| Is Wide Excision Alone Sufficient
for Ductal Carcinoma in Situ (DCIS)?
There is continued controversy
surrounding the optimal local therapy for DCIS.
The term “DCIS” refers to a heterogeneous group of breast
lesions of varying clinical behavior.
Many patients with localized DCIS have been offered
breast-conserving surgery (wide excision), and with clear margins,
subsequently go on to receive breast radiation.
One of the challenges has been identifying patients for whom
radiation therapy is not necessary. Some have advocated the use of margins, grade, and lesion
size in determining which patients can safely omit radiation therapy. Our prospective trial of patients
with small, low or intermediate grade DCIS with margins of at least 1 cm
(or, a re-excision containing no residual DCIS), managed with wide
excision alone (no radiation therapy or tamoxifen), closed prematurely at
a median follow-up of 40 months, after accruing 158 patients, due to an
unacceptable number of local recurrences. The local recurrence rate was
2.4% per patient per year, corresponding to a 5-year rate of 12%.
Of the 13 recurrences, 9 were DCIS and 4 were invasive.
None had axillary nodal involvement and none had metastatic disease. Despite attempts to limit this
study to patients with “favorable” features, we were unable to
demonstrate that such patients can omit radiation therapy without an
increased risk for local recurrence.
While most of the local recurrences were noninvasive, the
possibility of an invasive recurrence and its potential impact on survival
raises concern. We believe that a subset of
patients with DCIS exists, for whom excision alone is adequate. However, the process of selecting such patients remains
unresolved. Until such a
subgroup can be reliably identified, it seems prudent to consider
radiation therapy after excision of DCIS.
Patients and their caregivers should discuss the risks and benefits
of radiation therapy in order to make informed decisions regarding its use. Bibliographic
reference:
Julia Wong Department of Radiation Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
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