604

clofibrate or cholesterol reduction was presumed to be

responsible. Withdrawal of this protective effect might beassociated with an increased incidence of IHD in group I

compared with group 11, and may explain the slight excess inIHD mortality during the post-trial period. Unfortunately, ithas not proved practicable to conduct an adequate follow-upof morbidity caused by myocardial infarction in hospitalpatients and outpatients and no data are available for analysisof any change in incidence of non-fatal infarction during thefollow-up surveys.The importance of undertaking a complete follow-up in

long-term clinical trials cannot be over-emphasised. it should,we believe, be an integral part of the responsibity andcommitment of investigators at the inception of a trial. Ofcourse, it presents its own problems: as the years go by, theresponse, enthusiasm and interest of participants and

investigators wane. A big effort may be needed. We have hadour particular difficulties in that the follow-up to the end of1978, which we considered was complete, has proved not tobe; 43 deaths have had to be added to the previouslypublished figures. Their distribution between the three

groups is such that the addition has only a minimal effect onthe results already reported. The experience, however, re-emphasised the need to have more than one system ofascertainment even in the most straightforward of mortalitystudies.The overall results of the WHO clofibrate trial indicate the

power of a clinical trial of adequate scale with sufficientfollow-up. All potent drugs used in the primary prevention ofdisease must be examined during and after their period ofadministration. There is no short-cut, except perhaps whenthe risk of the disease is likely to be as great or greater than therisk of the drugs, as in the top few percentage at risk-eg inthose with familial hypercholesterolaemia.Indeed, similar comprehensive trials are needed to prove

the safety of all new and potent drugs as much as theirefficacy. At present, there is no monitoring system to providesound data on the risks of drugs used over many years. Theestablishment of drug data banks by drug regulatoryauthorities should allow small but significant changes in theincidence of, or mortality from, commonly occurring diseasesto be detected. It is in such a context that prescriptionmonitoring systems4 have to be assessed.The initial hypothesis behind this trial-namely, that

reduction of high plasma cholesterol would reduce theincidence of IHD-was confirmed, though only for non-fatalinfarction. Clofibrate was merely the chosen method ofreduction. The excess of deaths in the "treated" group has,not unnaturally, diverted attention from this result.

The investigators are again indebted to the individuals and organisationsmentioned in the earlier reports. 1,2

Requests for reprints should be addressed to M. F. O. CardiovascularResearch Unit, Hugh Robson Building, George Square, Edinburgh EH89XF.

REFERENCES

1. Committee of Principal Investigators A cooperative trial in the prevention of ischaemicheart disease using clofibrate. Br Heart J 1978; 40: 1069-118

2. Committee of Principal Investigators. WHO cooperative trial on primary prevention ofischaemic heart disease using clofibrate to lower serum cholesterol: mortality follow-up. Lancet 1980; ii: 379-85.

3. Heady JA A cooperative trial on the primary prevention of ischaemic heart diseaseusing clofibrate: Design, methods and progress. Bull WHO 1973; 48: 243-56.

4. Inman, WHW. Postmarketing surveillance of adverse drug reactions in generalpractice. Br Med J 1981, 282: 1131-32, 1216-17.

LOW-DOSE AMINOGLUTETHIMIDE INTREATMENT OF ADVANCED BREAST CANCER

R. STUART-HARRIST. BOZEK

J.-C. GAZETA. KURKURE

M. DOWSETT

J. A. MCKINNAS. L. JEFFCOATE

L. CARRI. E. SMITH

Division of Medicine and Medical Breast Unit,Royal Marsden Hospital, London SW3; and Department ofEndocrinology, Chelsea Hospital for Women, London SW3

Summary The clinical and endocrine effects oflow-dose aminoglutethimide without

hydrocortisone in patients with advanced breast cancer wereinvestigated. In a dose escalation study low-dose

aminoglutethimide alone (62-5-125 mg twice daily) was aseffective as conventional doses with hydrocortisone in

lowering serum oestrone and oestradiol concentrations butcaused minimum adrenal inhibition, as assessed by serumdehydroepiandrosterone sulphate. 11 of 57 (19%) evaluablepatients had tumour regression by objective criteria on thistreatment, but the frequency of side-effects was similar to thatwith conventional doses. Low-dose aminoglutethimide isactive in the treatment of breast cancer. It appears to work byinhibition of the aromatase enzyme system in peripheraltissues rather than adrenal suppression.

