961 resultados para 2-STAGE COMBUSTION


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Rapport de synthèse : Le rétinoblastome est la tumeur de l'oeil la plus fréquente chez l'enfant. Un diagnostic précoce est important pour sauver le globe oculaire et la survie du patient. Le but de notre étude est de déterminer l'évolution de l'intervalle diagnostique, c'est-à-dire le délai entre les premiers symptômes et la date du diagnostic officiel du rétinoblastome, sur une période de 40 ans en Suisse. Matériel et méthode : Il s'agit d'une étude rétrospective faite sur 139 patients suisses traités pour rétinoblastome durant trois différentes périodes : (1) 1963-1983 ; (2) 1984-1993 ; et (3) 1994-2004. On compare certaines caractéristiques : le sexe du patient, la latéralité de la maladie, les premiers symptômes, leurs observateurs, l'intervalle diagnostique, l'âge au diagnostic, le stade de la maladie, l'histoire familiale. Résultats : 37 patients (26.6%) ont été traités dans la première période ; 44 (31.7%) dans la période 2 et 58 (41.7%) dans la période 3. L'intervalle diagnostique diminue de façon significative de 6.97 mois dans la période 1 à 3.58 dans la période 2 à 2.25 dans la période 3 pour le total des malades. Ceci reste significatif pour les rétinoblastomes unilatéraux. De plus, dans ce même groupe, on observe une diminution significative des stades avancés de la maladie, groupe E selon Murphree (61.5% dans la période 1 ; 46.7% dans la période 2 et 22.2 % dans la période 3). Lorsque la maladie est bilatérale, les mêmes observations se font de façon un peu moins marquée. Il n'y a aucun patient diagnostiqué au stade E de la maladie en présence d'une anamnèse familiale positive. Leucocorie (48.2%) et strabisme (20.1 %) sont les symptômes les plus fréquents durant les 3 périodes. Les seuls facteurs qui influencent significativement le risque d'avoir un stade E de la maladie sont la durée de l'intervalle diagnostic et la période de diagnostic. Conclusion : On constate un progrès dans le diagnostic du rétinoblastome en Suisse, surtout lors de maladie unilatérale. De même, des améliorations sont notées dans la maladie bilatérale mais de façon non significative. Il est donc important de mieux enseigner aux médecins à reconnaître les symptômes oculaires de la maladie et à référer les patients plus tôt aux spécialistes. Abstract : OBECTIVES : Retinoblastoma is the most frequent intraocular malignancy in children. Early diagnosis is essential for globe salvage and patient survival. The aim of our study was to determine how time to diagnosis of retinoblastoma has evolved over a 40-year period in Switzerland. METHOD AND PATIENTS : A retrospective study of 139 Swiss patients with retinoblastoma was performed comparing 3 periods: (1) 1963-1983; (2) 1984-1993; and (3) 1994-2004. Factors taken into account were gender, laterality of retínoblastoma, age at first symptoms, type and first observer of symptoms, time to diagnosis, age at diagnosis, disease stage, and family history. RESULTS : Thirty-seven patients (26.6%) were treated in period 1, 44 (31.7%) in period 2, and S8 (41.7%) in period 3.Overall, the diagnostic interval decreased in a significant way from 6.97 months in period 1 to 3.58 in period 2 and to 2.25 in period 3. When looking separately at unilateral and bilateral disease, the decrease oí the diagnostic interval remained statistically significant in unilateral retinoblastoma; there was also a significant reduction in the number of patients with advanced group E disease (Murphree classification) (61.5% in period 1, 46.7% in period 2, 22.2% in period 3). In bilateral disease, the same observations were made to a lesser extent. However, there were no cases with group E disease in 10 patients with positive family history. Leukornria (48.2%) and strabismus (20.1 %) were the 2 most frequent symptoms throughout the 3 periods. The only factors that statistically influenced the chances of having a diagnosis of group E disease were the diagnostic interval and period of diagnosis. Conclusion : Progress has been made in the diagnosis of retinoblastoma in Switzerland, notably in unilateral disease. Improvement to a lesser extent has also been observed in bilateral cases but without statistical significance. Greater effort is needed to teach physians-in-training to recognize the importance of ocular symptoms and refer patients earlier.

