Biomedical subjects
Harri Juusela
Publications and source records attributed to Harri Juusela.
Test sensitivity of prostate-specific antigen in the Finnish randomised prostate cancer screening trial.
We estimated the sensitivity of serum prostate-specific antigen (PSA) as a screening test for prostate cancer in the Finnish randomised, population-based prostate cancer screening trial. The study population consisted of 80,458 men aged 55-67 years identified from the national population registry and randomised to the screening or control arm of the trial. The screening algorithm was based on determination of serum PSA concentration. Test sensitivity was estimated based on interval cancer incidence during the first 4 years of follow-up among screening participants with a negative screening test. Interval cancers were defined as those occurring among men with a negative screening test. Altogether, 19 interval cancers were detected among 17,897 men with serum PSA < 3 ng/ml during the first screening interval. A further 5 cases were diagnosed among 811 men with PSA 3.0-3.9 ng/ml with a benign digital rectal examination or free total PSA ratio > or = 0.16. Test sensitivity based on serum PSA of 3 ng/ml was estimated to be 0.89 (95% confidence interval 0.84-0.93) and that based on PSA of 4 ng/ml combined with an ancillary test (digital rectal examination or free total PSA ratio in the PSA range 3.0-3.9) was 0.87 (0.82-0.92). Test sensitivity achieved with serum PSA in prostate cancer screening appears excellent in the context of a population-based effectiveness trial.
Second round results of the Finnish population-based prostate cancer screening trial.
PURPOSE: Large randomized trials provide the only valid means of quantifying the benefits and drawbacks of prostate-specific antigen (PSA) screening, but the follow-up of ongoing studies is still too short to allow evaluation of mortality. We report here the intermediate indicators of screening efficacy from the second round of the Finnish trial. EXPERIMENTAL DESIGN: The Finnish trial, with approximately 80,000 men in the target population, is the largest component in the European Randomized Study of Screening for Prostate Cancer. The first round was completed in 1996-1999. Each year 8,000 men 55-67 years of age were randomly assigned to the screening arm, and the rest formed the control arm. Men randomized to the screening arm in 1996 were reinvited 4 years later, in 2000, and PSA was determined. RESULTS: Of the eligible 6415 men, 4407 (69%) eventually participated in the second round of screening. Of the first-round participants, up to 84% (3833 of 4556) attended rescreening. A total of 461 screenees (10.5%) had PSA levels of > or = 4 microg/liter. Altogether, 97 cancers were found, yielding an overall detection rate of 2.2% (97 of 4407). Seventy-nine cases were found among the 3833 second-time screenees (detection rate 2.1%) and 18 in those 574 men (3.1%) who had not participated previously. A PSA of > or = 4 microg/liter, but negative biopsy in the first screening round was associated with an up to 9-fold risk of cancer in rescreening relative to those with lower PSA levels at baseline. Ninety-one (94%) of all of the detected cancers were clinically localized. CONCLUSIONS: As surrogate measures of an effective screening program, both compliance as well as the overall and advanced prostate cancer detection rates remained acceptable. Men defined as screen-positive but with a negative confirmation of cancer at prevalence screen formed a high-risk group at rescreening.
Tumor characteristics in a population-based prostate cancer screening trial with prostate-specific antigen.
PURPOSE: Early diagnosis of prostate cancer is a necessary, but not sufficient, prerequisite for an effective screening program aiming at mortality reduction. We compared tumor characteristics between the screening and control arms in the Finnish population-based screening trial. EXPERIMENTAL DESIGN: The Finnish trial is the largest component in the European Randomized Study of Screening for Prostate Cancer. A total of 24,000 men aged 55-67 years were randomized to the screening arm, whereas 35,973 men formed the control arm during the first three screening years. At the time of invitation, 22,732 men were eligible for screening, and 15,685 (69%) participated. A prostate-specific antigen (PSA) concentration of > or ==" BORDER="0">4 micro g/liter was defined as a screening-positive finding. RESULTS: The detection rate among screenees was 2.4% (377 of 15,685), whereas 0.6% (40 of 7,047) of nonparticipants in the screening arm and 0.3% (112 of 35,973) of the controls were diagnosed with prostate cancer during the first postrandomization year in the absence of screening. In the screening arm, 82% of the cancers were clinically organ confined compared with 65% in the control arm. Yet, both the absolute number and cumulative incidence of advanced cancer were higher in the screening arm. No differences were seen in the WHO grade distribution between the study groups. The median PSA was substantially lower among screen-detected cases (7.1 micro g/liter) than among nonattenders (15.7 micro g/liter) and controls (13.2 micro g/liter). CONCLUSIONS: Our findings on intermediate indicators of PSA screening provide encouraging, yet inconclusive evidence for eventual mortality reduction.
