Dr Maricel Maffini is a quiet, unassuming woman. In the weeks leading up First National Breast Cancer Conference several New Zealand journalists interviewed her and all told me she was lovely. And she is. She was great to listen to, not only in the formal circumstances of the conference sessions or an interview, but elsewhere too. I was fortunate enough to be able to spend quite a bit of time with her, and to share both a dinner and breakfast with her during the conference.
English is not her native tongue, so although she speaks very well and is easy to understand, she doesn't speak with quite the same confidence and forcefulness as Susan Love, but don't mistake that for lack of passion.
She is highly knowledgeable and during our interview leaves no doubt how she feels about the impact that environmental hormones has on our health, the reluctance of policy makers to make the hard decisions that might protect us, and those who have vested financial interests in not addressing the dangers of the chemicals to which we are exposed on a daily basis.
Maricel Maffini completed her Ph.D. on prostate cancer at the National University of Litoral, Santa Fe, in her home country, Argentina. She went from there to Tufts University in Boston, US, on a post-doctoral scholarship where she continued her work on endocrine disrupting chemicals (EDCs) and prostate cancer. She was working on gaining insight into the impact of androgens* on cell proliferation.
She is still at Tufts, now as a Research Assistant Professor in the Department of Anatomy and Cellular Biology, working in Dr Ana Soto's laboratory, part of one of the foremost and recognised research teams working on EDCs. She shifted her focus away from prostate cancer when the lab began to look at carcinogenesis from the developmental perspective rather than from a genetic one.
"A cancer tumour," she explains, "is when cells proliferate in an uncontrolled and non-orderly way."
"We wanted to test a hypothesis - that breast cancer is development gone wrong," she said, echoing Dr Susan Love's view.
The endocrine system is very powerful; it is involved in growth, metabolism, reproductive health and lactation. Clearly anything that impacts upon the endocrine system has the potential for far reaching effects on human behaviour, development and health.
"We have a great model for carcinogeneisis with bisphenol A [BPA] and breast cancer, and we study rats because tumours and their responses are similar in rats and humans," Maricel told Upfront.
In particular, Maricel is looking at the impact on girls from as early as conception. Does breast cancer "start" in the womb? She explained that we already know that in utero exposure to endogenous or natural oestrogen (produced by the mother during pregnancy) impacts on the subsequent risk of developing breast cancer. For example, twins have a higher risk of breast cancer in adulthood because of their greater exposure to oestrogen during their mother's pregnancy. On the other hand, women who develop pre-eclampsia have lower levels of oestrogen and their daughters a lower risk of breast cancer.
There is considerable evidence that EDCs are impacting on health across the population - in fact, we live in a chemical soup. However, there are problems with epidemiological studies (which consider the impacts through observation of part of the population) not the least of which is the fact that people, in their everyday lives, are not exposed to just a single chemical. There is also no control over the period or time of exposure; many people suffer from chronic long term exposure to EDCs. So it is difficult to say that on a population level, this specific chemical causes this particular effect. It is easy to see how this situation enables the industries involved to avoid taking responsibility or making changes.
Research has shown that there are higher concentrations of BPA in the placenta, amniotic fluid and breast milk. There is chronic, low level peri-natal exposure to this chemical. The impacts of this include early puberty, ovarian malformation and changes in behaviour. So, the work that Maricel, and others on Ana Soto's team are doing, looks specifically at the effects of in utero exposure to BPA on the development of the mammary gland in mice and rats.
They expose the rodent fetuses (or pups) to environmentally relevant doses of BPA. Pre-natally this causes larger foetal mammary glands and longer milk ducts. The long lasting consequences include alteration to the mouse mammary gland at puberty and in adulthood.
If the mice are also exposed through lactation the effects appear earlier, and the milk ducts become blocked with a condensed fluid leading to a pre-tumour state. The rats become more susceptible to tumours, and carcinoma in situ, and more tumours develop and develop earlier in the rat's life. It is interesting to note that the doses that Maricel is working with are half the dose deemed by the Environmental Protection Agency to be safe.
Where Do We Go From Here?
The issue of EDCs and environmental oestrogens has received recent coverage in Upfront (Issue 67 June/July 2006) and in our Stop Cancer Where It Starts project, and it was very gratifying to hear Maricel confirm many of the things that we have already discussed in these forums. Rather than repeat here much of that content, I was particularly interested in Maricel's ideas on where we go from here, what we can do.
"At the lab, we are encouraged to be outspoken," she said. "To encourage advocacy groups, to give them the scientific knowledge to fight the vested financial interests."
"We need to start talking to the obstetricians and gynecologists, and paediatricians. It is important to talk to women - the mothers and grandmothers."
She believes that doctors and midwives have an important role to play in ensuring women make better decisions about the long term health of their children, starting from conception.
She says that industry accuses her and other scientists, such as Drs Ana Soto, Frederick vom Saal and Carlos Sonnenschein with whom she works, of scaremongering, but Maricel believes that there is nothing wrong with people avoiding exposure to these chemicals, nothing wrong with making informed decisions and taking the precautionary approach. She points out that the latest edition of the baby care book that bears the name of Dr Benjamin Spock** includes a chapter on the effect of chemicals on the unborn baby.
The big question is "can we stop breast cancer where it starts?"
What Can We Do?
The "easy" things:
avoid plastics and don't microwave in them,
buy organic produce and hormone-free meats and dairy,
wash/rinse fruits and vegetables thoroughly,
use pesticide-free lawn care,
clean with least-toxic products (or substitutes),
reduce exposure to cosmetics, especially young girls.
The "hard" things:
change the way testing is done by regulatory agencies (e.g. Environmental Protection Agency),
hold corporations responsible,
use the precautionary principle,
develop better testing methods to assess total body burden,
educate the public and health care professionals about risks and ways to prevent unnecessary exposures.
* a sex hormone which controls the development and maintenance of masculine characteristics.
** he died in 1998.
Copyright © 2007 Sue Claridge
Dr Maricel Maffini - The Impacts of a Chemical Soup