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Albitization is a common process during which hydrothermal fluids convert plagioclase and/or K-feldspar into nearly pure albite; however, its specific mechanism in granitoids is not well understood. The c. 1700 Ma A-type metaluminous ferroan granites in the Khetri complex of Rajasthan, NW India, have been albitized to a large extent by two metasomatic fronts, an initial transformation of oligoclase to nearly pure albite and a subsequent replacement of microcline by albite, with sharp contacts between the microcline-bearing and microcline-free zones. Albitization has bleached the original pinkish grey granite and turned it white. The mineralogical changes include transformation of oligoclase (similar to An(12)) and microcline (similar to Or(95)) to almost pure albite (similar to An(0 center dot 5-2)), amphibole from potassian ferropargasite (X-Fe 0 center dot 84-0 center dot 86) to potassic hastingsite (X-Fe 0 center dot 88-0 center dot 97) and actinolite (X-Fe 0 center dot 32-0 center dot 67), and biotite from annite (X-Fe 0 center dot 71-0 center dot 74) to annite (X-Fe 0 center dot 90-0 center dot 91). Whole-rock isocon diagrams show that, during albitization, the granites experienced major hydration, slight gain in Si and major gain in Na, whereas K, Mg, Fe and Ca were lost along with Rb, Ba, Sr, Zn, light rare earth elements and U. Whole-rock Sm-Nd isotope data plot on an apparent isochron of 1419 +/- 98 Ma and reveal significant disturbance and at least partial resetting of the intrusion age. Severe scatter in the whole-rock Rb-Sr isochron plot reflects the extreme Rb loss in the completely albitized samples, effectively freezing Sr-87/Sr-86 ratios in the albite granites at very high values (0 center dot 725-0 center dot 735). This indicates either infiltration of highly radiogenic Sr from the country rock or, more likely, radiogenic ingrowth during a considerable time lag (estimated to be at least 300 Myr) between original intrusion and albitization. The albitization took place at similar to 350-400 degrees C. It was caused by the infiltration of an ascending hydrothermal fluid that had acquired high Na/K and Na/Ca ratios during migration through metamorphic rocks at even lower temperatures in the periphery of the plutons. Oxygen isotope ratios increase from delta O-18 = 7 parts per thousand in the original granite to values of 9-10 parts per thousand in completely albitized samples, suggesting that the fluid had equilibrated with surrounding metamorphosed crust. A metasomatic model, using chromatographic theory of fluid infiltration, explains the process for generating the observed zonation in terms of a leading metasomatic front where oligoclase of the original granite is converted to albite, and a second, trailing front where microcline is also converted to albite. The temperature gradients driving the fluid infiltration may have been produced by the high heat production of the granites themselves. The confinement of the albitized granites along the NE-SW-trending Khetri lineament and the pervasive nature of the albitization suggest that the albitizing fluids possibly originated during reactivation of the lineament. More generally, steady-state temperature gradients induced by the high internal heat production of A-type granites may provide the driving force for similar metasomatic and ore-forming processes in other highly enriched granitoid bodies.

