The Truth About Breast Cancer Part 4

THE TRUTH ABOUT BREAST CANCER--PART 4 RACHEL'S ENVIRONMENT & HEALTH WEEKLY #574 - November 27, 1997 Environmental Research Foundation, P.O. Box 5036, Annapolis, MD 21403; Fax (410) 263-8944; [email protected] Back issues available online at http://www.rachel.org Subscriptions are free. To subscribe, E-mail the words SUBSCRIBE RACHEL-WEEKLY YOUR NAME to: [email protected].

Late last month the NEW ENGLAND JOURNAL OF Three days later in the Sunday TIMES, Gina Kolata MEDICINE (NEJM) published a study (by David J. Hunter) delivered the message once again, summarizing the Hunter comparing the levels of DDE and PCBs in the blood of two study this way: "One more environmental scare bit the dust groups of women, one group with breast cancer, the other last week as scientists from the Harvard School of Public without.[1] The Hunter study failed to find a positive Health reported that their large and meticulous study found no relationship between breast cancer and DDE or PCBs in the evidence that exposure to the chemicals DDT and PCB's [sic] blood. DDE is a breakdown product of the organochlorine are linked to breast cancer."[4] Another scare bit the dust. pesticide DDT, which was banned in the U.S. in the mid- Case closed. 1970s; PCBs are a group of 209 chlorinated industrial Including the recent Hunter study, there are now 11 chemicals, also banned in the U.S. The Hunter study is the published studies of organochlorine compounds (DDE, PCBs, largest of its kind to date, comparing 236 pairs of women for methoxychlor, beta-hexachlorobenzene, and chlordane --the DDE and 230 pairs for PCBs. last 3 being pesticides) in relation to breast cancer. Four The NEW ENGLAND JOURNAL OF MEDICINE put a studies, including the largest two of the 11, have shown no far-reaching title on the new study: "Plasma Organochlorine relationship between DDE, PCBs and breast cancer.[1,5,6,7] Levels and the Risk of Breast Cancer." (Plasma is the part of Six smaller studies have indicated a positive relationship, the blood that contains fat-soluble chemicals such as suggesting that some organochlorines may be implicated organochlorines.) The title seemed to suggest that a study of somehow in breast cancer.[8,9,10,11,12,13] One additional two chemicals --DDE and PCBs --could tell us something study was equivocal, subject to differing interpretations.[14] definitive about all of the 15,000 different organochlorine The equivocal study was by led by Nancy Krieger, who compounds in relation to breast cancer. examined DDE and PCB levels in the blood of 150 women In case we missed the message, the editors of the with breast cancer and 150 women without breast cancer. The JOURNAL provided an editorial that spelled it out. The 300 women were chosen to represent racial/ethnic groups: 100 editorial, by Stephen H. Safe, a Texas researcher whose work whites, 100 African-Americans and 100 Asian-Americans. is often funded by the Chemical Manufacturers Association, Taken together, the 300 women showed no statistically- had a slightly different though equally far-reaching title: significant relationship between DDE, PCBs and breast "Xenoestrogens and Breast Cancer." (Xenoestrogens are cancer. However, when the racial/ethnic groups were studied industrial chemicals that interfere with normal sex hormones individually, the whites and the African-Americans with breast such as estrogen.) cancer showed elevated levels of DDE in the blood, compared Dr. Safe's editorial in NEJM began, "Chemophobia, the to whites and African-Americans without breast cancer.[14] unreasonable fear of chemicals, is a common public reaction Asian and recently-immigrated Asian-American women tend to scientific or media reports suggesting that exposure to to have a much lower incidence of breast cancer than white various environmental contaminants may pose a threat to Americans, perhaps because of a protective effect from their health." Surely this is an odd message from a scientist. He is diet.[15,16] Omitting the Asian-Americans from the Krieger saying, if you fear chemicals because scientific reports study essentially reverses the study's conclusions. indicate that they might harm your health, you are suffering Thus out of 11 studies, 4 are negative and 7 show elevated from an irrational phobia. Perhaps Dr. Safe did not write the levels of organochlorines of one kind or another in tissues of editorial in his capacity as a scientist. women with breast cancer. One of those seven were not Dr. Safe concludes his chemophobia editorial saying it is statistically signficant. Is it time to close the book on this time we all stopped worrying about organochlorines and breast inquiry? cancer. He writes, "The results of Hunter along with those of Stephen Safe and Gina Kolata obviously want us to think other recent studies should reassure the public that weakly so. Dr. Safe and Ms. Kolata both try to make us believe that estrogenic organochlorine compounds such as PCBs, DDT and recent work has revealed that breast cancer can be completely DDE are not a cause of breast cancer."