Sentinel Lymph Nodes for Breast Carcinoma: A Paradigm Shift. Edi Brogi MD PhD Attending Pathologist Director of Breast Pathology

Sentinel Lymph Nodes for Breast Carcinoma: A Paradigm Shift Edi Brogi MD PhD Attending Pathologist Director of Breast Pathology

Sentinel Lymph Nodes 2014 AJCC 2010 staging Micrometastases Occult metastases Z0011 and B-32: implications for SLN evaluation Routine Intraoperative review of MSKCC current protocols

Assessing LN status of patients with breast carcinoma used to be simple

Today, LN involvement comes in 3 different flavors pn1 MACROMETASTASIS size >2 mm pn1mic MICROMETASTASIS size >0.2 mm and <2 mm >200 cells in one LN section pn0 pn0(i-) pn0(i+) ISOLATED TUMOR CELLS (ITCs) single cells and clusters <0.2 mm, even in H/Estained slides pn0(mol-) and pn0(mol+) AJCC 2010

Micrometastases (<2 mm) Annals Surgery 1971 First defined by Huvos et al. in 1971 75% 8-y OS for 63 pts with mets only in level I LNs 94% 8-y OS for pts with micromets 64% 8-y OS for pts with macromets

practical approach to measuring size of LN met 100X FOV = 2 mm 1/5 of 200X FOV = 0.2 mm 100X final magnification The diameter of a 100X field of vision (FOV) (10X objective and 10X ocular piece) is about 2 mm 200X final magnification The diameter of a 200X FOV (20X objective and 10X ocular piece) is about 1 mm One fifth of a 200X FOV diameter is about 0.2 mm

SEER micrometastasis study 209,720 patients (SEER) 1992-2003 pn0 pn1mi (0.3-2 mm) pn1 (>2 mm) N1mi significant at multivariate analysis (p<0.0001) vs N0 (HR1.35) vs N1 (HR 0.82) Chen SL et al Ann Surg Oncol. 2007, 12:3378-84

SENTINEL LYMPH NODE 1 st LN draining tumor bed 1 st site of local mets SLN identification Tc 99 -radiotracer hot and/or isosulphane blue dye blue and/or or palpable intraoperatively 0 Usually 1-3 SLNs identified

Histologic evaluation of SLNs SLN site of first local metastasis AND Only 1-3 SLNs per patient More extensive evaluation of SLNs aimed to identify occult metastases

Occult metastases An occult metastasis is any metastasis that is either missed or not identified on initial examination using a standard evaluation protocol

Section through plane A LN is diagnosed as negative all mets are occult A A

Section through plane B LN is diagnosed as positive for met larger mets are still occult B B

ENHANCED PATHOLOGY ADDITIONAL EVALUATION OF SLNs NEGATIVE IN THE INITIAL H/E-STAINED SECTION DEEPER H/E LEVELS +/- CYTOKERATIN STAINS PATHOLOGIST

ENHANCED PATHOLOGY OF SLN Many different protocols have been used to identify occult metastases in SLNs

What is the clinical significance of occult metastases? MSKCC retrospective study NASBP B-32

Significance of occult metastases MSKCC retrospective study 368 LN-neg women treated between 1976-78 all had MRM and axillary dissection no systemic rx All LNs blocks retrieved and re-evaluated using same enhanced pathology protocol 50µ 1 H&E and 1 AE1:AE3 stained section from each of two levels 50µ apart H&E and IHC H&E and IHC

Significance of occult metastases MSKCC retrospective study Patient median age: 57 y (24-83) Tumor Type DUCTAL 319 (87%) LOBULAR 49 (13%) Tumor size cm <1.0 64 (17%) 1.1-2.0 180 (49%) >2.0 123 (34%) missing 1 (<1%) Tan, L. K. et al. J Clin Oncol; 26:1803-1809 2008

Significance of occult metastases MSKCC retrospective study 83/368 (23%) with occult metastases IHC+/HE- 50 (14%) IHC+/HE+ 33 (9%) pn0i+ (<0.2 mm): 61 (73.5%) pn1mic (0.3-2 mm): 17 (20.5%) pn1a (>2mm): 5 (6%) Tan, L. K. et al. J Clin Oncol; 26:1803-1809 2008

