Cytotoxicity assay as a potential alternative method for animal testing for batch release of Italian fish autogeneous vaccines

Background

Vaccination is widely used in fish aquaculture for three primary reasons: to prevent bacterial disease spreading, minimize antibiotic use and fight antibiotic resistance. Vaccine production is an expensive and consuming process, mainly in terms of money, resources, and animals for quality control. The replace, reduce, and refine (3Rs) philosophy suggests developing and validates alternative methods to animal testing for scientific purposes, even for biologicals and vaccines.

Aim

The current study explored the potential use of mouse and fish cells in the in vitro toxicity grade assessment through different methods, as an alternative assay to in vivo residual toxicity tests for autogenous fish vaccine control.

Methods

BF2 and L929 cell lines were exposed to vaccine dilutions in two different ways of administration and toxicity grade was recorded by MTS assay, compared to the in vivo gold standard test.

Results

Autogenous vaccines (AVs) caused no reactions in the in vivo test. In the in vitro assay, the different toxicity grade recorded was statistically significant between the cell lines adopted and the AVs way of administration.

Conclusions

Data obtained represent the first application of 3Rs method to fish AVs produced in Italy, more investigations are needed to collect solid results and standardize new in vitro methods for vaccine quality control.

The Stromal Vascular Fraction from Canine Adipose Tissue Contains Mesenchymal Stromal Cell Subpopulations That Show Time-Dependent Adhesion to Cell Culture Plastic Vessels

Adipose-derived mesenchymal stromal cells (MSCs) are extensively studied in both human and veterinary medicine. Their isolation is usually performed by collagenase digestion followed by filtration and removal of nonadherent tissue remnants 48 h after seeding. We observed that waste tissue fragments contain cells that adhere belatedly to the plastic. We aimed to investigate their basic properties to speculate on the possible existence of MSC subpopulations. Adipose tissue from three dogs was enzymatically digested. Three cell populations that adhered to the culture plastic 48, 96, and 144 h after seeding were obtained. After expansion, they were analyzed by flow cytometry for MSC-positive (CD90, CD44, and CD29) and -negative (CD14, MHCII, and CD45) markers as well as for endothelial, pericyte, and smooth muscle cell markers (CD31, CD146, and alpha-SMA). Furthermore, cells were assessed for viability, doubling time, and trilineage differentiation ability. No significant differences were found between the three subpopulations. As a result, this procedure has proven to be a valuable method for dramatically improving MSCs yield. As a consequence of cell recovery optimization, the amount of tissue harvested could be reduced, and the time required to obtain sufficient cells for clinical applications could be shortened. Further studies are needed to uncover possible different functional properties.

Dietary fatty acids and endometrial cancer risk within the European Prospective Investigation into Cancer and Nutrition

BACKGROUND

Diet may impact important risk factors for endometrial cancer such as obesity and inflammation. However, evidence on the role of specific dietary factors is limited. We investigated associations between dietary fatty acids and endometrial cancer risk in the European Prospective Investigation into Cancer and Nutrition (EPIC).

METHODS

This analysis includes 1,886 incident endometrial cancer cases and 297,432 non-cases. All participants were followed up for a mean of 8.8 years. Multivariable Cox proportional hazard models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI) of endometrial cancer across quintiles of individual fatty acids estimated from various food sources quantified through food frequency questionnaires in the entire EPIC cohort. The false discovery rate (q-values) was computed to control for multiple comparisons.

RESULTS

Consumption of n-6 γ-linolenic acid was inversely associated with endometrial cancer risk (HR comparing 5th with 1st quintileQ5-Q1=0.77, 95% CI = 0.64; 0.92, ptrend=0.01, q-value = 0.15). This association was mainly driven by γ-linolenic acid derived from plant sources (HRper unit increment=0.94, 95%CI= (0.90;0.98), p = 0.01) but not from animal sources (HRper unit increment= 1.00, 95%CI = (0.92; 1.07), p = 0.92). In addition, an inverse association was found between consumption of n-3 α-linolenic acid from vegetable sources and endometrial cancer risk (HRper unit increment= 0.93, 95%CI = (0.87; 0.99), p = 0.04). No significant association was found between any other fatty acids (individual or grouped) and endometrial cancer risk.

CONCLUSION

Our results suggest that higher consumption of γ-linolenic acid and α-linoleic acid from plant sources may be associated with lower risk of endometrial cancer.

Expression of a recombinant ASFV P30 protein and production of monoclonal antibodies

Background: African Swine Fever (ASF) is an infectious disease that affects domestic pig and wild boar populations. The African Swine Fever Virus (ASFV) has a genome characterized by a very complex DNA (170-193 kb) that encodes for more than 200 different proteins. Among these, the highly immunogenic phosphoprotein p30 plays a fundamental role in the induction of specific antibodies. To date, the lack of a vaccine against the disease requires continuous studies to improve knowledge about the virus and the development of new tests in addition to virological ones. Aim: The aim of this work was to produce specific monoclonal antibodies (mAbs) against the p30 protein of ASFV, which could find useful applications in routine diagnostics and the implementation of new diagnostic tools. Methods: ASFV p30 encoding gene was amplified and used for the generation of the recombinant baculovirus by transfection of the Sf21 insect cells. The recombinant protein was analyzed by immunofluorescence assay, purified, and used for mice Balb-c immunization. The hybridomas obtained were cultured and screened, using an indirect Enzyme-linked Immunosorbent Assay (iELISA), in order to select clones that secrete the mAbs of interest. Results: The expression of recombinant p30 protein was assessed using direct Immunofluorescence. The purified p30 protein fractions were analyzed by Coomassie gels staining confirming the presence of bands with a molecular weight of 30 kDa and used for the immunization of Balb-c mice. Six clones of pure hybridomas secreting the specific mAbs against recombinant p30 were obtained and tested in iELISA. The mAbs were also characterized by Western blot and Immunofluorescence assay. The best results were obtained with the anti-p30 mAb 2B8E10 clone which showed high reactivity with both recombinant and viral p30 protein, respectively. Conclusion: In this work, a recombinant p30 protein produced in an insect cell system was purified and used to immunize Balb-c mice. Six anti-p30 mAbs-secreting hybridomas clone cells were obtained. These mAbs displayed high reactivity against the recombinant protein, but only 2B8E10 mAb showed excellent functionality against the p30 protein produced by ASFV. These results open the possibility to develop different diagnostic assays.

A new Montanide"&#".ord($0).";""&#".ord($0).";" Seppic IMS 1313-adjuvanted autogenous vaccine as useful emergency tool to resolve a Salmonella enterica subsp. enterica serovar abortusequi abortion outbreak in mares

Background:

In Italy, an autogenous registered vaccine, adjuvanted with aluminum hydroxide, can be administrated to contrast Salmonella enterica subsp. enterica serovar abortus equi infection, coupled to a specific antimicrobial treatment.

