Management of DCIS Fei-Fei Liu Radiation 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 protocol is complex; hence not generalizable.

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 RTRT RR > 10 mm to <10 mm < 1 mm

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 Uniformity WedgesIMRT

Pignol et al, JCO 26:2085, 2008 Improved Acute Skin Reaction with IMRT

Doses of RT cGy/16#/3.5 wks + boost (10 Gy/5#s) cGy/25#/5 wks + boost (10 Gy/5#s)

Quiz #1 Which famous personality had DCIS? 1.Melissa Etheridge 2.Liona Boyd 3.Belinda Stronach 4.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 PlaceboTamoxifenP All Breast Cancer13.4%8.2% Ipsilateral BC Invasive4.2%2.1%0.03 Non-invasive5.1%3.9%0.43 Contralateral BC 3.4%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 Trial Tam vs. Anastrozole 4000 ER+ve DCIS post-meno women

Quiz # What is the IMRT acronym? 1.Intermittent Moderate RT 2.Infinite Modulated RT 3.Incredibly Modern RT 4.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?