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DR COOMBES AND OTHERS: REFERENCES

1. Coombes RC, Powles TJ, Gazet JC, Ford HT, Laurence DJR, Neville AM.Assessment of biochemical markers in breast cancer. Lancet 1977; i:

132-34.2. Powles TJ, Dady PJ, Easty G, Williams J, Coombes RC. Use of inhibitors

of prostaglandin synthesis in breast cancer. Prostaglandins and Throm-boxane Res (in press).

3. Stimson WH, Sinclair JM. An immunoassay for a pregnancy-associated&agr;-macroglobulin using antibody enzyme conjugates. FEBS Letters 1974;47: 190-92.

4. Laurence DJR, Stevens U, Bettleheim B, et al. Role of plasma CEA in diag-nosis of gastrointestinal, mammary and bronchial carcinoma. Br Med J1972; iii: 605-09.

5. Jones B, Worwood M. An automated immunoradiometric assay for ferritin.J Clin Pathol 1975; 28: 540-42.

6. Roberts JG, Keyser JW, Baum M. Serum &agr;-I-acid glycoprotein as an indexof dissemination in breast cancer. Br J Surg 1975; 62: 816-19.

7. Gehrke CW, Kuo KC, Waalkes TP, Borek E. Patterns of urinary excretionof modified nucleosides. Cancer Res 1979; 39: 1150-53.

8. Grant RA. Estimation of hydroxyproline by the autoanalyser. J Clin Pathol1964; 17: 685-86.

STEROID-RECEPTOR ASSAYS IN HUMANBREAST CANCER

A Statement by the British Breast Group andColleagues*

STEROID hormones produce effects on target cells bybinding initially to receptor proteins present in the

cytoplasm. The steroid-receptor complex is then translo-cated into the nucleus and binds specifically to certainacceptor sites on the chromatin, thereby promoting thevarious biochemical processes concerned with tissue

growth and function. In 1971, Jensen and his col-

leagues2 suggested that the analysis of the oestradiol-receptor content of tumour tissue from patients withadvanced breast cancer might provide a predictive testfor response to endocrine therapy. Various reports3 fromthe United States and Europe, including that from theBritish Breast Group’s cooperative study established inEdinburgh and at Guy’s Hospital,4 have tended to sup-port this and provide good evidence that knowledge ofthe receptor status of tumours is of value in the manage-ment of patients with advanced breast cancer.A joint meeting was held on Feb. 23, 1979, between

the British Breast Group and the oncology section of theRoyal Society of Medicine to review the data accumu-lated in British laboratories on the analysis of œstradiolreceptors and to assess their value in relation to clinical

experience. Some experts from abroad were invited todiscuss this work, together with interested colleaguesfrom the United Kingdom. Much of the data fromcentres in the United Kingdom has been incorporated ina review. This present report by the British BreastGroup provides what we consider to be a reasoned state-ment on the current status of cestradiol receptor analysesin relation to the management of breast cancer. It in-cludes certain views and conclusions from a recent "con-

*Members of the British Breast Group—Prof. M. Baum, Mr E. A.Benson, Mr Roger Blamey, Dr Diana Brinkley, Dr R. D. Bulbrook,Mr Ian Burn, Prof. A. Cuschieri, Dr J. A. Dossett, Dr C. W. Elston,Prof. A. P. M. Forrest, Mr David George, Dr I. H. Gravelle, Prof.Keith Griffiths, Dr J. L. Haybittle, Mr J. L. Hayward, Dr R. J. B. King,Dr Peter Maguire, Dr Rosemary Millis, Prof. A. M. Neville, Dr TrevorPowles, Dr Maureen Roberts, Dr R. D. Rubens, Prof. R. A. Sellwood,Dr Helen Stewart, Dr B. A. Stoll, Prof. M. P. Vessey. Colleagues-DrDiana M. Barnes, Mr T. Cook, Dr Evert Engelsman, Dr R. A.Hawkins. Mr V. Humeniuk, Dr Elwood Jensen, Dr R. E. Leake, Prof.Heinrich Maas, Dr P. V. Maynard.

sensus" meeting on receptors held in Washington at theNational Institutes of Health6 and attended by represen-tatives of the Group.

