CANCERS

Health Evidence Bulletins - Wales
Team Leader: Dr. Gordon Avery

Date of Completion: 17.09.98

CANCER BULLETIN

INTRODUCTION

The original series of twelve Protocols for Investment in Health Gain were written in the early 1990s to suggest areas where the introduction, or more widespread use, of certain practices could lead to worthwhile improvements in health for the people of Wales. The documents also highlighted current practices which were of questionable value. This revision has been prepared by reviewing the earlier Protocol for Investment in Health Gain: Cancer1 to provide some clear, updated statements with a precise indication of the strength of the evidence and its sources for each statement; and to introduce new statements covering subjects of important current interest.
The extent of knowledge of cancer care is so wide ranging that it has been decided to concentrate on three common cancers, namely lung, colorectal and breast. The project has obtained funding for a further two years which should enable a future bulletin to consider other types of cancer.
The format of the sections on the three major cancers included in this document is:

- Surgery
- Radiotherapy
- Chemotherapy
- Combined approaches
- Follow up & continuing care

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The greatest emphasis is given to diagnosis and treatment since these are the elements most amenable to direct influence by the health agencies. Where it is appropriate, and the information is available, a commentary is made on where it is best to carry out treatment and by whom. The use of protocols and guidelines and the setting and auditing of minimum standards are also referred to where the evidence is available to support this.

It should be noted that whilst the epidemiology and risk factors are covered only very briefly, a full understanding of the causes of cancer and knowledge of the age, sex, geographical distribution and social class, occupation and economic status of cancer patients is vital to a better understanding of the disease. It is also important for the purpose of targeting intervention programmes.

The statements represent a methodical summary of the evidence in this area found through a formal literature search across a wide range of sources2. The evidence has been critically appraised using internationally accepted methods2 . It has been compiled into this document under the direction of a public health physician, and reviewed by a multidisciplinary team, most of whom are directly involved in patient care. The bulletin is available electronically, via the NHS Cymruweb (http://cymruweb.nhs.wales/hebw, in Wales only) and the Internet (http://hebw.cardiff.ac.uk). Information on the methodology adopted (including a copy of the documentation), the formats in which the document is issued and details of other publications in the series, is available on request.3

The convention used in this document to indicate the type of evidence is:4

‘Type I evidence’ - at least one good systematic review (including at least one randomised controlled trial)
‘Type II evidence’ - at least one good randomised controlled trial
‘Type III evidence’ - well designed interventional studies without randomisation
‘Type IV evidence’ - well designed observational studies
‘Type V evidence’ - expert opinion; influential reports and studies

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Many health issues do not lend themselves to investigation by randomised controlled trial. By valuing evidence from these trials more highly than observational studies there is a danger that interventions with limited effectiveness might be judged to be more worthy than those based on observation. Similarly, those observational studies which clearly prove effectiveness (and make a randomised trial unethical) might be undervalued. Randomised controlled trials are a valuable form of evidence and, when available, they are included. If not, high quality evidence has been sought within the other categories. Information assigned as type V evidence includes very important reports or recommendations which should rightly be highly regarded.

The health gain notation (used to indicate the potential benefit to health) is5:

‘beneficial’ - effectiveness clearly demonstrated (1)
‘likely to be beneficial’ - effectiveness not so firmly established (2)
‘trade-off between beneficial and adverse effects’ - effects weighed according to individual circumstances (3)
‘unknown’ - insufficient / inadequate for recommendation (4)
‘unlikely to be beneficial’ - ineffectiveness is not as clearly demonstrated as for 6 (5)
‘likely to be ineffective or harmful’ - ineffectiveness or harm clearly demonstrated (6)

It should be stressed that these gradings, while aiming to be impartial, represent only the best advice of the professionals involved in preparing the Bulletin. Although the statements are deliberately brief, statistically significant quantitative information has been provided where possible. This is usually given as Number Needed to Treat (NNT), Odds Ratio (OR) or % change, in keeping with the original source of the information.6 Cost-benefit issues are not considered.

