143 PROTECTION BY CERVICAL SMEARS
have been obtained of all women domiciled in the Oxford area, first diagnosed as having carcinoma of the cervix in the period 1965-73 and who had died before the end of 1973. Of seventy-one such cases, sixty-four had never had a cervical smear in the Oxford area, so far as can be found from our records, until the attendance which led to diagnosis. Of the seven women who should have been "protected" (having had at least one smear) the details are as follows: Three had adenocarcinoma, all with smears reported as negative; in one, the smear was reported negative in the few months preceding biopsy, and in the others, 2 and 5 years before. In the first two cases, the smears appear on review to have contained neoplastic cells which had not been recognised. One patient, aged 83, had a negative smear a year before the diagnosis of an anaplastic carcinoma, the biopsy of which left some doubt as to whether it was of squamous or glandular origin. The smear was ha:morrhagic, and there was suspicion of a uterine lesion at the time. One patient had a normal smear 2 years before the development of a completely anaplastic carcinoma. In two cases of squamous carcinoma a single smear had been reported negative at intervals before diagnosis of 7 months and 2z years. On review, both showed abnormalities which ought to have led at least to repetition of the smear, and one might have been worth a biopsy. Thus three and possibly four of the seven cases had adenocarcinoma, which is notoriously harder to detect in smears and, being uncommon, is not the primary object of population screening. Only two carcinomas developed after smears which, on review, appear adequate and negative; one was an anaplastic carcinoma and the other adenocarcinoma. Certain comparisons between screened and unscreened groups are open to the valid objection that the screened group include a substantial number of women who are self-selected. Certainly death from carcinoma of the cervix is expected to occur mainly in the higher age-groups, and the proportion of the elderly population which has been covered by screening is relatively low. (Unfortunately the coverage in the different age-groups is not known.) This, coupled with the well-known social-class gradient, would lead to an inverse relation between cervical-cancer deaths and cervical smears, even if the smears gave no protection at all. Nevertheless, over a period of 22 years none of our patients, of whatever age or class, on whom a positive smear has led to the biopsy diagnosis of carcinomain-situ or microcarcinoma has died of cervical cancer, and of thirty-five patients with fully invasive carcinomas discovered primarily by the smear, only two have died. That the sixtyfour deaths in the "unprotected" group would have occurred anyway, even if smears had been done, seems unlikely in the light of the facts presented. Our experience fits well with the belief that, barring human error, even one smear test offers considerable "protection" at least against the common squamous type of cervical carcinoma.
StR,—The
names
period of 2 years will be screened by history, physical examination, mammography, and thermography. Thermography is
being used "experimentally"—i.e., no action is predicated on the thermography readings. The first project began in 1973 and the last started about 6 months ago; consequently our results are incomplete and not yet ready for thorough evaluation. Nevertheless, some preliminary data based upon examination of approximately 165 000 women are available, and we would like to present them for comparison with Dr Chamberlain’s. Not all figures are totally comparable: Variable No. screened
West London 1215
Aged over 50 Recommended for biopsy or surgical consultation
Biopsy done Cancer reported
Churchill Hospital,
Oxford OX3 7LJ.
A. I. SPRIGGS M. M. BODDINGTON
SCREENING FOR BREAST CANCER
SIR,-We read with interest the report by Dr Chamberlain and her colleagues (Nov. 22, p. 1026) and thought it would be
of interest to compare the West London findings with the preliminary results of the breast cancer detection demonstration
projects (B.C.D.D.P.S) that are being conducted in the United States under the joint auspices of the National Cancer Instiand the American Cancer Society. There are twenty-seven projects distributed across the United States. Many are in university settings, some in community hospitals, and some are self-standing endeavours. In each project, 10 000 symptom-free women recruited over a
tute
41.6%
47.2%
19.0% 9.8% 1.4% 76.0% 57.0% 29.0% 11.0%
3.9% 19%* 0.5%* 88.0% 57-0% 22.5% 10.0%*
Method of detection: mammography Method of detection: physical examination Positive nodes Interval cancers (false negative) *Final confirmed figures for all items that are necessary to make these calcuiations are not available; these are, therefore, estimates from data that are available.
In
comparing the
two
series the
following points
should be
noted:
(1) Almost all the West London women were over 40; in the B.C.D.D.P.S screened were aged 35-74. (2) The facts that the West London women contained a high-risk group (215 women) and that B.C.D.D.P. screening began at age 35 rather than 40 do not explain the substantial difference in biopsy-rate. In both series about half of those referred for surgical consultation (biopsy recommended) had biopsies. (3) "False negatives" for the West London group are cancers detected in the 6 months after first screening. False negatives (or "interval cancers") for the B.C.D.D.P. represent cancers detected within the first year after a screening at which biopsy had not been recommended. (4) "Methods of detection" is a term used by the West London team:
women
the nearest we can get in the B.C.D.D.P. is the existence of abnormal findings in each of the two examinations (mammographic and physical) represented by the percentages 88% and 57%. In the future we will be able to report on whether this information was used to recommend biopsy.
In both series, physical examination without mammography would have "detected" only 57% of the cancers found. The proportion of breast-cancer patients with axillary lymph-nodes containing tumour was also remarkably similar, suggesting that these screened women will have a better prognosis than the woman with breast cancer seen in ordinary practice where approximately 45% are found to have tumour in axillary nodes at the time of radical mastectomy.
Diagnosis Branch, Division of Cancer Biology and Diagnosis, National Cancer Institute, Bethesda, Maryland 20014, U.S.A.
WILLIAM POMERANCE
Bethesda, Maryland.
ROBERT J. CONNOR DIANE J. FINK JAMES E. HAMNER ALAN S. RABSON THEODORE WEISS
American Cancer Society.
WILLIAM M. MARKEL
National Cancer Institute,
Laboratory of Clinical Cytology,
B.C.D.D.P.s 165 000
IMMUNOTHERAPY FOR ACUTE LYMPHOID LEUKÆMIA SIR,-Dr Jose and Dr Ekert (Oct. 11, p.713) reported preliminary results indicating that B.C.G. interspersed with chemotherapy is more efficient in maintaining remission of acute lymphoid leukaemia (A.L.L.) than chemotherapy alone. These results lead in the same direction as those of the E.O.R.T.C. Haemopathy Working Party’ which found that BCG is at least 1. E.O.R.T.C. Hemopathies Working Party. Paper read at the third meeting of the International Society of Hæmotology European and African Division, held in London, August, 1975.