Biomed & Pharmacorher (1993) 47. 219-221 0 Elsevier, Paris

219

Notes

Tumour markers and origin of tumours.

This study set out to determine whether tumour marker expression by a metastatic tumour deposit could be used to identify its primary site of origin. The marker ex- pression was determined using immunohistological ex- amination of tissue sections taken from a series of low metastatic tumour deposits of known primary site of origin and their corresponding primary turnours. The latter aspect of the study was included to determine whether tumour marker expression could vary between primary and secondary turnouts.

The antibodies to the following tumour markers were used in the immunohistological assays: I) polymorphic epithelial mucin (antibodies NCRC I I and SM3), 2) carcinoembryonic antigen, 3) carcinoembtyonic an- tigen with non-specific antigen co-specificity, 4) Ca 125, 5) Ca 19.9, 6) prostate specific antigen and 7) thyroglobulin.

The results demonstrated that the correct site of origin could be predicted in 70% of turnouts in men and 54% of turnouts in women. The specificities for various types of primary tumours varied from 68% for breast tumours to 98% for prostatic carcinoma. These results are comparable with radiological investigation including CT scanning but have a significant cost saving benefit. Expansion of the tumour marker profile to include additional markers could improve levels of predication.

10 Ellis (1) City Hospital,

Nottingham NG5 IPB, UK

Randomised controlled trials in general practice.

This paper describes the feasibility of establishing an international register of randomised controlled trials (RCTs) conducted in, or relevant to, primary care, which may then be used as a resource for systematic overviews.

A retrospective literature review was undertaken to identify RCTs suitable for inclusion in such a register using three different strategies: i) approaching journal editors, ii) Medline search, and iii) manually searching individual journals. The number, nature, and site of publication of RCTs were documented.

No journal had an infrastructure in place with which to identify all the RCTs it published. A total of 366 RCTs relevant to primary care were identified from I IO different journals between 1987-1991 using Medline. Of

these, only 69 trials appeared in primary care journals. An analysis of the seven major primary care research journals found that l3-38% of RCTs which had been identified by manual searching had been missed by a Medline search. 17.7% (n = 47) of RCTs were con- cerned with mental disease (including neuroses, tobacco abuse and alcohol abuse) and 16.2% (n = 43) with hy- pertension. Given the diversity of publication sources and topic areas, the results of this study confirms the need for a centrally based register of RCTs covering all branches of medicine, including primary care. This view is consistent with the initiative being developed by the Cochrane Centre in the UK.

C Silagy (2) University of Oxford,

Oxford OX2 6HE, UK

RU486 and postcoital contraception.

Emergency contraception taken after unprotected inter- course or after condom failure prevents unwanted preg- nancy. A high dose of oestrogen in combination with a progestogen (CEP) is usually given within 72 h of coi- tus. This regimen has a failure rate of between 1% and 7% and is associated with a high incidence of nausea and vomiting which may affect efficacy and compli- ance. The anti-progesterone mifepristone (RU486) ap- pears to inhibit implantation. In this study, the efficacy and side effects of the standard regimen were compared with a single dose of 600 mg RU486. Eight hundred women with a history of regular cycles were ran- domised; 402 received RU486 and there were no con- ceptions, 398 received CeP and four women conceived. The failure rate for CEP was 1% overall, 2.5% when only women having intercourse in the fertile phase of the cycle were considered and 17% when the observed number of pregnancies was compared with the expected number. RU486 was associated with significantly fewer side effects but caused a delay in the onset of menses in over 20% of women. This study demonstrates that the antiprogesterone RU486 is a highly effective emer- gency post coital contraceptive.

A Glasier (3) Family Planning and

Well Woman 8erviee.s Edinburgh EH4 INL, UK

(2) Luncer (1993) 341, 715 (3) BMJ (1992) 306. 897 (I) EM/ (1993) 306, 295