Analysing and modelling the growth behaviour of Listeria monocytogenes on RTE cooked meat products after a high pressure treatment at 400 MPa

Various predictive models are available for high pressure inactivation of Listeria monocytogenes in food, but currently available models do not consider the growth kinetics of surviving cells during the subsequent storage of products. Therefore, we characterised the growth of L. monocytogenes in sliced cooked meat products after a pressurization treatment. Two inoculum levels (10(7) or 10(4) CFU/g) and two physiological states before pressurization (freeze-stressed or cold-adapted) were evaluated. Samples of cooked ham and mortadella were inoculated, high pressure processed (400 MPa, 5 min) and subsequently stored at 4, 8 and 12 °C. The Logistic model with delay was used to estimate lag phase (λ) and maximum specific growth rate (μmax) values from the obtained growth curves. The effect of storage temperature on μmax and λ was modelled using the Ratkowsky square root model and the relative lag time (RLT) concept. Compared with cold-adapted cells the freeze-stressed cells were more pressure-resistant and showed a much longer lag phase during growth after the pressure treatment. Interestingly, for high-pressure inactivation and subsequent growth, the time to achieve a concentration of L. monocytogenes 100-fold (2-log) higher than the cell concentration prior to the pressure treatment was similar for the two studied physiological states of the inoculum. Two secondary models were necessary to describe the different growth behaviour of L. monocytogenes on ready-to-eat cooked ham (lean product) and mortadella (fatty product). This supported the need of a product-oriented approach to assess growth after high pressure processing. The performance of the developed predictive models for the growth of L. monocytogenes in high-pressure processed cooked ham and mortadella was evaluated by comparison with available data from the literature and by using the Acceptable Simulation Zone approach. Overall, 91% of the relative errors fell into the Acceptable Simulation Zone.

Quality of raw and smoked fillets from clinically healthy Atlantic salmon, Salmo salar L., following an outbreak of pancreas disease (PD)

Pancreas disease (PD) is a viral disease of farmed salmonid fish, which causes huge economic losses. Pathological changes in skeletal muscle, pancreas and heart are hallmarks of PD. Stakeholders in the fish-smoking industry have claimed that fillets from PD-affected Atlantic salmon, Salmo salar L., are of poor quality. We therefore examined harvest-ready, clinically healthy Atlantic salmon from a population of fish previously affected by PD. Histopathological changes in skeletal muscle tissues ranged from minor to severe. Fillet quality measurements showed that fish with severe skeletal muscle changes provided a paler raw fillet and a yellowish and harder cold-smoked fillet than normal. PD had no significant effect on fillet gaping, bacteriological quality or off-odour development during storage. An unexpected finding was a significant subendocardial fibrosis in 23% of the PD-affected fish. The latter may indicate susceptibility to stress-related heart failure.

Lens autofluorescence in diabetes compared with the level of glycosylated hemoglobin A1c

The autofluorescence of the crystalline lens has been measured by an ocular fluorophotometer in two comparable groups of patients with insulin-dependent diabetes mellitus. One group has had a high level of HbA1c since the onset of diabetes (mean 10.1 per cent) and the other group a very low level (mean 6.5 per cent). The group with low HbA1c during the disease period showed a significantly lower lens fluorescence than the group with high HbA1c.

Fluorophotometric evaluation of ocular barriers and of the vitreous body in the aphakic eye

8 aphakic patients were studied with fluorophotometry and 3-mirror examination of the vitreous body one month after cataract extraction. 4 were extracapsular with posterior chamber pseudophakos (ECCE) and 4 were intracapsular with anterior chamber pseudophakos (ICCE). A mathematical model is used to calculate blood-ocular fluorescein permeability (P) and vitreous diffusion coefficient (D) from fluorophotometric scans. All 30-minutes scans in the ECCE group and 2 in the ICCE showed a profile resembling that in phakic eyes, and P- and D-values were calculated. In the remaining two patients from the ICCE group scans showed rapid filling of the vitreous cavity with fluoroscein and calculations could not be made. Clinical examination showed vitreous detachment in these two eyes whereas the others had a normal vitreous structure evaluated by 3-mirror examination. It is shown that fluorophotometric readings can be made in both intra- and extracapsularly operated eyes. Rapid mixing of the dye in the vitreous cavity is seen in relation to vitreous detachment.

