norway, regular use of aspirin and particularly DOACs, were associated with lower PPV of FIT for detection of CRCs and advanced adenomas. ClinicalTrials.gov ID NCT01538550.

Topics: Adenoma; Administration, Oral; Aged; Anticoagulants; Aspirin; Colonoscopy; Colorectal Neoplasms; Cross-Sectional Studies; Early Detection of Cancer; Female; Humans; Immunochemistry; Male; Middle Aged; Occult Blood; Platelet Aggregation Inhibitors; Predictive Value of Tests; Warfarin

Balancing the risks for thromboembolism and postpolypectomy bleeding in patients requiring anticoagulation and antiplatelet agents is challenging. We investigated the incidence and risk factors for postpolypectomy bleeding on anticoagulation, including heparin bridge and other antithrombotic therapy.. We performed a retrospective cohort and case control study at 2 tertiary-care medical centers from 2004 to 2012. Cases included male patients on antithrombotics with hematochezia after polypectomy. Nonbleeding controls were matched to cases 3 to 1 by antithrombotic type, study site, polypectomy technique, and year of procedure. Our outcomes were the incidence and risk factors for postpolypectomy bleeding.. There were 59 cases and 174 matched controls. Postpolypectomy bleeding occurred in 14.9% on bridge anticoagulation. This was significantly higher than the overall incidence of bleeding on antithrombotics at 1.19% (95% confidence interval, 0.91%-1.54%) (59/4923). We identified similarly low rates of bleeding in patients taking warfarin (0.66%), clopidogrel (0.84%), and aspirin (0.92%). Patients who bled tended to have larger polyps (13.9 vs 7.3 mm; P < .001) and more polyps ≥2 cm (41% vs 10%; P < .001). Bleeding risk was increased with restarting antithrombotics within 1 week postpolypectomy (odds ratio [OR] 4.50; P < .001), having polyps ≥2 cm (OR 5.94; P < .001), performing right-sided cautery (OR 2.61; P = .004), and having multiple large polyps (OR 2.92; P = .001). Among patients on warfarin, the presence of bridge anticoagulation was an independent risk factor for postpolypectomy bleeding (OR 12.27; P = .0001).. We conclude that bridge anticoagulation is associated with a high incidence of postpolypectomy bleeding and is an independent risk factor for hemorrhage compared with patients taking warfarin alone. A higher threshold to use bridge anticoagulation should be considered in patients with an elevated bleeding risk.

Topics: Aged; Anticoagulants; Aspirin; Case-Control Studies; Clopidogrel; Colonic Polyps; Colonoscopy; Colorectal Neoplasms; Female; Gastrointestinal Hemorrhage; Heparin, Low-Molecular-Weight; Humans; Incidence; Male; Middle Aged; Platelet Aggregation Inhibitors; Postoperative Hemorrhage; Retrospective Studies; Risk Factors; Thromboembolism; Ticlopidine; Time Factors; Warfarin

Few large studies have evaluated the adverse events associated with therapeutic colonoscopy for colorectal neoplasia, including bleeding and bowel perforation. Our aim was to investigate factors associated with these events, using a Japanese national inpatient database.. We extracted data from the nationwide Japan Diagnosis Procedure Combination database for patients who underwent therapeutic colonoscopy for colorectal neoplasia between 2013 and 2014. Therapeutic colonoscopy included endoscopic submucosal dissection (ESD), EMR, and polypectomy. Outcomes included bleeding, perforation, cerebro-cardiovascular events, and in-hospital death. A multivariable logistic regression model was used to evaluate factors associated with bleeding and bowel perforation.. We analyzed 345,546 patients, including 16,812 (4.9%) who underwent ESD, 219,848 (63.6%) who underwent EMR, and 108,886 (31.5%) who underwent polypectomy. The rates of bleeding, bowel perforation, cardiovascular events, cerebrovascular events, and death were 32.5, 0.47, 0.05, 0.88, and 1.32 per 1000 patients, respectively. In the multivariate analysis, a higher bleeding rate was associated with being male, comorbid diseases, ESD, tumor size ≥2 cm, and use of drugs including low-dose aspirin, thienopyridines, non-aspirin antiplatelet drugs, novel oral anticoagulants, warfarin, non-steroidal anti-inflammatory drugs (NSAIDs), and steroids. A higher bowel perforation rate was associated with being male, renal disease, ESD, tumor size ≥2 cm, and drugs including warfarin, NSAIDs, and steroids.. Although the incidence of adverse events after therapeutic colonoscopy was low, several patient-related factors were significantly associated with bleeding and bowel perforation.