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Three types of garnet have been distinguished in pelitic schists from an epidote-blueschist-facies unit of the Ambin and South Vanoise Brianconnais massifs on the basis of texture, chemical zoning and mineral inclusion characterization. Type-1 garnet cores with high Mn/Ca ratios are interpreted as pre-Alpine relicts, whereas Type-1 garnet rims, Type-2 inclusion-rich porphyroblasts and smaller Type-3 garnets are Alpine. The latter are all characterized by low Mn/Ca ratios and a coexisting mineral assemblage of blue amphibole, high-Si phengite, epidote and quartz. Prograde growth conditions during Alpine D-1 high-pressure (HP) metamorphism are recorded by a decrease in Mn and increase in Fe (+/-Ca) in the Type-2 garnets, culminating in peak P-T conditions of 14-16 kbar and 500degreesC in the deepest parts of the Ambin dome. The multistage growth history of Type-1 garnets indicates a polymetamorphic history for the Ambin and South Vanoise massifs; unfortunately, no age constraints are available. The new metamorphic constraints on the Alpine event in the massifs define a metamorphic T `gap' between them and their surrounding cover (Brianconnais and upper Schistes Lustres units), which experienced metamorphism only in the stability field of carpholite-lawsonite (T < 400degreesC). These data and supporting structural studies confirm that the Ambin and South Vanoise massifs are slices of `eclogitized' continental crust tectonically extruded within the Schistes Lustres units and Brianconnais covers. The corresponding tectonic contacts with top-to-east movement are responsible for the juxtaposition of lower-grade metamorphic units on the Ambin and South Vanoise massifs.

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BACKGROUND: We aimed to compare panitumumab, a fully human monoclonal antibody against EGFR, plus radiotherapy with chemoradiotherapy in patients with unresected, locally advanced squamous-cell carcinoma of the head and neck. METHODS: In this international, open-label, randomised, controlled, phase 2 trial, we recruited patients with locally advanced squamous-cell carcinoma of the head and neck from 22 sites in eight countries worldwide. Patients aged 18 years and older with stage III, IVa, or IVb, previously untreated, measurable (≥10 mm for at least one dimension), locally advanced squamous-cell carcinoma of the head and neck (non-nasopharygeal) and an Eastern Cooperative Oncology Group performance status of 0-1 were randomly assigned (2:3) by an independent vendor to open-label chemoradiotherapy (two cycles of cisplatin 100 mg/m(2) during radiotherapy) or to radiotherapy plus panitumumab (three cycles of panitumumab 9 mg/kg every 3 weeks administered with radiotherapy) using a stratified randomisation with a block size of five. All patients received 70-72 Gy to gross tumour and 54 Gy to areas of subclinical disease with accelerated fractionation radiotherapy. The primary endpoint was local-regional control at 2 years, analysed in all randomly assigned patients who received at least one dose of their assigned protocol-specific treatment (chemotherapy, radiation, or panitumumab). The trial is closed and this is the final analysis. This study is registered with ClinicalTrials.gov, number NCT00547157. FINDINGS: Between Nov 30, 2007, and Nov 16, 2009, 152 patients were enrolled, and 151 received treatment (61 in the chemoradiotherapy group and 90 in the radiotherapy plus panitumumab group). Local-regional control at 2 years was 61% (95% CI 47-72) in the chemoradiotherapy group and 51% (40-62) in the radiotherapy plus panitumumab group. The most frequent grade 3-4 adverse events were mucosal inflammation (25 [40%] of 62 patients in the chemoradiotherapy group vs 37 [42%] of 89 patients in the radiotherapy plus panitumumab group), dysphagia (20 [32%] vs 36 [40%]), and radiation skin injury (seven [11%] vs 21 [24%]). Serious adverse events were reported in 25 (40%) of 62 patients in the chemoradiotherapy group and in 30 (34%) of 89 patients in the radiotherapy plus panitumumab group. INTERPRETATION: Panitumumab cannot replace cisplatin in the combined treatment with radiotherapy for unresected stage III-IVb squamous-cell carcinoma of the head and neck, and the role of EGFR inhibition in locally advanced squamous-cell carcinoma of the head and neck needs to be reassessed. FUNDING: Amgen.