In keeping with the original Protocols, these revised documents are designed to assist Health Authorities in developing local strategies and in commissioning high quality health care. It is anticipated, however, that they will be of value to all health professionals in keeping abreast of the huge and increasing body of medical literature and can provide an agenda for future action in a wide variety of settings. It should be stressed that the publications will act as a supplement to, not a substitute for, clinical skills and experience. We anticipate that some of the conclusions reached will be controversial. Every effort has been made to include the best evidence within a subject area. Readers who are aware of any important topics or studies that have been overlooked are encouraged to contact the project team.3

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The Cancer Bulletin

This document has drawn heavily on the authoritative and thoroughly researched documents produced by the NHS Executive Guidance on Commissioning Cancer Services7 (summaries of these documents are also published by University of York Centre for Research and Development as Effective Health Care bulletins), and the Scottish Intercollegiate Guidelines Network (SIGN)8,9. An additional valuable source has been the guideline produced by the South East Wales Breast Group10 and a document provided, pre-publication from the Royal College of Radiologists Clinical Oncology Information Network by the Lung Cancer Working Group11. Original sources referenced in the document have been cross checked and additional sources have been examined where appropriate.

The statements within each subject area concentrate on specific interventions and the current state of knowledge. Expert recommendations for good practice which are common to all the subjects covered include:

  • speedy referral and access to expert diagnostic and treatment services
  • information, if required, being readily available to the patient in a presentable form
  • involvement by the patient in decision making on the treatment options
  • good communication between health professionals
  • arrangements being made for follow up and continuing care, if required
  • use of multidisciplinary teams
  • ready and early access to a comprehensive palliative care service when and where required.

Support within the health service should be available to ensure that all cancer patients have access to appropriate standards of care, including all the standard treatments, and access to all of the support services including those provided by palliative care services and the voluntary agencies.

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BIBLIOGRAPHY AND REFERENCES

  1. Welsh Health Planning Forum. Protocol for Health Gain. Cancers. Cardiff: Welsh Office NHS Directorate, 1991.
  2. Barker J, Weightman AL and Lancaster J. Project for the Enhancement of the Welsh Protocols for Investment in Health Gain; Project Methodology 2. Cardiff: Duthie Library UWCM, 1997
  3. Contact: Protocol Enhancement Project Office, Duthie Library, UWCM, Heath Park, Cardiff CF14 4XN.
  4. This table is adapted from the Bandolier system (derived from the work at McMaster University, Canada) using the NHS Centre for Reviews and Dissemination criteria for a systematic review. See ref.erence 2 or http://www.jr2.ox.ac.uk/Bandolier/band6/b6-5.html and the Database of Abstracts of Reviews of Effectiveness (DARE) in the Cochrane Library.
  5. This notation is modified from the tables used in Enkin M, Kierse MJNC, Renfrew M and Neilson J. A Guide to Effective Care in Pregnancy and Childbirth. 2nd ed. Oxford: Oxford University Press, 1995. pp. 389-390.
  6. Number Needed to Treat (NNT) = The number of patients to be treated to be sure of gaining one positive outcome;Odds Ratio (OR): If equal to 1, the effects of the treatment are no different from those of the control treatment. If the OR is greater (or less) than 1, then the effects of the treatment are more (or less) than those of the control treatment. Note that the effect being measured may be adverse or desirable.
  7. NHS Executive. Guidance for Purchasers. Improving Outcomes in Breast Cancer. 1. The Manual. 2. The Research Evidence. London: Department of Health, 1996; Improving Outcomes in Colorectal Cancer. 1. The Manual. 2. The Research Evidence. London: Department of Health , 1997; Improving Outcomes in Lung Cancer. 1. The Manual. 2. The Research Evidence. London.: Department of Health, 1998.
  8. Scottish Intercollegiate Guidelines Network (SIGN). Colorectal Cancer. A National Clinical Guideline Recommended for Use in Scotland. Edinburgh: SIGN, 1997.
  9. Scottish Intercollegiate Guidelines Network (SIGN). Management of lung cancer.. A National Clinical Guideline recommended for use in Scotland. Edinburgh: SIGN, 1998.
  10. South East Wales Breast Group. The Development and Maintenance of a High Quality Breast Service in South East Wales. Cardiff: Velindre NHS Trust, 1996
  11. Royal College of Radiologists Clinical Oncology Information Network. Guidelines for the non-surgical management of lung cancer. (Now published). Clinical Oncology 1999; 11(1): Version 1

This initiative is funded by the Wales Office of Research and Development for Health and Social Care and the Health Authorities in Wales.

Internal Review Group, Cancer Bulletin December 1998

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Health Evidence Bulletins: Wales, Duthie Library, UWCM, Cardiff CF14 4XN. e-mail: weightmanal@cardiff.ac.uk