Genetic markers of toxicity from capecitabine and other fluorouracil-based regimens: investigation in the QUASAR2 study, systematic review, and meta-analysis.

PURPOSE: Fluourouracil (FU) is a mainstay of chemotherapy, although toxicities are common. Genetic biomarkers have been used to predict these adverse events, but their utility is uncertain. PATIENTS AND METHODS: We tested candidate polymorphisms identified from a systematic literature search for associations with capecitabine toxicity in 927 patients with colorectal cancer in the Quick and Simple and Reliable trial (QUASAR2). We then performed meta-analysis of QUASAR2 and 16 published studies (n = 4,855 patients) to examine the polymorphisms in various FU monotherapy and combination therapy regimens. RESULTS: Global capecitabine toxicity (grades 0/1/2 v grades 3/4/5) was associated with the rare, functional DPYD alleles 2846T>A and *2A (combined odds ratio, 5.51; P = .0013) and with the common TYMS polymorphisms 5'VNTR2R/3R and 3'UTR 6bp ins-del (combined odds ratio, 1.31; P = 9.4 × 10(-6)). There was weaker evidence that these polymorphisms predict toxicity from bolus and infusional FU monotherapy. No good evidence of association with toxicity was found for the remaining polymorphisms, including several currently included in predictive kits. No polymorphisms were associated with toxicity in combination regimens. CONCLUSION: A panel of genetic biomarkers for capecitabine monotherapy toxicity would currently comprise only the four DPYD and TYMS variants above. We estimate this test could provide 26% sensitivity, 86% specificity, and 49% positive predictive value-better than most available commercial kits, but suboptimal for clinical use. The test panel might be extended to include additional, rare DPYD variants functionally equivalent to *2A and 2846A, though insufficient evidence supports its use in bolus, infusional, or combination FU. There remains a need to identify further markers of FU toxicity for all regimens.

5-fluorouracil-based therapy induces endovascular injury having potential significance to development of clinically overt cardiotoxicity.

AIM: This study aimed to elucidate the influence of 5-fluorouracil (5-FU)-based therapy on the vascular endothelium and its association with 5-FU-induced heart ischemia. METHODS: The study prospectively accrued patients (n = 106) having completely resected colorectal cancer and receiving adjuvant treatment with 5-FU, folinic acid, and oxaliplatin. The levels of plasma von Willebrand factor (vWf), urine albumin-to-creatinine ratio (UACR), coagulation factor II + VII + X, and fibrin D-dimer were serially assessed before, during, and after chemotherapy. RESULTS: The vWf level increased from median (range) 1.43 kU/l (0.48 to >3) to 2.64 kU/l (0.23 to >3) (P = 0.001), the UACR increased from 1.1 ± 0.2 mg/mmol (mean ± SE) to 2.1 ± 0.3 mg/mmol (P = 0.001), the coagulation factor II + VII + X activity decreased from 1.00 ± 0.02 to 0.94 ± 0.02 U/l (P = 0.001), and the fibrin D-dimer level increased from 1.1 ± 0.2 to 2.1 ± 0.3 kU/l (P = 0.001) at baseline and during chemotherapy, respectively. The changes in the levels of vWf (P = 0.3), UACR (P = 0.8), coagulation factor II + VII + X (P = 0.8), and fibrin D-dimer (P = 0.6) in nine (8.5%) patients having clinical signs of cardiotoxicity were not significantly different from that of the patients not having cardiotoxicity. The 5-FU-induced rise in plasma biomarkers was not significantly related to the cardiovascular morbidity or its risk factors (P = 0.9). CONCLUSIONS: 5-FU therapy induces global reversible endothelial injury leading to a procoagulant state. The ensuing endothelial dysfunction may be of significance to the pathogenesis of 5-FU-induced clinically overt cardiotoxicity. Cardiovascular disease is not significant for the vulnerability of the endothelium to 5-FU-based chemotherapy.

Oxidative damage to guanine nucleosides following combination chemotherapy with 5-fluorouracil and oxaliplatin.