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Nyssomyia whitmani (Antunes and Coutinho, 1939) has been considered as a complex of cryptic species, and some of the populations of this complex plays an important role in the transmission of Leishmania spp. in Brazil. The present study reports the biological aspects concerning the productivity out of eggs and the development time of the descendants of females obtained in Dourados municipality, Mato Grosso do Sul state. The females were captured with modified electric aspirators, fed in hamsters and further individualized in containers for breeding. At the insectary, temperature and relative humidity were maintained on average of 24.5 °C and 67.3%, respectively. From 944 females 3737 eggs were obtained, 748 (20.0%) evolved to the stage of larvae, and 93 (12.4%) of these reached adult stage. The life cycle lasted 80.6 days and the last larval instar was the longest. The use of a higher protein diet revealed a significant improvement in larval development.

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BACKGROUND: MYCN oncogene amplification has been defined as the most important prognostic factor for neuroblastoma (NB), the most common solid extracranial neoplasm in children. High copy numbers are strongly associated with rapid tumor progression and poor outcome, independently of tumor stage or patient age, and this has become an important factor in treatment stratification. PROCEDURE: By real-time quantitative PCR analysis, we evaluated the clinical relevance of circulating MYCN DNA of 267 patients with locoregional or metastatic NB in children less than 18 months of age. RESULTS: For patients in this age group with INSS stage 4 or 4S NB and stage 3 patients, serum-based determination of MYCN DNA sequences had good sensitivity (85%, 83%, and 75% respectively) and high specificity (100%) when compared to direct tumor gene determination. In contrast, the approach showed low sensitivity patients with stages 1 and 2 disease. CONCLUSION: Our results show that the sensitivity of the serum-based MYCN DNA sequence determination depends on the stage of the disease. However, this simple, reproducible assay may represent a reasonably sensitive and very specific tool to assess tumor MYCN status in cases with stage 3 and metastatic disease for whom a wait and see strategy is often recommended.

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BACKGROUND: Since 1981 Princess Margaret Hospital has used initial active surveillance (AS) with delayed treatment at relapse as the preferred management for all patients with clinical stage I nonseminomatous germ cell tumors (NSGCT). OBJECTIVE: Our aim was to report our overall AS experience and compare outcomes over different periods using this non-risk-adapted approach. DESIGN, SETTING, AND PARTICIPANTS: Three hundred and seventy-one patients with stage I NSGCT were managed by AS from 1981 to 2005. For analysis by time period, patients were divided into two cohorts by diagnosis date: initial cohort, 1981-1992 (n=157), and recent cohort, 1993-2005 (n=214). INTERVENTION: Patients were followed at regular intervals, and treatment was only given for relapse. MEASUREMENTS: Recurrence rates, time to relapse, risk factors for recurrence, disease-specific survival, and overall survival were determined. RESULTS AND LIMITATIONS: With a median follow-up of 6.3 yr, 104 patients (28%) relapsed: 53 of 157 (33.8%) in the initial group and 51 of 214 (23.8%) in the recent group. Median time to relapse was 7 mo. Lymphovascular invasion (p<0.0001) and pure embryonal carcinoma (p=0.02) were independent predictors of recurrence; 125 patients (33.7%) were designated as high risk based on the presence of one or both factors. In the initial cohort, 66 of 157 patients (42.0%) were high risk and 36 of 66 patients (54.5%) relapsed versus 17 of 91 low-risk patients (18.7%) (p<0.0001). In the recent cohort, 59 of 214 patients (27.6%) were high risk and 29 of 59 had a recurrence (49.2%) versus 22 of 155 low-risk patients (14.2%) (p<0.0001). Three patients (0.8%) died from testis cancer. The estimated 5-yr disease-specific survival was 99.3% in the initial group and 98.9% in the recent one. CONCLUSIONS: Non-risk-adapted surveillance is an effective, simple strategy for the management of all stage I NSGCT.

