NEW STUDY LINKS DDT TO BREAST CANCER

From:    Hank Roth                                Kill 
To:      All                                      Msg #9, 01-Sep-93 04:58am
Subject: DDE -1-

*-*-* pnews conferences *-*-*
/* Written 1993 by [email protected] in igc:toxics.rachel */
/* ---------- "RACHEL: DDT & Breast Cancer" ---------- */
=======================================================================
                        --- April 22, 1993 ---

  R A C H E L ' S   H A Z A R D O U S   W A S T E   N E W S   # 3 3 4 

              News and Resources for Environmental Justice

                   Environmental Research Foundation
                  P.O. Box 5036, Annapolis, MD  21403
             Fax (410) 263-8944; Internet: [email protected]
[email protected]======
                                -1-

NEW STUDY LINKS DDT TO BREAST CANCER

Do trace residues of industrial chemicals harm humans?

A new study published yesterday in the JOURNAL OF THE NATIONAL 
CANCER INSTITUTE reports that breast cancer in American women is 
strongly associated with DDE (a form of DDT) in their blood.[1]  
Breast cancer strikes 176,000 women in the U.S. each year, and 
each year 46,000 die of it.  DDE is a residue derived from the 
well-known pesticide, DDT. DDT was banned in the U.S. in the 
early 1970s but trace residues are still measurable nearly 
everywhere in the environment.  Furthermore, DDT is still heavily 
used today in many locations outside the U.S. 

The principal author of the new study, Dr. Mary Wolff at the Mt. 
Sinai School of Medicine in New York, says, "[Our] findings 
suggest that environmental chemical contamination with 
organochlorine residues may be an important etiologic [causal] 
factor in breast cancer.  Given the world-wide dissemination of 
organochlorine insecticides in the environment and the food 
chain, the implications are far-reaching for public health 
intervention worldwide." 

The study shows that women with high levels of DDE in their blood 
have a four-times-greater risk of breast cancer than women with 
low levels of DDE in the blood.  (In this case, "high" means 20 
billionths of a gram of DDE in each milliliter of blood and "low" 
means 2 billionths of a gram in each milliliter of blood.  There 
are 28.3 grams in an ounce, and 4.7 milliliters in a teaspoon.) 

The study group was selected from 14,290 New York City women who 
had attended a mammography (breast x-ray) clinic and had each 
donated 30 milliliters of blood.  Within the group of 14,290, 58 
women who later developed breast cancer were selected for a case-
control study.  The 58 "cases" were matched with 164 "controls," 
women from the large group who did not have breast cancer but who 
were matched to the "case" women in several key respects (such as 
age, menopausal status, and so forth). All their blood samples 
were analyzed for DDE and PCBs.  DDE is created when DDT is 
metabolized (processed by a living organism that has eaten it).  
PCBs are industrial chemicals originally used as insulators in 
electrical equipment.  PCBs were banned in the U.S. in 1976 but 
are still measurable in all parts of the environment.  (In the 
study, PCBs were also associated with breast cancer but the 
association was not statistically significant. There was one 
chance in 6 that the association was due to random chance and 
statistical significance was defined as one chance in 20, or 
less.) 

For fifty years, the incidence of breast cancer in American women 
has risen at a steady 1 percent per year.[2]  In 1940, an 
American woman's lifetime risk of getting breast cancer was one 
in 16.  Today it is one in 8.  (See Table 1, which shows the risk 
of breast cancer in the U.S. today for women at various ages.)  
However, death from breast cancer has remained steady throughout 
the past 20 years because of life-saving, though brutal, 
treatment methods (chemotherapy, radiation therapy, and surgery). 

No one doubts that something in the environment is responsible 
for the rising incidence of breast cancer in the U.S.  Japanese 
women have only one-fifth as much breast cancer as American 
women; but when Japanese women move to the U.S., they are 
stricken with breast cancer at U.S. rates. 

