A recently reported study of L-phenylalanine mustard6 dealt with a diseasefree interval of only 18 months following treatment - probably too short a time for any valid conclusion to be drawn. All such trials require 3 to 8 years to organize, administer, complete and report.7'8 Immunotherapy, either stimulative or suppressive, has barely touched the field of breast cancer although it has been actively studied in the treatment of melanoma and lung cancer. No investigations have demonstrated immune properties in breast cancer that are sufficient to stimulate large-scale studies of this treatment modality. Survival rates for women with breast cancer are not accurately known. It appears that nearly 5000 years after the first recorded mention of breast cancer it is not possible to claim a significant overall cure rate despite the modest accomplishments that can be claimed with early clinical stage I disease, which has a 5-year tumour-free survival of approximately 75%. At present, survival is known to be a function of the clinical stage, the cell type, the age at diagnosis and the treatment, as well as some unknown and undefined characteristic constituting the host-tumour relation. It is almost certain that a better understanding of this hosttumour relation will be the clue that leads to better results. Cure of breast cancer seems unlikely in the near future. And, in the future, methods designed to identify, understand and treat patients with this disease will probably not be defined in terms of our currently accepted staging characteristics - for example, tumour size and type, and menopausal status - but in terms of some as yet undiscovered relation between the patient and her cancer. C. BARBER MUELLER, MD, FRCs[C1 Professor of surgery MeMaster University Hamilton, Ont.

References 1. MUELLER CB, JEFI'RIEs W: Cancer of the breast: its outcome as measured by the rate of dying and causes of death. Ann Surg 182: 334, 1975 2. MANSFIELD M: Early Breast Cancer: Its History and Results of Treatment, Basel, Karger, 1976 3. DUNCAN W, KERR GR: The curability of breast cancer. Br Med J 2: 781, 1976 4. PARK WW, LEES JC: The absolute curability of cancer of the breast. Surg Gynecol Obstet 93: 129, 1951 5. McGunut WY: Current status of estrogen receptors in human breast cancer. Cancer 36 (suppl): 638, 1975 6. FISHER B, CAREONE P, ECONOMOU 5G. et al: 1-phenylalanine mustard (L-PAM) in the management of primary breast cancer. A report of early findings. N Engl I Med 292: 117, 1975 7. FISHER B: Status of adjuvant therapy: results of the national surgical adjuvant breast project studies on oophorectomy, postoperative radiation therapy, and chemotherapy. Other comments concerning clinical trials. Cancer 28: 1654, 1971 8. TORMEY DC: Combined chemotherapy and surgery in breast cancer - review. Cancer 36: 881. 1975

Pollution in the operating room Long before the establishment of universal national health insurance schemes, the right of workers to good health was recognized implicitly in the enactment of legislation regulating safety standards and working conditions, including atmospheric pollution within the working environment. Of recent concern has been pollution of operating rooms. Recent epidemiologic evidence1 suggests that long-term exposure to trace concentrations of waste gases and vapours from anesthetics is detrimental to the health of operating-room personnel and their offspring. Although a cause-and-effect relation has not been established, the data suggest a more than casual connection. The paper by Oulton in this issue of the Journal (page 1148) is timely and deserves to be widely read. It has always been apparent to those working in an operating room that waste anesthetic gases permeate the air. Where no attempt has been made to scavenge waste gases, average concentrations are 300 to 400 parts per million (ppm) and 10 ppm for nitrous oxide and halogenated agents, respectively. Permissible concentrations are unknown at present; however, acceptable values will probably approximate to 30 ppm of nitrous oxide and 0.5 ppm of halogenated agents. These concentrations may be achieved with proper scavenging systems, but future studies may lead to recommendations for lower concentrations. It is known from shortand long-term studies that intellectual function becomes impaired at 500 ppm of nitrous oxide and 10 ppm of halothane.1 The three main sources of gas contamination are faults in anesthetic technique, excess gas "pop-off" and leakage from high- and low-pressure circuits; one must now add malfunctioning scavenging systems. Between 1967 and 1970, preliminary studies in Russia,3 Denmark,4 the United Kingdom5 and the United States6 suggested that spontaneous abortion occurred at an increased rate in women exposed to waste anesthetic gases over a long period. In 1972 a 2-year study was initiated by the American Society of Anesthesiologists under the auspices of the National Institute for Occupational Safety and Health (NIOSH).1 In the NIOSH study, questionnaires were sent to 49 585 exposed operating-room personnel in four professional societies and to 23 911 unexposed individuals in two professional societies who served as a comparison (control) group; one of the