Case Description:

Here, we report the case of an abortion outbreak by Salmonella abortus equi in Central Italy where mares were vaccinated but immediately developed a strong local reaction, maybe due to the adjuvant. Promptly, another autogenous vaccine, substituting the aluminum hydroxide with a new generation adjuvant (Montanide™ Seppic IMS1313), was produced and administrated. The new formulated vaccine did not cause any adverse outcome and conferred high protection titers against the infection. To the best of our knowledge, this is the first reported case of immunization by a vaccine adjuvanted with Montanide™ Seppic IMS1313 in horses.

Conclusion:

This approach may be used as a preventive strategy for further outbreaks in association with the application of recommended biosafety principles.

Association between menopausal hormone therapy, mammographic density and breast cancer risk: results from the E3N cohort study

BACKGROUND

Menopausal hormone therapy (MHT) is a risk factor for breast cancer (BC). Evidence suggests that its effect on BC risk could be partly mediated by mammographic density. The aim of this study was to investigate the relationship between MHT, mammographic density and BC risk using data from a prospective study.

METHODS

We used data from a case-control study nested within the French cohort E3N including 453 cases and 453 matched controls. Measures of mammographic density, history of MHT use during follow-up and information on potential confounders were available for all women. The association between MHT and mammographic density was evaluated by linear regression models. We applied mediation modelling techniques to estimate, under the hypothesis of a causal model, the proportion of the effect of MHT on BC risk mediated by percent mammographic density (PMD) for BC overall and by hormone receptor status.

RESULTS

Among MHT users, 4.2% used exclusively oestrogen alone compared with 68.3% who used exclusively oestrogens plus progestogens. Mammographic density was higher in current users (for a 60-year-old woman, mean PMD 33%; 95% CI 31 to 35%) than in past (29%; 27 to 31%) and never users (24%; 22 to 26%). No statistically significant association was observed between duration of MHT and mammographic density. In past MHT users, mammographic density was negatively associated with time since last use; values similar to those of never users were observed in women who had stopped MHT at least 8 years earlier. The odds ratio of BC for current versus never MHT users, adjusted for age, year of birth, menopausal status at baseline and BMI, was 1.67 (95% CI, 1.04 to 2.68). The proportion of effect mediated by PMD was 34% for any BC and became 48% when the correlation between BMI and PMD was accounted for. These effects were limited to hormone receptor-positive BC.

CONCLUSIONS

Our results suggest that, under a causal model, nearly half of the effect of MHT on hormone receptor-positive BC risk is mediated by mammographic density, which appears to be modified by MHT for up to 8 years after MHT termination.

Generation of recombinant baculovirus expressing atoxic C-terminal CPA toxin of Clostridium perfringens and production of specific antibodies

Background

Clostridium perfringens is the causative agent of several diseases and enteric infections in animals and humans. The virulence of C. perfringens is largely attributable to the production of numerous toxins; of these, the alpha toxin (CPA) plays a crucial role in histotoxic infections (gas gangrene). CPA toxin consists of two domains, i.e., the phospholipase C active site, which lies in the N-terminal domain amino acid (aa residues 1–250), and the C-terminal region (aa residues 251–370), which is responsible for the interaction of the toxin with membrane phospholipids in the presence of calcium ions. All currently produced clostridial vaccines contain toxoids derived from culture supernatants that are inactivated, mostly using formalin. The CPA is an immunogenic antigen; recently, it has been shown that mice that were immunized with the C-terminal domain of the toxin produced in E. coli were protected against C. perfringens infections and the anti-sera produced were able to inhibit the CPA activity. Monoclonal and polyclonal antibodies were produced only against full-length CPA and not against the truncated forms.

Results

In the present study, we have reported for the first time; about the generation of a recombinant baculovirus capable of producing a deleted rCPA toxin (rBacCPA250–363H6) lacking the N-terminal domain and the 28 amino acids (aa) of the putative signal sequence. The insertion of the L21 consensus sequence upstream of the translational start codon ATG, drastically increases the yield of recombinant protein in the baculovirus-based expression system. The protein was purified by Ni-NTA affinity chromatography and the lack of toxicity in vitro was confirmed in CaCo-2 cells. Polyclonal antibodies and eight hybridoma-secreting Monoclonal antibodies were generated and tested to assess specificity and reactivity. The anti-sera obtained against the fragment rBacCPA250–363H6 neutralized the phospholipase C activity of full-length PLC.

Conclusions

The L21 leader sequence enhanced the expression of atoxic C-terminal recombinant CPA protein produced in insect cells. The monoclonal and polyclonal antibodies obtained were specific and highly reactive. The availability of these biologicals could contribute to the development of diagnostic assays and/or new recombinant protein vaccines.

Socio-economic position across the lifecourse and risk of breast cancer: findings from EPIC-Italy

Backgrounds

Socio-economic position (SEP) is linked to many health outcomes but the link between SEP and breast cancer (BC) is complex. This study explores the relationship between SEP from early life and future risk of BC.

Methods

We used data from the Italian component of the European prospective investigation into cancer and nutrition: EPIC-Italy (up to 26,391 women). Cox proportional hazard models were used to estimate the association between measures of life course SEP (father’s occupation, educational level, highest household occupation) with risk of BC, adjusting for health behaviours (smoking, alcohol, physical activity, Mediterranean diet), height, weight and reproductive factors (postmenopausal status, age at first full term pregnancy). To mimic life course experiences, we analysed the relationship between father’s occupation and risk of BC, sequentially adjusting for SEP in young adulthood and adulthood, as well as the impact of social mobility.

Results

We observed a significant association between father’s occupation and risk of BC, where participant with low SEP had lower risk to develop BC (HR[95%CI] = 0.88[0.78; 0.99]). This association was borderline significant when we analysed educational level and highest household occupation. These associations were only slightly modified after adjustment for health behaviours, height and weight but more strongly affected by reproductive factors. However, the association between father’s occupation and BC remained borderline significant in the fully adjusted model (HR[95%CI] = 0.91[0.80; 1.03]). Stable low trajectory showed a lower risk of BC (HR[95%CI] = 0.82[0.71; 0.96]) slightly attenuated after adjusted for reproductive factors (HR[95%CI] = 0.88 [0.75; 1.03]).

Conclusions

Our findings suggest that low early-life SEP and stable low trajectory are associated with a lower risk of BC, which is partly explained by reproductive factors.

Key messages

Low early life socioeconomic position and stable low trajectory are associated with a lower risk of BC. Reproductive factors, especially age at the first full term pregnancy, explain part of these associations.