PURPOSE: Recent in vitro and animal studies have suggested that the cytotoxicity of 5-fluorouracil and oxaliplatin is linked to increased formation of reactive oxygen species (ROS). This prospective study was undertaken to examine the generation of oxidative stress, in 106 colorectal cancer patients, by 5-fluorouracil and oxaliplatin combination (FOLFOX) therapy as measured by urinary excretion of 8-oxo-7,8-dihydro-2-deoxyguanosine (8-oxodG) and 8-oxo-7,8-dihydro-guanosine (8-oxoGuo). METHODS: The amounts of 8-oxoGuo and 8-oxodG were measured in 3 spot urine samples from 106 patients by using ultra performance liquid chromatography and tandem mass spectrometry. Furthermore, we collected information on other clinical and demographic variables hypothesized to be associated with oxidative stress. Repeated measures linear mixed models were used to model the relationship between urinary concentrations of 8-oxoGuo and 8-oxodG and the treatment effect and the other variables. RESULTS: The analysis showed that chemotherapy increased the excretion of 8-oxoGuo and 8-oxodG around 15% (P < 0.0001 and P = 0.02, respectively) though there was a significant interaction with CRP levels. Additionally, we found that sex, smoking status, age, and c-reactive protein were related to urinary excretion of 8-oxoGuo and 8-oxodG in colorectal cancer patients. CONCLUSION: These results indicate that FOLFOX induces ROS in patients and that ROS-generating mechanisms interact.

The association of polymorphisms in 5-fluorouracil metabolism genes with outcome in adjuvant treatment of colorectal cancer.

AIM: The purpose of this study was to investigate whether specific combinations of polymorphisms in 5-fluorouracil (5-FU) metabolism-related genes were associated with outcome in 5-FU-based adjuvant treatment of colorectal cancer. METHODS: We analyzed two cohorts of 302 and 290 patients, respectively, one cohort for exploratory analyses and another cohort for validating the exploratory analyses. A total of ten polymorphisms in genes involved in 5-FU pharmacodynamics and pharmacokinetics were studied. End points were disease-free survival (DFS) and overall survival. Multifactor dimensionality reduction was used to identify genetic interaction profiles associated with outcome. RESULTS: Low-expression alleles in thymidylate synthase (TYMS) were associated with decreased DFS and overall survival (DFS:hazard ratio [HR] exploration 2.65 [1.40-4.65]; p = 0.004, HR validation 1.69 [1.03-2.66]; p = 0.03). A specific multifactor dimensionality reduction derived combination of dihydropyrimidine dehydrogenase and TYMS polymorphisms was associated with increased DFS (HR exploration 0.69 [0.49-0.98]; p = 0.04, HR validation 0.66 [0.45-0.95]; p = 0.03). Specific combinations of functional polymorphisms in DPYD and TYMS were demonstrated to be associated with DFS and overall survival in patients receiving adjuvant 5-FU-based treatment. Specifically high TYMS expression alleles seem to be associated with decreased DFS.

Fluorouracil induces myocardial ischemia with increases of plasma brain natriuretic peptide and lactic acid but without dysfunction of left ventricle.

PURPOSE: Fluorouracil (FU) is a cornerstone of colorectal cancer treatment; however, it has clinical and subclinical influence on the heart. This study aimed to clarify the pathophysiology, risk factors, and long-term effects of FU cardiotoxicity. PATIENTS AND METHODS: The study prospectively accrued colorectal cancer patients (n=106) completely resected and adjuvantly treated with FU and oxaliplatin according to the FOLFOX4 regimen (infusional FU, folinic acid, and oxaliplatin). Serial measurements were made of systolic and diastolic features of the left ventricle by radionuclide ventriculography, plasma levels of N-terminal pro-brain natriuretic peptide (NT-proBNP), lactic acid, and ECG before chemotherapy, immediately after a treatment infusion, and at follow-up 2 weeks after cessation of the intended 12 treatment courses and were further evaluated by multivariate regression analysis that included cardiovascular history and its risk factors. RESULTS: In the entire cohort, NT-proBNP significantly increased from baseline 14.5±3.2 pmol/L (mean±standard error) to 28.3±5.3 pmol/L during FU therapy (P<.001). Nine patients (8.5%) with cardiotoxicity had significantly higher NT-proBNP of 55.3±40.8 pmol/L compared with 25.4±4.1 pmol/L in those without (P<.001). In multivariate analysis, the FU-induced rise of NT-proBNP was significantly higher in females (P<.001). Plasma lactic acid significantly increased from baseline (1.3±0.1 mmol/L to 1.8±0.1 mmol/L) during FU therapy (P<.001). Left ventricular ejection fraction at baseline of 0.66±0.01 remained unchanged at 0.65±0.01 during FU therapy and 0.66±0.01 at follow-up (P=.4). CONCLUSION: FU therapy generally induces myocardial neuroendocrine changes with increasing plasma NT-proBNP and lactic acid but without long-term dysfunction of the left ventricle. The usability of NT-proBNP as a predictive marker for FU cardiotoxicity remains to be clarified.

