mammograms. Although patients seen at public health departments represent¬ ed a small proportion of the women in our survey, intervention projects are currently under way to target public
health department clients. We appreciate Drs Caplan and Gann's information, which showed a lack of knowledge by women on most ofthe risk factors for breast cancer. Although age was not included as a risk factor, it is important for women to know that age is the most important risk factor for breast cancer and that women are at "high risk" if they are 50 years of age or older. Few women in our survey knew that breast cancer risk increases with age. The
of knowledge about increased risk with a family history of disease was of considerable interest. Women may incorrectly think they need a mammogram only if they have a family history of breast cancer, since this was a major reason given for not getting mam¬ mograms in a recent survey (40%).5 The most common reason for never having a mammogram was "My doctor has not told me to get one" (45%).5 These find¬ ings support our conclusion that physi¬ cians should educate their patients about the benefits of mammography
high level
when they are performing clinical breast examinations. The clinical opportunity to detect breast cancer early is great, since ap¬ proximately 85% of women aged 45 years and older have seen a physician within the last 2 years.6 About 45 000 women will die of breast cancer this year. This number could be dramatical¬
ly reduced if there
were an
increase in
associations between cancer risk and variables of selenium status will only be detectable if the selenium gradient in the study population is sufficiently
large.
Hunter et al1 utilized toenail selenium levels as indexes of selenium status of nurses from 11 US states. The mean toenail selenium levels of 0.822 \m=+-\0.18\g=m\g/g are comparable with those previously observed2 for adults in
1. Thompson GB, Kessler LG, Boss LP. Breast cancer screening legislation in the United States: a commentary. Am J Public Health. 1989;79:1541-1543. 2. Repeal of Expansion of Medicare Part B Benefits, \s=s\10185.101st Cong, House of Representatives, Report 101\x=req-\
261, p 15. September 26,1989. 3.
Screening Mammography: Low-Cost Services
Do Not
Compromise Quality. Washington, DC: General Accounting
Office; 1990. GA0/HR0-90-32.
4. 1989 survey of physicians' attitudes and practices in early
detection. CA.
1990;4:77-101. SM, Marchant DJ. Use of mammography in the United States: 1990. MMWR. 1990;39. 6. Schoenborn CA, Marano M. Current estimates from the National Health Interview Survey: United States 1987. Vital Health Stat. 1987;10:118. cancer
5. Sutton
Selenium and Breast Cancer To the Editor.\p=m-\The antiproliferative and antitumorigenic effects of selenium are so well documented that results of epidemiologic studies suggesting the absence of a protective effect against human cancers1 must be subjected to special scrutiny. In principle, inverse
David J. Hunter, MB, BS, ScD Meir J. Stampfer, MD, DrPH Graham A. Colditz, MB, BS, DrPH Frank E. Speizer, MD Walter C. Willett, MD, DrPH Harvard Medical School Boston, Mass J. Steven Morris, PhD University of Missouri Columbia
Georgia (0.81 \m=+-\0.14\g=m\g/g) or Boston, Mass(0.74\m=+-\0.13\g=m\g/g), two relatively low-selenium regions of the United
States. The narrow range of the values indicates that the dietary selenium intakes of the majority of subjects were similar, and from their magnitude it follows that they were below the threshold at which a protective effect from selenium can be expected. The study actually suggests, or does not exclude, the possi¬ bility of a reduced breast cancer risk in subjects with toenail selenium levels ex¬ ceeding 1.0 (Jtg/g, although the number of subjects in this category was small. Accordingly, no conclusions as to the possible influence of selenium on breast cancer incidence can be drawn from this study. The same criticism applies to the recent study by Van Noord et al.3 G. N. Schrauzer, DSc University of California San Diego 1. Hunter DJ, Morris JS, Stampfer MJ, Colditz GA, Speizer FE, Willett WC. A prospective study of selenium status and breast cancer risk. JAMA. 1990;264:1128-1131. 2. Morris JS,
Stampfer MJ, Willett W. Dietary selenium in
humans: toenails
as an
indicator. Biol Trace Elem Res.