Vitamin B6 catabolism and lung cancer risk: results from the Lung Cancer Cohort Consortium (LC3)

BACKGROUND

Increased vitamin B6 catabolism related to inflammation, as measured by the PAr index (the ratio of 4-pyridoxic acid over the sum of pyridoxal and pyridoxal-5'-phosphate), has been positively associated with lung cancer risk in two prospective European studies. However, the extent to which this association translates to more diverse populations is not known.

MATERIALS AND METHODS

For this study, we included 5323 incident lung cancer cases and 5323 controls individually matched by age, sex, and smoking status within each of 20 prospective cohorts from the Lung Cancer Cohort Consortium. Cohort-specific odds ratios (ORs) and 95% confidence intervals (CIs) for the association between PAr and lung cancer risk were calculated using conditional logistic regression and pooled using random-effects models.

RESULTS

PAr was positively associated with lung cancer risk in a dose-response fashion. Comparing the fourth versus first quartiles of PAr resulted in an OR of 1.38 (95% CI: 1.19-1.59) for overall lung cancer risk. The association between PAr and lung cancer risk was most prominent in former smokers (OR: 1.69, 95% CI: 1.36-2.10), men (OR: 1.60, 95% CI: 1.28-2.00), and for cancers diagnosed within 3 years of blood draw (OR: 1.73, 95% CI: 1.34-2.23).

CONCLUSION

Based on pre-diagnostic data from 20 cohorts across 4 continents, this study confirms that increased vitamin B6 catabolism related to inflammation and immune activation is associated with a higher risk of developing lung cancer. Moreover, PAr may be a pre-diagnostic marker of lung cancer rather than a causal factor.

No association between circulating concentrations of vitamin D and risk of lung cancer: an analysis in 20 prospective studies in the Lung Cancer Cohort Consortium (LC3)

Background

There is observational evidence suggesting that high vitamin D concentrations may protect against lung cancer. To investigate this hypothesis in detail, we measured circulating vitamin D concentrations in prediagnostic blood from 20 cohorts participating in the Lung Cancer Cohort Consortium (LC3).

Patients and methods

The study included 5313 lung cancer cases and 5313 controls. Blood samples for the cases were collected, on average, 5 years before lung cancer diagnosis. Controls were individually matched to the cases by cohort, sex, age, race/ethnicity, date of blood collection, and smoking status in five categories. Liquid chromatography coupled with tandem mass spectrometry was used to separately analyze 25-hydroxyvitamin D2 [25(OH)D2] and 25-hydroxyvitamin D3 [25(OH)D3] and their concentrations were combined to give an overall measure of 25(OH)D. We used conditional logistic regression to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for 25(OH)D as both continuous and categorical variables.

Results

Overall, no apparent association between 25(OH)D and risk of lung cancer was observed (multivariable adjusted OR for a doubling in concentration: 0.98, 95% CI: 0.91, 1.06). Similarly, we found no clear evidence of interaction by cohort, sex, age, smoking status, or histology.

Conclusion

This study did not support an association between vitamin D concentrations and lung cancer risk.

Novel associations between blood DNA methylation and body mass index in middle-aged and older adults

BACKGROUND/OBJECTIVES

There is increasing evidence of a relationship between blood DNA methylation and body mass index (BMI). We aimed to assess associations of BMI with individual methylation measures (CpGs) through a cross-sectional genome-wide DNA methylation association study and a longitudinal analysis of repeated measurements over time.

SUBJECTS/METHODS

Using the Illumina Infinium HumanMethylation450 BeadChip, DNA methylation measures were determined in baseline peripheral blood samples from 5361 adults recruited to the Melbourne Collaborative Cohort Study (MCCS) and selected for nested case-control studies, 2586 because they were subsequently diagnosed with cancer (cases) and 2775 as controls. For a subset of 1088 controls, these measures were repeated using blood samples collected at wave 2 follow-up, a median of 11 years later; weight was measured at both time points. Associations between BMI and blood DNA methylation were assessed using linear mixed-effects regression models adjusted for batch effects and potential confounders. These were applied to cases and controls separately, with results combined through fixed-effects meta-analysis.

RESULTS

Cross-sectional analysis identified 310 CpGs associated with BMI with P<1.0 × 10^-7, 225 of which had not been reported previously. Of these 225 novel associations, 172 were replicated (P<0.05) using the Atherosclerosis Risk in Communities (ARIC) study. We also replicated using MCCS data (P<0.05) 335 of 392 associations previously reported with P<1.0 × 10^-7, including 60 that had not been replicated before. Associations between change in BMI and change in methylation were observed for 34 of the 310 strongest signals in our cross-sectional analysis, including 7 that had not been replicated using the ARIC study.

CONCLUSIONS

Together, these findings suggest that BMI is associated with blood DNA methylation at a large number of CpGs across the genome, several of which are located in or near genes involved in ATP-binding cassette transportation, tumour necrosis factor signalling, insulin resistance and lipid metabolism.

Expression of deleted, atoxic atypical recombinant beta2 toxin in a baculovirus system and production of polyclonal and monoclonal antibodies

Background

Clostridium perfringens is an important animal and human pathogen that can produce more than 16 different major and minor toxins. The beta-2 minor toxin (CPB2), comprising atypical and consensus variants, appears to be involved in both human and animal enterotoxaemia syndrome. The exact role of CPB2 in pathogenesis is poorly investigated, and its mechanism of action at the molecular level is still unknown because of the lack of specific reagents such as monoclonal antibodies against the CPB2 protein and/or the availability of a highly purified antigen. Previous studies have reported that purified wild-type or recombinant CPB2 toxin, expressed in a heterologous system, presented cytotoxic effects on human intestinal cell lines. Undoubtedly, for this reason, to date, these purified proteins have not yet been used for the production of monoclonal antibodies (MAbs). Recently, monoclonal antibodies against CPB2 were generated using peptides designed on predicted antigenic epitopes of this toxin.

Results

In this paper we report, for the first time, the expression in a baculovirus system of a deleted recombinant C-terminal 6xHis-tagged atypical CPB2 toxin (rCPB2_Δ1–25-His₆) lacking the 25 amino acids (aa) of the N-terminal putative signal sequence. A high level of purified recombinant rCPB2_Δ1–25-His₆ was obtained after purification by Ni²⁺ affinity chromatography. The purified product showed no in vitro and in vivo toxicity. Polyclonal antibodies and twenty hybridoma-secreting Mabs were generated using purified rCPB2_Δ1–25-His₆. Finally, the reactivity and specificity of the new antibodies were tested against both recombinant and wild-type CPB2 toxins.

Conclusions

The high-throughput of purified atoxic recombinant CPB2 produced in insect cells, allowed to obtain monoclonal and polyclonal antibodies. The availability of these molecules could contribute to develop immunoenzymatic methods and/or to perform studies about the biological activity of CPB2 toxin.