Validity of clinical symptoms in benign esophageal disease, assessed by questionnaire

A questionnaire designed to test the value of questions identifying benign esophageal disease was sent to patients representing four well-defined entities: angina pectoris (n = 30), benign esophageal disease (n = 25), gastroduodenal ulcer or former gallstones (n = 27) and normal subjects (n = 38). By means of logistic regression, three key-questions were selected. A combination of an affirmative answer to "difficulty in swallowing solid food" and to "pain in the chest" or "heartburn at night" or both did not occur in the group of normal subjects, while occurring in 68% of the patients with esophageal diseases. The combination occurred in only 10% of the patients with angina pectoris and 15% of those suffering from gastroduodenal ulcer or gallstones. The predictive accuracy of the combination of the three questions is estimated for various hypothetic prevalences of esophageal disease. These questions appear to identify approximately two-thirds of individuals with esophageal disease with acceptable false-positive rates and can therefore be used in epidemiological studies.

Information systems in food safety management

Information systems are concerned with data capture, storage, analysis and retrieval. In the context of food safety management they are vital to assist decision making in a short time frame, potentially allowing decisions to be made and practices to be actioned in real time. Databases with information on microorganisms pertinent to the identification of foodborne pathogens, response of microbial populations to the environment and characteristics of foods and processing conditions are the cornerstone of food safety management systems. Such databases find application in: Identifying pathogens in food at the genus or species level using applied systematics in automated ways. Identifying pathogens below the species level by molecular subtyping, an approach successfully applied in epidemiological investigations of foodborne disease and the basis for national surveillance programs. Predictive modelling software, such as the Pathogen Modeling Program and Growth Predictor (that took over the main functions of Food Micromodel) the raw data of which were combined as the genesis of an international web based searchable database (ComBase). Expert systems combining databases on microbial characteristics, food composition and processing information with the resulting "pattern match" indicating problems that may arise from changes in product formulation or processing conditions. Computer software packages to aid the practical application of HACCP and risk assessment and decision trees to bring logical sequences to establishing and modifying food safety management practices. In addition there are many other uses of information systems that benefit food safety more globally, including: Rapid dissemination of information on foodborne disease outbreaks via websites or list servers carrying commentary from many sources, including the press and interest groups, on the reasons for and consequences of foodborne disease incidents. Active surveillance networks allowing rapid dissemination of molecular subtyping information between public health agencies to detect foodborne outbreaks and limit the spread of human disease. Traceability of individual animals or crops from (or before) conception or germination to the consumer as an integral part of food supply chain management. Provision of high quality, online educational packages to food industry personnel otherwise precluded from access to such courses.

Biogenic amine formation and microbial spoilage in chilled garfish (Belone belone belone) - effect of modified atmosphere packaging and previous frozen storage

AIMS

To evaluate biogenic amine formation and microbial spoilage in fresh and thawed chilled garfish.

METHODS AND RESULTS

Storage trials were carried out with fresh and thawed garfish fillets at 0 or 5 degrees C in air or in modified atmosphere packaging (MAP: 40% CO2 and 60% N2). During storage, sensory, chemical and microbial changes were recorded and histamine formation by isolates from the spoilage microflora was evaluated at 5 degrees C. Photobacterium phosphoreum was responsible for histamine formation (>1000 ppm) in chilled fresh garfish. The use of MAP did not reduce the histamine formation. Strongly histamine-producing P. phosphoreum isolates formed 2080-4490 ppm at 5 degrees C, whereas below 60 ppm was formed by other P. phosphoreum isolates. Frozen storage inactivated P. phosphoreum and consequently reduced histamine formation in thawed garfish at 5 degrees C markedly.

CONCLUSIONS

Photobacterium phosphoreum can produce above 1000 ppm of histamine in chilled fresh garfish stored both in air and in MAP. Freezing inactivates P. phosphoreum, extends shelf life and markedly reduces histamine formation in thawed MAP garfish during chilled storage.

SIGNIFICANCE AND IMPACT OF THE STUDY

At 5 degrees C, more than 1000 ppm of histamine was formed in garfish; thus even when it is chilled this product represents a histamine fish-poisoning risk.