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Prostate cancer (PCa) is a potentially curable disease when diagnosed in early stages and subsequently treated with radical prostatectomy (RP). However, a significant proportion of patients tend to relapse early, with the emergence of biochemical failure (BF) as an established precursor of progression to metastatic disease. Several candidate molecular markers have been studied in an effort to enhance the accuracy of existing predictive tools regarding the risk of BF after RP. We studied the immunohistochemical expression of p53, cyclooxygenase-2 (COX-2) and cyclin D1 in a cohort of 70 patients that underwent RP for early stage, hormone naïve PCa, with the aim of prospectively identifying any possible interrelations as well as correlations with known prognostic parameters such as Gleason score, pathological stage and time to prostate-specific antigen (PSA) relapse. We observed a significant (p = 0.003) prognostic role of p53, with high protein expression correlating with shorter time to BF (TTBF) in univariate analysis. Both p53 and COX-2 expression were directly associated with cyclin D1 expression (p = 0.055 and p = 0.050 respectively). High p53 expression was also found to be an independent prognostic factor (p = 0.023). Based on previous data and results provided by this study, p53 expression exerts an independent negative prognostic role in localized prostate cancer and could therefore be evaluated as a useful new molecular marker to be added in the set of known prognostic indicators of the disease. With respect to COX-2 and cyclin D1, further studies are required to elucidate their role in early prediction of PCa relapse after RP.

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OBJECT: The aim of this study was to evaluate the long-term safety and efficacy of bilateral contemporaneous deep brain stimulation (DBS) in patients who have levodopa-responsive parkinsonism with untreatable motor fluctuations. Bilateral pallidotomy carries a high risk of corticobulbar and cognitive dysfunction. Deep brain stimulation offers new alternatives with major advantages such as reversibility of effects, minimal permanent lesions, and adaptability to individual needs, changes in medication, side effects, and evolution of the disease. METHODS: Patients in whom levodopa-responsive parkinsonism with untreatable severe motor fluctuations has been clinically diagnosed underwent bilateral pallidal magnetic resonance image-guided electrode implantation while receiving a local anesthetic. Pre- and postoperative evaluations at 3-month intervals included Unified Parkinson's Disease Rating Scale (UPDRS) scoring, Hoehn and Yahr staging, 24-hour self-assessments, and neuropsychological examinations. Six patients with a mean age of 55 years (mean 42-67 years), a mean duration of disease of 15.5 years (range 12-21 years), a mean "on/off' Hoehn and Yahr stage score of 3/4.2 (range 3-5), and a mean "off' time of 40% (range 20-50%) underwent bilateral contemporaneous pallidal DBS, with a minimum follow-up period lasting 24 months (range 24-30 months). The mean dose of levodopa in these patients could not be changed significantly after the procedure and pergolide was added after 12 months in five patients because of recurring fluctuations despite adjustments in stimulation parameters. All but two patients had no fluctuations until 9 months. Two of the patients reported barely perceptible fluctuations at 12 months and two at 15 months; however, two patients remain without fluctuations at 2 years. The mean improvements in the UPDRS motor score in the off time and the activities of daily living (ADL) score were more than 50%; the mean off time decreased from 40 to 10%, and the mean dyskinesia and complication of treatment scores were reduced to one-third until pergolide was introduced at 12 months. No significant improvement in "on" scores was observed. A slight worsening after 1 year was observed and three patients developed levodopa- and stimulation-resistant gait ignition failure and minimal fluctuations at 1 year. Side effects, which were controlled by modulation of stimulation, included dysarthria, dystonia, and confusion. CONCLUSIONS: Bilateral pallidal DBS is safe and efficient in patients who have levodopa-responsive parkinsonism with severe fluctuations. Major improvements in motor score, ADL score, and off time persisted beyond 2 years after the operation, but signs of decreased efficacy started to be seen after 12 months.

