not eliminate the possibility of the presence of cancer; in fact, this information should also be given to women over 50 years of age when they receive screening results. A woman in this age group should be told that a clinical breast examination is an important part of normal health care and reminded that if any abnormalities are found during physical examination or self-examination further follow-up is warranted regardless of mammography results. This instruction is part of the Alberta and other provincial screening programs. Dr. Harris comments that screening is, at best, a secondary measure. Certainly screening has much to offer: the finding that it can reduce breast cancer mortality by 40% in women over 50 years of age (see references 4 to 7 in our article) provides us with the first documented change in survival rates. However, Harris quite rightly notes that primary prevention should be a focus of continuing research. He mentions the possible association between breast feeding and breast cancer, which has been investigated with interesting but conflicting results.' There is, of course, more than adequate evidence of the health benefits to the infant of breast feeding, and thus this practice should be encouraged regardless of its link to breast cancer. We agree that researchers should continue to determine possible causes of breast cancer that are easily identifiable and manageable in North America. Heather Bryant, MD, PhD, CCFP, FRCPC Director Zeva Mah, MSc Research associate Screen Test: the Alberta Program for the Early Detection of Breast Cancer Alberta Cancer Board Calgary, Alta.

References 1. Kelsey JL, Gammon MD: The epidemi1412

CAN MED ASSOCJ 1992; 147 (10)

ology of breast cancer. CA Cancer J Clin 1991; 41: 146-165 2. The Workshop Group: Reducing deaths

from breast cancer in Canada. Can Med AssocJ 1989; 141: 199-201

[Dr. Baines responds.] Those of us who believe that there is still no compelling evidence to support breast screening programs for women under 50 years of age sometimes feel that we are sailing in the eye of a hurricane,"-3 so it is very welcome to hear voices of support from Drs. Sterns and Johnstone. All the prepublication controversy' 2,4,5 about the NBSS is clear evidence that results showing that screening does not benefit younger women can be politically unpopular. It also demonstrates how strongly stakeholders will react. What is bemusing is that published data6-8 show striking similarities to the NBSS results (see pages 1459 to 1476 in this issue). What is certain is that continuing controversy (fuelled by distortion2'9) will cause continuing con-

References 1. Allison M: Mammography trial comes under fire. Science 1992; 256: 11281130 2. Merz B: Author of Canadian breast cancer study retracts warnings. J Natl Cancer Inst 1992; 84: 832-834 3. Miller AB: Re: "Author of Canadian breast cancer study retracts warnings" [C]. Ibid: 1365-1366 4. Breast screening in women under 50 [E]. Lancet 1991; 337: 1575-1576 5. Miller AB: Breast screening in women under 50 [C]. Lancet 1991; 338: 113114 6. Tabar L, Fagerberg G, Duffy SW et al: Update of the Swedish two-county program of mammographic screening for breast cancer. Radiol Clin North Am 1992; 30: 187-210 7. Frisell J, Eklund G, Hellstrom L et al: Randomized study of mammographic screening - preliminary report on mortality in the Stockholm trial. Breast Cancer Res Treat 1991; 18: 49-56 8. Andersson I, Aspergren K, Janzon L et al: Mammographic screening and mortality from breast cancer: the Malmo Mammographic Screening Trial. BMJ 1988; 297: 943-948 9. Miller AB, Baines CJ, Sickles EA: Canadian National Breast Screening Study [C]. Am J Roentgenol 1990; 155: 11331134

fusion. Dr. Harris raises the question Reproductive hazards of priorities, seeming to suggest and the workplace that more might be achieved from programs to encourage breast- I n her editorial (Can Med feeding than from screening proAssoc J 1992; 147: 157-160) grams. This raises the more proDr. A. Baird alludes Patricia vocative question What should to so-called occupational fetal prohave high priority for a society? tection refers to a She policies. - a dangerous question that I do case brought before the US Sunot propose to answer. Court in which a company All this discussion arises be- preme car batteries that manufactured cause Ms. Mah and Dr. Bryant women who were pregexcluded showed the sad paradox: older nant or capable of bearing chilwomen, who have a higher risk of dren from jobs that exposed them breast cancer than young women, to of lead deemed dangerunderestimate the risk. This is a ouslevels to the health of the unborn. problem that Canadian physicians The article states that "the court should be able to overcome. upheld this policy." Although a lower court had Cornelia J. Baines, MD, MSc the policy the US Supreme upheld Deputy director Court actually struck it down in a National Breast Screening Study Associate professor landmark ruling.1"2 It ruled that Department of Preventive Medicine and Biostatistics University of Toronto Toronto, Ont.

