Detailed screening data for the 40- to 49-year age group of all Swedish trials should be analyzed to specifically estimate the natural history and performance of screening in this age group.

For PSA values of 0-3.9 ng/mL, the positive predictive value and sensitivity of DRE, tumor volume, and tumor grade were strongly dependent on PSA level. DRE has a poor performance in low PSA ranges.

Based on an extensive cost‐effectiveness analysis, the Dutch nation‐wide breast cancer screening programme started in 1990, providing a biennial screen examination to women aged 50 to 69 years. The programme is monitored by the National Evaluation Team, which annually collects tabulated regional evaluation data to determine performance indicators. This study presents (trends in) the outcomes of initial and subsequent screening rounds, 1990–1995, and compares them to the predictions of the cost‐effectiveness‐analysis. Up to 1996, 88% of the target population was covered by the programme and more than 2.4 × 106 women were invited. The overall attendance rate was 77.5% with little differences between screening rounds and age groups; the highest rate was found in non‐urbanised areas (82.4%). Of 1,000 initially (and 2 years thereafter) screened women, 13.4 (6.6) were referred for further investigation, 9.7 (4.4) were biopsied and 6.4 (3.4) had breast cancer. The positive predictive values of screen test and biopsy were 47% (51%) and 66% (78%), respectively. DCIS was diagnosed in 0.9 (0.5) and invasive cancers ≤10 mm in 1.5 (1.0) per 1,000 screens. Lymph node metastases were found in 28% (24%) of the invasive cancers. Except the increasing attendance, which was much higher than expected, the results were fairly constant over the years. Contrary to initial screens, the results of subsequent screens did not fulfil expectations with regard to breast cancer detection and tumour size distribution. We conclude that the nation‐wide screening programme is being implemented successfully. Given the results, the programme should contribute to a substantial breast cancer mortality reduction in the future. The discrepancy between observed and expected results in subsequent screens has to be watched carefully. Int. J. Cancer 75:694–698, 1998.© 1998 Wiley‐Liss, Inc.

BACKGROUND In the European Randomized Study of Screening for Prostate Cancer (ERSPC, Rotterdam region), men aged 55–74 years are screened for prostate cancer by prostate‐specific antigen (PSA) sampling, digital rectal examination (DRE), and transrectal ultrasound investigation (TRUS). All men with a PSA ≥4 ng/ml and/or a suspicious DRE and/or a suspicious TRUS are biopsied. METHODS Logistic regression analysis was applied to derive a predictive index that equals the chance to find prostate cancer in a biopsy given the outcomes of the screening tests. This model was used to assess the number of cancers that could have been detected if all men had been biopsied (extrapolation). Furthermore, the model was used to study the possibilities for improvement of the current screening protocol. RESULTS PSA was the dominant predictor for prostate cancer in a biopsy, followed by prostate volume, DRE, and TRUS result. It is assessed that 69% (95% CI, 52–86%) of cancers that could be identified if all men were biopsied are currently detected. Application of the same methods to screening data obtained in Göteborg (the Swedish ERSPC partner) yielded almost identical results. It was found that, in the Rotterdam protocol, a considerable number of men were biopsied according to the screening protocol with an assessed lower chance to have prostate cancer than men who were not biopsied according to the protocol. CONCLUSIONS The chance to detect prostate cancer in a biopsy can be modeled quite accurately as a function of serum PSA, prostate volume, DRE, and TRUS results. Important improvements in the screening protocol can be achieved by the application of the predictive index. Prostate 39:316–322, 1999. © 1999 Wiley‐Liss, Inc.

SummaryThe nationwide breast cancer screening programme in The Netherlands for women aged 50-69 started in 1989. In our study we assessed the occurrence and stage distribution of interval cancers in women screened during 1990-1993. Records of 0.84 million screened women were linked to the regional cancer registries yielding a follow-up of at least 2.5 years. Age-adjusted incidence rates and relative (proportionate) incidences per tumour size including ductal carcinoma in-situ were calculated for screen-detected and interval cancers, and cancers in not (yet) screened women, comparing them with published data from the UK regions North West and East Anglia. In total 1527 interval cancers were identified: 0.95 and 0.99 per 1000 woman-years of follow-up in the 2-year interval after initial and subsequent screens respectively. In the first year after initial screening interval cancers amounted to 27% (26% after subsequent screens) of underlying incidence, and in the second year to 52% (55%). Generally, interval cancers had a more favourable tumour size distribution than breast cancer in not (yet) screened women. The Dutch programme detected relatively less (favourable) invasive cancers in initial screens than the UK programme, whereas the number of interval cancers confirms UK findings. Measures should be considered to improve the detection of small invasive cancers and to reduce false-negative rates, even if this will lead to increasing referral rates.