Ductal Carcinoma
In Situ
393
1. “Large areas of DCIS of a size that the lesion cannot be
removed by an oncologically acceptable excision . . .
while still conserving a cosmetically acceptable breast.”
2. “Patients with multiple areas of DCIS in the same breast
that cannot be encompassed through a single incision.”
3. “Patients who cannot undergo radiation therapy be-
cause of other medical problems, such as collagen vas-
cular diseases, or prior therapeutic radiation to the chest
for another illness, and for whom treatment by excision
alone is not appropriate.”
Local recurrence on the chest wall is an unusual com-
plication in the treatment of DCIS by total mastectomy. A
meta-analysis of published studies reported that the fre-
quency of local recurrence following mastectomy alone was
1.4% (95% CI, 0.7 to 2.1).
348
The recurrent lesion may consist
of DCIS,
349
or it may manifest invasion.
350
Some of these re-
currences are accompanied by residual breast parenchyma,
which may harbor persistent DCIS.
351
Most published de-
scriptions of local recurrence after mastectomy for DCIS
do not comment on the presence or absence of breast pa-
renchyma associated with the recurrence. It is essential that
persistent breast tissue be looked for and mentioned in the
report that describes the specimen from the site of any lo-
cal recurrence, regardless of whether the primary lesion had
been
in situ
or invasive.
Recurrent carcinoma in residual breast tissue constitutes
persistence of the original primary tumor or a new primary
carcinoma and has a much more favorable prognosis than
the more frequent true local recurrence in a mastectomy
scar, which is usually a manifestation of systemic metastases.
Recurrent carcinoma in persistent breast tissue is adequately
treated in most cases by local excision supplemented by ra-
diotherapy and/or systemic chemotherapy, depending upon
the size of the lesion and whether invasion is present.
72,352
In
one report, the 5- and 10-year survival of patients with an in-
vasive local recurrence after mastectomy for DCIS was 83%
and 63%, respectively.
350
This result supports the conclusion
that the chest wall recurrences were a manifestation of per-
sistent carcinoma rather than evidence of systemic metasta-
ses in a substantial number of these patients.
Recurrence in the preserved nipple is a rare complication
of nipple-sparing mastectomy for DCIS. In one instance,
recurrence as invasive carcinoma occurred 17 years after a
subcutaneous mastectomy that was accompanied by irradia-
tion of the nipple.
353
Additional examples of recurrence in
the preserved nipple after subcutaneous mastectomy were
described by Price et al.
354
Another unusual type of recur-
rence consisted of two separate foci of invasive carcinoma
at subcutaneous drainage sites 8 years after a patient un-
derwent a modified mastectomy for DCIS.
351
No mammary
parenchyma was seen at the sites of recurrence. It was sug-
gested that DCIS cells dislodged at operation persisted at the
drain sites and gave rise to recurrent carcinoma.
Recurrent DCIS has been detected as a result of the mam-
mographic appearance of calcifications in residual breast
tissue after total mastectomy and saline implant reconstruc-
tion.
349
Helvie et al.
355
reported six patients who developed
invasive recurrent invasive carcinoma at the mastectomy site
DCIS are negative for high molecular weight cytokeratin,
even in epithelia that show marked cautery effect.
334
In 1999, the DCIS “Consensus Conference” proposed a
10-mm margin as the limit of oncologic safety.
187
Ten years
later, there was “consensus” among experts at St. Gallen on
avoiding the need to insist on a large (e.g., 1 cm) free mar-
gin.
335
In the interim years, various progressively lesser ex-
tents of optimal clearance were proposed, that is, 3, 2 to 3,
2, and 1 mm.
336–339
Although the need for negative margins
has been assimilated in various guidelines for DCIS manage-
ment, the absolute need for the attainment of a widely nega-
tive margin has been questioned on the basis of the NSABP
B1 and B24 trials that only required margins of tumor not
touching ink. In this study, only 72 (2.8%) of 2,612 patients
treated with breast conservation with and without radiation
therapy died of breast carcinoma after 15 years of follow-
up.
340
In 2012, Morrow et al.
341
concluded that “bigger is not
better” and suggested that a margin with no tumor at the
inked surface was satisfactory. This approach places reliance
on postsurgical adjuvant radiation and tamoxifen therapy.
Given such fluidity, and divergence, of recommendations
in the recent past, it would behoove pathologists to report
the pathologic findings in an objective manner, that is, re-
port the presence of tumor at ink as “positive,” and the clos-
est distances of tumor to various margins. The use of vague
terms (such as “abutting,” “near,” “approximating,” and
“free”), without further elaboration, should be avoided.
Innovative approaches such as placement of radioactive
“seeds” to enhance tumor localization and thereby ensure
adequate margin clearance,
342,343
as well as the intraoperative
assessment of surgical margins by the use of radiofrequency
spectroscopy during breast-conserving surgery of DCIS,
344
show early promise.
TREATMENT AND PROGNOSIS
Mastectomy
Until the last quarter of the 20th century, the standard treat-
ment for DCIS was mastectomy. Prior to the introduction of
modified mastectomy procedures, the operation was a clas-
sical radical mastectomy. Even after the widespread adop-
tion of the modified radical mastectomy, an
en bloc
axillary
dissection was routinely performed, yielding ALN metasta-
ses in only isolated instances.
18,19,73,74
These operations en-
sured at least a 99% cure rate.
19,73,74,309
Systemic recurrences
that occurred in 1% or less of patients after such treatment
resulted from contralateral carcinomas or foci of invasion
that were undetected.
72,73,345,346
The operation was deemed
justified because of the very low local recurrence rate and
the presence of unsuspected frankly invasive foci discovered
in the mastectomy specimens from about 5% of breasts that
had only DCIS in the biopsy specimen.
81,347
Mastectomy remains a treatment option for patients with
DCIS, but it is infrequently indicated under circumstances
outlined by a Consensus Conference on the Treatment of
In
Situ
Ductal Carcinoma (DCIS).
246
The situations in which
mastectomy was recommended were as follows:
