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Which staging system to use for gynaecological cancers: a survey with recommendations for practice in the UK
  1. Glenn McCluggage1,
  2. Lynn Hirschowitz2,
  3. Raji Ganesan2,
  4. Sean Kehoe3,
  5. Andrew Nordin4
  1. 1Department of Pathology, Royal Group of Hospitals Trust, Belfast, UK
  2. 2Department of Pathology, Birmingham Women's Hospital, Birmingham, UK
  3. 3Department of Gynaecological Oncology, John Radcliffe Hospital, Oxford, UK
  4. 4Department of Gynaecological Oncology, East Kent Gynaecological Oncology Centre, Margate, UK
  1. Correspondence to Professor W Glenn McCluggage, Department of Pathology, Royal Group of Hospitals Trust, Grosvenor Road, Belfast BT12 6BA, UK; glenn.mccluggage{at}belfasttrust.hscni.net

Abstract

Aims There are two commonly used staging systems for gynaecological cancers, namely Fédération Internationale de Gynécologie et d'Obstétrique (FIGO) and TNM. The authors wished to ascertain which staging system is most commonly used in dealing with gynaecological cancers in the UK.

Methods The authors undertook a survey among participants in the National Gynaecological Pathology EQA scheme to investigate whether gynaecological pathologists in the UK use FIGO or TNM staging in their routine reporting of gynaecological cancers.

Results There were 105 respondents out of 278 participants (38%). Of the analysed results, a majority of respondents (64%) use FIGO staging, while 32% use both FIGO and TNM. 80% of respondents stated that their multidisciplinary team meeting uses FIGO staging, while 18% use both FIGO and TNM. Only an extremely small minority of pathologists and multidisciplinary team meetings use TNM alone. A survey of members of the British Gynaecological Cancer Society revealed similar findings.

Conclusions Since FIGO and TNM are not always equivalent, and there may be confusion when more than one staging system is used, it is recommended that FIGO staging be used for gynaecological cancers. The survey revealed support for the use of TNM, as well as FIGO, only for cervical cancer, since FIGO does not take the lymph node status into account. Given the prevalent practice in the UK, the British Association of Gynaecological Pathologists, British Gynaecological Cancer Society and gynaecological clinical reference group of the National Cancer Intelligence Network recommend that FIGO staging be used for gynaecological cancers with recording of the lymph node status for cervical cancer. This may be done by providing a TNM stage for this cancer type only or by recording the lymph-node status at the multidisciplinary team meeting.

  • Gynaecological cancer
  • FIGO
  • TNM
  • gynaecological pathology

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Introduction

Two staging systems are in widespread use for gynaecological cancers. These are the Fédération Internationale de Gynécologie et d'Obstétrique (FIGO) system, which is specific for gynaecological cancers, and TNM, which is applicable to all tumour sites. Updated, evidence-based FIGO staging systems for most gynaecological cancers and a new FIGO staging for uterine sarcomas were introduced in 2009.1 2 Recently TNM staging has been revised by the International Union Against Cancer (UICC), and TNM 7 has been published. This incorporates most of the components of the amended FIGO staging system. Although the Royal College of Pathologists' Cancer Datasets recommend that in addition to FIGO staging, TNM should be recorded to allow standardisation of staging across all cancer sites,3–6 there is some controversy and confusion among specialists dealing with gynaecological cancers as to what staging system to use. Problems may arise, since FIGO and TNM are not always directly comparable, particularly in the recording of lymph-node involvement. In the FIGO system, lymph-node involvement is incorporated into the final stage, but in the TNM system, this forms a separate staging component. For example, a FIGO stage IIIC endometrial cancer (IIIC on the basis of lymph-node involvement) may be pT1, lymph-node involvement being recorded as a separate staging component, pN1. The introduction of FIGO substaging in vulval carcinomas according to the number of nodes involved and the size of the metastases has complicated the substaging component of nodal involvement for this tumour type in the TNM system; in addition, these substages do not exactly correspond in FIGO and TNM 7. With these factors in mind, we undertook a survey among participants in the National Gynaecological Pathology external quality assurance (EQA) scheme and members of the British Gynaecological Cancer Society (BGCS) to determine which staging system for gynaecological cancers is most commonly used in the UK. In reporting the survey results, we provide recommendations regarding the staging of gynaecological cancers in the UK. These recommendations have been endorsed by the British Association of Gynaecological Pathologists (BAGP), BGCS and gynaecological clinical reference group of the National Cancer Intelligence Network (NCIN). The latter is a multidisciplinary group representing stakeholder organisations involved in the delivery of gynaecological oncology in the UK. The authors of this paper comprise the president (W G McCluggage) and secretary (L Hirschowitz) of BAGP, the chair of the Working Group for Cancer Services of the Royal College of Pathologists (L Hirschowitz), the president (S Kehoe) and national pathology representative (R Ganesan) of BGCS and the chair of the gynaecological clinical reference group of the NCIN (A Nordin).