Dietary inflammatory index, Mediterranean diet score, and lung cancer: a prospective study

PURPOSE

To investigate prospectively the associations of Dietary Inflammatory Index (DII) and Mediterranean Diet Score (MDS) with lung cancer.

METHODS

We used data from men and women aged 40-69 years at recruitment in 1990-1994, who were participants in the Melbourne Collaborative Cohort Study (n = 35,303). A total of 403 incident lung cancer cases were identified over an average 18-year follow-up. Hazard ratios (HR) were estimated using Cox regression, adjusting for smoking status and other risk factors, with age as the time metric.

RESULTS

An inverse correlation was observed between the DII and MDS (ρ = -0.45), consistent with a higher DII being pro-inflammatory and less 'healthy,' while a high MDS reflects a 'healthier' diet. The DII was positively associated with risk of lung cancer in current smokers [HRQ4 vs Q1 = 1.70 (1.02, 2.82); Ptrend = 0.008] (p interaction between DII quartiles and smoking status = 0.03). The MDS was inversely associated with lung cancer risk overall [HR7-9 vs 0-3 = 0.64 (0.45, 0.90); Ptrend = 0.005] and for current smokers (HR7-9 vs 0-3 = 0.38 (0.19, 0.75); Ptrend = 0.005) (p interaction between MDS categories and smoking status = 0.31).

CONCLUSIONS

The MDS showed an inverse association with lung cancer risk, especially for current smokers. A high DII, indicating a more pro-inflammatory diet, was associated with risk of lung cancer only for current smokers. A healthy diet may reduce the risk of lung cancer, especially in smokers.

Flavonoid and lignan intake in relation to bladder cancer risk in the European Prospective Investigation into Cancer and Nutrition (EPIC) study

BACKGROUND

There is growing evidence of the protective role of dietary intake of flavonoids and lignans on cancer, but the association with bladder cancer has not been thoroughly investigated in epidemiological studies. We evaluated the association between dietary intakes of total and subclasses of flavonoids and lignans and risk of bladder cancer and its main morphological type, urothelial cell carcinoma (UCC), within the European Prospective Investigation into Cancer and Nutrition (EPIC) study.

METHODS

A cohort of 477 312 men and women mostly aged 35-70 years, were recruited in 10 European countries. At baseline, dietary flavonoid and lignan intakes were estimated using centre-specific validated questionnaires and a food composition database based on the Phenol-Explorer, the UK Food Standards Agency and the US Department of Agriculture databases.

RESULTS

During an average of 11 years of follow-up, 1575 new cases of primary bladder cancer were identified, of which 1425 were UCC (classified into aggressive (n=430) and non-aggressive (n=413) UCC). No association was found between total flavonoid intake and bladder cancer risk. Among flavonoid subclasses, significant inverse associations with bladder cancer risk were found for intakes of flavonol (hazard ratio comparing fifth with first quintile (HRQ5-Q1) 0.74, 95% confidence interval (CI): 0.61-0.91; P-trend=0.009) and lignans (HRQ5-Q1 0.78, 95% CI: 0.62-0.96; P-trend=0.046). Similar results were observed for overall UCC and aggressive UCC, but not for non-aggressive UCC.

CONCLUSIONS

Our study suggests an inverse association between the dietary intakes of flavonols and lignans and risk of bladder cancer, particularly aggressive UCC.

FGF receptor genes and breast cancer susceptibility: results from the Breast Cancer Association Consortium

BACKGROUND

Breast cancer is one of the most common malignancies in women. Genome-wide association studies have identified FGFR2 as a breast cancer susceptibility gene. Common variation in other fibroblast growth factor (FGF) receptors might also modify risk. We tested this hypothesis by studying genotyped single-nucleotide polymorphisms (SNPs) and imputed SNPs in FGFR1, FGFR3, FGFR4 and FGFRL1 in the Breast Cancer Association Consortium.

METHODS

Data were combined from 49 studies, including 53 835 cases and 50 156 controls, of which 89 050 (46 450 cases and 42 600 controls) were of European ancestry, 12 893 (6269 cases and 6624 controls) of Asian and 2048 (1116 cases and 932 controls) of African ancestry. Associations with risk of breast cancer, overall and by disease sub-type, were assessed using unconditional logistic regression.

RESULTS

Little evidence of association with breast cancer risk was observed for SNPs in the FGF receptor genes. The strongest evidence in European women was for rs743682 in FGFR3; the estimated per-allele odds ratio was 1.05 (95% confidence interval=1.02-1.09, P=0.0020), which is substantially lower than that observed for SNPs in FGFR2.

CONCLUSION

Our results suggest that common variants in the other FGF receptors are not associated with risk of breast cancer to the degree observed for FGFR2.

Circulating sex hormones and breast cancer risk factors in postmenopausal women: reanalysis of 13 studies

Background:

Breast cancer risk for postmenopausal women is positively associated with circulating concentrations of oestrogens and androgens, but the determinants of these hormones are not well understood.

Methods:

Cross-sectional analyses of breast cancer risk factors and circulating hormone concentrations in more than 6000 postmenopausal women controls in 13 prospective studies.

Results:

Concentrations of all hormones were lower in older than younger women, with the largest difference for dehydroepiandrosterone sulphate (DHEAS), whereas sex hormone-binding globulin (SHBG) was higher in the older women. Androgens were lower in women with bilateral ovariectomy than in naturally postmenopausal women, with the largest difference for free testosterone. All hormones were higher in obese than lean women, with the largest difference for free oestradiol, whereas SHBG was lower in obese women. Smokers of 15+ cigarettes per day had higher levels of all hormones than non-smokers, with the largest difference for testosterone. Drinkers of 20+ g alcohol per day had higher levels of all hormones, but lower SHBG, than non-drinkers, with the largest difference for DHEAS. Hormone concentrations were not strongly related to age at menarche, parity, age at first full-term pregnancy or family history of breast cancer.

Conclusion:

Sex hormone concentrations were strongly associated with several established or suspected risk factors for breast cancer, and may mediate the effects of these factors on breast cancer risk.

Second to fourth digit ratio (2D:4D) and prostate cancer risk in the Melbourne Collaborative Cohort Study

Background:

The ratio of the lengths of index and ring fingers (2D:4D) is a marker of prenatal exposure to sex hormones, with low 2D:4D being indicative of high prenatal androgen action. Recent studies have reported a strong association between 2D:4D and risk of prostate cancer.

Methods:

A total of 6258 men participating in the Melbourne Collaborative Cohort Study had 2D:4D assessed. Of these men, we identified 686 incident prostate cancer cases. Hazard ratios (HRs) and confidence intervals (CIs) were estimated for a standard deviation increase in 2D:4D.

Results:

No association was observed between 2D:4D and prostate cancer risk overall (HRs 1.00; 95% CIs, 0.92–1.08 for right, 0.93–1.08 for left). We observed a weak inverse association between 2D:4D and risk of prostate cancer for age <60, however 95% CIs included unity for all observed ages.

Conclusion:

Our results are not consistent with an association between 2D:4D and overall prostate cancer risk, but we cannot exclude a weak inverse association between 2D:4D and early onset prostate cancer risk.

Identification of a novel prostate cancer susceptibility variant in the KLK3 gene transcript

Genome-wide association studies (GWAS) have identified more than 30 prostate cancer (PrCa) susceptibility loci. One of these (rs2735839) is located close to a plausible candidate susceptibility gene, KLK3, which encodes prostate-specific antigen (PSA). PSA is widely used as a biomarker for PrCa detection and disease monitoring. To refine the association between PrCa and variants in this region, we used genotyping data from a two-stage GWAS using samples from the UK and Australia, and the Cancer Genetic Markers of Susceptibility (CGEMS) study. Genotypes were imputed for 197 and 312 single nucleotide polymorphisms (SNPs) from HapMap2 and the 1000 Genome Project, respectively. The most significant association with PrCa was with a previously unidentified SNP, rs17632542 (combined P = 3.9 × 10⁻²²). This association was confirmed by direct genotyping in three stages of the UK/Australian GWAS, involving 10,405 cases and 10,681 controls (combined P = 1.9 × 10⁻³⁴). rs17632542 is also shown to be associated with PSA levels and it is a non-synonymous coding SNP (Ile179Thr) in KLK3. Using molecular dynamic simulation, we showed evidence that this variant has the potential to introduce alterations in the protein or affect RNA splicing. We propose that rs17632542 may directly influence PrCa risk.

Dietary patterns and risk of breast cancer

Background:

Evidence is emerging that prudent/healthy dietary patterns might be associated with a reduced risk of breast cancer.

Methods:

Using data from the prospective Melbourne Collaborative Cohort Study, we applied principal factor analysis to 124 foods and beverages to identify dietary patterns and estimated their association with breast cancer risk overall and by tumour characteristics using Cox regression.

Results:

During an average of 14.1 years of follow-up of 20 967 women participants, 815 invasive breast cancers were diagnosed. Among the four dietary factors that we identified, only that characterised by high consumption of fruit and salad was associated with a reduced risk, with stronger associations observed for tumours not expressing oestrogen (ER) and progesterone receptors (PR). Compared with women in the lowest quintile of the factor score, the hazard ratio for women in the highest quintile was 0.92 (95% confidence interval (CI)=0.70–1.21; test for trend, P=0.5) for ER-positive or PR-positive tumours and 0.48 (95% CI=0.26–0.86; test for trend, P=0.002) for ER-negative and PR-negative tumours (test for homogeneity, P=0.01).

Conclusion:

Our study provides additional support for the hypothesis that a dietary pattern rich in fruit and salad might protect against invasive breast cancer and that the effect might be stronger for ER- and PR-negative tumours.

BCL2 in breast cancer: a favourable prognostic marker across molecular subtypes and independent of adjuvant therapy received

BACKGROUND

Breast cancer is heterogeneous and the existing prognostic classifiers are limited in accuracy, leading to unnecessary treatment of numerous women. B-cell lymphoma 2 (BCL2), an antiapoptotic protein, has been proposed as a prognostic marker, but this effect is considered to relate to oestrogen receptor (ER) status. This study aimed to test the clinical validity of BCL2 as an independent prognostic marker.

METHODS

Five studies of 11 212 women with early-stage breast cancer were analysed. Individual patient data included tumour size, grade, lymph node status, endocrine therapy, chemotherapy and mortality. BCL2, ER, progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2) levels were determined in all tumours. A Cox model incorporating the time-dependent effects of each variable was used to explore the prognostic significance of BCL2.

RESULTS

In univariate analysis, ER, PR and BCL2 positivity was associated with improved survival and HER2 positivity with inferior survival. For ER and PR this effect was time dependent, whereas for BCL2 and HER2 the effect persisted over time. In multivariate analysis, BCL2 positivity retained independent prognostic significance (hazard ratio (HR) 0.76, 95% confidence interval (CI) 0.66-0.88, P<0.001). BCL2 was a powerful prognostic marker in ER- (HR 0.63, 95% CI 0.54-0.74, P<0.001) and ER+ disease (HR 0.56, 95% CI 0.48-0.65, P<0.001), and in HER2- (HR 0.55, 95% CI 0.49-0.61, P<0.001) and HER2+ disease (HR 0.70, 95% CI 0.57-0.85, P<0.001), irrespective of the type of adjuvant therapy received. Addition of BCL2 to the Adjuvant! Online prognostic model, for a subset of cases with a 10-year follow-up, improved the survival prediction (P=0.0039).

CONCLUSIONS

BCL2 is an independent indicator of favourable prognosis for all types of early-stage breast cancer. This study establishes the rationale for introduction of BCL2 immunohistochemistry to improve prognostic stratification. Further work is now needed to ascertain the exact way to apply BCL2 testing for risk stratification and to standardise BCL2 immunohistochemistry for this application.

Plasma concentration of Propionibacterium acnes antibodies and prostate cancer risk: results from an Australian population-based case-control study

BACKGROUND

Recent studies in prostatic tissue suggest that Propionibacterium acnes (P. acnes), a bacterium associated with acne that normally lives on the skin, is the most prevalent bacterium in the prostate and in men with benign prostatic hyperplasia. Its prevalence is higher in samples from patients subsequently diagnosed with prostate cancer. The aim of our study was to test whether circulating levels of P. acnes antibodies are associated with prostate cancer risk and tumour characteristics using plasma samples from a population-based case-control study.

METHODS

We measured plasma concentration of P. acnes antibodies for 809 cases and 584 controls using a recently developed ELISA assay. We compared antibody titres between cases and controls using unconditional logistic regression adjusted for batch and variables associated with the study design (i.e., age, year of selection and centre). The primary analysis included P. acnes titres in the model as a dichotomous variable using the median value for controls as the cut-off value.

RESULTS

P. acnes antibody titres for both cases and controls ranged from 1 : 16 (i.e., low concentration) to 1 : 65,536 (i.e., high concentration; median value=1 : 1024). The odds ratio for prostate cancer associated with titres at or above the median value was 0.73 (95% CI 0.58-0.91, P=0.005). The association appeared to be particularly strong for advanced prostate cancer (AJCC Stage grouping III-IV) for which the odds ratio was 0.59 (95% CI 0.43-0.81, P=0.001) but there was insufficient evidence that the association differed by tumour stage (p heterogeneity=0.07).

CONCLUSION

These results need to be confirmed in prospective studies but they are consistent with the hypothesis that P. acnes has a role in prostate cancer.