Topics: Adult; Aged; Aged, 80 and over; Anti-Inflammatory Agents, Non-Steroidal; Anticoagulants; Aspirin; Cerebrovascular Disorders; Colonic Polyps; Colonoscopy; Colorectal Neoplasms; Comorbidity; Endoscopic Mucosal Resection; Female; Gastrointestinal Hemorrhage; Hospital Mortality; Humans; Incidence; Intestinal Perforation; Japan; Kidney Diseases; Male; Middle Aged; Platelet Aggregation Inhibitors; Retrospective Studies; Risk Factors; Sex Factors; Steroids; Tumor Burden; Warfarin

Pre-clinical studies suggest that oral anticoagulant agents, such as warfarin, may inhibit metastases and potentially prolong survival in cancer patients. However, few population-based studies have examined the association between warfarin use and cancer-specific mortality.. Using prescribing, cause of death, and cancer registration data from the UK Clinical Practice Research Datalink, four population-based cohorts were constructed, comprising breast, colorectal, lung, and prostate cancer patients diagnosed between 1 January 1998, and the 31 December 2010. Comparing pre-diagnostic warfarin users to non-users, multivariable Cox proportional hazard models were used to estimate hazard ratios (HRs) and 95 % confidence intervals (CIs) for cancer-specific mortality.. Overall, 16,525 breast, 12,902 colorectal, 12,296 lung, and 12,772 prostate cancers were included. Pre-diagnostic warfarin use ranged from 2.4 to 4.7 %. There was little evidence of any strong association between warfarin use pre-diagnosis and cancer-specific mortality in prostate (adjusted HR 1.03, 95 % CI 0.84-1.26), lung (adjusted HR 1.06, 95 % CI 0.96-1.16), breast (adjusted HR 0.81, 95 % CI 0.62-1.07), or colorectal (adjusted HR 0.88, 95 % CI 0.77-1.01) cancer patients. Dose-response analyses did not reveal consistent evidence of reductions in users of warfarin defined by the number of prescriptions used and daily defined doses.. There was little evidence of associations between pre-diagnostic use of warfarin and cancer-specific mortality in lung, prostate, breast, or colorectal cancer patients.

Topics: Administration, Oral; Adult; Aged; Aged, 80 and over; Anticoagulants; Breast Neoplasms; Cohort Studies; Colorectal Neoplasms; Databases, Factual; Female; Humans; Incidence; Lung Neoplasms; Male; Middle Aged; Neoplasm Metastasis; Proportional Hazards Models; Prostatic Neoplasms; Warfarin

We used the prothrombin time international normalized ratio(PT-INR)to investigate the change in degree and term of warfarin following co-administration and after discontinuation of capecitabine. In this study, approximately 3 years of medical records of 7 patients receiving co-administration therapy of warfarin and capecitabine were obtained from 4 hospitals. We observed daily increases in PT-INR values up to peak PT-INR levels following co-administration of warfarin and capecitabine. Interestingly, the peak PT-INR values of 4 of the patients remained remarkably high despite discontinuation of capecitabine. The peak PT-INR values for concomitant warfarin and capecitabine were attained after an average of 31.3 days of usage. When compared with the average PT-INR values attained before co-administration, the PT-INR values following co-administration significantly increased by 3 times (p<0.05). After discontinuation of capecitabine for an average of 15.1 days, i. e., for approximately 14 days, the PT-INR values returned to the PT-INR values attained prior to co-administration. These results suggest that capecitabine has influence on the anticoagulant effect of warfarin during not only the co-administered term but also the discontinuation term, and that this influence occasionally continues after discontinuation of capecitabine. These findings also suggest that a period of approximately 14 days after discontinuation is necessary for the interaction of capecitabine to dissipate and the PT-INR values to return the levels attained before receiving concomitant warfarin and capecitabine.

