BACKGROUND The evaluation of organized mammographic service screening programs is a major challenge in public health. In particular, there is a need to evaluate the effect of the screening program on the mortality of breast carcinoma, uncontaminated in the screening epoch by mortality from 1) cases diagnosed in the prescreening period and 2) cases diagnosed among unscreened women (i.e., nonattenders) after the initiation of organized screening. METHODS In the current study, the authors ascertained breast carcinoma deaths in the prescreening and screening epochs in 7 Swedish counties from tumors diagnosed in these epochs and in the age group 40–69 years in 6 counties and 50–69 years in 1 county. Data regarding deaths were obtained from the Uppsala Regional Oncologic Center in conjunction with the National Cause of Death Register. The total number of women in the eligible age range living in each county was obtained from the annual population data of Statistics Sweden. Detailed screening data were provided by the screening centers in the seven counties, including the number of invited, the number attended, and whether each individual breast carcinoma case was exposed (screen‐detected and interval cases combined) or unexposed (not‐invited or nonattenders) to mammographic screening. There were 2044 breast carcinoma deaths from 14,092 incident tumors diagnosed in the prescreening and screening epochs, and the total number of person‐years was 7.5 million. Data were analyzed using Poisson regression with corrections for self‐selection bias and lead‐time bias when appropriate. RESULTS The mortality reduction for breast carcinoma in all 7 counties combined for women actually exposed to screening compared with the prescreening period was 44% (relative risk [RR] = 0.56; 95% confidence interval [95% CI], 0.50–0.62). When all incident tumors were considered, both those exposed and those unexposed to screening combined, counties with > 10 years of screening were found to demonstrate a significant 32% mortality reduction (RR = 0.68; 95% CI, 0.60–0.77) and counties with ≤ 10 years of screening showed a significant 18% reduction in breast carcinoma mortality (RR = 0.82; 95% CI, 0.72–0.94) for the screening epoch compared with the prescreening epoch. Within the screening epoch, after adjustment for self‐selection bias, a 39% mortality reduction (RR = 0.61; 95%CI, 0.55–0.68) was observed in association with invitation to screening. CONCLUSIONS Organized service screening in 7 Swedish counties, covering approximately 33% of the population of Sweden, resulted in a 40–45% reduction in breast carcinoma mortality among women actually screened. The policy of offering screening is associated with a mortality reduction in breast carcinoma of 30% in the invited population, exposed and unexposed combined. The results of the current study indicate that the majority of the breast carcinoma mortality reduction is indeed due to the screening. [See editorial on pages 451–7, this issue.] Cancer 2002;95:458–69. © 2002 American Cancer Socie...

After extended follow-up, there was a clinically and statistically significant increased risk of a new breast cancer event in survivors who took HT.

Adherence to long-term pharmacological treatment for chronic conditions is often less than optimal. Till date, a limited number of population-based studies have assessed adherence to adjuvant hormonal therapy in breast cancer, a therapy with proven benefits in terms of reductions of recurrence and mortality. We aimed to examine rates of adherence and early discontinuation in Sweden where prescribed medications are subsidized for all residents and made available at reduced out-of-pocket costs. Individual-level data were obtained from Regional Clinical Quality Breast Cancer Registers, the Swedish Prescribed Drug Register, and several other population-based registers. Multivariate logistic regression was used to analyze factors associated with adherence to prescribed medication for a period of 3 years. Between January 1 and December 31, 2005, 1,741 patients in central Sweden were identified with estrogen receptor positive breast cancer, and at least one prescription dispensation of either tamoxifen or an aromatase inhibitor. Of these women, 1,193 (69%) were fully adherent to therapy for 3 years (medication possession ratio of 80% or higher and a maximum of 180 days between refills). During the 3-year follow-up, 215 women (12%) had prematurely discontinued therapy. Adherence was positively associated with younger age, large tumor size, being married, and being born in the Nordic countries, while no clear association was observed with education or income. During the 3 years of follow-up, 31% of women were non-adherent to therapy. Further efforts must be undertaken to promote adherence over the entire recommended treatment period.

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