DFS by pattern of LN staining IHC-/H&E- IHC+/H&E- IHC+/H&E+ Tan, L. K. et al. J Clin Oncol; 26:1803-1809 2008

DFS by largest cluster size Negative <0.2 mm 0.3-2.0 mm Tan, L. K. et al. J Clin Oncol; 26:1803-1809 2008

MSKCC retrospective study Strenght Patients received no adjuvant therapy data informative of the biologic significance of small tumor deposits in LNs Limitation Nowadays most patients receive some form of adjuvant therapy (chemo-tx + hormone-tx + radio-tx + immuno-tx) data NOT informative in the greatest majority of cases

NSABP B-32 Clinically Negative Axillary Nodes (n=5,611) Randomization GROUP 1 SLNB and ALND GROUP 2 SLNB SLN+ on H&E ALND SLN- on H&E No ALND

NASBP-32 study QUESTION Is SLN biopsy equivalent to ALND for axillary staging of patients with cn0 LNs?

NSABP B-32 SLN negative patients OS similar for SLN&ALND and SLN w/o ALND % Surviving 0 20 40 60 80 100 * 300 deaths triggered the definitive analysis * 309 reported as of 12/31/2009 84.6% of pts in the study received systemic therapy Treatment N Deaths SNR and AD 1975 140 SNR only 2011 169 HR=1.20 p=0.117 Data as of December 31, 2009 0 2 4 6 8 Years After Entry

NSABP B-32 SLN negative patients DFS similar for SLN&ALND and SLN w/o ALND % Disease-Free 0 20 40 60 80 100 84.6% of pts in the study received systemic therapy Treatment N Deaths SNR and AD 1975 315 SNR only 2011 336 HR=1.05 p=0.542 Data as of December 31, 2009 0 2 4 6 8 Years After Entry

NASBP-32 study QUESTION 1 Is SLN biopsy equivalent to ALND for axillary staging of patients with cn0 LNs? ANSWER: YES

NASBP-32 study QUESTION 2 What is the significance of a false negative SLN biopsy in clinically LN-negative patients? in other words, What is the significance of occult mets in patients with clinically negative LNs? Or: What is the best method for histologic evaluation of SLNs?

NSABP B-32 Pathology Methods SLNs sliced at 2.0 mm intervals All slices paraffin-embedded Original lab examined only one H&E-stained slide from each block All SLN-negative blocks were sent to Univ. of VT lab for additional evaluation Weaver D et al. AJSP 2009;33:1583-1589

NASBP B-32 additional pathology evaluation at the central lab 1 surface H&E B32 protocol 1 H&E and 1 CK-IHC at 2 levels 0.5 mm apart to identify mets >1 mm comprehensive protocol 1CK IHC every 0.18 mm to identify mets >0.2 mm Weaver D et al. AJSP 2009;33:1583-1589

NASBP B-32 pathologic evaluation Weaver D Am J Surg Pathol. 2009;11:1583-9 Micro mets N1mic 0.2 mm ITCs N0i+

ITCs or MICROMETASTASIS pn0i+: <0.2mm pn1mi: >0.2mm

Deeper section shows MICROMETASTASIS pn1mi: 0.4mm

NSABP B-32 Occult metastases SLN biopsy and ALND 1924 SLN neg pts with F/U info SLN biopsy alone 1960 SLN neg pts with F/U info 1608 had no occult mets 316 had occult mets 1660 had no occult mets 300 had occult mets Weaver D. et al. NEJM, 2011;364:412-21

NSABP B-32 Occult metastases SLN biopsy and ALND 1924 SLN neg pts with F/U info SLN biopsy alone 1960 SLN neg pts with F/U info 1608 had no occult mets 316 had occult mets 1660 had no occult mets 300 had occult mets 15.9% of pts had occult mets Weaver D. et al. NEJM, 2011;364:412-21

