Risk reduction strategies for ductal carcinoma in situ

Ductal carcinoma in situ (DCIS) is a premalignant condition that, if left untreated, may progress to invasive breast cancer. After lumpectomy, DCIS can recur, and about half of recurrences are invasive. In 4 randomized trials, radiation has been shown to decrease the local recurrence rate by about half, though it does not change survival. Based on the results of 3 randomized trials, tamoxifen probably decreases cancer recurrence by about 30%, particularly in young women. Low fat diets, weight loss, and physical activity decrease invasive breast cancer recurrence and may be recommended to certain women with DCIS. Prognostic factors include age, extent of DCIS, margin status, grade, and presence of necrosis, although how these affect adjuvant therapy is unclear. Research evaluating other drugs to reduce recurrence risk and on different ways of delivering radiation continues.