Posts Tagged ‘Cancer’
Breast Cancer Study Finds No Link with EMF Exposure
A study of Long Island women recently found that there was no association between breast cancer and exposure to electromagnetic fields.
The study, published in the American Journal of Epidemiology, examined 576 women with breast cancer and 585 women without the disease. Researchers at Sony Brook University measured the electromagnetic fields in various rooms of the houses of the women, and also mapped the power lines around each house.
Like previous such studies, it found no association between EMF exposure and breast cancer risk. The study also took pains to examine only women who had lived in their houses for at least 15 years, to test if there was any association with long term exposure to EMF.
Dr. M. Cristina Leske, who headed up the six-year, $2.5 million study, said in a press release announcing the results of the study,
The results are reassuring in that residential levels of EMF, such as from electrical wiring in or around the home, were not related to breast cancer. Given these results, we now have valuable information that leads us to conclude that we can now focus on other possible risk factors. Our team is most grateful for the support of the Long Island women, who made our study possible.
Sources:
Study finds no link between breast cancer, power lines. Associated Press, June 25, 2003.
Breast Cancer and Electromagnetic Fields Study. Press Release, Stony Brook University, June 25, 2003.
Marin County Breast Cancer Data Faulty
Back in March, this site noted the controversy over breast cancer rates in Marin County, California. Marin County is one of the wealthiest counties in the United States and also has one of the highest breast cancer rates — 198 cases per 100,000 population compared to a national average of 139 per 100,000 for the rest of the country.
Activists who believe that pollution is a major contributor to breast cancer seized on this cancer cluster as evidence for their views, although a number of alternative explanations were possible. But now it turns out that there is an even better explanation — the data that claimed Marin County had a breast cancer incidence of 198 cases per 100,000 population appears to have been faulty.
The faulty data came to light after research in 2002 said that the rate of cancer for white women in Marin County had increased from 191 cases per 100,000 in 1998 to 230 cases per 100,000 in 1999. That sort of massive jump was extremely suspicious.
It turns out that such estimates had been using faulty data from the U.S. Census Bureau that dramatically undercounted the population of women in Marin County. Census data from 2000 showed that the 1990 estimates that such studies had been using underreported the number of white women 45-64 in Marin County by close to 20 percent. Revised breast cancer rates have not been released.
Ironically, another recent study of breast cancer among women in Marin County will also not please the activist who want pollution to be the cause and accuse researchers of “blaming the victim” anytime another cause is put forward.
A study by researchers at the University of California, San Francisco and published in the online journal Breast Cancer Research found a strong correlation between alcohol consumption and breast cancer among women in Marin County. Women who consumed two drinks a day had twice the breast cancer risk, and the risk increased with self-reported alcohol consumption.
That study was small, comparing 285 Marin County women with breast cancer to 286 healthy women living in the county. But it did find no correlation between breast cancer and length of time living in Marin County, suggesting the high breast cancer rate in Marin County has something to do with a confounding factor that women there share rather than something to do with Marin County itself.
Source:
Marin County breast cancer rates not as high as once thought. Justin Pritchard, Associated Press, April 4, 2003.
Study: Marin breast cancer related to alcohol consumption. Associated Press, May 7, 2003.
Tags: Cancer
Study Finds No Evidence for an Acrylamide/Cancer Connection
A study conducted by researchers at the Harvard School of Public Health and the Karolinska Institute in Sweden found little evidence to back up fears that acrylamide might be increasing the risk of cancer in human beings.
Acrylamide is a compound that is created in many foods when they are baked or fried at high temperatures, including such snack foods as potato chips. In 2002 Swedish researches made a splash by claiming that acrylamide was present in many common foods at unsafe levels.
The study, published in the British Journal of Cancer, looked at the dietary habits of 987 people with either colon, bladder, rectum or kidney cancer, as well as 500 cancer-free people.
The study found that there was no link between acrylamide consumption and the risk of bladder or kidney cancer. There was a positive association between consumption of acrylamide and a reduced risk of kidney cancer, though this is likely due to confounding factors (i.e. people who consume high levels of acrylamide are also likely consuming large amounts of dietary fiber).
Paul Nurse, chief executive of Cancer Research UK, told Reuters,
We know that acrylamide can be carcinogenic to animals, but this study suggests that either the levels in food are too low to affect cancer risk, or that the body is able to deactivate the chemical in some way.
This is only the first of many studies that will be published on acrylamide, but at least the news here is encouraging.
Source:
Study doubts acrylamide in food causes cancer. Patricia Reaney, Reuters, January 28, 2003.
Tags: Cancer
The Wealth/Breast Cancer Link
The San Francisco Chronicle recently ran an excellent article looking at the surprising results of studies that have tried to find why breast cancer rates in places like Marin County are so much higher than the national average. The answer turns out to be that a large part of the difference appears to be due to relative affluence of women in such areas.
In Marin County, 198 of every 100,000 white women was diagnosed with breast cancer between 1995 and 1999. For the nation as a whole, the rate for white women is only 139 cases per 100,000. Studies of the phenomenon find that the factor that most closely correlates with the increased risk of breast cancer is that women in Marin County have a relatively wealthy, upper-middle class lifestyle.
Why would being wealthy increase the rate of breast cancer incidence? There are a number of factors that appear to be behind this phenomenon,
- Such women tend to have their first children later in life. Pregnancy and breast feeding cause cells in the breast to mature and some scientist hypothesize that the sooner this happens, the lower the risk of breast cancer.
- Wealthy women are more likely to have mammograms and other medical attention.
- Drinkning the equivalent of two glasses of wine daily raises the risk of breast cancer in some studies, and the rate of female alcohol consumption in Marin County is more than twice as high as the national average.