Materials and methods

All participants in the National Gynaecological Pathology external quality assurance (EQA) scheme were asked to complete a short survey online (http://www.surveymonkey.com). The questions asked are shown in table 1. Participants were given the opportunity to provide comments if they wished. A similar survey was undertaken among members of the BGCS.

Table 1

Results of the National Gynaecological Pathology External Quality Assurance survey

Results

The results of the survey among EQA members are shown in table 1. Out of 278 participants in the EQA, 105 (38%) completed the survey. Only the results of the first 100 were analysed (this is a limitation of survey monkey if used free of charge). Since only five responses were not evaluated, there is unlikely to be any selection bias. Sixty-four per cent of respondents routinely use FIGO staging in reporting gynaecological cancers, 3% use TNM, 32% both FIGO and TNM, and 1% use no staging system. The corresponding figures for staging systems used by the gynaecological oncology multidisciplinary team (MDT) meeting of those responding were 80%, 2%, 18% and 0%. When asked which staging system respondents considered should be used, 54% said FIGO, 7% TNM, and 38% FIGO and TNM (1% did not answer this question). The corresponding figures for which staging systems respondents thought their MDT meeting should use were 79% (FIGO), 2% (TNM) and 17% (FIGO and TNM; 2% did not answer this question).

Eighty-one per cent of respondents supported the use of TNM as well as FIGO for selected gynaecological cancers (specifically cervical cancer), while 13% did not support this. Thirty per cent of participants supported the use of TNM instead of FIGO for selected gynaecological cancers, while 69% did not support this. The respondents worked in a cancer centre (56%), a cancer unit (28%) or a diagnostic centre (15%). Comments were largely regarding the preference to use FIGO rather than TNM and the necessity to consult with other professional groups before taking a unilateral decision to use FIGO rather than TNM.

There were 23 responses to the survey from a BGCS membership of over 300. The results are shown in table 2 and are essentially similar to those of the pathologists' EQA survey. Almost all respondents used FIGO staging in their practice and in their MDT meeting, and considered that FIGO should be used. A few respondents used FIGO and TNM, and none used TNM alone. There was considerable support for the use of TNM as well as FIGO for cervical cancer with 19 of 23 (83%) respondents supporting this.

Table 2

Results of the British Gynaecological Cancer Society survey

Discussion

The results of this survey show that most gynaecological pathologists in the UK exclusively report gynaecological cancers using FIGO staging systems. A significant minority use FIGO and TNM, while very few use TNM alone. The figures were similar when respondents detailed which staging system is routinely used in their gynaecological oncology MDT meeting. Although only 38% of participants in the EQA scheme participated in the survey, it is possible that some replies were on behalf of multiple pathologists working in the same department. Given the results (and similar results from the BGCS survey to which the response was lower), we recommend that FIGO rather than TNM staging be used for gynaecological cancers. This viewpoint has been endorsed by the councils of the BAGP and BGCS, and the gynaecological clinical reference group of the NCIN.

