[Factors determining the choice between mastectomy and conservative treatment in the Côte-d'Or department (France). The Côte-d'Op6 register of gynecological cancers].

The aim of this study is to check, for a defined period and within a geographic area, whether the increased use of breast conserving treatment was related to changes in tumor characteristics, or whether changes in therapeutical practice persisted after adjustment on patients and tumor characteristics. From 1982 to 1990, 1,952 women with invasive carcinomas were registered in the French "departement" of Côte-d'Or. Seventeen hundred and seven non metastatic patients were treated by loco-regional surgery. A breast conserving surgery was performed in 60% of cases. The incidence of this treatment raised from 32% in 1982 to 73% in 1987. In univariate analysis, factors determining the type of tumor excision were: age, hormonal status, tumor size, tumor location, "clinical seriousness", nodal status, multiple tumors, inflammatory tumors, neoadjuvant treatments and year of diagnosis. Age and tumoral factors remained significant in a logistic regression analysis. Other factors being constant, the odds ratios of mastectomy was 12.9 times lower in 1987-1990 than in 1982, and 2.1 times lower than in 1985-1986, showing a "period effect". Ninety four percent of patients treated by breast conserving surgery were irradiated post operatively, showing that the clinical research recommendations were well transferred to the clinical practice in this department.