the policy violated equality rights under federal law by targeting only the childbearing capacity of LE 15 NOVEMBRE 1992

women, despite "evidence of the, debilitating effect of lead exposure on the male reproductive system."" This echoes Baird's concerns about the discriminatory use of medical evidence on human fertility. The court also expressed concern that companies might choose to exclude those workers at risk instead of providing a safer workplace: "[the law] plainly forbids illegal sex discrimination as a method of diverting attention from an employer's obligation to police the workplace." Although the highest courts of Canada have yet to pronounce on such issues, three reasons suggest why the reasoning in the US case seems likely to prove persuasive here. First, the language and purpose of federal human rights law in both countries have strong parallels. Second, the Canadian Supreme Court has begun to interpret broadly the societal commitment to equality, and its jurisprudence exhibits sensitivity to women's reproductive choices. Third, at least two Canadian human rights tribunals have already found that some fetal protection policies constitute unlawful sex discrimination,3 including one tribunal as recently as March 1992.4 Finally, although the US case makes an important analytic contribution it still seems unlikely to be the final chapter on North American fetal protection policies. The ruling means that only

sex-specific exclusionary policies are unlawful. Whether US or Canadian companies will pursue more egalitarian, less intrusive fetal protection policies remains to be seen. One such possibility involves the rigorous counselling of all workers at risk about occupational hazards to reproduction. The US ruling likely authorizes such policies. Moreover, the ruling leaves open the possibility that other fetal protection policies may prove lawful under the following conditions: (a) they are gender NOVEMBER 15,1992

neutral, (b) they limit employ- asks for an explanation for a dement or require transfers on the parture from the norm noted on basis of documented occupational the computer printout. There is hazards to both male and female no warning, actual or implied. fertility and (c) they are adopted Weinerman also claims harassas measures of last resort to avoid ment because she received one the prohibitive costs that threaten such letter. The definition of habusiness survival. The challenge rassment is "worry by repeated remains to devise safer work- attacks." I hardly feel this is true places that advance our human in her case. According to the article, a rights. pediatric anesthetist received a Derek J. Jones, JD letter asking why she saw so many Senior legal adviser more patients under the age of 5 Protection of Life Project her colleagues. I challenge than Law Reform Commission of Canada that doctor to produce this letter. Associate member McGill Centre for Medicine, Failing that, she should apologize Ethics and Law to the MMA for misleading the Montreal, Que. meeting and to the MMRC for holding it up to ridicule. References 1. Auto Workers v. Johnson Controls, Inc. (1991), 111 SCt 1196 2. Annas GJ: Fetal protection and employment discrimination - the Johnson Controls case. N Engl J Med 1991;

325: 740-743 3. Wiens v. Inco Metals Co. (1988), 9 CHRR D/4795 (Ont) 4. Emrick Plastics v. Ontario Human Rights Commission (1992), 90 DLR (4th) 476 (Ont Div Ct), lease to appeal filed with Ont Ct Appeal

Reviewing physicians' practices W M ) ' s. Jane Stewart's article (Can Med Assoc J 1992; 147: 90-91) about the annual meeting of the Manitoba Medical Association (MMA) contains remarks to which I wish to respond. It is correct that the Manitoba Medical Review Committee (MMRC) wrote more than 600 letters to physicians, but the letters were written over 10 years. At the meeting, Dr. Rivian Weinerman described them as "warning" letters. The committee is composed mainly of practising physicians, and we recognize that all practices do not fit a statistical norm. The initial letter simply

lain F. Elliott, MD Chairman Manitoba Medical Review Committee Winnipeg, Man.

A survey of resuscitation training in Canadian undergraduate medical programs W r e have followed with inx terest and some concern the correspondence on the article by Dr. David H. Goldstein and Robert K. Beckwith (Can Med Assoc J 1991; 145: 2327). As two senior physicians who have been involved in teaching life support programs since before the 1974 "standards" perhaps we may be allowed a few comments. First, we wholeheartedly support the comments of Drs. James M. Christenson and Lyle F. McGonigle (Can Med Assoc J 1992; 147: 150-151) with respect to the educational aspects of the course packages. Although the approach seems dogmatic, the content and the techniques are regularly, even frequently, reviewed. Indeed, the approach fulfils many of the criteria of case-oriented, CAN MED ASSOC J 1992; 147 (10)

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