Expression of matrix metalloproteinase 9 (MMP-9) and tissue inhibitor of metalloproteinases 1 (TIMP-1) by colorectal cancer cells and adjacent stroma cells--associations with histopathology and patients outcome.

AIM: To elucidate cellular features accountable for colorectal cancers' (CRC) capability to invade normal tissue and to metastasize, we investigated the level of the collagenase matrix metalloproteinase 9 (MMP-9) and its physiological inhibitor tissue inhibitor of metalloproteinases 1 (TIMP-1) in cancer cells and supporting stroma cells of CRC. METHODS: Immunoreactivity of MMP-9 and TIMP-1 by carcinoma cells, lymphocytes and fibroblasts in archival specimens of paraffin-embedded primary tumours were retrospectively associated with outcome in 340 consecutive patients completely resected for CRC stages II-IV and subsequently treated with adjuvant 5-fluorouracil. RESULTS: Expression of MMP-9 by carcinoma cells was demonstrated in 9% of specimens without association to recurrence free survival (RFS) (HR = 1.0; 95% CI: 0.6-1.8; P = 0.9) or overall survival (OS) (HR = 0.9; 95% CI: 0.5-1.6; P = 0.6). TIMP-1 expression by carcinoma cells, which appeared in 64% of the specimens, was inversely related with RFS (HR = 1.3; 95% CI: 0.9-1.8; P = 0.08) and OS (HR = 1.5; 95% CI: 1.1-2.1; P = 0.02). Expression of TIMP-1 by fibroblasts at the invasive border was directly related to RFS (HR = 0.7; 95% CI: 0.6-0.9; P = 0.02) and OS (HR = 0.7; 95% CI: 0.6-1.0; P = 0.05). Expression of MMP-9 by lymphocytes correlated significantly with the degree of peritumoural inflammation (P = 0.02) but not with RFS (HR = .9; 95% CI: 0.7-1.1; P = 0.2) or OS (HR = 0.8; 95% CI: 0.7-1.0; P = 0.07). CONCLUSION: TIMP-1 in cancer cells is associated with poor prognosis independent of its function as inhibitor of MMP-9. MMP-9 and TIMP-1 are important mediators of the host-cancer cell interaction in the tumour microenvironment with significant influence on the histopathology and on prognosis of CRC.

[Cardiotoxicity induced by 5-fluorouracil or capecitabine]. / Hjertepåvirkning fra 5-fluorouracil og capecitabin.

5-fluorouracil and capecitabine have significant antineoplastic activity towards various solid tumors. Cardiotoxicity causing angina, arrhythmia and infarction are serious adverse events associated with these agents. The pathogenesis is discussed and symptoms of cardiotoxicity, intervention with nitroglycerine and risk factors as cardiac comorbidity are described. Following cardiotoxicity, lack of alternative active agents may provide grounds to rechallenge with 5-FU. In this situation, dose-modified 5-FU-based chemotherapy supported by medical antiangina prevention is feasible.

Effect of N-acetylcysteine on the accuracy of the prothrombin time assay of plasma coagulation factor II+VII+X activity in subjects infused with the drug. Influence of time and temperature.

OBJECTIVES: The prothrombin time (PT) assay of factor II+VII+X activity is an important predictor of liver damage in paracetamol poisoned patients. It complicates interpretation of results that the antidote, acetylcysteine (NAC) depresses this activity. The aim was to investigate if NAC influences the accuracy of the plasma PT assay. MATERIALS AND METHODS: The accuracy of Nycotest PT was studied using plasma added NAC in vitro and plasma from subjects infused with NAC. The latter results were compared with those obtained by analysis of PT by CoaguChek S. RESULTS: Therapeutic NAC concentrations added to plasma in vitro decreased factor II+VII+X activity at 37 degrees C in a time-dependent manner. This effect was quenched at temperatures <24 degrees C. Activity lost at 37 degrees C could partly be recovered by subsequent incubation at 5 or 20 degrees C. Incubation at 37 degrees C prior to assay led to a significant additional depression of factor II+VII+X activity in plasma from subjects infused with NAC during the first 3h of infusion indicating that it contained reactive NAC. The risk that this NAC interfered with the accuracy of the PT assay was considered minimal with samples stored below 24 degrees C. This was supported by similarity of results obtained by analysis of appropriately stored plasma and simultaneously drawn blood by CoaguChek S. CONCLUSIONS: Residual reactive NAC does not interfere with the accuracy of the PT assay of plasma stored below 24 degrees C, but NAC-induced loss in activity at 37 degrees C may be partly recovered during subsequent storage below 24 degrees C.

