Dokuz Eylül Üniversitesi Onkoloji Enstitüsü, İZMİR
Keywords: Ductal carcinoma in situ, Diagnosis, Treatment, Prognosis
Ductal carcinoma in situ (DCIS) is a non-invasive disease of the breast, and its incidence has increased markedly in recent two decades due to widespread adoption of screening mammography. The natural history of DCIS varies according to the histological type and grade of the tumor, and when it is left untreated about one third of low grade lesions develop subsequent invasive breast carcinoma after 30 years, whereas it takes about 5 years in high grade lesions. In patients who treated the recurrence rate is reported 1-32% of DCIS cases, and about half of these recurrences are invasive.
In the past, mastectomy was the primary treatment modality for patients with DCIS, but breast-conserving surgery has become the standard approach in recent years because of the obtaining same results with the addition of radiotherapy. However total mastectomy remains the treatment of choice for multicentric and/or extensive disease [Van Nuys Prognostic Index (VNPI) score 10-12].
Three randomized trials have reported a statistically significant decrease in the risk of recurrence with radiation therapy in combination with lumpectomy compared with lumpectomy alone, but there was no survival advantage with the addition of radiotherapy. Similarly, two randomized trials have suggested an additional benefit, in terms of recurrence, with the addition of adjuvant tamoxifen therapy, although in one trial the benefit was not statistically significant. Current data suggest that lumpectomy±radiotherapy for patients with VNPI score 4-6, lumpectomy+ radiotherapy those with score 7-9, and total mastectomy for patients with score 10-12. Adjuvant tamoxifen is recommended to younger patients who had breast-conserving surgery for high risk DCIS with hormon receptor positive.
Of the ongoing and recently completed four randomized trials, two trials are investigating the outcomes of the patients with low risk who treated lumpectomy alone, and other two ones are evaluating the effectiveness of aromatase inhibitors as an alternative to tamoxifen.