Although the number of responses to the BGCS survey was low, it is our view that most gynaecological oncologists and medical and surgical oncologists dealing with gynaecological cancers use FIGO rather than TNM in their everyday practice. It is important that different centres use the same staging systems in order to facilitate comparison and exchange of data between centres and to allow for consistent transfer of data to cancer registries. Worldwide, most clinical trials and retrospective and prospective studies also use FIGO rather than TNM. Hopefully, our recommendations will result in a more standardised approach to the staging of gynaecological cancers in the UK. It may also generate debate in other countries and result in similar recommendations by other societies dealing with patients with gynaecological cancer.

Given that FIGO does not take into account the lymph-node status in cervical cancer, we specifically wanted to know whether there was any support for the use of TNM, in addition to or instead of FIGO for this tumour type. Our survey shows that there is considerable support for the use of TNM in addition to FIGO for cervical cancer among pathologists and members of the BGCS, the latter being a multidisciplinary society with diverse membership, including gynaecological oncologists, medical and clinical oncologists, pathologists, radiologists and nurse specialists. Given this support and because of the therapeutic and prognostic importance of recording nodal status, we recommend that while FIGO staging is primarily used for cervical cancer, the lymph node status is also recorded at the MDT meeting. This may be done by incorporating the TNM stage or by simply recording the lymph-node status. Cervical cancer remains the only gynaecological cancer subtype that is subject to clinical staging in the FIGO system, and the final staging of these tumours is carried out at the MDT meeting to take into account clinical findings. Since pathology reports are often used to determine the final tumour stage by Cancer Registries, mechanisms should be put in place at a local level to ensure that correct staging information is recorded. This may be done by pathologists issuing supplementary reports to provide accurate FIGO and TNM staging information or more likely by using the MDT notes to collate this information.

A criticism of the TNM system with respect to tumours of all types is that these staging systems are not evidence-based. For gynaecological cancers in particular, a minimum number of six nodes is specified in lymphadenectomy specimens, but no evidence base is provided to support this statement. An important aspect of the revised TNM and FIGO staging of endometrial carcinoma that has not been widely publicised is that vascular invasion deep in the myometrium, in the cervical stroma, in the parametria or in ovarian hilar vessels should not upstage endometrial carcinomas if the tumour is confined to vessels in these areas but should be noted because of its possible adverse prognostic implications.

One perceived advantage of using TNM rather than FIGO staging for gynaecological cancers is that this allows for some standardisation between gynaecological and non-gynaecological cancers. Pathologists who routinely report cancers from gynaecological and non-gynaecological sites are likely to be more familiar with TNM rather than FIGO. There are other organ systems where two staging systems are in use—for example, TNM and Dukes for colorectal carcinoma. However, we believe there is a clear preference among specialists dealing with gynaecological cancer in the UK to use FIGO rather than TNM alone or FIGO together with TNM. One important point is that when recording the FIGO stage on the pathology report, this should be designated the provisional FIGO stage. The term provisional indicates that other information (eg, radiological evidence of distant metastasis) may be present and that the final FIGO stage should be determined at the MDT meeting.

In summary, we have found strong support among specialists dealing with gynaecological cancer in the UK for the use of FIGO rather than TNM staging. The BAGP, BGCS and gynaecological clinical reference group of the NCIN recommend that FIGO staging be used for gynaecological cancers. The TNM-style recording of lymph node status for cervical cancer is also recommended, since this is not included in FIGO staging. The forthcoming revised national gynaecological cancer clinical dataset will incorporate this policy.

Take-home messages

  • There are two staging systems in widespread use for gynaecological cancers, namely FIGO and TNM, and there is controversy and confusion among specialists dealing with gynaecological cancers as to what staging system to use.

  • FIGO and TNM are not always directly comparable, particularly in the recording of lymph-node involvement.

  • The results of our survey show that most gynaecological pathologists in the UK exclusively report gynaecological cancers using FIGO staging systems. A significant minority use FIGO and TNM, while very few use TNM alone.

  • The BAGP, BGCS and gynaecological clinical reference group of the NCIN recommend that FIGO staging be used for gynaecological cancers. The TNM-style recording of lymph-node status for cervical cancer is also recommended, since this is not included in FIGO staging.

References

Footnotes

  • Competing interests None.

  • Provenance and peer review Not commissioned; externally peer reviewed.

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