METASTATIC CANCER

There is now considerable evidence that oestradiol-

receptor status of metastatic breast-cancer tissue is a

good predictor of response to endocrine therapy in pa-tients with advanced disease. Less than 10% of patientswhose tumour tissue does not contain cytosolic cestradiolreceptor respond to endocrine therapy, whereas approx-imately 50% of patients with oestradiol-receptor-positivetumour tissue can generally be expected to show anobjective response to such treatment. Furthermore, highconcentrations of oestradiol receptor in their tumour tis-sue appear to increase the probability of response.’ Datafrom the United States7 and from the United King-dom8,9 also indicate that response is more likely if thetumour contains receptor for progesterone. There is evi-dence to suggest that progesterone-receptor synthesis isoestrogen dependent, the presence of progesterone recep-tor generally indicating, therefore, that not only is therea receptor for oestradiol in the cytosol capable of bindingthe hormone, but also that at least some of the cellularmechanisms by which oestradiol stimulates protein syn-thesis are functional.

PRIMARY CANCER

Information is also rapidly accumulating on the valueof cestradiol-receptor assay in primary breast tumour tis-sue removed at initial surgery. In advanced disease,metastatic tumour tissue is often inaccessible-for

example, when present in bone or viscera. Analysis ofreceptors in the primary tumour might therefore be ofvalue in determining the endocrine responsiveness ofsubsequent metastatic disease. In order to validate thisapproach, it is necessary to know if there is any changein receptor phenotype during the postoperative disease-free interval. It is especially important to know whetheror not cestradiol-receptor-negative primary tumours cangive rise to receptor-positive secondary deposits. Theresults so far obtained suggest that this type of pheno-typic change rarely occurs and that œstradiol-receptor-negative primary tumours give rise to metastatictumours which are unresponsive to endocrine therapy.

PROGNOSIS

Data now available illustrate the potential value ofcestradiol-receptor status of primary tumours in relationto prognosis. Generally, primary tumours lacking cestra-diol receptor recur earlier than receptor-positivetumours.’"’" The disease-free interval is prolonged inpatients with cestradiol-receptor-positive primarytumours, in the absence of any postoperative systemictherapy. When other clinical variables such as node in-volvement are also taken into consideration, oestradiol-receptor-positive tumours still recurred later than recep-tor-negative tumours. Furthermore, patients without

axillary-lymph-node metastases, but with an cestradiol-receptor-negative tumour, have the same high rate ofrecurrence as all patients with axillary-node involve-ment." Patients with receptor-positive tumours also sur-vive longer than those with receptor-negative tumours.’

299

RELATIONS TO HISTOLOGY

Several reports indicate that oestradiol-receptor statuscorrelates with the degree of differentiation of the pri-mary tumour.5,13 A large proportion of highly differen-tiated grade I carcinomas are oestradiol-receptor posi-tive, whereas the reverse is true for the poorlydifferentiated grade III carcinomas. Despite this correla-tion, receptor status and tumour grade are not equiva-lent, and both together provide more prognostic infor-mation than either of them separately. Receptor analysisoffers a refined, more easily quality-controlled assay ofbiological material that is less subjective than histology.

Also of interest is the correlation between the amountof elastic tissue in primary tumours and the subsequentresponse to endocrine therapy14—the greater the degreeof tumour elastosis, the higher the response rate.There is therefore good evidence that the oestradiol-

receptor assay is a valuable prognostic indicator which,along with lymph-node status and tumour grade, cannow be effectively used by the clinician in the manage-ment of patients with early breast cancer. In addition,the assay results from primary tumour analysis may wellbe useful in the choice of the best form of therapy whenthe disease has disseminated.