Topics: Aged; Antineoplastic Combined Chemotherapy Protocols; Breast Neoplasms; Capecitabine; Colorectal Neoplasms; Deoxycytidine; Female; Fluorouracil; Humans; Male; Retrospective Studies; Treatment Outcome; Warfarin

Little is known about the major presenting features of patients with colorectal cancer (CRC) in a population-based setting, especially regarding bleeding-related symptoms.. To determine the proportion of CRC patients presenting with bleeding-related symptoms, to compare bleeders and nonbleeders and to explore the role of anticoagulants in bleeders.. This was a nationwide, population-based, retrospective study, investigating all patients diagnosed with CRC in Iceland from 2008 to 2011. Bleeding-related symptoms were defined as overt bleeding, iron deficiency anaemia or a positive faecal occult blood test. Obstructive symptoms were defined as a confirmed diagnosis of ileus or dilated intestines on imaging.. Data were available for 472/496 (95%) patients, males 51%, mean age 69 (±13) years. In all, 348 (74%) patients had bleeding-related symptoms; of these 348 patients, 61% had overt bleeding. Bleeders were less likely than nonbleeders to have metastases at diagnosis, 19% vs. 34% (P < 0.001). Overt bleeders were less likely than nonbleeders to have obstructive symptoms, 2% vs. 16% respectively (P < 0.0001). Occult bleeders were more likely to have proximal cancer (69%) than both overt (17%) and nonbleeders (44%) (P < 0.0001); however, they were less likely than nonbleeders to have metastases (22% vs. 35%, P < 0.05). Bleeders were more likely to use warfarin than nonbleeders (9% vs. 3%, P < 0.05); the use of low-dose aspirin was the same (24%).. The majority of patients with CRC present with bleeding-related symptoms. Bleeders with CRC present earlier than nonbleeders. Warfarin use may induce bleeding in some patients, resulting in an earlier diagnosis.

Topics: Aged; Aged, 80 and over; Anemia, Iron-Deficiency; Anticoagulants; Aspirin; Colorectal Neoplasms; Female; Gastrointestinal Hemorrhage; Hemorrhage; Humans; Iceland; Male; Middle Aged; Occult Blood; Retrospective Studies; Warfarin

Topics: Adenoma; Adenomatous Polyps; Anticoagulants; Aspirin; Coffee; Colonic Polyps; Colonoscopy; Colorectal Neoplasms; Female; Heart Failure; Humans; Male; Mortality; Platelet Aggregation Inhibitors; Warfarin

The risk of serious complications after colonoscopy has important implications for the overall benefits of colorectal cancer screening programs. We evaluated the incidence of serious complications within 30 days after screening or surveillance colonoscopies in diverse clinical settings and sought to identify potential risk factors for complications.. Patients age 40 and over undergoing colonoscopy for screening, surveillance, or evaluation based an abnormal result from another screening test were enrolled through the National Endoscopic Database (CORI). Patients completed a standardized telephone interview approximately 7 and 30 days after their colonoscopy. We estimated the incidence of serious complications within 30 days of colonoscopy and identified risk factors associated with complications using logistic regression analyses.. We enrolled 21,375 patients. Gastrointestinal bleeding requiring hospitalization occurred in 34 patients (incidence 1.59/1000 exams; 95% confidence interval [CI], 1.10-2.22). Perforations occurred in 4 patients (0.19/1000 exams; 95% CI, 0.05-0.48), diverticulitis requiring hospitalization in 5 patients (0.23/1000 exams; 95% CI, 0.08-0.54), and postpolypectomy syndrome in 2 patients (0.09/1000 exams; 95% CI, 0.02-0.30). The overall incidence of complications directly related to colonoscopy was 2.01 per 1000 exams (95% CI, 1.46-2.71). Two of the 4 perforations occurred without biopsy or polypectomy. The risk of complications increased with preprocedure warfarin use and performance of polypectomy with cautery.. Complications after screening or surveillance colonoscopy are uncommon. Risk factors for complications include warfarin use and polypectomy with cautery.