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control groups was the membership of the American Academy of Pediatrics. In 1974 detailed analysis of the results of the survey led the investigators "to strongly suggest that working in the operating rooms (and presumably exposure to trace concentrations of anesthetic agents) entails a variety of health hazards for operating-room personnel and their offspring". Briefly, the findings of the NIOSH study were as follows: 1. The risk of spontaneous abortion is increased for women who are exposed to the operating-room environment during the 1st trimester of pregnancy and who have been exposed during the year preceding pregnancy; the risk is estimated to be 1.3 to 2 times that of unexposed personnel. 2. There is evidence of an increased risk of congenital abnormalities among the liveborn babies of exposed women, including the wives of exposed male anesthetists (P = 0.04); the latter was unexpected and "a matter for serious concern". 3. The risk of cancer was increased (approximately 1.3 to 2 times) in exposed female respondents but not in exposed male respondents. 4. Hepatic disease (even excluding hepatitis) was more frequent in exposed male anesthetists than in male pediatricians (P < 0.01) and in exposed female respondents compared with unexposed controls (P = 0.04, < 0.01, and 0.08 for three comparisons). 5. Higher rates of renal disease were found in exposed female groups than in other groups. The investigators cautioned that, because of several factors, "the increased rates for the exposed groups may be due to some undetected bias" and that "there may be an unknown hazard in these locations which is unrelated to anesthetics". In this connection, it is unfortunate that radiologists and radiographers were not also chosen as a control group; portable x-ray equipment is used increasingly in the operating room and one wonders about the precautions taken to shield those who have to remain there. No provision was made in the questionnaire for a history of exposure to x-rays, though it is realized that this might have introduced too many variables. Walts, Forsythe and Moore7 criticized aspects of the study and particularly the decision of the NIOSH investigators to consider P = 0.05 as significant; WaIts and associates would have preferred a significance level of 0.01. The problems of a retrospective study are well known; one must be cautious in interpreting

the results of such a study as demonstrating a cause-and-effect relation. Nevertheless, one has to agree with the investigators in the NIOSH study that "an increase in disease rates in operating room personnel is present, and that exposure to waste anesthetic gases in the operating room provides the most reasonable explanation". The laboratory evidence is more controversial since it comes from work with nonprimates.8'9 A second study is planned for 1978, by which time most, if not all, operating rooms will have scavenging systems and more useful results will be obtained. Some may argue that premature adoption of recommendations based on retrospective studies poses serious ethical problems in trying to conduct controlled trials; it should not be a problem in this case. The conclusion to be drawn from available evidence is that long-term exposure to waste anesthetic gases is probably a health hazard. Whatever the hazard, operating-room personnel certainly have the right to object to working in contaminated environments. It is therefore the responsibility of all concerned to ensure adequate scavenging systems. Nonrecirculating air-condi-

tioning systems are not enough, though they decrease concentrations of waste gases appreciably. Fortunately, as Oulton shows, the technical capability is readily available. Scavenging systems, 'both for anesthetic machines and ventilators, are easily installed, inexpensive (between $300 and $400, including labour costs, for each room) and fairly safe. The main danger in the use of scavenging systems is obstruction of the venting tubes, leading to a serious increase in the patient's intrathoracic pressure; another danger is the build-up of excessive negative pressure in the 'venting systems. Preventive measures include regular maintenance programs for the gas machines and careful technique. The maintenance and respiratory technology departments should be consulted as their advice and expertise are indispensable. Monitoring equipment to analyse the air for traces of anesthetic gases is expensive (from $3000 to $5000). Provincial departments of health should probably provide this service through centrally located portable monitors that are loaned periodically to the regional hospitals. Unavailability of these monitors, however, should not deter installation of scavenging systems, since

these have already been shown to be effective in reducing the concentrations of waste anesthetic gases in operating rooms.