INFLUENCE ON TREATMENT

There are some clinicians who believe that, despiteknowledge of the receptor status of the tumour, adminis-tration of a non-toxic drug such as the anti-oestrogentamoxifen in advanced disease, in order to assess clinicalresponse to endocrine therapy, is justifiable, even in pa-tients known to have an oestradiol-receptor-negativetumour. These clinicians would argue, therefore, thatknowledge of receptor status may not be entirely neces-sary in the management of advanced disease. We agreethat in certain circumstances-e.g., in the absence of areceptor assay on the primary tumour-major surgeryin order to remove metastatic tissue for receptor assayis not justifiable.There is obviously a need, however, to identify those

tumours which may have ceased to respond to endocrinetherapy but which can be influenced by cytotoxic drugs.For this reason, great interest was generated by a reportthat patients with receptor-negative tumours showed agreater response-rate to chemotherapy than those withreceptor-positive tumours.11 Unfortunately data pre-sented at the British and American meetings did notconfirm the initial report, and it was stressed that pro-spective trials, in which receptor status was assessed im-mediately before chemotherapy, were required to clarifythis point. Although, ultimately, accurate data from

receptor analysis in conjunction with good controlledclinical trials will decide all these issues, in the meantimethe potential value of the cestradiol-receptor analysis ofprimary tumours cannot be denied. Furthermore,knowledge of the receptor status could become essentialin the selection of patients with early disease for sys-temic therapy, and the results of current clinical trialsof adjuvant tamoxifen therapy will be of value in this re-spect.

WHO SHOULD DO RECEPTOR ASSAYS

The question of who should accept responsibility fordoing receptor assays is not too difficult to resolve. The

reliability of the steroid-receptor assay is paramount. Toachieve reliability, analyses must be the responsibility ofa small number of regional laboratories with consider-able experience in this work. Progress is being made inthe development of radioimmunoassays and immunocy-tochemical analyses for receptor proteins, and these mayeventually be the responsibility of pathology depart-ments ; however, routine availability of such proceduresis not imminent. The currently established methods ofassays must therefore continue to be used, and it is

generally accepted that the multiple-point dextran-coated charcoal assay offers the most reliable data.

SAMPLING

The state of the tissue sample reaching the laboratoryis of the utmost importance in providing accurate

results. Good cooperation between surgeon, pathologist,and biochemist is therefore essential. Tissue for receptorassay taken from the periphery of the tumour must befrozen immediately in liquid nitrogen or in solid carbondioxide, and an adjacent piece should be taken for histo-logical examination. Prolonged storage of the tissuebefore assay is to be discouraged, and receptor deter-mination should be completed within four weeks. Amajor effort is currently underway to establish effectivequality control for steroid-receptor determination andall laboratories accepting responsibility for such assaysshould consider carefully how they can best partake insuch a scheme.

CONCLUSION

Data from laboratories and clinics throughout theworld on the measurements of steroid receptors, lead tothe conclusion that such assays are likely to be of consid-erable value to the clinician in managing patients withcarcinoma of the breast. A reasonable suggestion, there-fore, is that if our experience in the use of these proced-ures is to increase, receptor assays should be included inthe protocols of future clinical trials in breast cancerwhenever possible. Moreover, the possibility that a

supraregional service takes responsibility in the UnitedKingdom for such assays should now be explored.

Requests for reprints should be addressed to Dr M. M. Roberts,Hon. Sec. British Breast Group, Edinburgh Breast Screening Clinic,Springwell House, 26 Ardmillan Terrace, Edinburgh EH11 2JL.

REFERENCES

1. King RJB, Mainwaring WIP. Steroid-cell interactions. London: Butter-

worth, 1974.2. Jensen EV, Block GE, Smith S, Kyser KA, de Sombre ER. Estrogen recep-

tors and breast cancer response to adrenalectomy. Nat Cancer Inst Mono-graph 1971; 34: 55-57.