Since the 1960s, medical specialists have been trying to track 
down the causes of breast cancer.  Throughout the 1980s, most 
scientists believed that a high-fat diet caused breast cancer.  A 
study of diet and breast cancer in 120,000 women has now 
discredited this theory and it has been abandoned.[2] 

Researchers are now focused on the female hormones estrogen and 
progesterone which, they suspect, may play a large role in breast 
cancer. 

It has been known since the early 1970s that breast cancer is 
somehow related to estrogen.  Beginning at menarche (the onset of 
menstruation) and continuing until menopause, a women experiences 
a sharply rising and falling exposure, first to estrogen and then 
to progesterone, in a repeating 4-week ovulation cycle. 

Late menarche and early menopause (both of which reduce a woman's 
lifetime exposure to estrogen) are both associated with reduced 
breast cancer risk.  In addition, women who have their ovaries 
removed early in life and are therefore exposed to much less 
estrogen that other women, rarely have breast cancer. 

Furthermore, women who have "estrogen replacement therapy" (i.e., 
take estrogen pills) have a 40 percent increased risk of breast 
cancer, and women who use birth control pills have a 50 percent 
increased risk of breast cancer.  These clues all relate estrogen 
to breast cancer. 

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 * Origin: The MotherLode BBS 788-5185 (1:363/168)
SEEN-BY: 13/13 133/2 151/100 143 1000 1003 363/3 32 34 81 118 157
SEEN-BY: 363/168 228 320 6969 365/47 369/35 374/1 12 14 17 46 98 147
SEEN-BY: 374/710 3607/1 3637/1 3641/1



From:    Hank Roth                                Kill 
To:      All                                      Msg #10, 01-Sep-93 04:59am
Subject: DDE -2-

*-*-* pnews conferences *-*-*
/* Written 1993 by [email protected] in igc:toxics.rachel */
/* ---------- "RACHEL: DDT & Breast Cancer" ---------- */
=======================================================================
                        --- April 22, 1993 ---

  R A C H E L ' S   H A Z A R D O U S   W A S T E   N E W S   # 3 3 4 

              News and Resources for Environmental Justice

                   Environmental Research Foundation
                  P.O. Box 5036, Annapolis, MD  21403
             Fax (410) 263-8944; Internet: [email protected]
[email protected]======
                                 -2-

But the EXACT relationship is not understood.

In recent years, menarche in American women has been occurring at 
earlier and earlier ages.  (Chinese women reach menarche at age 
17; today U.S. women reach menarche at 12.8 years, on average, 
but 200 years ago North American women reached menarche at age 
17.)  The declining age of menarche in U.S. women increases their 
lifetime exposure to estrogen, which possibly increases their 
risk of breast cancer. 

What is causing the declining age of menarche?  Some scientists 
say simply, improved nutrition.  Others say it may be caused by 
industrial chemicals in our food that mimic hormones and 
interfere with the internal mechanisms that regulate our bodies.  
DDT, DDE, PCBs and dioxin are examples of chemicals now known to 
mimic hormones and disrupt the endocrine system of fish, birds 
and mammals, including humans.[3] 

Dr. Patricia Whitten at Emory University in Atlanta, Ga., has 
examined historical records extending back 200 years in several 
countries.  Dr. Whitten's concludes that improved nutrition 
cannot account for all the changes in human reproduction that are 
observable in the historical record.  She believes that hormone-
mimicking industrial chemicals in the environment provide a more 
satisfactory explanation.[4] 

The debate over menarche has real consequences in the kinds of 
research that scientists are doing.  Scientists who believe 
hormone-mimicking industrial chemicals may play an important role 
are doing the kinds of studies reported today in the JOURNAL OF 
THE NATIONAL CANCER INSTITUTE, examining hormone-mimicking 
chemicals like DDT in relation to breast cancer. 