Prognostic significance of numeric aberrations of genes for thymidylate synthase, thymidine phosphorylase and dihydrofolate reductase in colorectal cancer.

BACKGROUND: Most human cancer cells have structural aberrations of chromosomal regions leading to loss or gain of gene specific alleles. This study aimed to assess the range of gene copies per nucleus of thymidylate synthase (TYMS), thymidine phosphorylase (TP) and dihydrofolate reductase (DHFR) in colorectal cancer, and to evaluate its prognostic significance following adjuvant chemotherapy, since these enzymes are closely related to efficacy of 5-fluorouracil (5FU). PATIENTS AND METHODS: Consecutive patients (n = 314), who were completely resected for colorectal cancer stages II-IV and adjuvantly treated with 5-FU were retrospectively evaluated. Paraffin embedded tumor specimens were assessed for gene copies per nucleus of TYMS, TP and DHFR by fluorescence in situ hybridisation (FISH) using specific peptide nucleic acid probes. Outcome according to gene copies per nucleus above and below the median were compared. Also TYMS expression, assessed by immunohistochemistry, was associated with TYMS copies per nucleus. RESULTS: The number of gene copies per nucleus were 1.7 (0.7-2.8), 1.8 (0.9-3.1) and 1.8 (1.1-2.7) median (range) for TYMS, TP and DHFR, respectively. TYMS expression was directly associated with TYMS genes per nucleus (p = 0.05). Cox multivariate analysis, adjusted for the prognostic impact of disease stage, vascular tumor invasion, and bowel obstruction at resection, revealed that high TYMS gene copy number was associated with significantly higher risk of recurrence (HR = 1.6; 95%CI 1.1-2.2; p = 0.02) and death (HR = 1.6; 95%CI 1.1-2.3; p = 0.01). No significant differences in outcome appeared according to TP and DHFR gene ratios. CONCLUSION: Aberration of TYMS gene is of significance to expression of TYMS, which may influence the biology and 5-FU sensitivity of colorectal cancer. This may be utilized in the allocation of patients for treatment approaches and for decision on follow-up programs.

The prognostic significance of thymidylate synthase and dihydropyrimidine dehydrogenase in colorectal cancer of 303 patients adjuvantly treated with 5-fluorouracil.

Cytotoxic effect of 5-fluorouracil 5-FU is mediated through inhibition of thymidylate synthase (TS), and 5-FU is catabolised by dihydropyrimidine dehydrogenase (DPD). Efficacy of 5-FU may therefore depend on the TS and DPD activity of colorectal cancer. Archival tumour specimens from 303 consecutive patients were analysed for the expression of TS and DPD using immunohistochemistry. All patients were completely resected for colorectal cancer stages II-III and have subsequently received adjuvant treatment with 5-FU. In a multivariate analysis adjusting for the impact of bowel obstruction and vascular tumour invasion, diffuse TS pattern was significantly associated with increased risk of recurrence (hazard ratio (HR) = 1.9; 95% confidence interval (CI): 1.1-3.2; p = 0.02), but without significant association to death (HR = 1.6; 95% CI: 0.9-2.8; p = 0.08). High TS intensity was not significantly associated with lower risk of recurrence (HR = 0.6; 95% CI: 0.3-1.1; p = 0.07) or death (HR = 0.6; 95% CI: 0.3-1.2; p = 0.2). High DPD intensity was significantly associated with increased risk of recurrence (HR = 1.5; 95% CI: 1.1-2.3; p = 0.03) and death (HR = 1.6; 95% CI: 1.1-2.5; p = 0.02). Patients with a combination of low TS and high DPD intensity were at significantly increased risk of both recurrence (HR = 2.1; 95% CI: 1.0-4.2; p = 0.04) and death (HR = 2.0; 95% CI: 1.0-4.0; p = 0.05). No relationship between tolerability and toxicity of 5-FU and TS and DPD expression was found. It is concluded that characterizing colorectal carcinomas by TS and DPD expression may disclose subsets of patients with significantly greater risk of disease recurrence and early death. This may be utilized in the selection of patients for treatment approaches and for decision on follow-up programs.