Introduction

AMINOGLUTETHIMIDE with hydrocortisone is an effectiveendocrine therapy for postmenopausal patients withadvanced breast cancer and achieves tumour regression inapproximately 30% ofpatients.1,2 At the conventional dosageof 1 g daily with hydrocortisone 20 mg twice daily adrenalsteroid synthesis is suppressed, principally by inhibition ofthe desmolase enzyme system which converts cholesterol to

pregnenolone; 3-5 the treatment has therefore sometimes beencalled "medical adrenalectomy". The main disadvantage oftherapy is a significant frequency of troublesome side-effects,including lethargy, ataxia, and rash, causing discontinuationof treatment in up to 10% of patients.2,6,7Aminoglutethimide also inhibits the aromatase enzyme

system which converts androgen precursors to oestrogens inperipheral tissues throughout the body.s-ll Aromataseconversion is believed to be the major mechanism for

oestrogen production in postmenopausal women.12,13 In-vitro aromatase inhibition occurs at lower concentrations of

aminoglutethimide than are necessary for desmolaseinhibition." We therefore postulated that it might be

possible to achieve oestrogen suppression and tumour

regression in postmenopausal patients by aromatase

inhibition with lower doses of aminoglutethimide than thosenecessary to induce adrenal suppression, and without theneed for supplementary hydrocortisone. We also hoped thatthis approach might be associated with a lower frequency ofside-effects, since lethargy and ataxia are dose related andseem to be related to serum levels of the drug.14 We nowreport our endocrine and clinical findings with low-doseaminoglutethimide used alone in the treatment ofpostmenopausal patients with advanced breast cancer.

Patients and Methods

Two sequential studies were carried out. The dose escalationstudy was aimed at assessing the extent to which low-dose

aminoglutethimide without hydrocortisone supplements could

605

suppress plasma oestrogen levels without severe adrenal

suppression. This was principally a study of endocrine effects,although most patients could also be assessed for tumour response.The second study, based on the results of the first, was a phase IIclinical trial of low-dose aminoglutethimide (125 mg twice daily).-This dose was chosen because it achieved maximum suppression ofplasma oestrone; the principal aim of this study was to assesstumour response.

33 patients with advanced breast cancer entered the dose

escalation study. Their mean age was 64 years (range 46-77); 32were postmenopausal and 1 was perimenopausal (less than 2 yearsfrom last menstrual period). The patients initially received 62’ 5 mgaminoglutethimide twice daily, and the twice-daily dose wasincreased to 125 mg during the second month, 250 mg during thethird month, 500 mg during the fourth month, and 500 mg withhydrocortisone 20 mg twice daily thereafter. During this studypatients showing tumour progression were withdrawn and givenconventional therapy.

32 patients with advanced breast cancer entered the clinical phaseII study. 30 were postmenopausal and 2 perimenopausal; the meanage was 61 years (range 45-82). Treatment was continued untilthere was clear evidence of disease progression or unless

unacceptable side-effects were encountered.

27 of the 57 patients assessable for response to treatment hadpreviously been treated with tamoxifen or oophorectomy; 2 patientshad received both treatments. The remaining 30 had received noprevious endocrine treatment.

