THE MANAGEMENT OF DUCTAL CARCINOMA IN-SITU (DCIS)

Objective: To help physicians and patients arrive at the most clinical ly effective approach to the management of ductal carcinoma in situ (D CIS). Options: Mastectomy, wide-excision breast-conserving surgery (BC S) plus radiotherapy and BCS alone. Outcomes: Overall survival, local recurrence, cosmesis, complications of therapy. Evidence: Review of En glish language literature published between 1976 and December 1996, id entified through MEDLINE. Nonsystematic review continued to July 1997. Also reviewed were reference lists of books and relevant articles. Re commendations: The first step in the diagnosis of DCIS, after history- taking and clinical examination, is a complete mammographic work-up. O nce DCIS is suspected, either image-guided core biopsy or open surgica l biopsy must be carried out. At surgical excision, the suspect area s hould be removed in 1 piece and a specimen radiograph obtained. Tissue should not be sent for frozen-section examination or hormone receptor analysis. The pathology report should address those features that bea r on treatment choice. The specimen should, whenever possible, be revi ewed by a pathologist experienced in breast disease. Treatment options for DCIS are mastectomy, wide-excision BCS plus radiotherapy or BCS a lone. Treatment should aim to achieve a high degree of local control w ith the first treatment plan. Final decisions on treatment should not be made until the pathological findings have been reviewed and the spe cimen radiograph compared with the mammogram. Mastectomy is indicated when lesions are so large or diffuse that they cannot be completely re moved without causing unacceptable cosmesis or when there is persisten t involvement of the margins, especially with high-grade malignant les ions. Subcutaneous mastectomy should not be used to treat DCIS. Mastec tomy should not be followed by adjuvant local radiotherapy or systemic therapy. Bilateral mastectomy is not normally indicated for patients with unilateral DCIS. BCS requires wide excision in patients with DCIS . It should be followed by mammography of the involved breast if the s pecimen radiograph does not clearly include all microcalcifications. B CS should normally be followed by radiotherapy. However, omission of r adiotherapy may be considered when lesions are small and are low grade , and when pathological assessment shows clear margins. BCS should be accepted by patients only after they have received a careful explanati on of the need for radiotherapy, its side effects and the associated l ogistic requirements. Axillary surgery, whether as a full or limited p rocedure, should not usually be performed in women with DCIS. Evidence is not available to support the use of tamoxifen in the treatment of women with DCIS. Patients should be offered the opportunity to partici pate in clinical trials whenever possible. Validation: The guidelines were reviewed and revised by a writing committee, by expert primary re viewers, by secondary reviewers selected from all regions of Canada, a nd by the Steering Committee. The final document reflects a consensus of ail these contributors. The guidelines are endorsed by the Canadian Association of Radiation Oncologists.