Anna Long and Judith HogarthCellular Pathology

Newcastle upon Tyne Hospitals NHS Foundation Trust

North of England Cancer Network

HER2 testing Audit

We will cover…HER2 testing – an introductionAudit parametersAimsResults Summary Limitations

HER2HER2 is a trans-membrane tyrosine kinase

that mediates cell growth and survivalHER2 signalling induces cell proliferationHerceptin® binds to HER2 receptors and

inhibits proliferation by disrupting HER2 mediated downstream signalling

Only those patients that exhibit elevated expression of the HER2 antigen will benefit from treatment

Getting the test right is critical!

HER2 testingHER2 status is routinely used in breast

cancer testing and is recognised as a prognostic and predictive marker.

Eligibility for treatment assessed by immunocytochemistry and/or in situ hybridisation

IHCIHC

ISHISH

If ≥ 2.0 = AmplifiedIf ≥ 2.0 = Amplified

If < 2.0 = Non-

amplified

If < 2.0 = Non-

amplified

Negative

Positive

Equivocal

1+1+00 2+2+ 3+3+

NECN HER2 testingAt time of audit, undertaken by three

centres in the NECNGateshead Health NHS Foundation Trust

(QEH) Newcastle upon Tyne Hospitals NHS

Foundation Trust (RVI)North Tees and Hartlepool NHS Foundation

Trust (UHNT)

Centre

Tests referred from

IHC method

ISH performed?

ISH method

QEH QEHSRHUHND

Dako HercepTest

No, referred to RVI

N/A

RVI RVICRINTGH

Ventana 4B5

Yes Ventana SISH

UHNT UHNTJCUH

Ventana 4B5

No, referred to Source BioScience

N/A(Vysis FISH at Source BioScience)

UKNEQASAll centres performing HER2 testing must participate in the relevant NEQAS HER2 IHC and ISH modules

UKNEQAS cite two recommended HER2 testing guidelines:ASCO/CAP (Wolff et al. 2006)UK updated guidelines (Walker et al.

2008)

Walker et al. (J Clin Path)Laboratories undertaking tests should be

defined by each Cancer Network.UK minimum laboratory workload:

250 IHC cases per annum100 ISH cases per annum

Total HER2 positive cases: 15-17%Total IHC 2+ HER2 cases: average range

18-19%Number of IHC 2+ cases that exhibit HER2

gene amplification: 17-24%

Data collected from January 2011-December 2012 inclusive

Aims of the auditAre centres within the cancer network meeting these standards? Therefore we have established within the NECN:

(1) How many tests are performed by each centre

(2) The HER2 positivity rate(3) The number of 2+ cases generated

by IHC(4) The number of 2+ cases that exhibit

HER2 gene amplification

(1) How many tests are performed by each centre

All centres meet minimum benchmark for IHC tests performed

Number of IHC tests performed annually

0

200

400

600

800

1000

1200

1400

QE RVI UHNT

Centre

Num

ber

of t

ests

2011 2012 standard

Number of ISH tests performed annually

*Equivocal QE cases stained using SISH at RVI, UHNT cases performed by Source BioScience

All centres meet minimum benchmark for ISH tests performed

In summary (1) – Minimum number of tests performedAll centres satisfy the minimum

requirement for number of IHC and ISH tests performed.

(2) HER2 positivity rate

NECN HER2 profile – positivity

2011 - Positive vs. negative rates fits within the standard set out by Walker et al (15-17%).

2012 sees this rate drop 0.7% outside this range.

461/2816426/2974

Positivity profile for each centre

Quoted range 2006-2007 = 15-17%

RVI and UHNT fell within the expected positivity range in 2011.

QEH rate slightly above expected range in 2011 = 17.7%

Both QE and RVI have seen a drop in the positivity rate in 2012 (below 15%)

UHNT has shown an increase in positivity rate in 2012 (above 17%).

UKNEQAS data 2009-2012= 14.5%

135/764

135/976181/1185

148/1212

145/867145/794

Positivity rates - QEH and RVI

Positivity rate of cases has dropped across all hospitals (range = 2.4 - 5.0%)

Positivity rate of cases has dropped across all hospitals (range = 0.5 - 10.1%)

NTGH positivity rate has more than halved (19.9 – 9.8%)

56/362

60/508

19/105

27/199

60/297

48/269

53/40652/412

77/52366/495

51/256

30/305

15.5 18.111.8 17.820.213.1

Positivity rates in referring hospitals UHNT

Positivity rate of cases has increased across all hospitals (range = 0.5 - 3.1%)

82/49182/47763/376

63/317

In summary (2) – Positivity ratesThe NECN as a whole falls below the expected

frequency of positive HER2 cases. The audit period spans 2011-2012, however the

published literature details HER2 cases from 2006-2007.

UKNEQAS data spanning 2009-2012, quotes a positive rate of 14.5%, which means the NECN in fact meets the expected frequency of positive cases.

2/3 referral centres in 2012 fell below 14.5% (QEH and RVI) QEH – all referring hospitals showed a similar decline in

positivity rate This would suggest some common factor ?the test itself.