1983;5:529-537. 3. Van Noord PAH, Collette HJA, Maas MJ, De Waard F.
Selenium levels in nails of premenopausal breast cancer patients assessed prediagnostically in a cohort-nested casereferent study among women screened in the DAM project. Int J Epidemiol. 1987;16:318-322.
early detection through mammography and clinical breast examination. NCI Breast Cancer Screening Consortium
control study of breast cancer in South Dakota (a high selenium area) to exam¬ ine the association with high selenium intake. However, over the range of expo¬ sure levels relevant to most of the US population, higher selenium intake does not appear to be associated with re¬ duced breast cancer incidence.
In Reply.\p=m-\The women in our study live in 11 large, geographically diverse US states, including Texas, a state with a high soil selenium level,1 and thus their selenium intake is broadly representative of the average intake for US women. The median toenail selenium concentration of the upper quintile in our study was 0.99 \g=m\g/g, approximately equal to the value of toenail selenium (0.999 \g=m\g/g) among women consuming more than 90 \g=m\g/d of selenium supplements in the Nurses' Health Study.2 Dr Schrauzer states that our study "actually suggests" a reduced risk of breast cancer in subjects with the highest selenium levels. In fact, the relative risk in the highest quintile of toenail selenium is 1.10, in the opposite direction to that hypothesis. We agree that the confidence interval (0.70 to 1.69) does not exclude a modest protective association, as stated in our original article. Indeed, we are conducting a case\x=req-\
Downloaded From: http://jama.jamanetwork.com/ by a University of Manitoba User on 06/04/2015
1.
Shamberger RJ, Tytko SA, Willis CE. Antioxidants and age-adjusted human cancer mortality. Arch Environ Health. 1976;37:231-235. 2. Hunter DJ, Morris JS, Chute CG, et al. Predictors of selenium concentration in human toenails. Am J Epidemiol. cancer, VI: selenium and
1990;132:114-122.
Intravenous Thrombolysis and Coronary Revascularization Rates To the Editor.\p=m-\Theimpact of intravenous thrombolysis on the rates of short\x=req-\ term interventional procedures (cardiac catheterization, angioplasty, and bypass surgery) was addressed recently by Naylor and Jaglal1 and, in an accompanying editorial, by Schlant.2 They explained the "paradoxic" increase in revascularization procedures (angioplasty and bypass surgery) on the basis that, although thrombolysis takes care of the offending occlusive thrombus, there remains the significant underlying atherosclerotic plaque, which
may or may not rerupture to cause post\x=req-\ infarction angina or sudden ischemic death. But neither article offered to explain why the number of revascularization procedures was higher in patients treated with tissue plasminogen activator than in the streptokinase-treated patients.1 In the current controversy concerning whether tissue plasminogen activator is superior to streptokinase as a thrombolytic agent,3 this finding by Naylor and Jaglal simply adds more fuel to the fire. Finally, instead of the answer "Only if we have to" to the question "Should we intervene following thrombolysis?" (SWIFT trial),4 the an¬ swer perhaps should be "Usually we have to." Tsung O. Cheng, MD George Washington University Washington, DC 1.
sis
Naylor CD, Jaglal SB. Impact of intravenous thrombolyon
short-term coronary revascularization rates:
a
meta-
analysis. JAMA. 1990;264:697-702. Thrombolytic therapy of patients with acute myocardial infarction. JAMA. 1990;264:738-739. 3. White HD. GISSI-2 and the heparin controversy. Lancet. 2. Schlant RC.
1990;336:297-298.
DP, Pocock SJ, for the SWIFT Investigators Group. The SWIFT study of intervention vs conservative management after anistreplase thrombolysis. Circulation. 1989;80(suppl II):II-418. Abstract.