Topics: Adult; Aged; Aged, 80 and over; Colonoscopy; Colorectal Neoplasms; Female; Humans; Incidence; Interviews as Topic; Intestinal Polyps; Male; Mass Screening; Middle Aged; Risk Factors; Time Factors; Warfarin

Antithrombotic drugs such as warfarin cause a general increase in bleeding tendency and therefore could influence fecal occult blood test results.. A population-based retrospective cohort study was conducted to investigate the performance of the fecal occult blood test for colorectal cancer screening in patients taking warfarin. The study population included 1356 tests performed in warfarin-treated patients and 64,088 tests in those not taking antithrombotics. Data on lower gastrointestinal evaluation were collected on 425 cases with a positive fecal occult blood test: all positives on warfarin and positive cases of a subsample of those tests in the group without antithrombotic treatment.. The positivity rate of the fecal occult blood test in the warfarin group was found to be doubled (7.7% (95%CI, 6.3%-9.2%)) compared with those not taking antithrombotics (3.6% (95%CI, 3.4%-3.7%)) (P <.0001). No significant difference in the positive predictive value for carcinoma and significant adenomas was found comparing the warfarin group to the no-antithrombotic group. The detection rates of both clinically significant adenomas and findings not indicative of significant neoplasia were increased in the warfarin group (8.9/1000 and 32.5/1000 respectively) compared with the no-antithrombotic group (4.0/1000 and 11.3/1000) (P = .02 and P <.0001 respectively), whereas that of carcinoma was not found to be different (3.7/1000 in the warfarin group vs 3.3/1000, P = .85).. Fecal occult blood test screening in warfarin users results in a higher, yet reasonable, positivity load and in a higher detection of premalignant lesions than in the general population. We consider fecal occult blood test screening appropriate for the warfarin-taking population.

Topics: Aged; Anticoagulants; Colorectal Neoplasms; Diagnosis, Differential; Female; Follow-Up Studies; Gastrointestinal Hemorrhage; Humans; Incidence; Israel; Male; Mass Screening; Middle Aged; Occult Blood; Retrospective Studies; Thrombosis; Warfarin

The fecal occult blood test (FOBT) is widely used for colorectal cancer screening. However, the impact of warfarin use on FOBT sensitivity and specificity remains unclear. This study compares the relative risk of neoplasia in FOBT-positive patients stratified by warfarin use.. The Clinical Outcomes Research Initiative database was used to identify patients with positive FOBT as the only indication for colonoscopy during 2005-2006. Patients were categorized on the basis of documented warfarin status within a 30-day period before FOBT. We compared the demographics and prevalence of significant colon findings (defined as polyp >9 mm or suspected malignant tumor) among the two groups. After adjusting for confounding variables, logistic regression was used to estimate the odds ratio of significant findings in warfarin-positive vs. warfarin-negative patients.. Of 10,266 patients with positive FOBT, 372 used warfarin, 9,265 did not use warfarin, and 629 were excluded because of missing warfarin status. Warfarin-positive patients were more likely male (65 vs. 50%; P<0.0001), Caucasian (88 vs. 80%; P<0.0001), and veterans (53 vs. 33%; P<0.0001). The prevalence of a significant finding was greater in the warfarin group, 16 vs. 11.4% (P<0.01). After adjusting for age and sex, the relative risk of significant colon findings among warfarin-positive patients was not significantly different from warfarin-negative patients (odds ratio 1.1, 95% confidence interval: 0.81-1.44).. No increased risk for significant colonic findings among FOBT-positive patients according to warfarin use was identified. These findings suggest that continuing warfarin before FOBT will not affect the positive predictive value of this screening test.