Occult mets more likely in younger pts, larger tumors, and mastectomy Characteristics All patients (N=3887) number/total number (%) P value Age 0.03 <49 172/947 (18.2%) >50 445/2940 (15.1%) Clinical tumor size <0.001 <2.0 cm 481/3260 (14.8%) 2.1-4.0 cm 123/567 (21.7%) >4.1 cm 13/60 (21.7%) Planned surgical treatment <0.001 Lumpectomy 510/3399 (15.0%) Mastectomy 107/488 (21.9%) Weaver D. et al. NEJM, 2011;364:412-21

Occult metastases and adjuvant therapy Adjuvant therapy Chemotherapy All patients (N=3887) number/total number (%) P value Yes 305/1548 (19.7%) <0.001 No 309/2319 (13.3%) Endocrine therapy Yes 454/2648 (17.1%) <0.001 no 160/1217 (13.1%) Weaver D. et al. NEJM, 2011;364:412-21

Occult mets slightly worse regional/ distant recurrence Recurrence Site No Occult Mets (n=3268) Occult Mets (n=616) Total Cohort (n=3884) Local 86 (2.6%) 16 (2.6%) 102 (2.6%) Regional 14 (0.4%) 7 (1.1%) 21 (0.5%) Distant 94 (2.9%) 23 (3.7%) 117 (3.0%) Contralateral 83 (2.5%) 16 (2.6%) 99 (2.6%) Weaver D. et al. NEJM, 2011;364:412-21

Occult Metastases and Survival Distant Disease Free Interval slightly but significantly shorter Weaver D. et al. NEJM, 2011;364:412-21

Occult Metastases and Survival Disease Free Survival slightly but significantly shorter Weaver D. et al. NEJM, 2011;364:412-21

Occult Metastases and Survival Overall Survival slightly but significantly worse 95.8% 94.6% Difference only 1.2% To achieve survival benefit in 1.2% of patients, 98.8% patients would have to be overtreated Weaver D. et al. NEJM, 2011;364:412-21

NASBP-32 Results Summary 15.9% prevalence of occult metastases 3.5% overall regional or distant recurrence 1.2% reduction in 5-years survival in women with occult metastases 0.6% reduction with ITC 2.4% reduction with micrometastasis

NASBP-32 study QUESTION 2 What is the significance of a false negative SLN biopsy in clinically LN-negative patients? ANSWER If SLN biopsy is Falsely Negative (= occult mets) we observe a minimal (<1%) increase in axillary recurrence rate a minimal (1.2%) decrease in OS and DFS (=the clinical significance of occult mets is clinically LN-negative patients is practically irrelevant) Furthermore, no additional therapy options are available in most of these cases, and if there were, there is no way to predict in which pts they should be used

NASBP-32 study results 1) SLN biopsy is equivalent to ALND for axillary staging of patients with cn0 LNs 2) The impact of False Negative SLN biopsy on OS and DFS is essentially neglegible

considering that 1) the impact of a False Neg SLN biopsy in cn0 patients is very limited and 2) about 16% of cn0 patients have additional positive LNs, Is ALND always necessary for cn0 patients with positive SLN biopsy?

Predictors of non-sln involvement in patients with positive SLN(s) Tumor features that also predict SLN status T size LVI Overviews Van Zee/2004 (20 studies) Degnim/2003 (11 studies) Cserni/2004 (25 studies) Characteristics of the SLN metastasis method of detection size of SLN met # positive SLNs extracapsular extension # negative SLNs Van Zee Ann Surg Oncol 2003 ;10(10):1140-51

www.mskcc.org/nomograms Van Zee KJ. Ann Surg Oncol 2003;10:1140-51

Selective ALND for SLN+ 1960 patients with SLN+ SLN+/no ALND (n=315) 15% of SLN+ SLN+/ALND (n=1645) 85% of SLN+ Nomogram score (median predicted likelihood of residual axillary disease) Axillary local recurrence (at 26 months) 10% 1.9% 37% 0.36% p=0.004 Difference 27% Difference 1.54% Park J et.al. Ann Surg 2007;245:462-8