Serum samples from patients in the first study were collectedbefore treatment and before each dose escalation, separated, andstored at -20°C until analysis. Serum oestrone, oestradiol, anddehydroepiandrosterone sulphate (DHA-S) were measured bystandard radioimmunoassay techniques.15,16 Chromatography ofether extracts on ’Sephadex LH 20’ was done before oestrogenassays. Cytoplasmic oestrogen-receptor data were available for only10 patients; these were therefore not analysed separately.Aromatase activity was not measured directly in any tumour biopsyspecimen.

Standard ’UICC criteria for assessment of objective tumour,response were used. 17 Side-effects and toxicity were assessed by aniridependent observer at each clinic visit.

Comparisons of the endocrine data obtained at each dose of

aminoglutethimide were made with the Student Neuman Keul’s test

Fig 1-Mean (±SEM) serum oestrone concentrations in 33 patientsreceiving stated doses of aminoglutethimide twice daily.

Xumbers on curves=numbers of patients. HC=hydrocortisone.

Fig 2-Mean (±SEM) serum oestradiol concentrations 1n 30 patientsreceiving stated doses of aminoglutethimide twice daily.

Fig 3-Mean (±SEM) serum DHA-S concentrations in 33 patientsreceiving stated doses of aminoglutethimide twice daily.

Informed consent was obtained from all patients and the studieswere approved by the Medical Ethical Committee of the RoyalMarsden Hospital.

Results

Endocrine InvestigationsThe lowest dose of aminoglutethimide, 62 - 5 mg twice

daily, caused a significant fall (p<0 01) in the mean oestroneconcentration from the pretreatment level (fig 1). Although afurther fall in oestrone levels occurred with 125 mg twice

daily, it was not significant. Thereafter, no further significantfall in oestrone level occurred with higher doses of

aminoglutethimide either alone or with hydrocortisone.The mean serum oestradiol concentration was significantly

reduced from pretreatment levels (p<0 01) by 62 - 5 mg twicedaily (fig 2). A further, but not significant, fall in meanoestradiol levels occurred at doses of 125 mg and 250 mgtwice daily. No further reduction was achieved by furtherdose escalation or by the addition of hydrocortisone.The mean serum DHA-S concentration at 62.5 5 mg twice

daily was slightly but significantly (p<0-05) lower than

606

TABLE,I-RESPONSE TO LOW-DOSE AMINOGLUTETHIMIDE BY PREVIOUSTHERAPY*

*2 patients received more than one form of therapy.

pretreatment levels (fig 3). Thereafter, no further significantchange in mean serum DHA-S concentration occurred untilhydrocortisone was added (p<0 01).

Tumour ResponseThere were objective criteria of response to therapy in 11 of

57 (19%) evaluable patients at doses of 62-5 5 mg or 125 mgtwice daily without hydrocortisone.27 of the 33 patients in the dose escalation study could be

assessed for tumour response. The remainder either had noassessable disease (3 patients) or withdrew because of toxiceffects after 1 month (3 patients). 1 patient had a completeresponse and 3 patients had partial responses (overall responserate 4/27, 15%). 2 showed evidence of response at 62’ 5 mgtwice daily (soft tissue and bone metastases) and 2 at 125 mgtwice daily (soft tissue and lymph-node metastases). A furtherpatient eventually achieved an objective response after 6months’ treatment with conventional doses and

hydrocortisone as part of the dose escalation study. 3 patientshave relapsed after 12, 14, and 15 months and the otherremains in remission after 15 months of treatment. 5 patientsshowed disease progression during dose escalation; 1 of thesewas changed to conventional dosage but showed continuedprogression.

30 of the 32 patients in the phase II study could be assessedfor tumour response. In the other 2 treatment was

discontinued because of drug-related toxic effects. 7 patients(23%) achieved partial responses; no complete responseswere observed. 10 patients had stable disease and 13 diseaseprogression during treatment. Response was achieved after amean of 11 weeks of therapy (range 2-29 weeks). All patientsremain in remission 5 to 14 months after the start of therapy.7 patients who showed disease progression during therapy

TABLE II-SIDE-EFFECTS IN 65 PATIENTS TREATED WITH 62-125 mgAMINOGLUTETHIMIDE TWICE DAILY

with 125 mg twice daily aminoglutethimide were

subsequently treated with conventional doses and

hydrocortisone; 1 achieved a soft-tissue response.

