2- Sub-base: sobre ella se asientan el resto de piezas del molde para favorecer el alineamiento y facilitar el transporte.
6.3 Procedimiento de fabricación de las probetas
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pre-operative and follow-up data, and a co-ordinated programme of audit.
Screening
• There is no justification for the routine use of PSA testing in primary care. GPs should be actively discouraged from using PSA tests for the purposes of early detection.
• Younger men with a strong family history form a distinct group and such men may warrant a selective approach to PSA testing and DRE, although such men should be fully counselled as to the uncertainties of treatment effective- ness for localised disease.
• Although prostate cancer is a serious public health problem, it appears to have a long natural history and it is impossible on current evidence to identify the tumours that will progress to be life-threatening.
• DRE and PSA testing, combined with TRUS and biopsy where indicated, can detect local- ised prostate cancer in approximately 3–5% of men aged over 50 years, depending on the criteria employed and the use of the tests cross-sectionally or serially. There is little evidence concerning the acceptability of these tests to the general population.
• Major questions remain concerning the efficacy and effectiveness of treatments and until these are resolved there is no justification for the introduction of a screening programme. • The potential costs of a screening programme
are huge, and the limited economic evaluations available provide little support for screening.
Research
Epidemiology
• Information about the natural history of prostate cancer is required, particularly to identify tumours which will progress to become life-threatening. • Further evidence concerning the discrepancy be-
tween trends in incidence and mortality is needed. • More precise information about aetiology and
risk factors is required, particularly genetic risk.
Diagnosis
• Definition of the optimum method of diagnosis is needed.
• Further understanding of the biomolecular and physiological properties of PSA is required, alone and in combination with other modalities. • Definition of the most clinically useful form of
reporting PSA levels is required, whether by age, density, velocity or molecular form.
• Information on the acceptability to patients of each of the diagnostic techniques is required. • Further assessment is needed of the reliability
of TRUS in the UK, particularly inter- and intra- observer variation.
• Investigation of the consequences of increasing numbers of biopsies is required, particularly tumour seeding and infectious complications, including the value of prophylaxis.
• Examination of the types of tumours detected using random biopsy techniques and the relationship between detection rate and PSA level is needed.
Staging
• Improving staging performance is a high research priority.
• Pursuit of molecular markers of likely progression is required.
• The prognostic value of bone, CT and MRI scanning in the UK requires investigation. • Investigation of the natural history of prostatic
tumours is needed, particularly T1 and T2. • Examination of the effectiveness of laparo-
scopic compared with pelvic lymphadenectomy is required, including an assessment of any complications arising.
• Further investigation into the value of DNA ploidy is required.
Treatment
• A large-scale, randomised, controlled trial comparing radical prostatectomy with conser- vative management for men with localised prostate cancer is urgently required to assess the comparative effectiveness and cost- effectiveness of these treatments. Such a trial should measure a range of short and medium term outcomes in addition to mortality and progression.
77 • Detailed investigation of short and medium term
outcomes is required for each of the major treat- ment modalities, particularly identifying treat- ment complications and effects upon quality of life, including sexual functioning and family life. • Further evidence is required concerning the
optimum approach for radical prostatectomy. • Further examination is needed of the signifi-
cance of PSA levels in detecting progression following radical treatment.
• The optimum programme of conservative man- agement needs investigation. The content of conservative management programmes needs to be made explicit and described fully to en- able this treatment modality to be investigated thoroughly. Issues which need to be addressed include the level or rate of change of PSA required before intervention, and the type of intervention used (TURP or hormonal therapy, for example).
• In-depth assessment of men’s perceptions of the acceptability of conservative management as a treatment option is required, particularly in view of increased public awareness of the disease.
• Comparative effectiveness of different forms of radiotherapy requires investigation (external beam, conformal and seed implants, for example).
• Standardisation of treatment complications to be measured in all studies is required, including clear definitions of types of incontinence and the introduction of patient-completed instru- ments for this purpose (such as the ICSmale questionnaire432).
Economic evaluation
• A full economic evaluation of the cost- effectiveness of the major treatment options is urgently required, particularly set within the context of a large randomised controlled trial. • Studies including UK costs are required. • Costs of various forms of surveillance for recur-
rence in the UK are needed, particularly in comparison with PSA testing.
Screening
• If data became available suggesting that radical treatments were effective and cost-effective, then it would become necessary to mount a full evalu- ation of the effectiveness and cost-effectiveness of screening versus no screening in the general population. Such a study, which would neces- sarily have to follow on from a randomised, con- trolled trial of treatment, would need to be on a large scale and involve the randomisation of men to screening or no screening, with outcome in terms of mortality assessed 10–15 years later. • The current practice in some urology centres
to screen men with a strong family history of prostate and/or breast cancer and to treat them radically should be evaluated through audit or research.
When (and if) evidence becomes available that suggests that radical treatment is effective, then the following research on screening might be required. • Economic evaluation of the cost-effectiveness
of various screening options, applied either to the general population or specific target groups, such as those with a family history of prostate or breast cancer, set within a randomised controlled trial.
• In-depth assessment of men’s perceptions of the acceptability of conservative management as a treatment option within a screening programme, particularly in view of increased public aware- ness of the disease and the perceived possibility of cure.
• While DRE and PSA can be used as ‘first line’ screening tests and are relatively simple to per- form, there has been insufficient investigation of the psychosocial implications of widespread availability of such tests.
• A full investigation of the most suitable method of counselling for men entering screening should be carried out.
• A full review of facilities and personnel required for screening will be needed, including the provision of special clinics and additional resources for treatment.
T
he authors would like to acknowledge the financial support received from the NHS R&D Health Technology Assessment Programme. We would also like to acknowledge the help and advice given by members of the expert panel, listed earlier. Further thanks are due to Caroline Caley, whoplayed an important role in searching the literature, copying and entering the references, organising the meeting of the expert panel, and assisting generally in a number of ways. Thanks too to the anonymous reviewers. Any omissions or errors are, of course, the responsibility of the authors.
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