NCCN VERSION 2 2015

The NCCN Guidelines® and this illustration may not be reproduced in any form without the express written permission of NCCN®.

MS-7

NCCN Guidelines Index

Breast Cancer Table of Contents

Discussion

NCCN Guidelines Version 2.2015

Breast Cancer

HER2 status of DCIS does not alter the management strategy and

routinely should not be determined.

MRI has been prospectively shown to have a sensitivity of up to 98% for

high-grade DCIS.

In a prospective, observational study, 193 women

with pure DCIS underwent both mammography and MRI imaging

preoperatively; 93 (56%) women were diagnosed by mammography

and 153 (92%) were diagnosed by MRI (

< .0001). Of the 89 women

with high-grade DCIS, 43 (48%) who were not diagnosed by

mammography were diagnosed by MRI alone. Another study evaluated

the role of MRI in determining appropriate candidacy for partial breast

irradiation for women with DCIS. Twenty percent of women with DCIS

were identified as ineligible for partial breast irradiation after a bilateral

breast MRI.

However, large prospective clinical trials will be

necessary to further investigate the clinical role of MRI for diagnosing

DCIS and to investigate its effect on recurrence rates or mortality. The

NCCN Panel has included breast MRI as optional during the initial

workup of DCIS, noting that the use MRI has not been shown to

increase likelihood of negative margins or decrease conversion to

mastectomy with DCIS.

Primary Treatment

Seemingly pure DCIS on core needle biopsy will be found to be

associated with an invasive cancer on surgical excision in about 25% of

patients.

For the vast majority of patients with limited disease where negative

margins are achieved with the initial excision or with re-excision,

lumpectomy or total mastectomy are appropriate treatment options.

Although mastectomy provides maximum local control, the long-term,

cause-specific survival with mastectomy appears to be equivalent to

that with excision and whole breast irradiation.

47-49

Patients with DCIS and evidence of widespread disease (ie, disease in

two or more quadrants) on mammography or other imaging, physical

examination, or biopsy require a total mastectomy without lymph node

dissection.

Prospective randomized trials have shown that the addition of whole

breast irradiation to a margin-free excision of pure DCIS decreases the

rate of in-breast disease recurrence, but does not affect survival

47,48,50-54

or distant metastasis-free survival.

Whole breast irradiation after

breast-conserving surgery reduces the relative risk of a local failure by

approximately one half. If whole breast radiation is used, the use of a

radiation boost (by photons, brachytherapy, or electron beam) to the

tumor bed is recommended to maximize local control, especially in

patients 50 years of age or younger.

There is retrospective evidence suggesting that selected patients have

a low risk of in-breast recurrence with excision alone without breast

irradiation.

56-59

For example, in a retrospective review, 10-year

disease-free survival (DFS) rates of 186 patients with DCIS treated with

lumpectomy alone were 94% for patients with low-risk DCIS and 83%

for patients with both intermediate- and high-risk DCIS.

In another

retrospective study of 215 patients with DCIS treated with lumpectomy

without radiation therapy, endocrine therapy, or chemotherapy, the

recurrence rate over 8 years was 0%, 21.5%, and 32.1% in patients

with low-, intermediate- or high-risk DCIS, respectively.

multi-institutional, nonrandomized, prospective study of selected

patients with low-risk DCIS treated without radiation has also provided

some support for the use of excision without radiation in the treatment

of DCIS.

At a median follow-up of 6.2 years, the 5-year risk of

ipsilateral breast recurrence was 6.1% (95% confidence interval [CI],

4.1%–8.2%) in the subset of patients with low-/intermediate-grade DCIS

and median tumor size of 6 mm. Margin widths were ≥5 mm in 69.2%