Purification by Strep-Tactin affinity chromatography of a delete envelope gp51 protein of Bovine Leukaemia virus expressed in Sf21 insect cells

Bovine leukaemia virus (BLV) causes disease in cattle and it is related to human T lymphotrofic viruses HTLV-1 and HTLV-2. The objective of this study was to express and purify deleted and stable forms of the gp51 envelope glycoprotein of BLV using a baculovirus system. Two forms of the gp51 were synthesised: one comprised the gp51 N-terminal 174 amino acids and a single 6xHis tag (Delta(175-268)gp51-His) and the second form contained the same amino acid sequence and a C-terminal Strep-tag II in addition to the 6xHis tag (Delta(175-268)gp51-STH). The two proteins were expressed and purified by immobilized metal-affinity chromatography (IMAC) or by Strep-Tactin column. The Strep-Tactin technology was more efficient than IMAC method and achieved a high pure recombinant deleted gp51. In addition the Delta(175-268)gp51-STH protein was further concentrated by IMAC. This purified antigen could be used for the isolation of immunoreactive molecules and to develop a competitive ELISA test.

Percentage of reactor animals to single comparative cervical intradermal tuberculin (SCCIT) in small ruminants in Punjab Pakistan

To investigate the percentage reactor animals to SCCIT in sheep and goat the present study was carried out by using bovine and avian PPDs at 7 Livestock Experiment Stations of Punjab and villages around two cities. The overall percentage of reactor animals to SCCIT at farms in sheep and goat was 0.9% and 2.4%, while it was 0.4% and 0.0% around two cities, respectively. Hundred percent of goat and 86% of sheep farms under study had positive reactor animals. The reactor animals to SCCIT around two cities were 0% in goat and 0.4% in sheep. Goats (P<0.05) and sheep (P<0.001) kept with large ruminants at farms had higher percentage of reactor animals. Age showed significant (P<0.01) association with tuberculosis in sheep and goat. In goats of more than 6 years of age, the reactor animals to SCCIT were 5, 8 and 11 times higher than goats of 4.1-6, 3-4 and <3 years of age. The reactor animals were significantly (P<0.05) higher in goats of <30kg (3.5%) and>40kg (3.5%) body weights, while these were less in goats weighing between 30 and 40kg (1.5%). Sheep and goat breeds showed significant (P<0.001; P<0.05) difference in percentage of reactor animals to SCCIT. Beetal (3.9%) and Teddy breeds (2.9%) had 3.3 and 2.4 times higher percentages of reactor animals to SCCIT as compared to Pak-Angora (1.2%) breed. However, no animal of Nachhi and Dera Din Pinah breeds showed positive reaction to PPDs.

Consumption of animal products, their nutrient components and postmenopausal circulating steroid hormone concentrations

BACKGROUND/OBJECTIVES

Little is known about nutritional factors that influence circulating concentrations of steroid hormones, which are consistently associated with risk of breast cancer for postmenopausal women. We aimed to investigate the association between consumption of animal products and the plasma concentrations of steroid hormones and sex hormone-binding globulin (SHBG).

SUBJECTS/METHODS

Cross-sectional analysis was conducted on plasma from 766 naturally postmenopausal women. We measured plasma concentrations of steroid hormones and SHBG, and estimated dietary intakes using a 121-item food frequency questionnaire. Log-transformed values of hormone concentrations were regressed on quartiles of intake of meat and dairy products among food items, and fats, proteins and cholesterol among nutrient intake.

RESULTS

Total red and fresh red meat consumption was negatively associated with SHBG levels (P for trend=0.04 and <0.01, respectively). Mean SHBG concentrations were approximately 8% and 13% lower for women in the highest quartile compared with the lowest quartile of total red and fresh red meat consumption, respectively. Positive associations were observed between dairy product consumption and total and free estradiol concentrations (P for trend=0.02 and 0.03, respectively). Mean concentrations of total and free estradiol were 15 and 14% higher for women in the highest quartile of dairy product consumption than for those in the lowest quartile, respectively. No associations were observed with consumption of processed meat, chicken, fish, eggs, cholesterol, fats or protein.

CONCLUSIONS

Our study suggests that greater consumption of total red and fresh red meat and dairy products might influence circulating concentrations of SHBG and estradiol, respectively. Confirmation and further investigation is required.

Abortion due to Salmonella enterica serovar Abortusovis (S. Abortusovis) in ewes is associated to a lack of production of IFN-γ and can be prevented by immunization with inactivated S. Abortusovis vaccine

Salmonellosis due to Salmonella enterica serovar Abortusovis (S. Abortusovis) is mainly characterized by abortion in sheep. Little is known about the immune response, which develops in the host as a result of infection. We evaluated the immune response of pregnant ewes vaccinated and successively exposed to full virulent S. Abortusovis. We found that vaccine constituted by inactivated S. Abortusovis induced both humoral and cellular-mediated immune response and that it provided protection against a challenge infection due to a fully virulent S. Abortusovis. Furthermore, we found an association between the lack of capability to produce IFN-gamma and abortion. This evidence suggests that protection against abortion can be associated to an IFN-gamma mediated mechanism. Our findings represent an interesting insight to better understand the interplay between host and S. Abortusovis and the effector mechanisms underpinning immune-based protection.

Public awareness about risk factors could pose problems for case-control studies: The example of sunbed use and cutaneous melanoma

In a large case-control study we found no association between sunbed use and melanoma risk, but indications for potential recall and recruitment biases made the interpretation of the results difficult. Associations with skin phototype (adj OR for skin type I vs. IV: (2.6, 95% CI 1.5-4.8)), hair colour (adj OR red/blond vs. brown/black 2.0 (95% CI 1.4-2.8)) and number of naevi on both arms (OR>10 vs. 10 3.13 (95% CI: 2.47; 3.97)) were comparable to previous studies, but negative associations were found between sun exposure and melanoma risk (adj. OR 0.87 (95% CI: 0.65-1.18)) and in cases between sun exposure and naevus count. These observations led us to speculate that cases may have underreported their sun exposure and, most likely, their sunbed exposure. High percentages of sunbed use among controls indicated possible recruitment bias: eligible controls who were sunbed users were probably more likely to accept the invitation to participate than non-users, possibly due to a feeling of 'guilt' or 'worry' about their habits. Such selective participation may have strongly influenced the risk estimates of sunbed use in our study.

Are all high-grade breast cancers with no steroid receptor hormone expression alike? The special case of the medullary phenotype

BACKGROUND

Medullary carcinoma (MC) of the breast is associated with favorable prognosis compared with other histological types, despite high nuclear grade, fast proliferation and lack of steroid hormone receptor expression. We retrospectively evaluated the clinical relevance of selected immunohistochemical features of tumors in three cohorts of patients with typical medullary (MC), 'atypical' medullary (AMC) or ductal (DC) breast carcinoma.