4. De Bono
health department clients. We appreciate Drs Caplan and Gann's information, which showed a lack of knowledge by women on most ofthe risk factors for breast cancer. Although age was not included as a risk factor, it is important for women to know that age is the most important risk factor for breast cancer and that women are at "high risk" if they are 50 years of age or older. Few women in our survey knew that breast cancer risk increases with age. The
of knowledge about increased risk with a family history of disease was of considerable interest. Women may incorrectly think they need a mammogram only if they have a family history of breast cancer, since this was a major reason given for not getting mam¬ mograms in a recent survey (40%).5 The most common reason for never having a mammogram was "My doctor has not told me to get one" (45%).5 These find¬ ings support our conclusion that physi¬ cians should educate their patients about the benefits of mammography
high level
when they are performing clinical breast examinations. The clinical opportunity to detect breast cancer early is great, since ap¬ proximately 85% of women aged 45 years and older have seen a physician within the last 2 years.6 About 45 000 women will die of breast cancer this year. This number could be dramatical¬
ly reduced if there
were an
increase in
associations between cancer risk and variables of selenium status will only be detectable if the selenium gradient in the study population is sufficiently
large.
Hunter et al1 utilized toenail selenium levels as indexes of selenium status of nurses from 11 US states. The mean toenail selenium levels of 0.822 \m=+-\0.18\g=m\g/g are comparable with those previously observed2 for adults in
1. Thompson GB, Kessler LG, Boss LP. Breast cancer screening legislation in the United States: a commentary. Am J Public Health. 1989;79:1541-1543. 2. Repeal of Expansion of Medicare Part B Benefits, \s=s\10185.101st Cong, House of Representatives, Report 101\x=req-\
261, p 15. September 26,1989. 3.
Screening Mammography: Low-Cost Services
Do Not
Compromise Quality. Washington, DC: General Accounting
Office; 1990. GA0/HR0-90-32.
4. 1989 survey of physicians' attitudes and practices in early
detection. CA.
1990;4:77-101. SM, Marchant DJ. Use of mammography in the United States: 1990. MMWR. 1990;39. 6. Schoenborn CA, Marano M. Current estimates from the National Health Interview Survey: United States 1987. Vital Health Stat. 1987;10:118. cancer
5. Sutton
Selenium and Breast Cancer To the Editor.\p=m-\The antiproliferative and antitumorigenic effects of selenium are so well documented that results of epidemiologic studies suggesting the absence of a protective effect against human cancers1 must be subjected to special scrutiny. In principle, inverse
David J. Hunter, MB, BS, ScD Meir J. Stampfer, MD, DrPH Graham A. Colditz, MB, BS, DrPH Frank E. Speizer, MD Walter C. Willett, MD, DrPH Harvard Medical School Boston, Mass J. Steven Morris, PhD University of Missouri Columbia
Georgia (0.81 \m=+-\0.14\g=m\g/g) or Boston, Mass(0.74\m=+-\0.13\g=m\g/g), two relatively low-selenium regions of the United
States. The narrow range of the values indicates that the dietary selenium intakes of the majority of subjects were similar, and from their magnitude it follows that they were below the threshold at which a protective effect from selenium can be expected. The study actually suggests, or does not exclude, the possi¬ bility of a reduced breast cancer risk in subjects with toenail selenium levels ex¬ ceeding 1.0 (Jtg/g, although the number of subjects in this category was small. Accordingly, no conclusions as to the possible influence of selenium on breast cancer incidence can be drawn from this study. The same criticism applies to the recent study by Van Noord et al.3 G. N. Schrauzer, DSc University of California San Diego 1. Hunter DJ, Morris JS, Stampfer MJ, Colditz GA, Speizer FE, Willett WC. A prospective study of selenium status and breast cancer risk. JAMA. 1990;264:1128-1131. 2. Morris JS,
Stampfer MJ, Willett W. Dietary selenium in
humans: toenails
as an
indicator. Biol Trace Elem Res.
