Influence on survival of early diagnosis of breast cancer by breast screening: results of a longitudinal study 1981-1990

Background and objective: Current meta-analyses have left in: doubt whether general breast screening increases survival rate This study investigated whether efforts at early diagnosis of cancer in the 1980s have had an effect on average tumor size at first diagnosis and on survival rate. Patients and methods: From 1981 to 1990, 1656 consecutive patients (average age 56.6 years) at the I. Women's Clinic at the Ludwig-Maximilian University of Munich and the Women's Clinic Berlin-Charlottenburg were operated on for primary breast cancer. In a retrospective analysis, average tumor size at the primary operation and survival rate were determined for two periods: 1981-1985 (n=849) and 1986-1990. Mean follow-up time was 63 months. Results: There was no difference between the two cohorts regarding age (p = 0.77) and axillary node status (p = 0.14). During the follow-up period there was a gradual decrease in the tumor size at first diagnosis. (Pearson's correlation coefficient: -0.79, p < 0.001). Average tumor size in, those operated on was 25 mm up to 1985, and 21 mm after 1986 (p < 0.001). Until 1985, the initial reason for mammography was the planned subsequent operation in 19% of patients (n = 164), and in 27% (n = 215; p < 0.001) since 1986. But there was no statistically significant rise in disease-specific survival rate (log rank, p=0.48). Multivariate analysis confirmed the conventional prognostic parameters; such as tumor size (relative risk 2.21) and axillary lymph node metastases (relative risk 3.57), but not the period of follow-up (p=0.90). Conclusion: During the stated periods of follow-up there was a significant decrease in average tumor size at initial diagnosis. But this did not result in any demonstrably better disease-specific survival rate.