[Non metastatic breast cancer surgery in the Rhône department between 1988 and 1994]. / Traitement chirurgical du cancer du sein de stade M0 entre 1988 et 1994 dans le département du Rhône.

ABSTRACT

BACKGROUND: From the results obtained in the breast cancer register, this report describes the usual surgical practice of breast cancer in the Rhône department (France). METHODS: This study concerned 4,028 cases of non-metastatic breast cancer diagnosed during the period 1988-1994. Three periods were determined (1988-89, 1990-92, 1993-94). Univariate analysis described the relation between the type of surgical practice and the explanatory factors. Logistic regression analysis was used to search for changes in surgical practice during the three periods. RESULTS: The proportion of conservative breast surgery rose from 53% in 1988 to 64.5% in 1994. Taking the period 1988-89 as the reference period, the adjusted odds ratio of conservative surgery during the period 1990-92 was 1.4 [1.1-1.7]. During the period 1993-94, this adjusted odds ratio was 1.9 [1.6-2.3]. Finally we observed that conservative surgery was less frequent in patients 70 years of age or older. CONCLUSION: Conservative breast surgery increased significantly during the defined period. This observation can be explain by two events. First there was a significant increase of small breast cancer (< 20 mm) among women aged 50 to 69 who benefited from the systematic screening breast cancer since 1988. Secondly a significant "period effect" was observed. This "period effect" proves a modification of surgical practice after adjustment for cancer characteristics.