PATIENTS AND METHODS

Evaluation was performed on node-negative tumor specimens from 40 patients who had either MC (12 patients), AMC (nine patients) or DC (19 patients), treated in a single institution. All had no hormonal receptor, Ki-67 > or =30%, G3, expansive pattern of growth and peritumoral lymphocytic infiltration. In addition, p27, p21 and HER2/neu overexpression, p53, cyclin E and E-cadherin expression, presence of apoptotic cells, stromal tenascin (TN), and type of immune cell infiltration (CD3- and CD68-positive cells) were assessed.

RESULTS

No difference in expression of HER2/neu, p21, p27, p53, number of apoptotic cells and CD68-positive cells was detected. Lower levels of stromal TN expression were found in MC compared with DC (P=0.0007), but differences between MC and AMC were not significant (P=0.27). A higher proportion of intratumoral CD3-positive cells was seen in MC than in AMC (P=0.046). No differences were seen between MC and DC (P=0.73). With a median follow-up of 67 months, three patients with DC had relapsed in distant sites, while one patient with AMC had a second primary. Two patients with MC had reappearance of DC in the breast.

CONCLUSIONS

The three distinct disease types, selected by having similar high proliferation, had similar expression of cell cycle regulators. The lower expression of TN and massive infiltration of T lymphocytes might both indicate a special interaction between tumor cells and microenvironment, important features for conferring improved prognosis through negligible invasive and metastatic potential to MC. In our series, however, patients with a previous MC are not free from the risk of developing a subsequent DC. Finally, defining AMC as a distinct entity from DC is not justified.

Analysis of possible factors affecting the specificity of the gamma interferon test in tuberculosis-free cattle herds

Bovine tuberculosis (TB) is still a zoonotic problem in the world. Despite the fact that eradication programs for bovine TB are being implemented in many countries, it remains a public health problem. These programs are mainly based on a single intradermal tuberculin test using bovine tuberculin purified protein derivative (PPD), isolation, and slaughtering of infected animals. The aim of this study was to assess the specificity of the gamma interferon (IFN-gamma) test in TB-free cattle herds, by using not only Australian tuberculins but also tuberculins produced at our institute, and to correlate the response with the type of production (beef cattle, dairy cattle, and a dual-purpose breed), the housing system, and the age of the animals. We studied 800 animals selected from 20 TB- and paratuberculosis-free herds. The animals were tested in parallel, after stimulation with Australian tuberculins and tuberculins produced at our institute, by using the skin test and two IFN-gamma assays. The results of this trial showed that the specificity of the IFN-gamma test is higher than that of the skin test (96.8%) and ranges from 97.3% (using only Australian tuberculins) to 98.6% (using tuberculins produced at our institute). We found that different categories of cattle could influence the specificity of the skin test but that these differences tended to be reduced in the IFN-gamma assay, especially when Italian PPDs were used.

Factor V Leiden and G20210A prothrombin mutation and the risk of subclavian vein thrombosis in patients with breast cancer and a central venous catheter

BACKGROUND

To analyze the influence of the prothrombotic gene mutation factor V G1691A (factor V Leiden) and prothrombin G20210A on the risk of a first episode of catheter-related deep venous thrombosis (DVT) in a group of patients with breast cancer treated with chemotherapy.

PATIENTS AND METHODS

Between January 1999 and February 2001, the occurrence of a first symptomatic DVT was investigated in a cohort of 300 consecutive patients with locally advanced or metastatic breast cancer treated at a single institution with fluorouracil-based chemotherapy, administered continuously through a totally implanted access port. A nested case-control study included 25 women (cases) with catheter-related DVT and 50 controls without DVT matched with cases for age, identical chemotherapy, stage of disease and prognostic features. The G1691A factor V and G20210A prothrombin mutation genotypes were analyzed.

RESULTS

Five cases [20%; 95% confidence interval (CI) 9% to 39%)] and two controls (4%; 95% CI 1% to 14%) were heterozygous carriers of G1691A factor V (P = 0.04). The age-adjusted odds ratio for catheter-related DVT was 6.1 (95% CI 1.1-34.3). Only one patient (case) had the G20210A prothrombin gene mutation. Time from start of chemotherapy infusion to DVT was not significantly different between patients with (median 31 days) and without (median 43 days) G1691A factor V mutation (P = 0.6).

CONCLUSIONS

Factor V Leiden carriers with locally advanced or metastatic breast cancer have an increased risk of developing catheter-related DVT during chemotherapy.

Androgenetic alopecia in men aged 40-69 years: prevalence and risk factors

BACKGROUND

The epidemiology of androgenetic alopecia (AGA) is not fully understood. Although a strong genetic basis has long been identified, little is known of its non-genetic causes.

OBJECTIVES

To estimate the prevalence of and to determine risk factors for AGA in men aged 40-69 years in Australia.

METHODS

Men (n = 1390) were recruited at random from the electoral rolls to serve as controls in a population-based case-control study of prostate cancer. All were interviewed in person and direct observations of AGA were made. Men were grouped into the following categories; no AGA, frontal AGA, vertex AGA and full AGA (frontal and vertex AGA). Epidemiological data collected from these men were used for an analysis of risk factors for each AGA category using unconditional logistic regression with AGA category as the response variable adjusting for age, education and country of birth.

RESULTS

The prevalence of vertex and full AGA increased with age from 31% (age 40-55 years) to 53% (age 65-69 years). Conversely, the proportion of men with only frontal AGA was very similar across all age groups (31-33%). No associations were found between pubertal growth spurt or acne, reports of adult body size at time of interview, urinary symptom score, marital status, or current smoking status or duration of smoking and the risk of any form of AGA. The consumption of alcohol was associated with a significant increase in risk of frontal and vertex AGA but not full AGA. Men with vertex AGA had fewer female sexual partners but average ejaculatory frequency did not differ between men in different AGA categories. Reported weight and lean body mass at reaching maturity at about 21 years of age were negatively associated with vertex balding (P for trend < 0.05) but not with frontal AGA or full AGA.

CONCLUSIONS

Evidence for environmental influences on AGA remains very slight. Our study failed to confirm previously reported or hypothesized associations with smoking and benign prostatic hypertrophy. The associations that we found with alcohol consumption and with lean body mass at age 21 years would be worthy of further research if they were able to be replicated in other studies.