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BACKGROUND: The risk of end stage renal disease (ESRD) is increased among individuals with low income and in low income communities. However, few studies have examined the relation of both individual and community socioeconomic status (SES) with incident ESRD. METHODS: Among 23,314 U.S. adults in the population-based Reasons for Geographic and Racial Differences in Stroke study, we assessed participant differences across geospatially-linked categories of county poverty [outlier poverty, extremely high poverty, very high poverty, high poverty, neither (reference), high affluence and outlier affluence]. Multivariable Cox proportional hazards models were used to examine associations of annual household income and geospatially-linked county poverty measures with incident ESRD, while accounting for death as a competing event using the Fine and Gray method. RESULTS: There were 158 ESRD cases during follow-up. Incident ESRD rates were 178.8 per 100,000 person-years (105 py) in high poverty outlier counties and were 76.3 /105 py in affluent outlier counties, p trend = 0.06. In unadjusted competing risk models, persons residing in high poverty outlier counties had higher incidence of ESRD (which was not statistically significant) when compared to those persons residing in counties with neither high poverty nor affluence [hazard ratio (HR) 1.54, 95% Confidence Interval (CI) 0.75-3.20]. This association was markedly attenuated following adjustment for socio-demographic factors (age, sex, race, education, and income); HR 0.96, 95% CI 0.46-2.00. However, in the same adjusted model, income was independently associated with risk of ESRD [HR 3.75, 95% CI 1.62-8.64, comparing the < $20,000 income group to the > $75,000 group]. There were no statistically significant associations of county measures of poverty with incident ESRD, and no evidence of effect modification. CONCLUSIONS: In contrast to annual family income, geospatially-linked measures of county poverty have little relation with risk of ESRD. Efforts to mitigate socioeconomic disparities in kidney disease may be best appropriated at the individual level.

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Want to know what conditions to expect over the next stage of RAGBRAI? How hilly will it be, what towns and parks are between here and there, or what services are coming up in the next town?

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We report about a 37 year old male patient with a pectus excavatum. The patient was in NYHA functional class III. After performed computed tomography the symptoms were thought to be related to the severity of chest deformation. A Ravitch-procedure had been accomplished in a district hospital in 2009. The crack of a metal bar led to a reevaluation 2010, in which surprisingly the presence of an annuloaortic ectasia (root 73 × 74 mm) in direct neighborhood of the formerly implanted metal-bars was diagnosed. Echocardiography revealed a severe aortic valve regurgitation, the left ventricle was massively dilated presenting a reduced ejection fraction of 45%. A marfan syndrome was suspected and the patient underwent a valve sparing aortic root replacement (David procedure) in our institution with an uneventful postoperative course. A review of the literature in combination with discussion of our case suggests the application of stronger recommendations towards preoperative cardiovascular assessment in patients with pectus excavatum.

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QUESTION UNDER STUDY: Cognitive impairment occurs during multiple sclerosis (MS) and contributes to the burden of the disease, but its effect in the initial phase of MS still needs to be better understood. METHODS: We prospectively studied 127 early MS patients presenting with a clinically isolated syndrome (CIS) or definite MS, a mean disease duration of 2.6 years, and with minor disability (mean Expanded Disability Status Scale score 1.8). Patients were tested for long-term memory, executive functions, attention, fatigue, mood disorders, functional handicap and quality of life (QoL). Twenty-one CIS patients were excluded from study as the diagnosis of MS could not be confirmed. RESULTS: Over the 106 MS patients analysed, 31 (29.3%) were cognitively impaired (23.6% for memory, 10.4% for attention and 5.7% for executive functions). Cognitive deficits were already present in CIS patients in whom the diagnosis was not yet confirmed (20%). Impaired cognition was associated with anxiety (p = 0.05), depression(p = 0.004), fatigue (p = 0.03), handicap (p <0.001) and a lower QoL (p <0.001). After adjustment for QoL, handicap, depression, anxiety and fatigue were no longer associated with the presence of cognitive deficits. CONCLUSIONS: In this well-defined early MS group one third of the patients already exhibited cognitive deficits, which were usually apparent in an effortful learning situation and were generally mild. Mood disorders, fatigue, handicap and decreased QoL were all associated with the occurrence of cognitive deficits. QoL itself appeared to take all the other factors into account. Our results confirm the existence of an interplay between cognitive, affective and functional changes and fatigue in early MS.