Dosage dependent hormonal counter regulation to combination therapy in patients with left ventricular dysfunction

The present study attempts to assess the efficacy combination therapy for heart failure. Genuine dose-response studies on combination therapy are not available and published studies involved adding one drug on top of 'usual treatment'. Sixteen different dosage combinations of trandolapril and bumetanide was tested in a double blind, double placebo-controlled, randomized, multiple cross-over study in a 16 times six balanced incomplete Latin square design. Patients reported optimal quality of life on the sub maximal dose bumetanide. Bumetanide decreased left ventricular function and increased heart rate and plasma noradrenaline in a dose dependent manner. Doses of bumetanide of more than 0.5 mg, given twice daily significantly decreased the quality of life and increased diuresis. Weight loss was maximal on 0.5 mg bumetanide twice daily. Trandolapril significantly reduced systolic blood pressure with the maximal effect at 0.5 mg daily. Both drugs significantly increased renin concentration with a significant potentiating interaction. It was not possible to detect beneficial effects of combination therapies. The optimal dosage of Bumetanide appeared to be 0.5 mg twice daily based on its effect on quality of life and weight loss. Estimated by the reduction in systolic blood pressure the optimal dosage of Trandolapril appeared to be 0.5 mg once daily.

CONCLUSIONS

It appears that patients should be given less than the usually recommended dosages. Patients may be treated with a low dose loop diuretic, if signs of water retention are present or if symptomatic relief is desired.

Nonbioluminescent strains of Photobacterium phosphoreum produce the cell-to-cell communication signal N-(3-Hydroxyoctanoyl)homoserine lactone

Bioluminescence is a common phenotype in marine bacteria, such as Vibrio and Photobacterium species, and can be quorum regulated by N-acylated homoserine lactones (AHLs). We extracted a molecule that induced a bacterial AHL monitor (Agrobacterium tumefaciens NT1 [pZLR4]) from packed cod fillets, which spoil due to growth of Photobacterium phosphoreum. Interestingly, AHLs were produced by 13 nonbioluminescent strains of P. phosphoreum isolated from the product. Of 177 strains of P. phosphoreum (including 18 isolates from this study), none of 74 bioluminescent strains elicited a reaction in the AHL monitor, whereas 48 of 103 nonbioluminescent strains did produce AHLs. AHLs were also detected in Aeromonas spp., but not in Shewanella strains. Thin-layer chromatographic profiles of cod extracts and P. phosphoreum culture supernatants identified a molecule similar in relative mobility (Rf value) and shape to N-(3-hydroxyoctanoyl)homoserine lactone, and the presence of this molecule in culture supernatants from a nonbioluminescent strain of P. phosphoreum was confirmed by high-performance liquid chromatography-positive electrospray high-resolution mass spectrometry. Bioluminescence (in a non-AHL-producing strain of P. phosphoreum) was strongly up-regulated during growth, whereas AHL production in a nonbioluminescent strain of P. phosphoreum appeared constitutive. AHLs apparently did not influence bioluminescence, as the addition of neither synthetic AHLs nor supernatants delayed or reduced this phenotype in luminescent strains of P. phosphoreum. The phenotypes of nonbioluminescent P. phosphoreum strains regulated by AHLs remains to be elucidated.

Shelf life and safety aspects of chilled cooked and peeled shrimps (Pandalus borealis) in modified atmosphere packaging

AIMS

To evaluate the growth of Listeria monocytogenes and shelf life of cooked and peeled shrimps in modified atmosphere packaging (MAP).

METHODS AND RESULTS

Storage trials with naturally contaminated cooked and peeled MAP shrimps (Pandalus borealis) were carried out at 2, 5 and 8 degrees C. Challenge tests at the same conditions were performed after inoculation with Listeria monocytogenes. Both storage trials and challenge tests were repeated after 4 months of frozen storage (-22 degrees C). Brochothrix thermosphacta and Carnobacterium maltaromaticum were responsible for sensory spoilage of cooked and peeled MAP shrimps. In challenge tests, growth of L. monocytogenes was observed at all of the storage temperatures studied. At 5 and 8 degrees C the concentration of L. monocytogenes increased more than a 1000-fold before the product became sensory spoiled whereas this was not observed at 2 degrees C. Frozen storage had only a minor inhibiting effect on growth of L. monocytogenes in the thawed product.

CONCLUSIONS

To prevent L. monocytogenes becoming a safety problem, cooked and peeled MAP shrimps should be distributed at 2 degrees C and with a maximum shelf life of 20-21 d. At higher temperatures shelf life is significantly reduced.

SIGNIFICANCE AND IMPACT OF THE STUDY

Information is provided to establish shelf life of cooked and peeled MAP shrimps.

