Question

Should ER, PR and HER2 status of invasive tumours be determined?

Recommendation

ER, PR and HER2 status of invasive tumours must be determined an assessed according to a standardised protocol.

 

The facility should participate in external audits for ER tests, PR tests and HER2 immunohistochemistry and amplification (e.g. SKML, NordiQC, UK-Neqas) to demonstrate sufficient quality of the staining technique.

Literature summary

Determining hormone receptor and HER2 status

In breast cancer treatment, analysis of oestrogen (ER), progesterone (PR) and HER2 receptors plays an important role in the adjuvant and metastatic setting. As a result, standardised receptor determination is of great importance. ER and PR are determined by means of immunohistochemistry of formalin-fixed and paraffin-embedded tumour material. Below are guidelines for the procedure of immunohistochemical staining, quality control and scoring method.

 

HER2 is an oncogene that is amplified in 10-15% of breast cancers. The gene codes for a membrane protein in the tumour cells. In tumours without HER2 amplification, there is usually a normal level of HER2 expression; in tumours with amplification there is usually a strong increase in expression of this protein. This has consequences for the choice of goal-oriented and conventional chemotherapy.

 

The determinations are performed on a representative cross-section of the tumour, and in addition any pre-existing breast tissue where possible; the material is formalin fixed and paraffin embedded. Specific requirements should be adhered to in determining the ER, PR and HER2 status, in terms of pre-analytical, analytical as well as postanalytical factors. The details fall outside the scope of this guideline.

 

Determining ER and PR

Scoring method

  • the percentage of tumour cells with nuclear staining is estimated in the tens; the intensity is not included in the scoring method
  • if the percentage is 10% or greater, the sample is referred to as ER or PR positive. ASCO recommends a threshold of 1% but there is little evidence for this
  • if the ER or PR status of the tumour is negative, it is necessary to look for staining of normal epithelium of the lobs and ducts around the tumour if a proportion of the cells here stain, the negative result ER or PR may be issued; if there is no staining of normal lobs, the staining should be repeated, possibly on another sample.

 

Quality control and validation of the technique

  • there should be a detailed staining protocol in writing, which is followed each time
  • a (preferably weak) positive control should be included in each stain; if the positive control is negative or weaker than normal, the stain should be repeated
  • the facility should participate in external audits to demonstrate sufficient quality of the staining technique; the SKML, NordiQC, and the UK-Neqas provide this service

 

HER2 analysis

There are indications that the intensity of the stain deteriorates if the section is not recent; for this reason, the stain must be performed within 2 months after a paraffin sample has been taken.

An in situ hybridisation for HER2 may be performed first, given false positive findings have been reported for HER2 to 12%, similar to immunohistochemistry [Perez, 2006].

 

Immunohistochemistry

Scoring method

Only membranous staining of invasive tumour cells must be evaluated as positive (in some cases there is cytoplasmic staining; this should not be included in the score).

A scoring system has been developed that categorises the stain as 0, 1+, 2+ of 3+; this system must be followed.

0:      less than 10% of the tumour cells stain

1+:    more than 10% of the tumour cells stain, in which there is no circumferential staining of all tumour cells and the colour intensity is weak

2+:    more than 10% of the tumour cells display circumferential staining of tumour cells, in which the intensity of the stain is assessed as not more than moderate

3+:    there is more than circumferential membranous staining in more than 30% of tumour cells, in which the intensity is assessed as strong

 

The area of the tumour with the strongest staining determines the score. There is normal expression of HER2 in tumours without amplification; this expression is usually too low to detect. If the normal lobs display membranous staining, the intensity of the entire stain is too strong and the result cannot be assessed as reliable.

 

Quality control and validation of the technique

  • there should be a detailed staining protocol in writing, which is followed each time
  • for each stain, a combination section of a negative, a 1+ and 3+ control should be included; if the positive control is negative or weaker than normal, the stain should be repeated. If the 1+ or negative control stains too strongly, the stain should also be repeated.
  • the facility should participate in external audits to demonstrate sufficient quality of the staining technique; the SKML, NordiQC, and the UK-Neqas provide this service

 

HER2 amplification test

Given a proportion of the tumours with a 2+ staining results are still amplified, an amplification test must be performed in the case of a 2+ result. The international accepted methods for this are fluorescent in situ hybridisation (FISH), chromogenous in situ hybridisation (CISH) and a silver-based in situ hybridisation (SISH). Some laboratories use the Dutch MLPA (PCR-based) technique.

