[Bilateral ductal carcinoma in situ of the breast: independent events or bilateral disease?]. / Carcinomes canalaires in situ bilatéraux: événements indépendants ou maladie bilatérale?

ABSTRACT

OBJECTIVES: In a retrospective study of bilateral Ductal Carcinoma In Situ (DCIS), cases were analysed to determine the relationship between the two events. MATERIAL AND METHODS: From 1971 to 2001, among 812 patients with DCIS in Bergonie Institute, 78 suffering from bilateral DCIS and only19 were treated entirely in our institute. It was either synchronous DCIS or asynchronous (before 6 months). We realised a comparative study between, clinical and pathological characteristics of each DCIS. RESULTS: In case of asynchronous DCIS, contra lateral DCIS occurred after a median 75-months period and until 22 years after the first event. We found at least for one histological subtype an agreement in 53% of cases. In 31% of cases, the grade was the same. For low plus intermediary grade versus high grade, the agreement was 53%. There was a subtype and grade agreement of 32% and a subtype or grade agreement in 63% of cases. CONCLUSION: Histological agreement between the two lesions indicated the possible existence of in situ bilateral disease in these women. The local relapse rate was 20% and all of them were invasive. The risk of relapse in controlateral breast is high and patient needs a long follow up even in case of mastectomy.