1983;5:529-537. 3. Van Noord PAH, Collette HJA, Maas MJ, De Waard F.
Selenium levels in nails of premenopausal breast cancer patients assessed prediagnostically in a cohort-nested casereferent study among women screened in the DAM project. Int J Epidemiol. 1987;16:318-322.
early detection through mammography and clinical breast examination. NCI Breast Cancer Screening Consortium
control study of breast cancer in South Dakota (a high selenium area) to exam¬ ine the association with high selenium intake. However, over the range of expo¬ sure levels relevant to most of the US population, higher selenium intake does not appear to be associated with re¬ duced breast cancer incidence.
In Reply.\p=m-\The women in our study live in 11 large, geographically diverse US states, including Texas, a state with a high soil selenium level,1 and thus their selenium intake is broadly representative of the average intake for US women. The median toenail selenium concentration of the upper quintile in our study was 0.99 \g=m\g/g, approximately equal to the value of toenail selenium (0.999 \g=m\g/g) among women consuming more than 90 \g=m\g/d of selenium supplements in the Nurses' Health Study.2 Dr Schrauzer states that our study "actually suggests" a reduced risk of breast cancer in subjects with the highest selenium levels. In fact, the relative risk in the highest quintile of toenail selenium is 1.10, in the opposite direction to that hypothesis. We agree that the confidence interval (0.70 to 1.69) does not exclude a modest protective association, as stated in our original article. Indeed, we are conducting a case\x=req-\
Downloaded From: http://jama.jamanetwork.com/ by a University of Manitoba User on 06/04/2015
1.
Shamberger RJ, Tytko SA, Willis CE. Antioxidants and age-adjusted human cancer mortality. Arch Environ Health. 1976;37:231-235. 2. Hunter DJ, Morris JS, Chute CG, et al. Predictors of selenium concentration in human toenails. Am J Epidemiol. cancer, VI: selenium and
1990;132:114-122.
Intravenous Thrombolysis and Coronary Revascularization Rates To the Editor.\p=m-\Theimpact of intravenous thrombolysis on the rates of short\x=req-\ term interventional procedures (cardiac catheterization, angioplasty, and bypass surgery) was addressed recently by Naylor and Jaglal1 and, in an accompanying editorial, by Schlant.2 They explained the "paradoxic" increase in revascularization procedures (angioplasty and bypass surgery) on the basis that, although thrombolysis takes care of the offending occlusive thrombus, there remains the significant underlying atherosclerotic plaque, which
may or may not rerupture to cause post\x=req-\ infarction angina or sudden ischemic death. But neither article offered to explain why the number of revascularization procedures was higher in patients treated with tissue plasminogen activator than in the streptokinase-treated patients.1 In the current controversy concerning whether tissue plasminogen activator is superior to streptokinase as a thrombolytic agent,3 this finding by Naylor and Jaglal simply adds more fuel to the fire. Finally, instead of the answer "Only if we have to" to the question "Should we intervene following thrombolysis?" (SWIFT trial),4 the an¬ swer perhaps should be "Usually we have to." Tsung O. Cheng, MD George Washington University Washington, DC 1.
sis
Naylor CD, Jaglal SB. Impact of intravenous thrombolyon
short-term coronary revascularization rates:
a
meta-
analysis. JAMA. 1990;264:697-702. Thrombolytic therapy of patients with acute myocardial infarction. JAMA. 1990;264:738-739. 3. White HD. GISSI-2 and the heparin controversy. Lancet. 2. Schlant RC.
1990;336:297-298.
DP, Pocock SJ, for the SWIFT Investigators Group. The SWIFT study of intervention vs conservative management after anistreplase thrombolysis. Circulation. 1989;80(suppl II):II-418. Abstract.
4. De Bono