Some in situ kits also use the chromosome 17 centromere probe, of which the benefit is being debated. This dual colour ISH is scored as follows:

  • Ratio HER2/centromere chromosome 17 < 1.8: no HER2 amplification
  • Ratio HER2/centromere chromosome 17 > 2.2: wel HER2 amplification
  • Ratio HER2/centromere chromosome 17 1.8-2.2: inconclusive for HER2 amplification (then repeat with another test)

 

If in situ hybridisation is performed without a centromere probe (e.g. CISH), the cut-off for HER2 low level and high level amplification is >6 and >10 copies of the HER2 gene or clusters respectively.

Authorization date and validity

Last review : 13-02-2012

Last authorization : 13-02-2012

The national Breast Cancer guideline 2012 is a living guideline, in other words there is no standard term of revision. NABON continually watches at new developments and clinical problems in the areas of screening, diagnostics, treatment and aftercare, and whether this requires an update.

Initiative and authorization

Initiative : Nationaal Borstkanker Overleg Nederland

Authorized by:
  • Nederlandse Internisten Vereniging
  • Nederlandse Vereniging voor Heelkunde
  • Nederlandse Vereniging voor Psychiatrie
  • Nederlandse Vereniging voor Radiologie
  • Nederlandse Vereniging voor Radiotherapie en Oncologie

General details

Approximately 14,000 women (and 100 men) are diagnosed with invasive breast cancer each year in the Netherlands, and about 1,900 have an in situ carcinoma. A woman's risk of having breast cancer over the course of her life is 12-13%. This means that breast cancer is the most common form of cancer in women in the Netherlands. Early detection, particularly via national breast cancer screening, combined with adjuvant therapy followed by locoregional treatment, improves the prognosis in women with breast cancer

The guideline on Breast Cancer Screening and Diagnostics, published in 2000, was updated in 2007. In 2002, the first multidisciplinary National Breast Cancer Guideline was published, it was revised in 2004, 2005 and 2006. In 2008 both guidelines were combined to Breast Cancer Guideline, which 2012 revision is now effected.

Scope and target group

This guideline is written for all the members of the professional groups that have contributed to its development.

 

This guideline is a document with recommendations and instructions to support daily practice. The guideline is based on the results of scientific research and expert opinion, with the aim of establishing good medical practice. It specifies the best general care for women with (suspected) breast cancer and for those who are eligible for screening. The guideline aims to serve as a guide for the daily practice of breast cancer screening, diagnostics, treatment and aftercare. This guideline is also used in the creation of informational materials for patients, in cooperation with the KWF (Dutch Cancer Society).

Member of workgroup

A core group consisting of a radiologist, surgeon, pathologist, medical oncologist and radiation therapist began preparing for the revision of the breast cancer practice guidelines in 2009. A multidisciplinary guideline development group was formed in early 2010 to implement the revision. This group consisted of mandated representatives from all of the relevant specialisations concerned with breast cancer, plus two delegates from the BVN (Dutch Breast Cancer Society) (see list of guideline development group members). The benefits of such a multidisciplinary approach are obvious: not only does it best reflect the care, but it offers the greatest possible expertise for the guideline. In composing the development group, geographic distribution of the members, balanced representation of the various organisations and agencies concerned, and a fair distribution in academic background were taken into account as much as possible.

 

The guideline development group received procedural and administrative support from IKNL (Comprehensive Cancer Centre for the Netherlands) and support on methodology from Bureau ME-TA. Partial funding was obtained from SKMS (Quality Funds Foundation of Dutch Medical Specialists). This subsidy would not have been possible without the extensive assistance provided by the NVvR (Radiological Society of the Netherlands).

Declaration of interest

Partial funding for the guideline revision was obtained from the Society of Dutch Medical Specialists in the framework of the SKMS. IKNL sponsored some of the cost. On two occasions, as well as at the beginning and end of the process, all of the members of the guideline development group were asked to fill out a statement of potential conflicts of interest, in which they stated their relationship with the pharmaceutical industry. A list of these statements of interest can be found in the appendices.

Patient involvement

In developing this guideline, four clinical questions were formulated. These questions emerge from an inventory of clinical problems collected in the field from professionals, patients and patient representatives.

