European randomized study of prostate cancer screening: first-year results of the Finnish trial

Approximately 20 000 men 55–67 years of age from two areas in Finland were identified from the Population Registry and randomized either to the screening arm (1/3) or the control arm (2/3) of a prostate cancer screening trial. In the first round, the participation rate in the screening arm was 69%. Of the 5053 screened participants, 428 (8.5%) had a serum prostate-specific antigen (PSA) concentration of 4.0 ng/ml or higher, and diagnostic examinations were performed on 399 of them. A total of 106 cancers were detected among them corresponding to a positive predictive value of 27%, which is comparable with mammography screening for breast cancer. The prostate cancer detection rate based on a serum PSA concentration of 4.0 ng ml−1 or higher was 2.1%. Approximately nine out of ten screen-detected prostate cancers were localized (85% clinical stage T1–T2) and well or moderately differentiated (42% World Health Organization (WHO) grade I and 50% grade II), which suggests a higher proportion of curable cancers compared with cases detected by other means. © 1999 Cancer Research Campaig

Cancer recurrence times from a branching process model

As cancer advances, cells often spread from the primary tumor to other parts of the body and form metastases. This is the main cause of cancer related mortality. Here we investigate a conceptually simple model of metastasis formation where metastatic lesions are initiated at a rate which depends on the size of the primary tumor. The evolution of each metastasis is described as an independent branching process. We assume that the primary tumor is resected at a given size and study the earliest time at which any metastasis reaches a minimal detectable size. The parameters of our model are estimated independently for breast, colorectal, headneck, lung and prostate cancers. We use these estimates to compare predictions from our model with values reported in clinical literature. For some cancer types, we find a remarkably wide range of resection sizes such that metastases are very likely to be present, but none of them are detectable. Our model predicts that only very early resections can prevent recurrence, and that small delays in the time of surgery can significantly increase the recurrence probability.Comment: 26 pages, 9 figures, 4 table

Thirty-minute compared to standardised office blood pressure measurement in general practice

Background: Although blood pressure measurement is one of themost frequently performed measurements in clinical practice, there are concerns about its reliability. Serial, automated oscillometric blood pressure measurement has the potential to reduce measurement bias and 'white-coat effect'. Aim: To study agreement of 30-minute office blood pressure measurement (OBPM) with standardised OBPM, and to compare repeatability. Design and setting: Method comparison study in two general practices in the Netherlands. Method: Thirty-minute and standardised OBPM was carried out with the same, validated device in 83 adult patients, and the procedure was repeated after 2 weeks. During 30-minute OBPM, blood pressure was measured automatically every 3minutes, with the patient in a sitting position, alone in a quiet room. Agreement between 30-minute and standardised OBPM was assessed by Bland-Altman analysis. Repeatability of the blood pressure measurement methods after 2 weeks was expressed as the mean difference in combination with the standard deviation of difference (SDD). Results: Mean 30-minute OBPM readings were 7.6/2.5 mmHg (95% confidence interval [CI] = 6.1 to 9.1/1.5 to 3.4 mmHg) lower than standardised OBPM readings. The mean difference and SDD between repeated 30-minute OBPMs (mean difference = 3/1 mmHg, 95%CI = 1 to 5/0 to 2 mmHg; SDD 9.5/5.3 mmHg) were lower than those of standardised OBPMs (mean difference = 6/2 mmHg, 95%CI = 4 to 8/1 to 4 mmHg; SDD 10.9/6.3 mmHg). Conclusion: Thirty-minute OBPM resulted in lower readings than standardised OBPM and had a better repeatability. These results suggest that 30-minute OBPM better reflects the patient's true blood pressure than standardised OBPM does