is sometimes claimed. True, it is difficult if you have nothing worth saying, and it is equally true that skill is required; as Samuel Johnson observed, what is written without effort is read without pleasure. It is also true that it is difficult to write well if you have neither talent nor interest. Even so, it is possible to learn to write well, even late in life; it is probably easier than many would suspect. How can physicians learn to write well? In addition to editing and teaching medical writing, which are applicable to few physicians, four parallel approaches lead to better writing: the practice of writing itself, revising and self-editing, instruction in writing, and reading. All are essential for anyone who wants to write well. Also essential is a certain attitude towards writing an attitude related in part to the pleasure of the craftsman ("words", wrote Evelyn Waugh, "should be an intense pleasure just as leather should be to a shoemaker") and in part to the recognition that good writing is a matter of good manners,3 so that it is a courtesy to one's readers to make oneself understood.

In learning to write well there is no substitute for writing regularly. This has long been recognized: as Epictetus advised, "If you would be a writer, write." 'Writing is a skill; it must be practised often. Three points are worth making on writing as a self-educational process. First, it is essential to make, and regularly renew, the connection between mind and paper through the physical activity of writing. The first draft is especially important; it is the rough instrument forged in the heat of initial enthusiasm, to be perfected in due time. It does not matter that this draft is grossly imperfect; what is important is to write it, preferably at one sitting, so that the ideas that flit through the mind become penned and so pinned down, for examination in the light of day. Second, having done this, you must, paradoxically, be prepared to give up the first draft in favour of a better one as a result of cool analysis. Sometimes you must be ruthless and, as Quiller-Couch4 recognized, even "murder your darlings". The third point is that there are

A. PACE-FLORIDIA, MD, FRCP(C] Chief, department of anesthesia Holy Cross Hospital of Calgary Calgary, Alta.

References 1. Ad Hoc Committee on the Effect of Trace Anesthetics on the Health of Operating Room Personnel, American Society of Anesthesiologists: Occupational disease among operating room personnel: a national study. Anesthesiology 41: 321, 1974 2. BRUCE DL, BACH MJ, ARarr 3: Trace anesthetic effects on perceptual, cognitive and motor skills. Anesthesiology 40: 453, 1974 3. VAISMAN Al: Working conditions in surgery and their effect on the health of anesthesiologists. Eksp Khlr Anesteziol 3: 44, 1967 4. ASKIOG V. HARVALD B: Teratogen effect of inhalation anaesthetics. Saertyk Nord Med 3: 490, 1970 5. KNILL-JONES RP, Morn DD, RODRIGUES LV, et al: Anaesthetic practice and pregnancy. Controlled survey of women ansesthetists In the United Kingdom. Lancet 1: 1326, 1972 6. COHEN EN, BELvILLE 3W, BROWN BW: Anesthesia, pregnancy, and miscarriage: a study of operating room nurses and anesthetists. Anesthesiology 35: 343, 1971 7. WALTS LF, FORSYThE AB, MOORE JG: Cri-

tique: occupational disease among operating room personnel. Anesthesiology 42: 608, 1975

8. STURROCK JE, NUNN iF: Synergism hetween halothane and nitrous oxide in the production of nuclear abnormalities in the dividing fibroblast. Anesthesiology 44: 461, 1976

9. COHEN EN: Ibid, p 459


and cancer


Learning to write well According to one medical editor1 "scientific writers are rarely literate". While no one expects physicians to write to Nobel-prize-winning literary standards, it is true that many physicians find it difficult to write with style. This is easy to explain. Communication among physicians is mainly oral hospital rounds, grand rounds and corridor consultations are ingrained behaviour patterns that are witness to the effectiveness and custom of wordof-mouth communication. And long before physicians graduate, any interest in the art of writing is neglected in favour of the purely utilitarian value of English composition (in high schools and colleges the English language, claims Lanham,2 is rarely enjoyed for its own sake), and examinations rely on the multiple-choice rather than the essay technique; moreover, medical writing is not taught in Canadian medical schools. Yet physicians need to write, and I sympathize with those who cannot write well. I recommend an approach to writing based on the premise that it is never too late to learn to write well. To write well is not as difficult as

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Pollution in the operating room.

A recently reported study of L-phenylalanine mustard6 dealt with a diseasefree interval of only 18 months following treatment - probably too short a t...
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