Response Related to Previous Endocrine Therapy7 of 30 previously untreated patients achieved responses,

along with 4 of 20 patients who had previously failed torespond to tamoxifen (table I).

Toxicity

Lethargy (31%), rash (15%), and nausea (12%) were themost frequent side-effects (table II). Side-effects were usuallymild, but occasionally they were severe,and treatment had tobe stopped in 5 (8%) patients (1 rash and peripheral oedema, 1rash, 2 severe nausea or vomiting, 1 severe lethargy andfever). No plasma electrolyte disturbances suggestive ofadrenal insufficiency were seen, except in 1 patient in whomtransient mild hyponatraemia (132 mmol/1) without clinicalside-effects developed. 35 patients (54%) had no side-effects.

Discussion

These studies have shown that aminoglutethimidealone in doses of 62-5-125 mg by mouth twice daily is aseffective as conventional doses of aminoglutethimide withhydrocortisone in reducing serum oestrogen concentrationsin postmenopausal patients. In contrast to the conventionaldose, this effect is achieved with only slight adrenal

suppression, as measured by serum DHA-S, suggesting thatthe effect is mediated through aromatase inhibition in

peripheral tissues. This hypothesis is supported by earlier in-vitro" and clinical’" findings that aminoglutethimide is anaromatase inhibitor.Serum oestrogen reduction was associated with objective

tumour responses. Thus, the concept of aromatase inhibitionas a means of controlling breast cancer is valid and shouldencourage further studies with other aromatase inhibitors. Sofar the only other inhibitor to be used in the treatment ofadvanced breast cancer is testolactone; response rates variedfrom 5% to 24%.’’ In-vitro studies suggest thattestolactone is a less potent aromatase inhibitor than

aminoglutethimide. 22Our response rate of 1907o is lower than that reported for

conventional-dose aminoglutethimide, 2’ but a larger numberof patients or a randomised trial would be required to

determine the relative efficacy of aromatase inhibition andother forms of endocrine treatment. More disappointingclinically was the significant toxicity even at these low doses;the proportion of patients stopping treatment because of side-effects (8%) was similar to that seen at conventional

dosage. 2,1,7 This finding was unexpected, since some side-effects are related to serum levels of the drug." No plasmaelectrolyte disturbances suggesting adrenal insufficiencywere seen, but we suspect that these side-effects could be dueto the absence of hydrocortisone, which may diminish side-effects when used with aminoglutethimide in conventionaldosage. Low-dose aminoglutethimide with hydrocortisone iscurrently being assessed (A. L. Harris, personalcommunication); the combination may prove a more

acceptable clinical alternative to conventional treatment thanlow-dose therapy alone.

Correspondence should be addressed to 1. E. S., Royal Marsden Hospital,Fulham Road, London SW3 6JJ.

References at foot of next page

607

Preliminary CommunicationFIBRINOPEPTIDE A AND SUDDEN CORONARY

DEATH

T. W. MEADE D. J. HOWARTHYVONNE STIRLING

Medical Research Council Epidemiology and Medical Care Unit,Northwick Park Hospital, Harrow, Middlesex

T. P. WELCH

Accident and Emergency DepartmentNorthwick Park HospitalM. R. CROMPTON

Department of Forensic Medicine, St George’s Hospital MedicalSchool, London

Summary Fibrinopeptide A (FPA) concentrationswere measured in blood taken by direct

cardiac puncture from 31 patients who had died suddenly ofischaemic heart disease (IHD) and from 8 patients who haddied suddenly of other causes. Mean FPA concentration inthe IHD group was five times higher than that in the non-IHD group. This difference was almost entirely due to thehigh FPA level in the IHD subjects with a history of thedisease. The FPA difference between the IHD and non-IHDgroups is unlikely to have been due to differences in methodsof resuscitation. A possible interpretation of the findings isthat thrombin production causes or aggravates the course ofevents leading to sudden IHD death, particularly in subjectswith a past history of IHD.

