Background It is of paramount importance to evaluate the impact of participation in organized mammography service screening independently from changes in breast cancer treatment. This can be done by measuring the incidence of fatal breast cancer, which is based on the date of diagnosis and not on the date of death. Methods Among 549,091 women, covering approximately 30% of the Swedish screening‐eligible population, the authors calculated the incidence rates of 2473 breast cancers that were fatal within 10 years after diagnosis and the incidence rates of 9737 advanced breast cancers. Data regarding each breast cancer diagnosis and the cause and date of death of each breast cancer case were gathered from national Swedish registries. Tumor characteristics were collected from regional cancer centers. Aggregated data concerning invitation and participation were provided by Sectra Medical Systems AB. Incidence rates were analyzed using Poisson regression. Results Women who participated in mammography screening had a statistically significant 41% reduction in their risk of dying of breast cancer within 10 years (relative risk, 0.59; 95% CI, 0.51‐0.68 [P < .001]) and a 25% reduction in the rate of advanced breast cancers (relative risk, 0.75; 95% CI, 0.66‐0.84 [P < .001]). Conclusions Substantial reductions in the incidence rate of breast cancers that were fatal within 10 years after diagnosis and in the advanced breast cancer rate were found in this contemporaneous comparison of women participating versus those not participating in screening. These benefits appeared to be independent of recent changes in treatment regimens.

Comparing the rate of missed cases from different studies may be misleading unless the same review method is used. No difference in detection rate could be shown whether the radiologist reviewed images from his/her own screening unit or not. Most of our interval cancers were not regarded as missed cases by either of the two methods.

The purpose of this study was to determine the safety and efficacy of percutaneous ultrasound (US) guided preferential radiofrequency ablation (PRFA) of unifocal human invasive breast carcinoma with largest radiological diameters of up to 16 mm. Thirty-three patients were enrolled in a study to be treated prior to scheduled partial mastectomy. A needle-shaped treatment electrode, successively developed in two different sizes, was placed into the center of the lesions using ultrasound guidance. A temperature of 85 degrees C was maintained for 10 min. The analysis of the resected specimen was performed using conventional histopathological methods with the aim to determine the size of the lesion as well as the potential viability of tumor cells. Of the 33 patients enrolled 31 were treated. In 26 (84%) patients a complete ablation of the tumor was achieved. Ultrasound guided preferential radiofrequency ablation of small breast carcinoma is feasible and patient friendly. The success rate depends on accurate preoperative diagnostic imaging as well as an exact position of the needle electrode.

Objectives To explain apparent differences among mammography screening services in Sweden using individual data on participation in screening and with breast cancer–specific survival as an outcome. Methods We analysed breast cancer survival data from the Swedish Cancer Register on breast cancer cases from nine Swedish counties diagnosed in women eligible for screening. Data were available on 38,278 breast cancers diagnosed and 4312 breast cancer deaths. Survival to death from breast cancer was estimated using the Kaplan–Meier estimate, for all cases in each county, and separately for cases of women participating and not participating in their last invitation to screening. Formal statistical comparisons of survival were made using proportional hazards regression. Results All counties showed a reduction in the hazard of breast cancer death with participation in screening, but the reductions for individual counties varied substantially, ranging from 51% (95% confidence interval 46–55%) to 81% (95% confidence interval 74–85%). Survival rates in nonparticipating women ranged from 53% (95% confidence interval 40–65%) to 74% (95% confidence interval 72–77%), while the corresponding survival in women participating in screening varied from 80% (95% confidence interval 77–84%) to 86% (95% confidence interval 83–88%), a considerably narrower range. Conclusions Differences among counties in the effect of screening on breast cancer outcomes were mainly due to variation in survival in women not participating in screening. Screening conferred similarly high survival rates in all counties. This indicates that the performance of screening services was similar across counties and that detection and treatment of breast cancer in early-stage reduces inequalities in breast cancer outcome.

Objectives-To examine the rate of incidence cancers detectable on review of previous screening mammograms using two reviewing methods. To compare the results with a previous study of interval cancers using the same reviewing methods. Setting-Almost 50 000 women are regularly invited for service screening at Stockholm Söder Hospital. From 1989 to 1993, 119 women were identified with breast cancer detected at screening and the previous round attendance (incidence cancer). Methods-Screening mammograms, obtained before detection of the incidence cancers, were reviewed first mixed with other screening images (ratio 1:8) and then non-mixed. Reviewers from the screening unit responsible for the mammograms as well as reviewers from other units interpreted all images by both single and double reading. Results-The proportion detected on retrospective review varied between 5% and 50% depending on the review method used and the number of reviewers included to classify a case as truly identified. Generally more cancers were detected when non-mixed samples of mammograms were reviewed than when mixed samples were reviewed (mean increase 23%) and when interpreted by double reading compared with single reading (mean increase 14%). Conclusions-In an experimental retrospective set up, fewer incidence cancers were identified in mixed than in nonmixed review. Generally more incidence cancers were identified on review (22%) than previously reported for interval cancers (14%), probably reflecting diVerences in tumour biology and growth. How many women with potentially visible incidence cancers would have benefited from earlier tumour detection still needs to be evaluated. (J Med Screen 2000;7:177-183) Keywords: breast neoplasm; mammography; incidence cancer; cancer Breast screening with mammography has in randomised trials been shown to reduce mortality from breast cancer.1-4 Maintaining these results in ordinary service screening requires continuous high quality of all the components of the screening procedure, including the radiologist's performance. The rate of breast cancers overlooked or misinterpreted as the result of observer error has sometimes been used as a quality measurement of radiological interpretation. 5Such cancers could be detected either at the next screen (incidence cancer) or in the time interval before the next screen (interval cancer). [6][7][8] Consequently, to be able to estimate the number of women who have breast cancers overlooked/misinterpreted, the mammograms of both interval and incidence breast cancers should be reviewed, preferably in a set up imitating the screening procedure. Most review studies have not included screen detected cancers, and few studies give details of how the review procedure was performed.When reviewing 44 screen detected cancers, not mixed with other screening images, van Dijck et al 9 classified 9% as "screening error" and 48% as showing "minimal signs present" on previous mammograms compared with 18% and 28% respectively of 40 interval cancers. In a study by Harvey et...