Preoperative and perioperative chemotherapy with 5-fluorouracil as continuous infusion in operable breast cancer expressing a high proliferation fraction: cytotoxic treatment during the surgical phase

BACKGROUND

Experimental data on perioperative chemotherapy (PeCT) indicate that its initiation might be most useful if administered as close as possible to the time of first 'disturbance of the tumour'. Regimens including 5-fluorouracil (5-FU) as continuous infusion are commonly used in the preoperative setting, especially for large tumours and locally advanced disease. We therefore evaluated the role of PeCT with 5-FU as continuous infusion after preoperative chemotherapy (PreCT), covering the surgical phase and acute wound healing period, in patients with breast cancer too large to attempt breast-conserving surgery upon diagnosis.

PATIENTS AND METHODS

Breast cancer patients, clinical stages T2-T3, N0-N2, M0, and Ki-67 labelling index >/= 20%, were treated every 3 weeks with a maximum of six courses of vinorelbine 20 mg total dose intravenously (i.v.) on days 1 and 3, cisplatin 60 mg/ m(2) i.v. on day 1 and 5-FU 200 mg/m(2)/day as a continuous infusion (ViFuP regimen). Patients who achieved a clinical and radiological objective remission with PreCT were also treated with perioperative 5-FU that was continued until 30 min before, and restarted immediately after surgery, prolonging infusion until 15 days after surgery.

RESULTS

Following preoperative treatment, 39 of 49 evaluable patients [80%; 95% confidence interval (CI) 70% to 90%] had an objective response. Pathological complete remission (pCR) was achieved in 14 (29%) patients. No relevant clinical or haematological toxicity due to PeCT was observed. In 36 patients submitted to PeCT the rate of pCR was 33% (95% CI 18% to 48%). The highest response of the primary tumour to PreCT and PeCT was observed in women with tumours not expressing estrogen and progesterone receptors (pCR 46%; 95% CI 19% to 73%).

CONCLUSIONS

Preoperative therapy can be protracted into the surgical (and wound healing) period without significant additional short-term toxicity. Proper selection of patients according to biological features might improve the therapeutic yield of preoperative therapies.

Measuring progress against cancer in Europe: has the 15% decline targeted for 2000 come about?

BACKGROUND

Against a background of increasing cancer rates in the mid-1980s, Europe Against Cancer launched an ambitious programme aiming to reduce cancer mortality by 15% by the year 2000. A programme of activities and research, focussing on three major themes [prevention (particularly tobacco control), screening, and education and training], was developed together with the European Code Against Cancer.

METHODS

To evaluate the outcome of the programme, all cancer mortality data were abstracted for each member state of the European Union (EU) until the most recent year available. For each gender group in each member state, age-specific rates were estimated for 2000. For each country-gender grouping, the standardized mortality rate (SMR) and expected numbers of deaths in 2000 were calculated based on the age-specific rates for 1985 and the population estimates for 2000. The ratio of the SMR in 2000 to that of 1985, was used as the measure to compare mortality rates.

RESULTS

In 1985, there were 850 194 cancer deaths in the EU. Based solely on demographic considerations, this number was expected to rise to 1 033 083 in the year 2000. Between 1985 and 2000, the number of cancer deaths increased in both men (+12%) and women (+9%). The target of a 15% reduction in the expected numbers of cancer deaths in the EU was not met, although the 10% reduction in number of deaths expected in men and 8% in women, along with a 11% reduction in risk of cancer death in men and a 10% reduction in women, was noteworthy. Only Austria and Finland achieved the 15% reductions in deaths in both men and women. The UK and Luxembourg (where the small population and annual number of deaths make interpretation difficult) came close to meeting these targets, as did Italy. Portugal and Greece had the poorest performance, with increases in each gender group.

CONCLUSIONS

Cancer deaths in the EU were expected to rise from 850 194 in 1985 to 1 033 083 in 2000. It is estimated that there will be 940 510 cancer deaths that year, due to the decline in risk observed since 1985. The Europe Against Cancer programme appears to have been associated with the avoidance of 92 573 cancer deaths in the year 2000. With few exceptions, most countries are experiencing declining trends in cancer death rates, which seem set to continue, at least in the near future. Renewed tobacco control efforts are clearly needed for women, and there is a strong case for the introduction of organized breast and cervix screening programmes in all member states. Continuing to emphasize prevention within cancer control will help to promote the continuing decline in death rates in the future.

Sexual factors and prostate cancer

OBJECTIVE

To assess whether prostate cancer might be related to hormone levels and, by inference, to differences in sexual activity.

PATIENTS, SUBJECTS AND METHODS

In a case-control study of men with prostate cancer aged < 70 years at diagnosis and age-matched control subjects, information was collected on two aspects of sexual activity; the number of sexual partners and the frequency of total ejaculations during the third to fifth decades of life.

RESULTS

There was no association of prostate cancer with the number of sexual partners or with the maximum number of ejaculations in 24 h. There was a negative trend (P < 0.01) for the association between risk and number of ejaculations in the third decade, independent of those in the fourth or fifth. Men who averaged five or more ejaculations weekly in their 20s had an odds ratio (95% confidence interval) of 0.66 (0.49-0.87) compared with those who ejaculated less often.

CONCLUSIONS

The null association with the number of sexual partners argues against infection as a cause of prostate cancer in this population. Ejaculatory frequency, especially in early adult life, is negatively associated with the risk of prostate cancer, and thus the molecular biological consequences of suppressed or diminished ejaculation are worthy of further research.

Impact of inhaled corticosteroids on the risk of early Pseudomonas aeruginosa acquisition in cystic fibrosis

AIM

To investigate the role of inhaled corticosteroids (IC) on the risk of Pseudomonas aeruginosa acquisition before the age of 10 y in cystic fibrosis (CF) patients.

METHODS

For each subject the cumulative dose kg(-1) of IC received for each year of age was calculated until the end of follow-up. The age at CF diagnosis, the nutritional status (NS) and the number of respiratory exacerbations (RE) were used as surrogate measures for the severity of CF.

RESULTS

A total of 83 patients (40 M, 43 F) entered the study. Their median length of follow-up was 4.4 y, for a total of 386 person-years at risk. Twenty-three patients acquired P. aeruginosa at a median age of 4.6 y (range 0.4-9.9 y). The estimated survival without P. aeruginosa acquisition was 65% at 10 y of age. The effect of different risk factors (IC, NS, RE and age at CF diagnosis) on the probability of P. aeruginosa acquisition was evaluated: none of them was significantly associated with the risk of P. aeruginosa acquisition. In particular, patients receiving very high cumulative doses of IC (4th quartile) had a non-significantly increased risk of P. aeruginosa acquisition compared with those receiving low doses of IC (1st quartile) (hazard ratio = 1.73, 95% confidence limits 0.40-7.38).

CONCLUSION

This retrospective study was not able to demonstrate any role of IC in increasing the risk of P. aeruginosa acquisition. This complication seems to occur at a constant pace that is independent of CF severity and age. Prospective multi-institutional randomized studies are needed to investigate the effects of high-dose IC in CF patients.