RVI - one referral hospital (NTGH) showed a marked decline in positivity rate (19.9-9.8%)

This would suggest an upstream factor is responsible for the observed shift.

(3) 2+ cases generated by IHC

2+ rate for NECN

Av. Quoted range 2006-2007 = 18-19%

UKNEQAS data 2009-2012 = 21.7%

The NECN falls below the quoted range for the whole audit period, and significantly below the UKNEQAS data.

2+ rate for centres

Av. Quoted range 2006-2007 = 18-19%

UKNEQAS data 2009-2012 = 21.7%

RVI and UHNT have shown <2% variation in 2+ rate.

QEH sees a 7.2% decrease

112/764

87/986

152/889

123/810180/1193

209/1230

16.0 15.1 17.0 15.217.18.8

% 2+ rates for referring hospitals QEH

Fall in 2+ rate observed in all hospitals (range = 4.9 – 8.8%)

Most significant decrease seen in SRH cases – more than halved.

58/363

52/518

18/107

16/199

36/300

19/269

16.0 10.0 16.8 8.0 12.0 7.1

% 2+ rates for referring hospitals - RVI and UHNT

Small increase seen in CRI and RVI cases (1.2% and 0.2 % respectively).Significant increase seen in NTGH cases (5.4%)

Small decrease seen in JCUH and UHNT cases (1.4% and 2.3% respectively).

57/40963/417

43/257

69/312

80/527 77/50164/386

49/322

88/503

74/488

In summary (3) – 2+ rate2+ rate within NECN falls below the

frequency cited in published and UKNEQAS data.

RVI and UHNT saw slight (<2%) fluctuations in 2+ rate between 2011 and 2012.

QEH showed a 7.2% decrease in 2+ reportingAll referring hospitals showed a decrease in

2+ rate (4.9-8.8% fall – SRH rate more than halved).

(4) 2+ cases that exhibit HER2 gene amplification

Number of 2+ cases that exhibit HER2 gene amplification - NECN

There has been a decline in the number of 2+ cases that exhibit HER2 gene amplification (3.8%).

Av. Quoted range 2006-2007 = 17-24%

UKNEQAS data 2009-2012 = 14.7%

70/441

49/406

15.9 12.1

2+ cases that exhibit HER2 gene amplification by centre

UHNT HER2 gene amplified cases increased 2.2%.

RVI saw a decrease of 6.7% in 2+ cases that demonstrated gene amplification….Why is this?

53/292

33/288 17/149

16/118

18.2 13.611.411.5

Amplified ISH performed at RVI

Quoted range 2006-2007 = 17-24%

UKNEQAS data 2009-2012 = 14.7%

There is significant variation in the reporting of HER2 gene amplified cases (range 0-36.8%).Most significant outliers = QEH (decrease of 10.3% to 0% amplified), UHND (increase of 22.1%), NTGH (decrease of 18.6%)

6/58

0/52

3/183/16

5/36

7/19

9/57

6/63

17/80

11/77

13/43

8/69

10.3 0.0 16.7 13.918.8 36.8 9.515.8 11.630.214.321.3

Amplified ISH UHNT cases (Source BioScience)

There is variation in the reporting of HER2 gene amplified cases (range 0.7-5.3%).

9/85

11/69

7/645/49

In summary (4) – 2+ amplified cases

There is marked variation in the positivity rate by HER2 gene amplification.

Significant outliers QEH (0% amplified 2012)UHND (increase of 22.1% from 2011 to 2012) NTGH (decrease of 18.6% from 2011 to

2012)This may be a symptom of variable 2+ rate

by IHC

In summary

Change in rates 2011 – 2012 by hospital

Hospital Change in positivity rate (%)

Change in 2+ rate (%)

Change in amplified 2+ rate (%)

QEH 2.2 6.0 10.3

SRH 5.0 8.8 2.1

UHND 2.4 4.9 22.9

NTGH 10.1 5.4 18.6

RVI 1.4 0.2 7.0

CRI 0.5 1.2 6.3

UHNT 0.5 2.3 5.3

JCUH 3.1 1.4 0.7

Limitations

Limiting factors

LimitationsPre-

analyticalAnalytical Post-

analyticalCold ischaemia

timeSubjective

interpretationSubjective

interpretation

Core vs excision Chosen HER2 test

Staffing

Fixation Methodology of test

Reporting confidence

Processing Staining platforms

Decalcification

Drying time

We need standardisation!

Future considerationsLook at 2013 data?

Thank youTrudy Johnson - QEHSharron Williams, Jim France – UHNTMerdol Ibrahim - UKNEQASImmunocytochemistry colleagues, RVI

Thank you for listening…

Questions?

References:Walker et al. HER2 testing in the UK: further update to recommendations. J Clin Path. 2008:61; 818-824.Wolff et al. American Society of Clinical Oncology/college of American Pathologists guideline recommendations for HER2 testing in breast cancer. J Clin Oncol. 2007: 25; 1-28.Ibrahim M. UKNEQAS HER2 audit data. UKNEQAS. 2009-2012. Personal communication.