Local recurrence after conservative surgery and radiation therapy for ductal carcinoma in situ: Possible importance of family history.

PURPOSE: The optimal treatment of ductal carcinoma in situ is controversial. Traditionally, women with this disease have been treated with mastectomy with excellent results, but recently the need for such extensive surgery has been questioned. Long-term data on the use of conservative surgery and radiation therapy for treatment are limited. A retrospective analysis was performed to assess treatment outcome and prognostic factors for patients with ductal carcinoma in situ treated with conservative surgery and radiotherapy.

PATIENTS AND METHODS: From 1976 to 1990, 76 women with ductal carcinoma in situ were treated with conservative surgery followed by radiation therapy. The median age at diagnosis was 48 years. Seventeen patients had a positive family history of breast cancer in a first-degree (n=8) or second-degree (n=9) relative. Median follow-up interval was 74 months for the 71 survivors. In 54 patients, the carcinoma was detected by mammography alone; in 13 patients, by mammography and physical examination; and in 4 patients, by physical examination with a normal mammogram; and in 5 patients, by physical examination alone without mammography. Fifty patients had re-excision after initial biopsy. Final margins were positive in 11, close in 11, negative in 34, and unknown in 20. The median volume of excised tissue was 60 cm3. The axilla was surgically staged in 30 patients (39%) and all were negative. The whole breast was irradiated to a dose of 45 to 50 Gy in all patients. Seventy-two patients also received a boost to the primary site. The median total radiation dose to the primary site was 61 Gy (range, 46 to 71).

RESULTS: Seven patients had a recurrence in the treated breast at 16, 18, 41, 63, 72, 83, and 104 months after treatment. The 5- and 10-year actuarial rates of local recurrence were 4% and 15%, respectively. Six of seven recurrences occurred in the vicinity of the original lesion. Four local recurrences were invasive, and three were ductal carcinoma in situ. Two patients developed a contralateral invasive carcinoma. The 5- and 10-year cause-specific survival rates were 100% and 96%, respectively. The 10-year actuarial rate of local recurrence was 25% in the group with a total excision volume less than 60 cm3, as compared with 0% in those with 60 cm3 or more excised (P=0.04). In patients with a positive family history, the 10-year actuarial rate of local recurrence was 37%, as compared with 9% in patients with a negative family history (P=0.008). Of the 17 patients with a positive family history, four developed either an ipsilateral or contralateral invasive breast cancer, whereas 1 of the 58 patients without a family history developed a subsequent invasive breast cancer (P=0.008).

CONCLUSION: These results suggest that patients with ductal carcinoma in situ treated with conservative surgery and radiotherapy (including a boost to the primary site) appear to benefit from wide, rather than limited, resection. These results also suggest that family history may be an important prognostic factor for progression of disease.