INTRODUCTION

THE suggestion that "sudden coronary death" is a

thrombotic event remains controversial. Early prospectiveresults from the Northwick Park Heart Study (NPHS) haveindicated that high concentrations of certain clotting factorsare associated with an increased risk of death fromcardiovascular disease, including sudden coronary death.’ IThese findings are compatible with the hypothesis that thereis a definable "hypercoagulable state" or "increased

thrombotic tendency" though they do not, of course, prove it.An additional part of the evidence for a thrombotic

component in sudden coronary death would be the

demonstration of indicators of’ thrombogenesis in theminutes or hours before the event, but the difficulty orimpossibility of obtaining this evidence is obvious. We havetherefore looked for biochemical evidence of thrombogenesisin blood taken very soon after sudden death, both coronaryand non-coronary. We measured the plasma level of

fibrinopeptide A (FPA), the initial cleavage product of thethrombin proteolysis of fibrinogen.2

METHODS

The study was carried out between 1979 and 1983 and wasapproved by the Harrow District ethical committee and by HerMajesty’s Coroner for the Northern District of Greater London.Subjects.-Those studied had either died in the accident and

emergency department of North wick Park Hospital, or had died at aknown point during their transfer to the department by ambulance.In all cases, death was sudden and unexpected at the time, though 2patients had malignant disease (see fig 1), and most of those dying ofischaemic heart disease (IHD) had probably had previous episodes.When death had been certified, up to 50 ml blood was taken bydirect cardiac puncture and transferred at once to tubes containing3 - 13% trisodium citrate. (Most of the blood in samples obtained bydirect cardiac puncture is likely to come from the ventricles, theright more often than the left3 Details of attempts at resuscitationwere recorded. In nearly all cases, medications (eg, bicarbonate) aregiven intravenously. Direct intracardiac adrenaline is onlyoccasionally used. A coroner’s necropsy was performed in all butone case. M.R.C. performed 76% of the necropsies. He had noknowledge of the FPA level. In all but 7 of the necropsy cases (allin the IHD group, see below) standard details concerning thepresence of occlusive thrombi and of evidence of past or recent

myocardial infarction were available.Analyses have been confined to findings where the interval

between death and blood sampling was certainly or probably lessthan 20 min. There were 31 such cases (22 male, 9 female) in whichthe cause of death was considered to be a manifestation of IHD andthe mean interval between death and sampling was 7 - 0 min. Therewere 8 (5 male, 3 female) in which other causes were responsible(non-IHD), including 1 case of sudden infant death syndrome(SIDS); and the mean interval between death and sampling was 8, 6’min. Mean ages of the IHD and non-IHD cases were 65 and 58

years, respectively.

R. STUART-HARRIS AND OTHERS: REFERENCES

1 Smith IE, Fitzharris BM, McKinna JA, et al Aminoglutethimide in the treatment ofmetastatic breast carcinoma Lancet 1978; ii: 646-49.

2 Santen RJ, Worgul TJ, Lipton A, et al. Aminoglutethimide as treatment of

postmenopausal women with advanced breast carcinoma. Ann Intern Med 1982; 96:94-101.

3 Cash R, Brough AJ, Cohen MNP, Satoh PS Aminoglutethimide (Elipten-Ciba) as aninhibitor of adrenal steroidogenesis J Clin Endocrinol Metab 1967, 27: 1239-48.

4. Dexter RN, Fishman LM, Ney RL, Liddle GW. Inhibition of adrenal corticosteroidsynthesis by aminoglutethimide: studies of the mechanism of action. J ClinEndocrinol Metab 1967, 27: 473-80.