Topics: Aged; Anticoagulants; Colonoscopy; Colorectal Neoplasms; Databases, Factual; Female; Humans; Logistic Models; Male; Middle Aged; Occult Blood; Odds Ratio; Predictive Value of Tests; Prevalence; Prospective Studies; Sensitivity and Specificity; Warfarin

Whether to continue or discontinue warfarin before fecal occult blood testing (FOBT) requires comparison of the risks and benefits of both choices. Clinical practice varies on this issue, and guidelines are silent. A small body of evidence about the effect of warfarin on test characteristics of FOBT is inconclusive, although it suggests no effect. Retrospective studies on this topic may be prone to transfer bias, which affects the composition of the groups assembled for study. Considering the risks and benefits of discontinuing warfarin qualitatively, along with the published literature and clinical context in 2010, where tolerance for false-positive results is higher than it used to be and where immunochemical FOBT is a better screening test than older, guaiac-based FOBT, "no" seems like the "commonsense" answer.

Topics: Anticoagulants; Colonoscopy; Colorectal Neoplasms; Humans; Occult Blood; Warfarin

The aim of this study was to evaluate the effect of medication with anticoagulant properties on the false positive rate in a population-based faecal occult blood test (FOBt) colorectal screening programme.. Eight hundred and forty-six consecutive individuals found to be FOBt-positive in the Scottish arm of the national colorectal cancer screening pilot were studied. All were aged between 50 and 69 years and underwent colonoscopy. Before the procedure the participants' current medication was recorded, and correlated with the colonoscopic findings.. Of 846 participants, 301 (35.6%) were taking regular anticoagulant medication at the time of FOB testing. Of these, 143 (47.5%) had colorectal neoplasia found on colonoscopy, whereas of those not taking anticoagulant medication, 308 (56.5%) were found to have neoplasia. This 9% difference was statistically significant (P = 0.012).. These results indicate that in a population screened for colorectal neoplasia by FOB testing, anticoagulant medication being taken at the time of testing is associated with an increased likelihood of a negative colonoscopy.

Topics: Aged; Anti-Inflammatory Agents, Non-Steroidal; Anticoagulants; Aspirin; Colonoscopy; Colorectal Neoplasms; Cyclooxygenase 2 Inhibitors; False Positive Reactions; Female; Humans; Male; Mass Screening; Middle Aged; Occult Blood; Warfarin

Topics: Antibodies, Monoclonal; Antibodies, Monoclonal, Humanized; Anticoagulants; Antineoplastic Combined Chemotherapy Protocols; Bevacizumab; Colorectal Neoplasms; Endothelial Growth Factors; Fluorouracil; Hemorrhage; Humans; Intercellular Signaling Peptides and Proteins; Leucovorin; Lymphokines; Neoplasm Metastasis; Thrombosis; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factors; Warfarin

Standard treatment for patients with metastatic colorectal carcinoma (MCC) involves treatment with weekly 5-flurouracil (5-FU) chemotherapy by continuous infusion, requiring the insertion of a central venous catheter (CVC). One of the main complications of CVCs is venous thromboembolic disease (VTE), with an incidence varying between 3 and 54% in different studies. During the past 14 months, 17 patients with MCC have been treated weekly with 5-FU in our unit, comprising 11 males and six females with a mean age of 60 years (range, 49-72 years). Thromboprophylaxis for all patients included 1 mg/day warfarin unless contraindicated. Three patients developed venography-confirmed CVC-related VTE, including two cases of occlusive superior venocaval VTE. All three patients were treated with intravenous thrombolytic drugs; two responded completely and one partially. We wonder whether the incidence of CVC-related VTE may be reduced further by using adjusted-dose warfarin rather than fixed low-dose warfarin. However, one has to be guarded because of the greater risk of bleeding with more intensive anticoagulation, especially in patients with liver metastases. Ongoing studies such as the warfarin prophylaxis study are essential to determine the safety and efficacy of different approaches in order to determine the optimum thromboprophylaxis for this group of patients.

Topics: Aged; Anticoagulants; Antineoplastic Agents; Catheterization, Central Venous; Colorectal Neoplasms; Female; Fluorouracil; Humans; Liver Neoplasms; Male; Middle Aged; Thromboembolism; Venous Thrombosis; Warfarin