SLNB After Preoperative Therapy

Anees B. Chagpar, MD, MSc, MPH, MA

Associate Professor of Surgery, Yale University School of Medicine

Director, The Breast Center – Smilow Cancer Hospital at Yale-New Haven

Overview

Pre-NAC SLNB Post-NAC SLNB

Identification rate ~100% > 90%

False negative rate < 5-10% Up to 33% (8-13%)

Second surgery Potentially Not necessarily

Ability to avoid ALND Low Higher

Ability to assess pCR May have removed

only positive node

Better able to assess

response

Influences

management

Maybe Maybe

SLNB after NAC

Study N Identification

rate

False negative

rate

Van Deurzen 2148 90.9% 10.5%

Kelly 1799 89.6% 8.4%

Xing 1273 89.7% 12.0%

Hunt 575 97.4% 5.9%*

Mamounas 428 84.8% 10.7%

Classe 195 90.3% 11.5%

San Antonio Breast Cancer Symposium, December 4-8, 2012

Z1071 schema

T0-4, N1-2, M0 invasive breast cancer (pretreatment axillary ultrasound with FNA or core biopsy

documenting axillary metastases)

↓ REGISTER*

↓

Neoadjuvant chemotherapy

↓ REGISTER*

↓

SLN and ALND

San Antonio Breast Cancer Symposium, December 4-8, 2012

Z1071 Consort Diagram 756 women with T0-4,

N1-2, M0 disease enrolled

701 women underwent axillary

surgery (663 cN1; 38 cN2)

687 women attempted SLN and ALND completed

(649 cN1; 38 cN2)

637 women SLN identified and

ALND completed (603 cN1; 34 cN2)

Exclusions • 34 pts terminated study prior to surgery

• 21 pts ineligible

Axillary surgery • 1 pt ALND was not completed

• 1 pt no nodes found on ALND • 12 pts SLN not performed

SLN surgery • 50 pts SLN not detected

Node positive disease 637 pts

Chemotherapy

Residual nodal disease

382 pts (60%)

SLN positive

326 pts

SLN negative / ALND positive 56 pts

Node negative

255 pts (40%)

ACOSOG Z-1071

• SLN identification rate = 92.5%

• Accuracy = 91.2%

• False negative rate

– Overall: 14.7%

– cN1 disease and 1 SLN: 31.5%

– cN1 disease and 2+ SLNs: 12.8%

• Only 2 SLNs examined: 21.1%

• Dual tracer: 10.8%

Clip

Clip N Residual

disease FNR 95% CI

Placed and

found 96 54 7.4% 2.0 – 17.9%

Placed, but

not found 76 50 14.0% 5.8 – 26.7%

Not placed 353 206 13.6% 9.2 – 19.0%

Role of Ultrasonography

• May provide staging information if done prior

to neoadjuvant chemotherapy without

removing only positive node

• Should we still do SLNB post-NAC in patients

with known axillary disease?

– If so, ultrasound no longer saves patients SLNB

SENTINA Trial 1737 patients

(103 institutions)

cN0 cN1

pN0 pN1

No axillary

surgery

SLNB

Re-SLNB +

ALND

Neoadjuvant Chemotherapy

SLNB +

ALND ALND

Neoadjuvant Chemotherapy

ycN1 ycN0

Arm Identification

Rate FNR

Pre-NAC SLNB 99.1%

Re-SLNB post-NAC 60.8% 51.6%

SLNB post-NAC 80.1% 14.2%

SENTINA Trial

Lobular vs non-lobulal tumor G3 vs G1-2 Unifocal vs multifocal L0 vs L1 V0 vs V1 Extracaps. extension no vs yes

ER/PgR negative vs positive

HER2-negative vs positive

Large center vs small Number of SLN (1 vs >1)

No pCR vs pCR

OR=.132 (.007, 2.51), p=.178 OR=1.20 (.406, 3.55), p=.741 OR=.961 (.322, 2.86), p=.942

OR=1.66 (.553, 4.99), p=.365

OR=2.33 (.069, 78.5), p=.637

OR=.386 (.103, 1.44), p=.157

OR=1.02 (.321, 3.27), p=.967

OR=1.67 (.496, 5.65), p=.406

OR=.416 (.147, 1.18), p=.098

OR=.505 (.306, .833), p=.008

OR=1.34 (.243, 7.37), p=.737

False Negative Rate post-NAC

So….

• Lower identification rate

• Higher false negative rate

• But does it matter?

– NSABP B-04

– ACOSOG Z-0011

Future Studies

• Alliance A11202

– Randomize SLN+ patients post-NAC to ALND vs.

axillary RT

• NSABP B-51

– Node positive patients undergoing NAC

– Node negative post-NAC

– Breast radiation if partial mastectomy

– Randomized to regional LN radiation (+ PMRT) vs.

no regional LN radiation (and no PMRT)

Yale Philosophy

Candidate for

Neoadjuvant Tx Consider clinical trials

Clinically LN- Clinically LN+ If US suspicious,

FNA or core

SLNB +/- ALND

NAC

Try for 3+ SLNs ALND or

SLNB +/- ALND