5. Kahnt FW, Neher R On the adrenal biosynthesis of steroids in vitro. III. Selectiveinhibition of adrenocortical function. Helv Chem Acta 1966, 49: 725-32.

6 Harris AL, Powles TJ, Smith IE. Aminoglutethimide in the treatment of advancedpostmenopausal breast cancer. Cancer Res 1982; 42 (suppl): 3405s-08s.

7. Smith IE, Harris AL, Morgan M, Gazet J-C, McKinna JA. Tamoxifen versusaminoglutethimide versus combined tamoxifen and aminoglutethimide in thetreatment of advanced breast carcinoma. Cancer Res 1982; 42 (suppl): 3430s-33s.

8 Chakraborty J, Hopkins R, Parke DV. Inhibition studies on the aromatization ofandrost-4-ene 3,17-drone by human placental microsomal preparations. Biochem J1972; 130: 19.

9. Thompson EA, Siiteri PK. The involvement of human placental microsomalcytochrome P-450 in aromatization. J Biol Chem 1974, 294: 5373-78.

10 Santen RJ, Santner S, Davis B, Veldhuis J, Samojlik E, Ruby E. Aminoglutethimideinhibits extraglandular estrogen production in postmenopausal women with breastcarcinoma J Clin Endocrinol Metab 1978; 47: 1257-65.

11 Graves PE, Salhanick HA Stereoselective inhibition of aromatase by enantiomers ofaminoglutethimide. Endocrinology 1979; 105: 52-57.

12 MacDonald PC, Rombaut RP, Siiteri PK. Plasma precursors of estrogen; I extent ofconversion of plasma androstenedione to estrone in normal males and nonpregnant,

normal, castrate and adrenalectomized females. J Clin Endocrinol Metab 1967; 27:1103-11.

13. Grodin JM, Siiteri PK, Macdonald PC Source of estrogen production in

postmenopausal women. J Clin Endocrinol Metab 1973; 36: 207-14.14. Murray FT, Santner S, Sanojlik EA, Santen RJ. Serum aminoglutethimide levels:

studies of serum halflife, clearance and patient compliance. J Clin Pharmacol 1979;19: 704-11.

15. Harris AL, Dowsett M, Jeffcoate SL, McKinna JA, Morgan M, Smith IE. Endocrineand therapeutic effects of aminoglutethimide in premenopausal patients with breastcancer. J Clin Endocrinol Metab 1982; 55: 718-22

16 Harris AL, Dowsett M, Jeffcoate SL, Smith IE. Aminoglutethimide dose and hormonesuppression in advanced breast cancer. Eur J Cancer Clin Oncol 1983, 19: 493-98

17. Hayward JL, Carbone PP, Heuson JC, Kumaoka S, Segaloff A, Rubens RD.Assessment of response to therapy in advanced breast cancer. a project of theprogramme on clinical oncology of the International Union Against Cancer,Geneva, Switzerland. Cancer 1977; 39: 1289-94.

18. Segaloff A, Weeth JB, Meyer KK, Rougue EL, Cunningham MEG. Hormonal therapyin cancer of the breast XIX Effect of oral administration of testolactone on clinicalcourse and hormonal excretion. Cancer 1962, 15: 633-35

19. Co-operative Breast Group. Results of studies of the co-operative breast group1961-63. Cancer Chemother Rep 1964; 41: 1-24.

20. Goldenberg IS. Clinical trial of testolactone (NSC 23759), medroxyprogesteroneacetate (NSC 26386) and oxylone acetate (NSC 47438) in advanced female

mammary cancer. Cancer 1969; 23: 109-12.21. Volk A, Deupree RH, Goldenberg IS, Wilde RC, Carabasi RA, Escher GC A dose

response evaluation of testolactone in advanced breast cancer. Cancer 1974, 33:9-13.

22. Brodie AMH. Overview of recent development of aromatase inhibitor. Cancer Res1982; 42 (suppl): 33125-45