Management of Management of DCISDCIS

Fei-Fei LiuFei-Fei LiuRadiation Oncologist/Senior ScientistRadiation Oncologist/Senior Scientist

Learning Objectives

1. Describe DCIS.2. Acquire familiarity of local

management for DCIS.3. Understand the role of systemic

treatment for DCIS.4. Appreciate some of the emerging

issues.5. Like radiation oncologists.

DCIS

Definition

Proliferation of malignant ductal epithelial cells which have not breached the BM.

DCIS

• Rising incidence due to screening

• 15-20% of all newly-diagnosed breast tumours– 90% of DCIS are

mammographically detected

DCIS

Diagnosis

• Mostly made on mammography

• Role of mri – – Might be more sensitive, but lacks

specificity– useful to r/o multiple lesions

DCIS

Classifications

Very complex; no single accepted system.

Tissue processing protocolis complex; hence notgeneralizable.

Learning Objectives

1. Describe DCIS.2. Acquire familiarity of local

management for DCIS.3. Understand the role of systemic

treatment for DCIS.4. Appreciate some of the emerging

issues.5. Like radiation oncologists.

Management of DCIS

Options

• Simple Mastecomy– no RCT of SM vs. lump – large or diffuse lesions– involvement of resection margins– no role for AxLND

• Lumpectomy + RT

Four RCT of Lump + RT for DCIS

UKCCRC; Lancet 362:95, 2003

Why Does Controversy Persist?

RCTs demonstrate benefit to RT in all subgroups but:

– margin width was not measured– tumour sizes missing

Identification of a LOW RISK Group

Van Nuys data

Margin WidthNo RT RT RR> 10 mm .03 .02 1.14

1 to <10 mm .20 .12 1.49< 1 mm .58 .30 2.54

Canadian Clinical Practice Guidelines for DCIS

• BCS should be followed by RT

• Mastectomy – large or diffuse lesions– involvement of resection margins

• No axillary dissection

• Omission of RT: small, low grade, no necrosis, negative margins

Olivotto et al, CMAJ 165:912, 2001

RT Is No Longer Given As Such

Modern Day Breast RT

• Tangential parallel pair

• Intensity Modulated Radiation Therapy (IMRT)

• Achieve optimal dose homogeneity in target volume (breast)

CT-Simulation

• Diagnostic CT unit with rapid spiral acquisition

• Full 3D dataset• Virtual simulation

software

CT Based Simulation & Planning

Standard Breast Tangents

115%

110%

105%

100%

95%

90%

Goal: Dose UniformityWedges IMRT

Pignol et al, JCO 26:2085, 2008

Improved Acute Skin Reaction with IMRT

Doses of RT

1. 4240 cGy/16#/3.5 wks+ boost (10 Gy/5#s)

2. 5000 cGy/25#/5 wks+ boost (10 Gy/5#s)

Quiz #1

Which famous personality had DCIS?

1. Melissa Etheridge2. Liona Boyd 3. Belinda Stronach4. Michael Jackson

Learning Objectives

1. Describe DCIS.2. Acquire familiarity of local

management for DCIS.3. Understand the role of systemic

treatment for DCIS.4. Appreciate some of the emerging

issues.5. Like radiation oncologists.

Tamoxifen in the Management

of DCIS

The Role of Tamoxifen in the Management of DCIS: NSABP B-

24

• N = 1804• Local excision + RT

Placebo TamoxifenP

All Breast Cancer 13.4% 8.2% 0.0009

Ipsilateral BCInvasive 4.2% 2.1% 0.03Non-invasive 5.1% 3.9% 0.43

Contralateral BC3.4% 2.0% 0.01

UKDCIS Trial: Effect of Tamoxifen

Why the Difference?

Trial Design

– 33% of patients in Tamoxifen arm of the UK trial had RT

– All patients in B24 had RT before TAMOXIFEN

– Exclusion of positive margins in the UK trial

Why the Difference?

Patient Population

– 34% of patients in B24 were <50 years vs. 9% in the UK Trial

– Both trials showed greatest benefit of Tamoxifen in women <50 years

NSABP B-24: Toxicity

3000 women; opened Jan 03

IBIS TrialTam vs. Anastrozole

4000 ER+ve DCIS post-menowomen

Quiz #

What is the IMRT acronym?

1. Intermittent Moderate RT2. Infinite Modulated RT3. Incredibly Modern RT4. Intensity Modulated RT

Learning Objectives

1. Describe DCIS.2. Acquire familiarity of local

management for DCIS.3. Understand the role of systemic

treatment for DCIS.4. Appreciate some of the emerging

issues.5. Like radiation oncologists.

Kuere et al; JCO 27:279, 2009

Take-Home Points

1. DCIS accounts for ~20% of newly-diagnosed BC

2. Surgery (mostly lumpectomy)

3. RT reduces the risk of local recurrence

4. There may a subset of women with DCIS that do not benefit from RT

Conclusions

5. Prospective validation of BCS alone is needed

6. Improvements in techniques of surgical resection, pathologic evaluation of DCIS, and adherence to synoptic reporting of DCIS will help identify potential candidates for BCS alone.

Any Questions?