Lens fluorescence and metabolic control in type 1 diabetic patients: a 14 year follow up study

BACKGROUND/AIMS

In this prospective study the authors followed the post-translational modification of the proteins of the lens of the eye by fluorometry over a period of 14 years in patients with type 1 diabetes mellitus.

METHODS

Twenty patients were examined at 6 years (baseline) and 20 years (follow up) after onset of diabetes mellitus. Glycaemic levels were assessed from HbA1c measured at regular intervals from the onset of diabetes mellitus.

RESULTS

Lens fluorescence at follow up was significantly related to mean HbA1c during the study period and to lens fluorescence at baseline (p<0.0001). Sixty per cent of the variation in rate of increase in lens fluorescence during the study period was statistically attributable to glycaemia levels.

CONCLUSION

The results confirm that the rate of fluorophore accumulation in the lens of adult diabetic patients is increased in proportion to glycaemic control. This parameter alone is, however, not sufficient to explain the entire variation in lens fluorophore accumulation. Consequently, lens fluorescence must be influenced by other factors before initiation and during the study period, and possibly even before onset of diabetes mellitus. The underlying mechanism could be a variation in susceptibility to lens protein denaturation by glycation.

Effects of high-pressure processing on Listeria monocytogenes, spoilage microflora and multiple compound quality indices in chilled cold-smoked salmon

AIMS

To evaluate the effect of high-pressure processing (HPP) on Listeria monocytogenes, microbial and chemical changes and shelf-life in chilled cold-smoked salmon (CSS).

METHODS AND RESULTS

First, challenge tests with L. monocytogenes were carried out using HPP of the product at 0.1 (control), 150, 200 and 250 MPa. Secondly, storage trials with the naturally contaminated product and HPP at 0.1 (control) and 200 MPa were realized. Shelf-life, microbial changes and chemical changes were determined and existing predictive models and multiple compound quality indices evaluated. HPP with 250 MPa did not inactivate L. monocytogenes but significant lag phases of 17 and 10 days were observed at ca 5 and 10 degrees C, respectively. HPP with 200 MPa had a marked effect on both colour and texture of CSS.

CONCLUSIONS

High-pressure processing was unable to prevent growth of L. monocytogenes or spoilage of chilled CSS. Existing mathematical models allowed growth rates of L. monocytogenes and shelf-life of samples without high-pressure treatments to be predicted.

SIGNIFICANCE AND IMPACT OF THE STUDY

High-pressure processing seems more appropriate for new types of salmon products than for a classical product like CSS where consumers expect specific quality attributes.

Modelling and predicting the simultaneous growth of Listeria monocytogenes and spoilage micro-organisms in cold-smoked salmon

AIMS

To evaluate and model the simultaneous growth of Listeria monocytogenes and spoilage micro-organisms in cold-smoked salmon.

METHODS AND RESULTS

Growth kinetics of L. monocytogenes, lactic acid bacteria (LAB), Enterobacteriaceae, enterococci and Photobacterium phosphoreum were determined in two series of challenge tests with sliced and vacuum-packed cold-smoked salmon (SVP-CSS). The product contained a high level of smoke components and at 2 degrees C levels of L. monocytogenes increased <100-fold in 193 days. Without the addition of spoilage micro-organisms, L. monocytogenes reached ca 108 CFU g-1 at 5, 10, 17.5 and 25 degrees C. Inoculation with spoilage micro-organisms reduced this level to 102-104 CFU g-1. LAB dominated the spoilage microfora of SVP-CSS and competition between LAB and L. monocytogenes in SVP-CSS was appropriately described by a simple expansion of the Logistic model. This interaction model aided in predicting the growth of L. monocytogenes in naturally contaminated SVP-CSS when it was used in combination with expanded versions of existing secondary models for L. monocytogenes and LAB.

CONCLUSIONS

Temperature, water activity/NaCl, simultaneous growth of LAB, smoke components and to a lesser extent lactate and pH control growth of L. monocytogenes in SVP-CSS. These factors must be included in mathematical models to predict growth of the pathogen in this product.

SIGNIFICANCE AND IMPACT OF THE STUDY

The suggested predictive model can be used to support assessment and management of the human health risk due to L. monocytogenes in SVP-CSS.

Identification of lactic acid bacteria from spoilage associations of cooked and brined shrimps stored under modified atmosphere between 0 degrees C and 25 degrees C

AIMS

To evaluate spoilage and identify lactic acid bacteria (LAB) from spoilage associations of cooked and brined shrimps stored under modified atmosphere packaging (MAP) at 0, 5, 8, 15 and 25 degrees C.

METHODS AND RESULTS

Bacterial isolates (102) from spoilage associations of cooked and brined MAP shrimps were characterized by phenotypic tests and identified as lactic acid bacteria (78 isolates), other Gram-positive bacteria (13 isolates) and Gram-negative bacteria (11 isolates). A selection of 48 LAB isolates were further characterized and identified by phenotypic tests and SDS-PAGE electrophoresis of whole cell proteins. Selected clusters of LAB isolates were analysed by plasmid profiling, pulsed field gel electrophoresis and 16S rRNA gene sequencing. Enterococcus faecalis was identified in spoilage associations at 15 degrees C and 25 degrees C, and its metabolic activity corresponded to chemical changes in spoiled products. Carnobacterium divergens, a non-motile Carnobacterium sp. nov. and Lactobacillus curvatus were the LAB species observed in spoilage associations of products stored at 0 degrees C, 5 degrees C and 8 degrees C.

CONCLUSIONS

Enterococcus spp. and Carnobacterium spp. were the dominant parts of spoilage associations of cooked and brined MAP shrimps stored at high and low temperatures, respectively.

SIGNIFICANCE AND IMPACT OF THE STUDY

The SDS-PAGE technique and simple biochemical keys allowed the majority of LAB isolates from spoilage associations of cooked and brined MAP shrimps to be identified at the species level.

Microbial spoilage and formation of biogenic amines in fresh and thawed modified atmosphere-packed salmon (Salmo salar) at 2 degrees C

AIMS

To evaluate the microbial spoilage, formation of biogenic amines and shelf life of chilled fresh and frozen/thawed salmon packed in a modified atmosphere and stored at 2 degrees C.

METHODS AND RESULTS

The dominating microflora, formation of biogenic amines and shelf life were studied in two series of storage trials with naturally contaminated fresh and thawed modified atmosphere-packed (MAP) salmon at 2 degrees C. Photobacterium phosphoreum dominated the spoilage microflora of fresh MAP salmon at more than 10(6) cfu g(-1) and the activity of this specific spoilage organism (SSO) limited the shelf life of the product to ca 14 and 21 d in the two experiments. Despite the high levels of P. phosphoreum, less than 20 mg kg(-1) histamine was observed in fresh MAP salmon prior to sensory spoilage. Freezing eliminated P. phosphoreum and extended the shelf life of MAP salmon at 2 degrees C by 1-2 weeks. Carnobacterium piscicola dominated the spoilage microflora of thawed MAP salmon and probably produced the ca 40 mg kg(-1) tyramine detected in this product at the end of its shelf life.

CONCLUSIONS

Photobacterium phosphoreum dominated the spoilage microflora of fresh MAP salmon but produced only small amounts of biogenic amines in this product. The elimination of P. phosphoreum by freezing allowed this bacteria to be identified as the SSO in fresh MAP salmon.

SIGNIFICANCE AND IMPACT OF THE STUDY

The identification of P. phosphoreum as the SSO in fresh MAP salmon facilitates the development of methods to determine and predict the shelf life of this product, as previously shown with fresh MAP cod.

Antimicrobial effect of essential oils on the seafood spoilage micro-organism Photobacterium phosphoreum in liquid media and fish products

AIMS

To evaluate the antimicrobial effect of nine essential oils (EO) on P. phosphoreum and determine the effect of oregano oil on the shelf-life of modified atmosphere-packed (MAP) cod fillets.

METHODS AND RESULTS

The antimicrobial effect of EO was studied in a liquid medium and in product storage trials. Oils of oregano and cinnamon had strongest antimicrobial activity, followed by lemongrass, thyme, clove, bay, marjoram, sage and basil oils. Oregano oil (0.05%, v/w) reduced growth of P. phosphoreum in naturally contaminated MAP cod fillets and extended shelf-life from 11-12 d to 21-26 d at 2 degrees C.

CONCLUSIONS

Oregano oil reduced the growth of P. phosphoreum and extended the shelf-life of MAP cod fillets.

SIGNIFICANCE AND IMPACT OF THE STUDY

Mild and natural preservation using EO can extend the shelf-life of MAP seafood through inhibiting the specific spoilage organism P. phosphoreum.