On the other hand, those who believe improved nutrition provide 
sufficient explanation for the change in menarche tend to ignore 
external influences, such as environmental chemicals.  Malcolm 
Pike at University of Southern California (USC) School of 
Medicine has emerged as a leader of this school of thought.  Pike 
argues as follows: nutrition is the cause of reduced age of 
menarche; nutrition is unlikely to worsen, so we're stuck with 
reduced age of menarche and therefore with increased exposure to 
estrogen.  Pike is experimenting with a technical fix, giving 
women additional chemicals (pharmaceuticals) to block their 
natural production of estrogen, then giving them controlled doses 
of estrogen, to maintain their chemical balance artificially.  
SCIENCE magazine reported January 29, 1993 that, "To the extent 
it's possible to see a trend emerging in the 1990s, this anti-
estrogen strategy appears to be a leading contender."  Dr. Walter 
Willett at Harvard University's School of Public Health is in 
Pike's camp.  He says, "In the end, I think we're going to have 
to go with a pharmacological fix."  SCIENCE comments "There may 
be some reluctance to support such experiments because people 
feel they are 'unnatural.'" But, says Willett, "our whole 
lifestyle is unnatural." 

Dr. Wolff's new study does not definitively prove that chemical 
residues cause breast cancer.  The number of "cases" is small. 
Additional research will be needed.  Nevertheless, an editorial 
in the JOURNAL OF THE NATIONAL CANCER INSTITUTE yesterday said, 
"Because the findings of Wolff [and associates] may have 
extraordinary global implications for the prevention of breast 
cancer, their study should serve as a wake-up call for further 
urgent research."[5] 
                                                --Peter Montague, Ph.D.
-----------------
[1] Mary S. Wolff and others, "Blood Levels of Organochlorine 
Residues and Risk of Breast Cancer," JOURNAL OF THE NATIONAL 
CANCER INSTITUTE Vol. 85 (April 21, 1993), pgs. 648-652. 

[2] Eliot Marshall, "Search for a Killer: Focus Shifts From Fats 
to Hormones," SCIENCE Vol. 259 (January 29, 1993), pgs. 618-621.  
See also, Eliot Marshall, "The Politics of Breast Cancer," 
SCIENCE Vol. 259 (January 29, 1993), pgs. 616-617. 

[3] Everyone interested in chemicals that mimic hormones must 
read Theo Colborn and Coralie Clement, editors, CHEMICALLY-
INDUCED ALTERATIONS IN SEXUAL AND FUNCTIONAL DEVELOPMENT: THE 
WILDLIFE/HUMAN CONNECTION [Advances in Modern Environmental 
Toxicology Vol. XXI] (Princeton, N.J.: Princeton Scientific 
Publishing Co., 1992). 

[4] Patricia L. Whitten, "Chemical Revolution to Sexual 
Revolution: Historical Changes in Human Reproductive 
Development," in Theo Colborn and Coralie Clement, cited above, 
pgs. 311-334. 

[5] David J. Hunter and Karl T. Kelsey, "Pesticide Residues and 
Breast Cancer: The Harvest of a Silent Spring?" JOURNAL OF THE 
NATIONAL CANCER INSTITUTE Vol. 85 (April 21, 1993), pgs. 598-599. 

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                                Table 1
          Risk of Developing Breast Cancer Today in the U.S.

          By age 25:  one in 19,608
          By age 30:  one in 2525
          By age 35:  one in 622
          By age 40:  one in 217
          By age 45:  one in 93
          By age 50:  one in 50
          By age 55:  one in 33
          By age 60:  one in 24
          By age 65:  one in 17
          By age 70:  one in 14
          By age 75:  one in 11
          By age 80:  one in 10
          By age 85:  one in 9
          Ever:       one in 8

          Source: See footnote 2.

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Descriptor terms:  pesticides; ddt; dde pcbs; breast cancer; 
morbidity; mortality; mary wolff; mt. sinai school of medicine; 
new york; women; hormones; estrogen; endocrine disruptors; 
menarche; menopause; estrogen replacement therapy; birth control 
pill; the pill; patricia whitten; 

------------------------------------
Hank Roth