Selective ALND for SLN+ 1960 patients with SLN+ SLN+/no ALND (n=315) 15% of SLN+ SLN+/ALND (n=1645) 85% of SLN+ Nomogram score (median predicted likelihood of residual axillary disease) Axillary local recurrence (at 26 months) 10% 1.9% 37% 0.36% p=0.004 Park J et.al. Ann Surg 2007;245:462-8

Outcome +/- ALND (NCDB) SLN only (n=802) SLN/ALND (n=2357) Axillary local recurrence SLN micrometastases (<2 mm) 5 yr relative survival 0.4% 99% 0.2% 98% Bilomoria KY et.al. JCO 2009;27:2946-53

Outcome +/- ALND (NCDB) SLN only (n=802) SLN/ALND (n=2357) SLN only (n=5596) SLN/ALND (n=22591) Axillary local recurrence SLN micrometastases (<2 mm) 5 yr relative survival 0.4% 99% 0.2% 98% SLN macrometastases (>2 mm) 1.0% 90% 1.1% 89% Bilomoria KY et.al. JCO 2009;27:2946-53

ALND trend for SLN+ (NCDB) SLN+ and no ALND % Bilomoria KY et.al. JCO 2009;27:2946-53

Published Series of SLN+ Patients with no ALND Reference pts Study Type Median f/u (mo) Def +SLN Incl IHC Only/ITCs BCS, % RT, % Adj Chemo, % HT, % Cases axillary failure/total cases (%) Tjan-Heijnen 2009 1757 Retrospective 56 No NA NA NA NA NA Bilimoria 2009 5,596 Retrospective 64 No 81 63 61 41 Actuarial 5-y (1.0) Hwang 2007 196 Retrospective 30 Yes 69 56 56 NA 1/196 (0.51) Pejavar 2006 16 Retrospective 156 No 100 100 NA NA Actuarial 10-year: 2.1 Naik 2004 210 Retrospective 25 Yes 71 NA NA NA 3/210 (1.4) Guenther 2003 46 Prospective 32 Yes 100 100 50 NA 0/46 (0) Fant 2003 31 Retrospective 30 Yes 100 97 100 84 1/31 (3.2) Sarvi 2002 64 Retrospective 31 Yes 100 100 NA NA 1/63 (1.6) Jeruss 2005 73 Prospective 28 No NA NA 85 NA 0/73 (0) Barkley 2010 131 Prospective 59 Yes 78 88 82 81 0/131 (0) Low regional recurrence rates in setting of adjuvant systemic therapy and RT

Is there a need for ALND in all cn0 patients with positive SLN biopsy? ACOSOG Z0011 Randomized Prospective Study

ACOSOG Z0011 Pts with T1-T2, cn0 and SLN+ biopsy treated by breast conservation and whole breast RT randomized to ALND Observation Systemic treatment chosen by treating clinican based only on SLN H/E results

Z0011 eligibility Eligible clinical T1-T2N0 breast cancer H&E-detected SLN metastases lumpectomy + whole breast RT adjuvant systemic therapy by choice Nodal RT Ineligible IHC-detected SLN metastases Matted nodes 3 or more involved SLNs Giuliano AE et.al. Ann Surg 2010;252:439

Z0011 systemic therapy Systemic therapy SLN+/ALND SLN+/no ALND chemo 58% 58% hormonal 46% 47% chemo and/or hormonal 96% 97% Giuliano AE et.al. Ann Surg 2010;252:439

Z0011 locoregional recurrence Recurrence @ 6.3 yrs median F/U SLN+ ALND (n=388) SLN+ no ALND (n=425) local 3.6% 1.9% regional node 0.5% 0.9% local+regional 4.1% 2.8% p=0.47 Additional positive LNs found in 27% of ALNDs Giuliano AE et.al. Ann Surg 2010;252:439

Z0011 survival overall disease-free Giuliano AE et.al. Ann Surg 2010;252:439

Z0011 survival Survival @ 6.3 yrs median F/U SLN+ ALND (n=388) SLN+ no ALND (n=425) Difference Disease-Free Survival Overall Survival 82.2% 83.8% +1.6% 91.9% 92.5% +0.6% Giuliano AE et.al. Ann Surg 2010;252:439