 

Also, A multidisciplinary guideline development group was formed in early 2010 to create and implement the revision. This group consisted of mandated representatives from all of the relevant specialisations concerned with breast cancer, plus two delegates from the BVN (Dutch Breast Cancer Society).

 

Method of development

Evidence based

Implementation

Feasibility has been taken into account in developing the guideline. This included attention to factors that could promote or hinder putting the advice into practice. Examples include the implementation of an analysis of problems, the multidisciplinary composition of the guideline development group, and making active use of support from the guideline development group members. Presenting the draft guideline to the field and communicating what, if anything, is being done with the responses, also promotes implementation. In this manner, a guideline has been developed that answers current questions in the field.

The guideline is distributed widely and is available in digital form on the Dutch Guideline Database. The guideline may also be brought to the attention of a wider audience in other periodicals or continuing education sessions, for example. To promote use of the guideline, we recommend that the regional tumour working groups and group practices, as well as scientific and professional organisations, repeatedly bring the guideline to the attention of their members. Any problems that may arise in using the guidelines can then be discussed and, when appropriate, submitted to the national guideline development group, as it is a "living" guideline. If desirable, parts of the guideline can be made more explicit by formulating regional additions or translation to the local situation in departmental and/or hospital protocols.

In principle, indicators are determined during development of the guideline that can be used to monitor implementation of the recommendations. Via a documentation project, these indicators can then be used to determine the extent of compliance with the guideline. The information from the documentation project becomes input for the revision of the guideline.

Methods and proces

This module has been evidence-based revised in 2008 and consensus based updated in 2012.

 

A revision of an existing guideline consists of revised and updated text. Revised text is new text based on an evidence-based review of the medical literature; updated text is the old guideline text which has been edited by the experts without performing a review of medical literature. Each section of the guideline states what type of revision has taken place. Each chapter of the guideline is structured according to a set format, given below. The purpose of this is to make the guideline transparent, so that each user can see on what literature and considerations the recommendations are based on.

 

Description of the literature

To the greatest extent possible, the answers to the fundamental questions (and therefore the recommendations in this guideline) were based on published scientific research. The articles selected were evaluated by an expert in methodology for their research quality, and graded in proportion to evidence using the following classification system:

 

Classification of research results based on level of evidence

A1

Research   on the effects of diagnostics on clinical outcomes in a prospectively   monitored, well-defined patient group, with a predefined policy based on the   test outcomes to be investigated, or decision analysis research into the   effects of diagnostics on clinical outcomes based on results of a study of   A2-level and sufficient consideration is given to the interdependency of   diagnostic tests.

A2

Research   relative to a reference test, where criteria for the test to be investigated   and for a reference test are predefined, with a good description of the test   and the clinical population to be investigated; this must involve a large   enough series of consecutive patients; predefined upper limits must be used,   and the results of the test and the "gold standard" must be   assessed independently. Interdependence is normally a feature of situations   involving multiple diagnostic tests, and their analysis must be adjusted   accordingly, for example using logistic regression.

B

Comparison   with a reference test, description of the test and population researched, but   without the other features mentioned in level A.

C

Non-comparative   trials

D

Opinions   of experts, such as guideline development group members

 

Conclusions

Based on the medical literature, one or more relevant conclusions are made for each section. The most important literature is listed according to the level of evidential strength, allowing conclusions to be drawn based on the level of
evidence. All the medical literature included in the conclusion is described in the bibliography.

 

Classification of conclusions based on literature analysis

1

Based   on 1 systematic review (A1) or at least 2 independent A2 reviews.

2

Based   on at least 2 independent B reviews

3

Based   on 1 level A2 of B research, or any level C research

4

Opinions   of experts, such as guideline development group members

 

Other considerations

Based on the conclusion(s), recommendations are made. However, there are other considerations that contribute to formulation of the recommendation besides literature evidence, such as safety, the patients' preferences, professional expertise, cost-effectiveness, organisational aspects and social consequences. The other considerations are mentioned separately. In this manner, it is clear how the guideline development group arrived at a particular recommendation.

 

Recommendations

The final wording of the recommendation is the result of the scientific conclusion, taking into account the other considerations. The purpose of following this procedure and drawing up the guidelines  in this format is to increase transparency.

 

References

An alphabetical list of literature references can be found at the end of the guideline.

 

All draft texts have been discussed by the guideline development group.

Search strategy

Searches are available upon request. Please contact the Richtlijnendatabase.