Conclusions

 

Level 1

Due to the high sensitivity of MRI, unexpected findings occur in 16-41% of the examinations performed. Of these, 29-43% are malignant.

 

A2    Deurloo 2005, Teifke 2003

B     LaTrenta 2003, Sim 2005, Linda 2008, Demartini 2009, Meissnitzer 2009, Destounis 2009, Abe   2010

 

Level 3

If a corresponding laesion on ultrasound is not found, the chance of malignancy is 6.3 - 20%.

 

B     La Trenta 2003, Sim 2005, Linda 2008, Demartini 2009, Meissnitzer 2009, Destounis 2009, Abe 2010

 

Level 3

If there are multifocal laesions on a pre-operative MRI scan, in which the laesion and the index tumour together have a maximum diameter of 3 cm and in which no corresponding laesion on ultrasound is found, the chance of a local recurrence after adjusted, more ample lumpectomy is acceptably small.

 

B      Elshof 2010

 

Level 3

If there is no corresponding laesion on ultrasound of additional BI-RADS 3 laesions outside the quadrant of the index laesion on a pre-operative MRI scan, surgical management does not need to be adjusted. The chance of recurrence is acceptably small.

 

B      Elshof 2010

Literature summary

Breast cancer can be detected by means of MRI with intravenous administration of Gadolineum. The pathophysiology is largely based on angiogenesis: there is an increase in the number of blood vessels and permeability of the vessel wall. The process is complex, benign abnormalities (fibroadenomas) and parenchyma may also stain [Kuhl, 2000]. The evaluation of an abnormality is based on a combination of morphology, enhancement and the kinetics of the enhancement [ACR, 2003].

The following patterns can be distinguished within the group of enhancing abnormalities: :

  • focus, dot-like enhancement < 5 mm
  • mass, 3 dimensional space-occupying process
  • non-mass-like enhancement, enhanced area with a specific distribution pattern, e.g.segmental

The kinetics of the enhancement can be subdivided into 3 types:

  • Type I: linear and persisting over time
  • Type II: plateau, occurs 2-3 minutes after injection
  • Type III: washout of the contrast, occurring 2-3 minutes after injection

 

The technique is highly sensitive, but this has an unfavourable influence on the specificity. A drawback of the high sensitivity in combination with low specificity is the occurrence of incidental or accidental findings: this is the case if there is enhancement of a laesion measuring 5 mm or greater, which is not expected on the basis of earlier images, such as elsewhere in the breast or contralateral. Incidental laesions are seen more often with younger women and in the presence of dense breast tissue. The incidence depends on the study population and varies from 16-41% [Deurloo, 2005; Teifke, 2003]. In the prospective study by Morakkabati-Spitz (2005), non-mass-like enhancement was seen with a segmental or linear distribution pattern in 50 of the 1,003 (5%) patients. In 17 patients this concerns DCIS, the positive predictive value of this type of contrast image for DCIS in this study is 34% (17/50) with a specificity of 96%.

Correlation with mammography and ultrasound is necessary to further characterise these laesions generally starting with 2nd look ultrasound. In a series of 7 retrospective cohort studies, the success percentage in identifying these laesions was 22.5 - 82% [LaTrenta, 2003; Sim, 2005; Linda, 2008; Demartini, 2009; Meissnitzer, 2009; Destounis, 2009; Abe, 2010]. If a corresponding laesion on ultrasound was found, the percentage of malignancies was 28.6 - 42.8%. If no correlation was found, this percentage was much lower: 6.3 - 20%. The chance of malignancy was greater for a mass compared to non-mass-like enhancement, as the mass was larger, if the laesion was in the proximity of the malignant index tumour and as this index tumour was larger. The corresponding laesion often has a noticeable benign aspect, with round oval shape and parallel orientation, though often with ill-defined margins [Abe, 2010].

 

In the presence of a corresponding laesion on ultrasound, the nature of the laesion can be determined by ultrasound-guided biopsy. If there is no corresponding ultrasound, patient management depends on the indication for the MRI.

 

Indication preoperative MRI

The prospective MARGIN study [Elshof, 2010] was conducted amongst 690 women with PA proven breast cancer and with a wish for BCT. They underwent a preoperative MRI. The additional laesions were subdivided on the basis of location; however, this subdivision is arbitrary and specifically aimed at determining the surgical plan: multifocal (maximum diameter of the index tumour and additional laesion of 3 cm), multicentric (maximum diameter index tumour and additional laesion greater than 3 cm) and contralateral. Second-look ultrasound was only performed for the last 2 groups. In the case of multifocality, the size of the lumpectomy was adjusted. If a corresponding laesion was not found during second-look ultrasound, a follow-up was considered as sufficient, because these laesions were classified as BI-RADS 3. The follow-up was an average of 58 months, in which no local recurrences or primary tumours were detected. It is assumed that this can be also attributed to radiotherapy and adjuvant chemotherapy.

In the case of BI-RADS 4 laesions and laesions that are decisive for surgical management, this approach is insufficient and MRI-guided biopsy is indicated.

Indication for MRI screening

In MRI screening a stricter work-up is indicated, see 2.3.1. If an additional laesion is classified as a BI-RADS 3, shirt interval follow-up is recommended: for menstruating women, this may be done in another phase of menstruation and can be performed in as short a period as possible. The breast tissue enhances the least between day 7 and day 20 after menstruation [Müller-Schimpfle, 1997; Kuhl, 2000]. If the women is not (or no longer) menstruating, follow-up of the size of the laesion after 6 months is indicated.

If an incidental finding consists of non-mass-like enhancement, DCIS may be suspected (BI-RADS 4). If a correlation with the mammogram does not show suspected MC, there are two possibilities: a direct MRI-guided biopsy is recommended or the MRI scan is first repeated: if the enhancement persists, then an MRI-guided biopsy is still performed.

MRI reporting

When reporting on MRI imaging, the BI-RADS final assessment categories are also applicable, with the undertstanding that this categories will be assigned in a more intuitive manner than is the case with mammography and ultrasound due to the lack of evidence-based knowledge of the predictive values of morphological and kinetic patterns.

 

BI-RADS final assessment category with MRI imaging

Final assessment category

Description

0

Assessment incomplete, e.g. due to movement artefacts or technical imperfections

1

No abnormal findings or enhancing patterns

2

Clear benign morphological finding with benign enhancing pattern

3

Probably benign: The radiologist thinks the laesion is benign, but prefers confirmation; a choice can be made from:

      
  • Repeat in another phase of the cycle, to further specify the enhancing pattern
  •   
  • Repeat in 6 months, to check the size increase
  •   
  • Second-look ultrasound, to perform ultrasound-guided punction; if the second-look        ultrasound is negative, follow-up MRI in 6 months is mandatory

4

The combination of morphology and enhancing pattern is suspicious . Malignancy cannot be excluded, but the laesion is atypical.

With occult laesions on mammography or ultrasound: consider MRI-guided biopsy

5

Highly suspicious of malignancy, both on the basis of morphology and enhanceing pattern.

With occult laesions on mammography or ultrasound: consider MRI-guided biopsy.

6

Biopsy-proven malignancy

 

Considerations

The availability of MRI in the Netherlands is rapidly increasing, but the scan can rarely be applied in the short-term, so that the time for diagnostic work-up is often extended by 1 to 2 weeks. The increase in the number of MRI’s performed on suspicion of breast cancer requires adjustments by the surgeon and radiologist. More attention should be given to the radiologist discussing MRI findings with the surgeon, and he/she should also be available in the operating room. The number of locations where MRI-guided biopsies are being performed is steadily growing, it is important that accessibility also increases.

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.