FLORENCE, ItalyRadiotherapy reduces the odds of local
recurrence in women with ductal carcinoma in situ (DCIS) who have
undergone breast-conserving surgery, according to 4-year follow-up
evidence from a trial conducted by the European Organization for
Research and Treatment of Cancer (EORTC).
These early EORTC findings, presented at the First European Breast
Cancer Conference, support the results of NSABPB-17, the only other
prospective randomized trial to explore outcome following
conservative treatment of preinvasive breast cancer.
In the multicenter EORTC trial, more than 1,000 women who underwent
local excision of lesions less than 5 cm in size were randomized to
receive either external irradiation with 50 Gy over 5 weeks or no
All study participants were under the age of 70, had good performance
status, exhibited microscopic free margins, and had neither
concurrent malignancies nor Pagets disease. Two-thirds of
patients in both treatment groups required only one operation, and
approximately one-fifth underwent axillary dissection. Follow-up
consisted of annual mammography.
Reporting on behalf of the EORTC Breast Cancer Cooperative Group, Dr.
J.P. Julien, of Henri Becquerel Center, Rouen, France, said that the
rate of local recurrence was 38% lower among women who had been
treated with postoperative radiation (P = .005). Similar risk
reductions were achieved for both invasive and noninvasive
recurrences, he noted (see Table).
However, Dr. Julien emphasized, radiotherapy had no impact on the
development of distant metastases or on overall survival. Likewise,
the time that elapsed before the occurrence of a first event was
similar in both study arms.
We shouldnt conclude that all patients with DCIS should
have radiotherapy, Dr. Julien cautioned. The challenge, he
said, will be to develop reliable methods of identifying those women
most likely to progress to invasive or metastatic disease. Central
pathology review of 845 EORTC study enrollees has spotlighted a
correlation between histologic features and clinical outcome,
although the influence of radiotherapy on the various subgroups has
yet to be analyzed.
The risk of local recurrence, and especially the risk of
invasive local recurrence, is not dependent on the grade of
DCIS, observed Dr. N. Bijker, of the Netherlands Cancer
Institute, Amster-dam. However, she continued,
high-grade DCIS is associated with an increased risk of distant
metastases and seems to be related to an increased risk of death.
Dr. Bijker explained that these findings support the theory that the
malignancy grade of invasive breast cancer sustains its preinvasive grade.