In vivo evidence of altered skeletal muscle blood flow in chronic tension-type headache

Painful impulses from tender pericranial muscles may play a major role in the pathophysiology of chronic tension-type headache. Firm evidence for peripheral muscle pathology as a cause of muscle pain and chronic headache is still lacking. Using a microdialysis technique, we aimed to estimate in vivo blood flow and interstitial lactate concentrations in the trapezius muscle at rest and during static exercise in patients with chronic tension-type headache and in healthy subjects. We recruited 16 patients with chronic tension-type headache and 17 healthy control subjects. Two microdialysis catheters were inserted into the trapezius muscle (on the non-dominant side) of subjects, and dialysates were collected at rest, 15 and 30 min after the start of static exercise (10% of maximal force) and 15 and 30 min after the exercise was completed. All samples were coded and analysed blind. The primary endpoints were to detect a difference between patients and controls in changes of muscle blood flow and the interstitial lactate concentration from baseline to exercise and post-exercise periods. The increase in muscle blood flow from baseline to exercise and post-exercise periods was significantly lower in patients than controls (P = 0.03). There was no difference in resting blood flow between patients and controls (P = 0.43). Resting interstitial concentration of lactate did not differ between patients (2.51 +/- 0.18 mM; mean +/- standard error of the mean) and controls (2.35 +/- 0.23 mM, P = 0.57). There was no difference in change in interstitial lactate from baseline to exercise and post-exercise periods between patients and controls (P = 0.38). The present study provides in vivo evidence of decreased blood flow in response to static exercise in a tender muscle in patients with chronic tension-type headache. We suggest that, because of increased excitability of neurones in the CNS, the central interpretation and response to normal sensory input are altered in patients with chronic tension-type headache. This may lead to enhanced sympathetically mediated vasoconstriction and thereby a decreased blood flow in response to static exercise.

Significance of volatile compounds produced by spoilage bacteria in vacuum-packed cold-smoked salmon (Salmo salar) analyzed by GC-MS and multivariate regression

Changes were studied in the concentration of 38 volatile compounds during chilled storage at 5 degrees C of six lots of commercially produced vacuum-packed cold-smoked salmon and sterile cold-smoked salmon. The majority of volatile compounds produced during spoilage of cold-smoked salmon were alcohols, which were produced by microbial activity. Partial least-squares regression of volatile compounds and sensory results allowed for a multiple compound quality index to be developed. This index was based on volatile bacterial metabolites, 1-propanol and 2-butanone, and 2-furancarboxaldehyde produced by autolytic activity. Only a few of the volatile compounds produced during spoilage of cold-smoked salmon had an aroma value high enough to indicate contribution to the spoilage off-flavor of cold-smoked salmon. These were trimethylamine, 3-methylbutanal, 2-methyl-1-butanol, 3-methyl-1-butanol, 1-penten-3-ol, and 1-propanol. The potency and importance of these compounds was confirmed by gas chromatography-olfactometry. The present study provides valuable information on the bacterial reactions responsible for spoilage off-flavors of cold-smoked salmon, which can be used to develop biosensors for on-pack shelf-life determinations.

Allelic loss of chromosome 2p21-16.3 is associated with reduced survival in sporadic colorectal cancer

BACKGROUND

Since allelic loss of genes involved in the development of colorectal cancer could serve as prognostic markers, we examined the correlation between loss of markers linked to the hMSH2/hMSH6 (2p21-16.3), hMLH1 (3p21.3), APC (5q21-22), p53 (17p13.1) and DCC (18q21.3) loci and survival in a series of 64 consecutively collected colorectal cancers.

METHODS

The association between allelic loss and survival was analysed by univariate and multivariate tests to identify independent variables of survival.

RESULTS

Loss of chromosome 2p21-16.3 reduced the overall 5-year survival from 52% to 15% (P = 0.0003). The prognostic significance was evident in patients with Dukes' A + B as well as Dukes' C tumours. A multivariate analysis comparing Dukes' staging, age at diagnosis, tumour localization, sex, loss of chromosome 2p21-16.3, 3p21.3, 5q21-22, 17p13.1 or 18q21.3 and microsatellite instability showed that only Dukes' staging (hazard ratio 3.0; 1.4-6.5 with 95% confidence interval, P = 0.0065) and loss of 2p21-16.3 (hazard ratio 6.2; 2.3-16.8 with 95% confidence interval, P = 0.0006) were independent variables of survival. Loss of 2p21-16.3 was, moreover, associated with increased loss of the other tumour suppressor loci (P = 0.012).

CONCLUSIONS

The results show that loss of 2p21-16.3 is an independent indicator of survival in patients with colorectal cancer.