3. McGuire WL, Carbone PP, Vollmer EP, eds. Estrogen receptors in humanbreast cancer. New York: Raven Press, 1975.

4. Roberts MM, Rubens RD, King RJB, et al. Oestrogen receptors and responseto endocrine therapy in advanced breast cancer. Br J Cancer 1978; 38:431-37.

5. King RJB, ed. Steroid receptor assays in human breast tumours. Cardiff:Alpha Omega Publishing, 1979.

6. Consensus meeting-steroid receptors in breast cancer, Washington, June1979. Cancer (in press).

7. McGuire WL, Zava DT, Horwitz KB, Chamness GC. Hormones, receptorsand breast cancer. In: Griffiths K, Neville AM, Pierrepoint CG, eds. Pro-ceedings of the sixth Tenovus workshop on tumour markers. Cardiff:Alpha Omega Publishing, 1978; 153-61.

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8. King RJB, Redgrave S, Hayward JL, Millis RR, Rubens RD. The measure-ment of receptors for oestradiol and progesterone in human breasttumours. In: King RJB, eds. Steroid receptor assays in human breasttumours. Cardiff. Alpha Omega Publishing. 1979: 55-72.

9. Barnes DM, Skinner LG, Ribeiro GT. Triple hormone receptor assay-amore accurate predictive tool for the treatment of advanced breast cancer.Br J Cancer 1979; 40: 862-65.

10. Maynard PV, Blamey RW, Elston CW, Haybittle JL, Griffiths K. Estrogenreceptor assay in primary breast cancer and early recurrence of the dis-ease. Cancer Res 1978; 38: 4292-95.

11. Cooke T, Shields R, George D, Maynard PV, Griffiths K. Oestrogen recep-tors and prognosis in early breast cancer. Lancer 1979; i: 995-97.

12. Bishop HM, Blamey RW, Elston CW, Haybittle JL, Nicholson RI, GriffithsK. Relationship of œstrogen-receptor status to survival in breast cancer.Lancet 1979; ii: 283-84.

13. Maynard PV, Davies CJ, Blarney RW, Elston CW, Johnson J, Griffiths K.Relationship between oestrogen-receptor content and histological grade inhuman primary breast tumours. Br J Cancer 1978; 38: 745-48.

14. Masters JRW, Millis RR, King RJB, Rubens RD. Elastosis and response toendocrine therapy in breast cancer. Br J Cancer 1979; 39: 536-39.

15. Lippman ME, Allegra JC, Thompson EB, et al. Relationship betweenestrogen receptors and response rate to cytotoxic chemotherapy in metas-tatic breast cancer. N Engl J Med 1978; 298: 1223-28.

Occasional Survey

EPSTEIN-BARR-VIRUS-INDUCEDONCOGENESIS IN IMMUNE-DEFICIENT

INDIVIDUALS

DAVID T. PURTILO

University of Massachusetts Medical Center, 55 Lake Avenue,North Worcester, Massachusetts 01605, U.S.A.

Summary Experimental and clinical evidence sup-ports the notion that the Epstein-Barr

virus (EBV) can become oncogenic in immune-deficienthosts. Renal transplant recipients and children with in-herited immune deficiency are at high risk for lympho-magenesis. Defective immune responses to EBV permitpersistence of polyclonal proliferation of B cells. Conver-sion from polyclonal to monoclonal proliferation is prob-ably the result of a cytogenetic error in a B cell. Thishypothesis can be tested prospectively in patients withimmune deficiency by immunological, EBV, and geneticstudies.

