Validation of an RNA cell cycle progression score for predicting death from prostate cancer in a conservatively managed needle biopsy cohort.

BACKGROUND: The natural history of prostate cancer is highly variable and difficult to predict accurately. Better markers are needed to guide management and avoid unnecessary treatment. In this study, we validate the prognostic value of a cell cycle progression score (CCP score) independently and in a prespecified linear combination with standard clinical variables, that is, a clinical-cell-cycle-risk (CCR) score. METHODS: Paraffin sections from 761 men with clinically localized prostate cancer diagnosed by needle biopsy and managed conservatively in the United Kingdom, mostly between 2000 and 2003. The primary end point was prostate cancer death. Clinical variables consisted of centrally reviewed Gleason score, baseline PSA level, age, clinical stage, and extent of disease; these were combined into a single predefined risk assessment (CAPRA) score. Full data were available for 585 men who formed a fully independent validation cohort. RESULTS: In univariate analysis, the CCP score hazard ratio was 2.08 (95% CI (1.76, 2.46), P<10(-13)) for one unit change of the score. In multivariate analysis including CAPRA, the CCP score hazard ratio was 1.76 (95% CI (1.44, 2.14), P<10(-6)). The predefined CCR score was highly predictive, hazard ratio 2.17 (95% CI (1.83, 2.57), χ(2)=89.0, P<10(-20)) and captured virtually all available prognostic information. CONCLUSIONS: The CCP score provides significant pretreatment prognostic information that cannot be provided by clinical variables and is useful for determining which patients can be safely managed conservatively, avoiding radical treatment.

Prognostic value of a cell cycle progression signature for prostate cancer death in a conservatively managed needle biopsy cohort.

BACKGROUND: The natural history of prostate cancer is highly variable and it is difficult to predict. We showed previously that a cell cycle progression (CCP) score was a robust predictor of outcome in a conservatively managed cohort diagnosed by transurethral resection of the prostate. A greater need is to predict outcome in patients diagnosed by needle biopsy. METHODS: Total RNA was extracted from paraffin specimens. A CCP score was calculated from expression levels of 31 genes. Clinical variables consisted of centrally re-reviewed Gleason score, baseline prostate-specific antigen level, age, clinical stage, and extent of disease. The primary endpoint was death from prostate cancer. RESULTS: In univariate analysis (n=349), the hazard ratio (HR) for death from prostate cancer was 2.02 (95% CI (1.62, 2.53), P<10(-9)) for a one-unit increase in CCP score. The CCP score was only weakly correlated with standard prognostic factors and in a multivariate analysis, CCP score dominated (HR for one-unit increase=1.65, 95% CI (1.31, 2.09), P=3 × 10(-5)), with Gleason score (P=5 × 10(-4)) and prostate-specific antigen (PSA) (P=0.017) providing significant additional contributions. CONCLUSION: For conservatively managed patients, the CCP score is the strongest independent predictor of cancer death outcome yet described and may prove valuable in managing clinically localised prostate cancer.

Manual versus target-controlled infusions of propofol.

Target-controlled infusion systems have been shown to result in the administration of larger doses of propofol, which may result in delayed emergence and recovery from anaesthesia. The aim of this study was to investigate if this was due to a difference in the depth of hypnosis (using the bispectral index monitoring) between the manual and target controlled systems of administration. Fifty unpremedicated patients undergoing elective surgery were randomly allocated to have their anaesthesia maintained with manual or target-controlled propofol infusion schemes. In both groups, the rate of propofol administration was adjusted according to standard clinical criteria while bispectral index scores were recorded by an observer not involved in the delivery of anaesthesia. The total dose of propofol used was higher in the target controlled group (mean 9.9 [standard deviation 1.6] compared with 8.1 [1.0] mg.kg(-1).h(-1) in the manual group [p < 0.0001]). The times to emergence and recovery end-points were comparable between the two groups. The difference in the total dosage of propofol was mainly due to higher rate of propofol administration in the first 30 min in the target controlled infusion group. The bispectral index scores were lower in the target controlled group during this time, being significantly so over the first 15 min of anaesthesia. We conclude that propofol administration by a target controlled infusion system results in the administration of higher doses of propofol and lower bispectral index values mainly in the initial period of anaesthesia.

A candidate prostate cancer susceptibility gene at chromosome 17p.

It is difficult to identify genes that predispose to prostate cancer due to late age at diagnosis, presence of phenocopies within high-risk pedigrees and genetic complexity. A genome-wide scan of large, high-risk pedigrees from Utah has provided evidence for linkage to a locus on chromosome 17p. We carried out positional cloning and mutation screening within the refined interval, identifying a gene, ELAC2, harboring mutations (including a frameshift and a nonconservative missense change) that segregate with prostate cancer in two pedigrees. In addition, two common missense variants in the gene are associated with the occurrence of prostate cancer. ELAC2 is a member of an uncharacterized gene family predicted to encode a metal-dependent hydrolase domain that is conserved among eukaryotes, archaebacteria and eubacteria. The gene product bears amino acid sequence similarity to two better understood protein families, namely the PSO2 (SNM1) DNA interstrand crosslink repair proteins and the 73-kD subunit of mRNA 3' end cleavage and polyadenylation specificity factor (CPSF73).

The predictive value of BRCA1 and BRCA2 mutation testing.

Genetic testing for mutations in BRCA1 and BRCA2, two genes predisposing to breast and ovarian cancers, is available to women with a relevant family history. The aim of this study was to estimate the positive and negative predictive value of clinical sequence analysis of these genes. A reference graph showing positive and negative predictive values over a range of pre-test risk was derived, taking into account the sensitivity and specificity of a full-sequence analysis test. High positive and negative predictive values were found for women with pre-test risk between 4% and 40%, a range of risk commonly seen in clinical testing. The predictive value of full sequence and single-site analysis of BRCA1 and BRCA2, therefore, compares favorably with other diagnostic medical tests. Our results provide a numerical estimate of the predictive value of BRCA testing, and as such, provide a valuable tool to healthcare providers and families as they interpret BRCA1 and BRCA2 test results.