Family history and prostate cancer screening with prostate-specific antigen.
PURPOSE: Early detection of prostate cancer has been recommended for men with affected first-degree relatives despite the lack of evidence for mortality reduction. We therefore evaluated the impact of family history in the Finnish prostate cancer screening trial. PATIENTS AND METHODS: Approximately 80,000 men were identified from the population register for the first screening round. Of the 32,000 men randomized to the screening arm, 30,403 were eligible at the time of invitation. A blood sample was drawn from the participants (n = 20,716), and serum prostate-specific antigen (PSA) was determined. Men with a PSA level > or = 4.0 ng/mL were referred for prostate biopsy. Information on family history was obtained through a self-administered questionnaire at baseline. RESULTS: A total of 964 (5%) of the 20,716 screening participants had a positive family history, and 105 (11%) were screening-positive. Twenty-nine tumors were diagnosed, corresponding to a detection rate of 3.0% (29 of 964) and a positive predictive value of 28% (29 of 105). Of the 19,347 men without a family history, 1,487 (8%) had a PSA level > or = 4.0 ng/mL. The detection rate was 2.4% (462 of 19,347) and the positive predictive value was 31% (462 of 1,487). The risk associated with a positive family history was not substantially increased (rate ratio, 1.3; 95% confidence interval, 0.9 to 1.8). The results were not affected by the age of the screenee or age at diagnosis of the affected relative. The program sensitivity was 6% (29 of 491) (ie, selective screening policy would have missed 94% of cancers in the population). No differences were seen in the characteristics of screen-detected cancers by family history. CONCLUSION: Our findings provide no support for selective screening among men with affected relatives.
Differences between local and review urinary cytology in diagnosis of bladder cancer. An interobserver multicenter analysis.
OBJECTIVES: The objective of the study is to evaluate the agreement of local and review urinary cytology in patients with newly diagnosed bladder cancer and in those being followed for their disease. In addition, the effect of the type of institution on agreement was determined. METHODS: A total of 652 consecutive patients with bladder cancer from 19 institutions were evaluated; 575 (88.2%) of the patients had cytopathological sample available for central review and were eligible for analysis. One hundred and twenty nine (22.4%) of the patients had newly diagnosed bladder cancer, whereas the remaining 446 (77.6%) patients were under follow-up. A voided urine sample was obtained prior to transurethral resection of the bladder (TURB) or routine follow-up cystoscopy and split for culture and cytology. The cytopathological samples were first analysed by a local pathologist, and then re-analysed by a central reviewer. The agreement of cytological readings was determined by Kappa coefficient. RESULTS: The sensitivities of local and review cytology in detection of primary bladder cancer were 38.8 and 31.0%, respectively. Recurrence was observed in 119 of the 446 (26.7%) patients under follow-up, of which both local and review cytology detected 21 (17.6%) cases. Specificities of local and review cytology were 97.6 and 96.6%, respectively. Overall agreement of urine cytology was good in patients with primary bladder cancer and moderate in those being followed for their disease as Kappa coefficients were 0.70 and 0.60, respectively. However, some disagreement was found when results were analysed according to type of institution, to type of primary tumour, and to result of follow-up cystoscopy. In patients with primary bladder cancer the Kappa coefficient was 0.86 (very good) in university hospitals and 0.36 (fair) in city hospitals. Accordingly, in patients under follow-up the Kappa coefficient was 0.65 (good) in university hospitals and 0.39 (fair) in district hospitals. Although the stage of primary tumour had no effect on agreement, agreement was moderate (Kappa coefficient 0.45) in those with low grade tumour and good (Kappa coefficient 0.67) in those with high grade tumour. In addition, Kappa coefficients were 0.65 (good) and 0.40 (fair) in those with and without recurrence at follow-up cystoscopy. CONCLUSIONS: Although overall agreement of routine cytology was from moderate to good in both diagnosis and monitoring of bladder cancer, there is some variation in agreement according to the type of institution. Accordingly, grade of primary tumour and the result of follow-up cystoscopy had effect on agreement reflecting subjectiveness and weak reproducibility of this test. This not only emphasises the need for continuing education and quality control for urine cytologic analysis, but also inspires the development of more objective tests.