Benefits and risks of palliative capecitabine based therapy to elderly patients with advanced colorectal cancer: Danish single centre experiences.

This study aimed to compare efficacy and toxicity of palliative chemotherapy for elderly and younger colorectal cancer patients. Patients aged 24-69 (n = 203) and 70-82 years (n = 57) with advanced colorectal cancer were consequetively treated with first line capecitabine monotherapy or combined with oxaliplatin (XELOX). The response rates were 37% and 33% (P = 0.61), the median times to progression were 5.5 and 6.0 months (P = 0.84, hazard ratio (HR) 1.09; 95% confidence interval: 0.71-1.68), and median overall survival times were 8.4 and 12.5 months (P = 0.07, HR 1.48; 1.04-2.38) for elderly and younger patients, respectively. Elderly patients had similar frequencies of Common Toxicity Criteria (CTC) grade 3 or 4 toxicity (P > 0.05) and number of treatment courses (P = 0.44), and maintained performance status as well as younger patients (P = 0.68). Palliative capecitabine based therapy for advanced colorectal cancer should be considered also for elderly who are in good performance without major comorbidities.

Risk factors and prevention of cardiotoxicity induced by 5-fluorouracil or capecitabine.

AIM: 5-fluorouracil (5-FU) and its prodrug capecitabine are cardiotoxic. This retrospective study aimed to identify risk factors and to give practical measures to make such chemotherapy feasible if cardiotoxicity occur. METHOD: Review of cardiotoxicity among 668 patients treated with 5-FU or capecitabine for gastrointestinal cancers. RESULTS: Cardiotoxicity occurred in 29 cases (4.3%). The number of cases according to cardiotoxicity CTC grades 2-4 for patients with and without pre-existing cardiovascular disease were none, 10, and 2 cases, and 3, 14, and no cases, respectively (P=0.16). In three patients intercurrent decrease of renal clearances to <30, 48 and 71 ml min(-1) led to markedly increased cardiotoxicity. Chemotherapy dose reduction to 70 or 50%, either alone or in addition to antiangina medication prevented cardiotoxicity during subsequent chemotherapy in nine (60%) and three (20%) cases out of 15 assessable patients (P=0.001), respectively. To abolish symptoms of cardiotoxicity, sublingual nitroglycerine was efficient for 15 patients and inefficient for two (P=0.001). CONCLUSION: Cardiac and renal co-morbidity are risk factors for 5-FU induced cardiotoxicity. In this situation, rechallenge with modified 5-FU-based chemotherapy regimen supported by symptomatic medical treatment is feasible.

Adjuvant chemotherapy in elderly patients (>or=75 yr) completely resected for colon cancer stage III compared to younger patients: toxicity and prognosis.

PURPOSE: To compare benefits and risks to adjuvant chemotherapy following complete resection of node-positive colon cancer stage III for patients aged >or=75 yr and younger. METHOD: A retrospective study compared recurrence-free and overall survival, toxicity, and dose intensity of adjuvant bolus 5-FU according to the Mayo regimen chemotherapy in consecutive patients aged 19-74 (n=203) and >or=75 yr (n=24). RESULTS: The estimated 5-yr proportional survival rates were 0.65 for patients age less than 75 yr compared to 0.65 (p=0.96) for elderly. The frequencies of anemia (0%), thrombocytopenia (0%), leukopenia (4%), infection (8%), vomiting (0%), mucositis (17%), diarrhea (13%) CTC grade 3 or 4 toxicity in elderly patients were not significantly different from that in younger patients (p > 0.05). Significantly more elderly (8%) had a decline in performance status to grade 3 or 4, as compared to younger patients (4%) (p=0.002). 5-FU dose reduction was necessary for significantly more elderly (51%) as compared to younger patients (28%) (p=0.02), and fewer elderly (54%) completed the scheduled six treatment courses as compared to younger patients (82%) (p=0.05). CONCLUSIONS: Adjuvant 5-FU chemotherapy should be considered for elderly patients aged >or=75 yr in good performance at high risk of recurrence of colon carcinoma after resection.