INTRODUCTION

DESPITE 15 years of intensive research, there is no

proof that Epstein-Barr virus (EBV) is the cause of Afri-can Burkitt’s lymphoma and nasopharyngeal carcinoma(NPC). An unexpected dividend from studies on Bur-kitt’s lymphoma was the demonstration that EBV causesinfectious mononucleosis.’ In this paper I review evi-dence for the suggestion that infectious mononucleosis isthe benign counterpart of malignant lymphoma and out-line how immunodeficiency and cytogenetic changes canconvert polyclonal infectious mononucleosis to mono-clonal malignant lymphoma. I also summarise the argu-ments for the hypotheses that persistent antigenic stimu-lation, together with immune deficiency, preconditionsindividuals to EBV-induced oncogenesis, and describehow malignant lymphoma may develop after EBV infec-tion. Finally, I propose studies that could test prospec-tively the hypothesis that EBV can be oncogenic in

patients with immune deficiency.

ASSOCIATION OF EBV AND IMMUNODEFICIENCY WITH

INFECTIOUS MONONUCLEOSIS AND BURKITT’S LYMPHOMA

The association of EBV with infectious mononuc-leosis and Burkitt’s lymphoma was first recognised whenHenle et awl. reported how a technician in their labora-tory acquired anti-EBV activity in her serum during anattack of acute infectious mononucleosis. A subsequentprospective study of college students revealed no case ofinfectious mononucleosis among 1100 seropositive stu-dents, whereas approximately 10% of 900 seronegativestudents acquired infectious mononucleosis and EBV

seropositivity each year.3 Infection during earlychildhood does not usually cause significant illness buthalf to two-thirds of individuals infected later in life getinfectious mononucleosis.2The polyclonal B-cell proliferation in infectious

mononucleosis is controlled by T cells and antibodies toEBV-specific antigens,4 whereas in Burkitt’s lymphomathe monoclonal B-cell proliferation is uncontrolled anda specific cytogenetic defect, the 14q+ marker chromo-some, is present. A highly specific 8 ;14 reciprocal trans-location is present in lymphoblastoid cell lines (LCL) de-rived from Burkitt’s lymphoma.5 EBV is incriminated asthe cause of Burkitt’s lymphoma in African childrenbecause viral markers (EBV/DNA and EBV-associatednuclear antigen [EBNA]) are identified in tumour cells;high titre antibodies to viral capsid antigen, earlyantigen, EBNA, and other antigens appear in sera ofBurkitt’s lymphoma patients; and the virus, isolatedfrom infectious mononucleosis or Burkitt’s lymphomapatients, immortalises B cells in vitro and producesmalignant lymphoma when injected into cotton-top mar-mosets.6 EBV from infectious mononucleosis and Bur-kitt’s lymphoma patients seem to be of the same strain,3but host factors, especially immunological responses,determine the outcome of EBV infections.’The notion that acquired or genetically-determined

immune deficiency is a key factor in Burkitt’s lymphomastemmed from Burkitt’s observation of the associationbetween Burkitt’s lymphoma and holoendemic malaria8and O’Conor’s proposal9 that holoendemic malaria incertain people produces immunosuppression. Recentobservations suggest that a specific cytogenetic changemust also occur before Burkitt’s lymphoma develops inimmunosuppressed subjects.5

Persons at high risk of developing leukaemia oftenhave inherited or acquired chromosomal defects and im-mune deficiency is associated with lymphomagenesis.’°Chromosomal defects and immunodeficiency are foundtogether in ataxia-telangiectasia 11 and sometimes in theX-linked lymphoproliferative syndrome (XLP) (Paquin,L. and Purtilo, D., unpublished observations), and pa-tients with either of these conditions are at high risk formalignant lymphoma. Lymphoma and leukaemia can beinduced in mice and in man by many agents that pro-duce similar cytogenetic changes5—for example, the

14q+ marker chromosome in Burkitt’s lymphoma andtrisomy 15 in mouse lymphoma cells.

INDUCTION BY EBV OF A CONDITION RESEMBLING

GRAFT-VERSUS-HOST RESPONSE (GVHR)EBV infection which destroys or suppresses the pob’

clonal B cells activates potent immune responses whichoften incidentally damage other host tissues to produce