Z0011 Implications patients who meet Z0011 criteria (<2 pos SLNs and BCT with Whole Breast RT) do not benefit from ALND Change of practice @MSK Implemented in September 2010

Handling of SLN @ MSKCC Grossly careful count number of SLNs Submit 1 LN per cassette If two or more LNs/cassette, each LN inked with different color Section SLN with cuts parallel to its longest axis Section thickness as close to 2 mm as possible 2 mm 2 mm 2 mm 2 mm

SLN sections If more than 3 sections, place non-adjacent surfaces face down to maximize evaluation Weaver D. Mod Pathol (2010) 23, S26 S32

Routine histologic evaluation of SLNs @ MSK 1 H&E stained section per block No routine levels No routine CK stains CK stains obtained only for work-up of uncertain morphologic findings Protocol in use since March 1 st, 2011

Intraoperative Evaluation of SLNs

Intraoperative evaluation (IOE) of SLN: WHICH METHOD IS BEST? FROZEN SECTION (FS) TOUCH PREP (TP) SCRAPE SMEAR (S) familiar to most pathologists time consuming freeze artifact potential loss critical tissue some pathologists unfamiliar rapid hard to validate findings

Comparable sensitivity of FS, TP and smear for intraoperative evaluation of SLN sensitivity: method+/sln+ (%) 100 90 80 70 60 50 40 30 20 10 0 All cases <=2 mm >2 mm Size of nodal metastasis frozen touch prep smear Brogi E et.al. Ann Surg Oncol 2005;12:173-80

INTRAOPERATIVE EVALUATION (IOE) OF SLN @ MSKCC FROZEN SECTION Before Z0011 IOE of SLNs in nearly all patients with cn0 (+/- T1a tumors) After Z0011 IOE of SLNs only for cn0 patients undergoing mastectomy

INTRAOPERATIVE EVALUATION OF SLN @ MSKCC NO FROZEN SECTION FOR PATIENTS WHO FULFILL Z0011 ELIGIBILITY CRITERIA T1-T2 cn0 breast conserving surgery whole breast irradiation

LN staging for breast carcinoma paradigm shift: summary NASBP B-32 and ACOSOG Z0011 prospective trials of cn0 patients have shown that: SLN bx equivalent to ALND The clinical impact of occult mets is negligible ALND does not provide substantial benefit for pts who meet Z0011 eligibility criteria Adequate pathologic evaluation of SLNs consists of 2 mm thick sections parallel to longest LN axis 1 H/E stained section/block No intraoperative evaluation of SLNs for pts who fulfill Z0011 eligibility criteria

pitfalls of LN evaluation BENIGN LESION SIMULATING CARCINOMA CARCINOMA SIMULATING BENIGN LESION

calponin ECTOPIC BREAST

Endosalpingiosis (glands w/o myoepithelium) WT-1 Corben A et al. AJSP 2010, 34(8):1211-6.

CARCINOMA MIMICKING HISTIOCYTES FS

AE1:AE3

CARCINOMA MIMICKING HISTIOCYTES AE1:AE3

CARCINOMA MIMICKING HISTIOCYTES Carcinoma Silicone lymphadenopathy

Breast carcinoma E-cadherin

Breast carcinoma LN met 1) Rule out specimen mix-up 2) Patient has occult invasive lobular carcinoma

possible mimics of metastatic carcinoma germinal center high endothelial venules

FS of SLN from a pt with Inv Lob Ca

Dermatopathic lymphadenopathy Langerhans s cells simulate met lobular carcinoma CD1a

CAPSULAR NEVUS FS FS

NEVUS CARCINOMA

FS

FS S100+ Ker- Warning: S100 shows variable positivity in some breast carcinomas

CARCINOMA MIMICKING NEVUS FS

carcinoma in subcapsular sinus LVI

Breast lumpectomy

SLN biopsy

SLN biopsy

capsular nevus with prominent intraparenchymal component CK AE1/AE3 S100 HMB45 MIB/A103

Pitfalls in morphologic interpretation of LNs: Summary Too many to summarize