[2] Estrogenic explained by "known risk factors." Listen to Dr. Safe: organochlorine compounds such as DDT, DDE and PCBs are "Robbins and coworkers recently showed that the high not a cause of breast cancer. Case closed. incidence of breast cancer in women from the San Francisco If we still didn't get the point, Gina Kolata of the NEW Bay area can be accounted for by known risk factors, YORK TIMES interviewed Dr. Safe, giving him an including parity [how many children they've had], age at first opportunity to amplify his message. Dr. Safe told Ms. Kolata full-term pregnancy, months of breast-feeding, age at it is time to quit researching the relationship between menopause, age at menarche [when a woman's period organochlorine chemicals and breast cancer: "For advocates commences], and alcohol consumption."[2] Ms. Kolata takes [of the idea that the two are connected], it's never ending. But the argument even further: "Dr. Hunter said that perhaps it was for other people, there may be times when we want to spend time to question the assumption that much breast cancer is our money on other things," Dr. Safe said.[3] No more caused by unknown environmental agents. A recent study, for research needed. Case closed. example, found that the high rate of breast cancer in the San Francisco Bay area can be completely attributed to known risk factors like a woman's age when she start to menstruate, has a [2] Stephen H. Safe, "Xenoestrogens and Breast Cancer," NEW ENGLAND first child, and when she begins menopause." JOURNAL OF MEDICINE Vol. 337, No. 18 (October 30, 1997), pgs. 1303- 1304. Dr. Safe and Ms. Kolata both make it sound as if this new [3] Gina Kolata, "Study Discounts DDT Role in Breast Cancer," NEW YORK study of women in San Francisco has revealed that all breast TIMES October 30, 1997, pg. 26. cancer can be explained by "known risk factors." If true, this [4] Gina Kolata, "DDT and Breast Cancer," NEW YORK TIMES November is important news. 2, 1997, pg. 2. [5] M. Unger and others, "Organochlorine compounds in human breast fat In fact the Robbins study of women in the San Francisco from deceased with and without breast cancer in a biopsy material from newly Bay area did not even try to explain the origins of all breast diagnosed patients undergoing breast surgery," ENVIRONMENTAL cancer.[17] Robbins observed that white women near San RESEARCH Vol. 34 (1984), pgs. 24-28. Studied 32 cases and 56 controls. Francisco Bay have a 14% higher incidence of breast cancer [6] Pieter van't Veer and others, "DDT (dicophane) and postmenopausal breast cancer in Europe: case-control study," BRITISH JOURNAL OF MEDICINE than the national average (and African-American women in Vol. 315 (July 12, 1997), pgs. 81-85. Studied 265 cases and 341 controls. the Bay area are 10% above the national average), and he set [7] Lizbeth Lopez-Carrillo and others, "Dichlorodiphenyltrichloroethane out to see if he could explain the 14% and 10% increases. He Serum Levels and Breast Cancer Risk: A Case Control Study from Mexico," CANCER RESEARCH Vol. 57 (September 1, 1997), pgs. 3728-3732. and his coworkers found that women in San Francisco tend to Studied 141 cases & 141 controls; 562 ppb for cases, 505 for controls, but not have fewer children, have them later in life, breast feed them statistically significant. less, and so forth, thus explaining the 14% and 10% increases [8] Frank Falck, Jr. and others, "Pesticides and Polychlorinated Biphenyl by "known risk factors." The 50% to 70% of breast cancer Residues in Human Breast Lipids and Their Relation to Breast Cancer," ARCHIVES OF ENVIRONMENTAL HEALTH Vol. 47 No. 2 (March/April, that can't be explained anywhere else in the U.S. also can't be 1992), pgs. 143-146. Studied 20 cases and 20 controls. A dose-response explained in San Francisco --despite the false impression that relationship was observed. Dr. Safe and Ms. Kolata managed to create. [9] Mary S. Wolff and others, "Blood Levels of Organochlorine Residues and What about Stephen Safe's conclusion (amplified by Ms. the Risk of Breast Cancer," JOURNAL OF THE NATIONAL CANCER INSTITUTE Vol. 85, No. 8 (April 21, 1993), pgs. 648-652. Studied 58 cases Kolata), that, based on four negative studies of DDE and and 341 controls. A dose-response relationship was observed. PCBs, we should stop trying to find the links between [10] Mirjana V. Djordjevic and others, "Assessment of chlorinated pesticides environmental estrogenic chemicals and breast cancer? and polychlorinated biphenyls in adipose breast tissue using a supercritical Stephen Safe knows that DDE is not estrogenic. DDT is fluid extraction method," CARCINOGENESIS Vol. 15, No. 11 (1994), pgs. 2581-2585. Found elevated levels of DDE, PCBs, chlordane, oxychlordane estrogenic, but DDE is not. DDE is a potent anti-androgen (it and transnonachlor in breast tissue of 5 women with breast cancer vs. 5 blocks the action of male hormones).