Breast Conservation Therapy for Intraductal Carcinoma of the Breast

Purpose: Between 1979 and 1987, 76 women with 77 ductal carcinomas in-situ of the breast were evaluated by The Radiation Oncology Center after breast conservation surgery.

Methods And Materials: Seventy breasts (91%) had tylectomy and irradiation and seven breasts (9%) had tylectomy alone. Median follow-up was 4.0 years, with a range of 2-10 years. Fifty patients (65%) had occult lesions discovered by mammography with a median mammographic size of 0.9 cm. The twenty-six patients with presenting symptoms had a median clinical tumor size of 1.95 cm. All patients had local excision of the primary tumor. Of 15 patients who had axillary dissections, one had nodal metastasis. Seventy breasts were irradiated. Seven patients refused radiotherapy.

Results: Overall 5-year actuarial survival was 99%; 5-year actuarial disease-free survival was 89%; the 5-year actuarial intramammary tumor control rate for irradiated patients was 93% vs. 57% for patients not irradiated (p < 0.001). Comedocarcinoma had a 5-year actuarial tumor control rate of 75%, 88% in the irradiated group as compared to 98% for all other histologic subtypes of ductal carcinoma in situ (p < 0.03). All six patients with local failure were successfully salvaged by further surgery. Multivariate analysis revealed significant factors in local control to be (a) radiotherapy, (b) comedocarcinoma histology, and (c) menopausal status.

Conclusions: Although the number of patients treated is small, and follow-up time is limited, these early results support the contention that the treatment of ductal carcinoma in situ by excision and irradiation is an acceptable alternative to mastectomy. We urge caution in treating patients with the comedocarcinoma subtype and counsel these patients to have more treatment than excision alone.