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OBJECTIVE: To analyse the effect of differentiation on disease-free survival (DFS) and overall survival (OS) in patients with stage I adenocarcinoma of the endometrium. PATIENTS AND METHODS: From 1979 to 1995, 350 patients with FIGO stage IA-IC with well (G1), moderately (G2) or poorly (G3) differentiated tumors were treated with surgery and high dose-rate brachytherapy with or without external radiation. Median age was 65 years (39-86 years). RESULTS: The 5-year DFS was 88+/-3% for the G1 tumors, 77+/-4% for the G2 tumors, and 67+/-7% for the G3 tumors (P=0.0049). With regard to the events contributing to DFS, the 5-year cumulative percentage of local relapse was 4.6% for the G1 tumors, 9.0% for the G2 tumors, and 4.6% (P=0.027) for the G3 tumors. Cumulative percentage of metastasis was 1.4, 6.3 and 7.2% (P<0.001), respectively, whereas percentages of death were 6.0, 7.9 and 20.7% (P<0.001). The 5-year OS was 91+/-3, 83+/-4 and 76+/-7%, respectively (P=0.0018). In terms of multivariate hazard ratios (HR), the relative differences between the three differentiation groups correspond to an increase of 77% of the risk of occurrence of either of the three events considered for the DFS (HR=1.77, 95% CI [0.94-3.33]), (P=0.078) for the G2 tumors and of 163% (HR=2.63, 95% CI [1.27-5.43]), (P=0.009) for the G3 tumors with respect to the G1 tumors. The estimated relative hazards for OS are, respectively, in line with those for DFS: HR=1.51 (P=0.282) for the G2 tumors; and HR=3.37 (P=0.003) for the G3 tumors. CONCLUSION: Patients with grade 1 tumors are those least exposed to either local relapse, metastasis, or death. In contrast patients with grade 2 tumors seem to be at higher risk of metastasis, whereas patients with grade 3 tumors appear at higher risk of death. Since we have looked at the first of three competing events (local relapse, metastasis and death), this suggests that patients with grade 3 tumors probably progress to death so fast that local relapse, if any, cannot be observed.

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Mutations of the TP53 and Ki-ras genes have been reported to be of prognostic importance in colorectal carcinomas. An increased intracellular concentration of the p53 protein, although not identical to, is sometimes seen in tumours with TP53 mutation and has been correlated with poor prognosis in some tumour types. Previous colorectal cancer studies, addressing the prognostic importance of Ki-ras mutation and TP53 aberrations, yielded contradictory results. The aim of this study was to determine in a clinically and therapeutically homogeneous group of 122 sporadic Dukes' B colorectal carcinomas with a median follow-up of 67 months (3-144 months) whether or not p53 protein expression, TP53 mutation and K-ras mutation correlated with prognosis. p53 staining was performed by immunohistochemistry, using the monoclonal antibody DO7 on paraffin-embedded tissue. Mutations in exons 5-8 of the TP53 gene and in codons 12 and 13 of the K-ras gene were assayed in paraffin-embedded tissue by the single-strand conformation polymorphism (SSCP) assay. Nuclear p53 staining was found in 57 (47%) tumours. Aberrant migration patterns indicating mutation of the TP53 gene were found in 39 (32%) tumours. Forty-six carcinomas (38%) showed a mutation of the Ki-ras codons 12 or 13. In a univariate analysis, patients with wild-type TP53 status showed a trend towards better survival, compared with those with mutated TP53 (log-rank test, P = 0.051). Likewise, tumours immunohistochemically positive for p53 showed a worse prognosis than p53-negative tumours (P = 0.010). The presence or absence of mutations in Ki-ras did not correlate with prognosis (P = 0.703). In multivariate analysis, only p53 immunoreactivity emerged as an independent marker for prognosis hazard ratio (HR) = 2.16, 95% confidence interval (CI) 1.12-4.11, P = 0.02). Assessment of p53 protein expression is more discriminative than TP53 mutation to predict the outcome of Dukes' stage B tumours and could be a useful tool to identify patients who might benefit from adjuvant therapy.