[18] DDE DOES women without rhe disease. interfere with sex hormones, but it doesn't mimic estrogen and [11] H. Mussalo-Rauhamas and others, "Occurrence of Beta- there's no good reason to think it would make a major Hexachlorocyclohexane in Breast Cancer Patients," CANCER Vol. 66, No. 10 (November 15, 1990), pgs. 2124-2128. Studied 44 cases and 33 controls. contribution to breast cancer. Likewise, many PCBs are not Found that Finnish women with elevated levels of beta- estrogenic --on the contrary, they are ANTI-estrogenic. Dr. hexachlorocyclohexane, a breakdown product of the pesticide Lindane, in Safe's own research has shown this again and again.[19] Thus their breast tissue had a 10-fold increased risk of breast cancer. See also, there is no good reason to think that DDE and a randomly- Rosemary Steinmetz and others, "Novel Estrogenic Action of the Pesticide Residue Beta-Hexachlorocyclohexane in Human Breast Cancer Cells," selected group of mixed PCBs will cause breast cancer. Listen CANCER RESEARCH Vol. 56 (December 1, 1996), pgs. 5403-5409. once more to Dr. Safe's editorial (titled "Xenoestrogens and [12] Eric Dewailly, "High Organochlorine Body Burden in Women With Breast Cancer"). He writes, "The results of Hunter along with Estrogen Receptor-Positive Breast Cancer," JOURNAL OF THE NATIONAL those of other recent studies should reassure the public that CANCER INSITUTE Vol. 86, No. 3 (February 2, 1994), pgs. 232-234. Studied 20 cases and 17 controls. Found a nine-fold increased risk of breast weakly estrogenic organochlorine compounds such as PCBs, cancer among women with estrogen-responsive breast tumors DDT and DDE are not a cause of breast cancer." But DDE is [13] M. Wassermann and others, "Organochlorine Compounds in Neoplastic not estrogenic, and neither are many PCBs. This is a false and Adjacent Apparently Normal Breast Tissue," BULLETIN OF argument and Dr. Safe --and the editors of the NEW ENVIRONMENTAL CONTAMINATION & TOXICOLOGY Vol. 15, No. 4 (1976), pgs. 478-484. Organochlorine compounds (DDT and PCBs) were ENGLAND JOURNAL OF MEDICINE --know it. higher in 9 breast cancer patients than in 5 controls, and in cancer patients the There are good, strong reasons to think that many cancerous tissue contains significantly more organochlorines than adjacent estrogen-mimicking chemicals, some of them organochlorines, normal tissues. might be associated with breast cancer, and these should be [14] Nancy Krieger and others, "Breast Cancer and Serum Organochlorines: A Prospective Study Among White, Black and Asian Women," JOURNAL OF carefully examined. But DDE and mixed PCBs are not in that THE NATIONAL CANCER INSTITUTE Vol. 86, No. 8 (April 20, 1994), category. They have been studied because they are convenient pgs. 589-599. In the same issue, see the editorial, pgs. 572-573 and "DDT and to study, not because they are particularly estrogenic. When Breast Cancer: The Verdict Isn't In," pgs. 576-577. Stephen Safe tells Gina Kolata we might want to end research [15] A.H. Wu and others, "Tofu and risk of breast cancer in Asian- Americans," CANCER EPIDEMIOLOGY, BIOMARKERS AND on organochlorines and breast cancer based on studies of DDE PREVENTION Vol. 5, No. 11 (November 1996), pgs. 901-906. and mixed PCBs, Dr. Safe is sounding like a camp follower of [16] Herman Adlercreutz, "Phytoestrogens: Epidemiology and a Possible Role the Chemical Manufacturers Association, not like a scientist. in Cancer Protection," ENVIRONMENTAL HEALTH PERSPECTIVES Vol. 103, Supplement 7 (October 1995), pgs. 103-112. [17] Anthony S. Robbins and others, "Regional Differences in Known Risk --Peter Montague Factors and theHigher Incidence of Breast Cancer in San Francisco," (National Writers Union, UAW Local 1981/AFL-CIO) JOURNAL OF THE NATIONAL CANCER INSTITUTE Vol. 89, No. 13 (July 2, 1997), pgs. 960-965. ======[18] William R. Kelce and others, "Persistent DDT metabolite p,p'-DDE is a potent androgen receptor antagonist," NATURE Vol. 375 (June 15, 1995), [1] David J. Hunter and others, "Plasma Organochlorine Levels and the Risk pgs. 581-585. of Breast Cancer," NEW ENGLAND JOURNAL OF MEDICINE Vol. 337, [19] For example, see M. Moore, S. Safe, and others, "Antiestrogenic Activity No. 18 (October 30, 1997), pgs. 1253-1258. Studied 236 pairs of women for of Hydroxylated Polychlorinated Biphenyl Congeners Identified in Human DDT levels and 230 pairs of women for PCB levels. Serum," TOXICOLOGY AND APPLIED PHARMACOLOGY Vol. 142 (1997), pgs. 160-168.