Breast Radiation in the Era of

Neoadjuvant Chemotherapy

Breast Cancer Management 2016

Eileen Connolly M.D., Ph.D.

Assistant Professor of Radiation Oncology

May 3rd, 2016

Learning Objectives

• Postmastectomy Radiotherapy (Adjuvant Data) o Evidence For

o Against

• Regional Nodal Radiotherapy for 1-3 LN+ (Adjuvant Data) o MA.20

o EORTC 22922

o Danish Experience (+/- IMN)

• Predicting Local Regional Recurrence after Neoadjuvant Chemotherapy o NSABP Experience

• Future

Currently No Guidelines for RT

after Neoadjuvant Chemotherapy

Currently No Guidelines for RT

after Neoadjuvant Chemotherapy

Postmastectomy Radiotherapy

(Adjuvant Data)

EBCTG Meta-analysis of

PMRT trials

Absolute Benefits of PMRT (n= 8135)

Impact of Number of Involved Nodes

MDACC Retrospective

MDACC Retrospective

MDACC Retrospective

Regional Nodal Radiotherapy

for 1-3 LN+ (Adjuvant Data)

MA.20

• pN+ or high risk node negative

(T2N0 & G3 or ER- or LVSI)

• BCS + ALND + systemic tx

• 85% 1-3 LN+

• 91% chem (86% A or 26% T)

• 76% Endocrine Tx

• RNI = IMNs, SCV, ICV ± axilla

R

a

n

d

o

m

i

z

e

d

2000-2007

N=1,832

Breast only

Breast + RNI

MA.20: 10-year Results (n=1832)

MA.20: 10-year Survival Data

MA.20: Hazard Ratios for OS

MA.20: Adverse Events

EORTC 22922

• BCS or MTX + ALND

• Medial/central N± or lateral N+

• BCS = 76%, MTX = 24%

• pN0 = 44%, pN1 43%

• Chemo 25%

• Endocrine Tx 30%

• Chemo + Endocrine Tx 30%

• RNI = IMNs, SCV, ICV ± axilla

R

a

n

d

o

m

i

z

e

d

1996-2004

N=4004

Breast or CW only

Breast or CW + RNI

EORTC 22922: DFS & OS

Summary • Adjuvant RT clearly indicated ≥4 LN+

• 1-3 LN+ there is a DFS benefit and reduction in LRR o With modern treatment no increased risk of cardiac toxicity

o ?? Need for IMN treatment

• Why did MA 2.0 and EORTC show OS benefit? o Studies were underpowered:

Importance of IMN coverage:

Danish Experience

Key Patient/Treatment Characteristics (median follow-up 8.9 years)

Predicting Local Regional

Recurrence after Neoadjuvant

Chemotherapy

Can Systemic Therapy Select for

Patients who Don’t Benefit from RT? NSABP Experience

MVA of Predictors for LRR after Mastectomy

(1070 patients, 128 events)

MVA of Predictors for LRR after

Lumpectomy + Breast RT

(1890 patients, 189 events)

10-Year Risk of LRR

Nomagram to Predict 10-Year Risk of LRR

Future

Alliance A11202

Conclusions

• Lack of randomized evidence demonstrating benefits of

RT or safety of omission of PMRT in patients after NAC.

• Ongoing NSABP and Alliance trials will address many of

the issues

• Outside of trial recommendations based on patients

highest clinical or pathologic stage o If clinically N+ after NAC adjuvant RT recommended

Thank You!