BACKGROUND.
Although in recent years there has been a dramatic increase in both the incidence of ductal carcinoma in situ (DCIS) and breast-conserving therapy for patients who have this disease, the optimal treatment for these patients remains controversial. Most data regarding outcomes have come from small, retrospective studies, with little data published from prospective, randomized studies. This study investigates the effects of age, postoperative breast irradiation, and other factors on local relapse free survival after breast-conserving surgery for women with DCIS in a large, single-institution series.
METHODS.
A review was performed of all patients with DCIS who underwent breast-conserving surgery at Memorial Sloan-Kettering Cancer Center from 1978 through 1990. Of the 171 cases identified, data on follow-up and radiation therapy were available for 157. All available pathology slides (132 of 157) were rereviewed to determine histologic subtype, nuclear grade, presence of necrosis, and microscopic tumor size. Sixty-five patients (41%) received postoperative radiation therapy; selection criteria evolved over the time period. The median follow-up was 74 months.
RESULTS.
Factors that were significantly (P ี
0.05) associated with a lower recurrence rate were older age, noncomedo subtype, lower nuclear grade, negative margins, and postoperative radiation therapy. The 6-year actuarial recurrence rate was 9.6% for patients who received postoperative radiation therapy and 20.7% for patients who had excision only (P ฯญ 0.05). Comparison of patients of ages ี70, 40 -69, and ฯฝ40 years revealed a significantly lower risk of recurrence with increasing age. Actuarial 6-year local relapse rates were 10.8%, 14.0%, and 47.2%, respectively (P ฯญ 0.047). A benefit from radiation therapy was suggested for each age group. There was no statistically significant correlation between age group and any histologic factor examined. In multivariate analysis, only margin status was statistically significant (P ฯญ 0.05).
CONCLUSIONS.
In addition to margin status, pathologic factors, and the use of radiation therapy, age is another factor that should be considered in assessing the risk of local recurrence after breast-conserving surgery for patients with DCIS.