Estimation of prostate cancer risk on the basis of total and free prostate-specific antigen, prostate volume and digital rectal examination.
BACKGROUND AND OBJECTIVE: Approximately 70% of the men with an elevated serum prostate-specific antigen (PSA) identified in prostate cancer screening do not have prostate cancer. Other available diagnostic variables may be utilized to reduce the number of false positive PSA results, but few algorithms for calculation of the combined impact of multiple variables are available. The objective of this study was to establish nomograms showing the probability of detecting prostate cancer at biopsy on the basis of total PSA, and the percentage of free PSA in serum, prostate volume and digital rectal examination (DRE) findings. METHODS: In a randomized, population-based prostate cancer screening trial 10284 men aged 55-67 years were screened during 1996 and 1997 in two metropolitan areas in Finland. Results for men (n=758) with a serum PSA of 4-20 microg/l were used to establish the risk nomograms. Of these 200 (26%) had prostate cancer at biopsy. RESULTS: Prostate cancer probability depended most strongly on the percentage of free PSA. Total PSA, prostate volume, and DRE also contributed to prostate cancer probability, whereas age and family history of prostate cancer did not. More false positive PSA results could be eliminated by using the multivariate risk model rather than the percentage of free PSA (p<0.001) or PSA density (p=0.003) alone. CONCLUSIONS: Wide variation in probability of detecting prostate cancer among screened men with a serum PSA of 4-20 microg/l was observed. The nomograms established can be used to avoid or defer biopsy in men with a low prostate cancer probability in spite of a serum PSA level exceeding 4 microg/l.
Factors explaining recurrence in patients undergoing chemoimmunotherapy regimens for frequently recurring superficial bladder carcinoma.
OBJECTIVES: To study the factors determining new recurrences in patients with frequently recurring superficial bladder tumors. METHODS: Of all 205 eligible patients, each received 5 weekly intravesical instillations of mitomycin C (MMC), with the first instillation given perioperatively. This was followed, according to randomization, by BCG instillations alone or by alternating instillations of interferon-alpha and BCG monthly for up to 1 year. Impact of 12 variables on time to first recurrence was retrospectively studied with the Cox multiple hazards regression and Kaplan-Meier analysis. RESULTS: Type of regimen was the most significant factor determining new recurrences, with preceding recurrence rate being the most important prognostic factor. Timing of the first MMC was the third significant predictor in the main multivariate analysis, with more than a two-fold relative risk for a new recurrence if the first MMC instillation was given later than on day 0. CONCLUSION: Preceding recurrence rate, most accurately reflects, in patients with frequently recurring tumors, the inherent risk for new recurrences. This risk can be considerably reduced by use of an effective chemoimmunotherapy regimen, and in addition, by inclusion of an early perioperative chemotherapy instillation in such a regimen.
Lead-time in prostate cancer screening (Finland).
OBJECTIVE: Lead-time in prostate cancer screening was estimated using data from the Finnish randomized, population-based trial. METHODS: Lead-time was defined as the duration of follow-up needed to accrue the same expected number of incident prostate cancer cases in the absence of screening as detected in the initial screening round. Expected numbers were calculated using an age-cohort model. RESULTS: Based on findings among 10,000 men screened in 1996-1997 with 292 screen-detected cancers, lead-time was estimated as approximately 5-7 years, depending on the reference rates used. This corresponds to a mean duration of the detectable preclinical phase (DPCP) of 10-14 years, given that the cancers were detected on average at the midpoint of the DPCP. CONCLUSIONS: The findings suggest that a screening interval substantially longer than the 2 years generally used for mammography screening is unlikely to cause a substantial loss of sensitivity. A long screening interval is further justified in order to diminish the extent of overdiagnosis, until mortality effects can be evaluated.