Current perspectives of treatment of ductal carcinoma in situ.

DCIS is a genetically diverse group of diseases with different prognosis. The similarities between DCIS and ductal infiltrating carcinoma (DIC) suggest that the key step in tumorigenesis is the transformation from high grade ductal hyperplasia to DCIS. The prognostic factors of DCIS include anatomo-pathologic factors, age and molecular factors. The key questions for DCIS management include: which patients are more likely to present an invasive failure; in which an excision is sufficient and who can be spared from radiation therapy. The role of post operative radiation therapy to reduce by 50-60% ipsilateral invasive and non-invasive local failure has been established in four randomized clinical trials. The question whether radiation therapy can be avoided in some patients remains controversial. Treatment with tamoxifen should be recommended to patients with estrogen receptor positive tumors who have been treated with conservative surgery. However, data from randomized trials suggest that addition of tamoxifen to locoregional treatment decreases the recurrence rate of invasive cancer as well as contralateral tumors. Sentinel lymph node biopsy is recommended for patients with clinically palpable, large DCIS in which the risk of microinvasion is high as well as in extensive DCIS requiring mastectomy. Mammography continues to be the best method to detect DCIS. Newer digital mammography improves the detection of microcalcifications. Current ultrasound can detect associated invasive cancer. MRI is also useful in DCIS. Combined with mammography, MRI increases the diagnoses of DCIS. Current trend includes the use of radiology guided-vacuum assisted-large bore needles that allow obtaining larger amounts of tissue, improving diagnostic yield.