- Women from some white ethnic subgroups are more likely to carry genetic mutations that predispose women to breast cancer.
A study of 130,000 California teachers, for example, found that those women had a 51 percent higher rate of breast cancer than the general population.
The idea that it is increasing affluence that leads to higher breast cancer incidence is met with resistance by breast cancer activists who are convinced that the increase must be due to exposure to environmental toxins. As Jean Rizzo, director of the Breast Cancer Fund in San Francisco told the San Francisco Chronicle,
There’s a blame-the-victim aspect to it: ‘You had your kids late, you didn’t breast feed. Bummer. Live with it.’
Apparently anything which might be psychologically discomfiting can immediately be ruled out as a possible cause of cancer.
Source:
Breast cancer amid affluence. Ulysses Torassa, San Francisco Chronicle, January 26, 2003.
Tags: Cancer
Deodorant Doesn’t Cause Breast Cancer
For the past few years this idiotic rumor that underarm deodorant contributes to breast cancer has been circulating around the Internet. To put the rumor to rest, researchers at the Fred Hutchinson Cancer Research Center in Seattle put it to the test and found, not surprisingly, that there was no link between deodorant and breast cancer.
The study included 813 women with breast cancer and 793 women without breast cancer. They were interviewed about their personal habits as they pertained to underarm deodorant usage and underarm shaving.
They found no increased risk for breast cancer related to either underarm deodorant usage or underarm shaving.
Source:
Deodorant not linked to breast cancer: study. Suzanne Rostler, Reuters, October 15, 2002.
Tags: Cancer
British Study Exonerates Nuclear Reactor in Childhood Cancer Clusters
Yet another study has looked at and refuted claims that the Sellafield nuclear plant in Great Britain was somehow responsible for cancer clusters that appeared in communities near the plant in the 1970s and 1980s.
The theory advanced to explain the clusters has been that children born to parents who worked at the Sellafield plant or at other nuclear power plants in Great Britain had a higher-than-normal risk of childhood cancers.
In 1999, a study examined the medical histories of more than 46,000 children who had at least one parent working at one of the implicated nuclear power plants. The study found that whose children had the same rate of childhood cancers as did children who didn’t have any parents who worked at the plant. Several other studies also found no link.
The latest study looked at the children of men who worked at the Sellafield plant. It found that although there was a small cancer cluster at Seascale — which started the whole Sellafield hysteria — children of parents who worked at the plant were no more likely to contract childhood cancers than were children whose parents did not work at the plant.
Source:
Child cancers ‘not caused by Sellafield’. The BBC, August 15, 2002.
Tags: Cancer
Ronald Bailey on the Long Island Cancer Cluster
Writing in Reason, Ronald Bailey has a nice look at the so-called Long Island Cancer Cluster and a recent study designed to find out why so many women in and around Long Island have breast cancer. After spending several years and $8 million, the National Cancer Institute study concluded that whatever might be contributing to the cancer cluster, it isn’t exposure to chemicals and pesticides in the Long Island area.
Research into breast cancer in Nassau and Suffolk counties in Long Island found that women there had rates of breast cancer that were roughly 3 percent higher than the rest of the nation. Some breast cancer advocates were convinced that the only possible explanation for the higher rate was due to chemicals in the area.
But a study of blood and urine from 3,000 women in the Long Island area found no evidence for this hypothesis. The study looked at levels of DDT, PCBs, chlordanes and chemicals indicative of cigarette smoking. The bottom line — women exposed to such chemicals were no more likely to develop breast cancer than women not exposed to such chemicals. This result was consistent with other studies such as an almost 33,000 patient study published in the New England Journal of Medicine in 1997 that found no evidence that exposure to DDT or PCB increased the risk of a woman developing breast cancer.
Why would advocates focus on DDT, PCBs, chlordanes and other chemicals? In part because those chemicals have all been found to be carcinogenic in mice, rats and other laboratory animals. Now animal tests are helpful in identifying substances that are potentially harmful to human beings, but they are not the last word. Some substances that are harmful to laboratory animals are perfectly safe in human beings, while some substances that do not harm mice or rats are nonetheless very harmful in human beings. Merely because animal tests indicate that a substance is likely to be carcinogenic does not mean that it actually is in human beings.
But that seems to be the message that some people are taking away from media reports on such research. The New York Times, for example, quotes Geri Barish, president of 1 in 9: The Long Island Breast Cancer Action Coalition, as wondering how, if these chemicals are carcinogenic in animal tests,
How could they absolutely say that a known carcinogen is not absolutely involved in the cause of cancer? . . . I refuse to accept the fact that they didn’t find anything. They didn’t find anything conclusive because in the scientific world it has to be exact.
Barish wants further studies to be done, but Dr. Barbara Hulka, a professor of epidemiology at the University of North Carolina, told The Times that so many studies have already been done looking for a link between DDT, PCBs and breast cancer that there may be nothing more to learn there. Hulka told The Times
I think it is important that these studies have been done. . . [but] There comes a point after so many studies are done that it becomes less productive to continue that line of work.
There have been so many epidemiological studies of DDT and PCBs, for example, that if they really caused or contributed to breast cancer one would think that at some point this would show up clearly in such studies. But in fact, all of the large studies of these chemicals have so far found no statistically significant connection between chemicals and cancer.
Perhaps it is time to recognize that cancer clusters are always going to occur largely because cancer is never going to be evenly distributed throughout a population, and begin taking the millions of dollars that have been devoted to looking at cancer clusters and spending it on more fruitful avenues of research.
Sources:
Looking for the link. Gina Kolata, The New York Times, August 11, 2002.
Cluster bomb. Ronald Bailey, Reason, August 14, 2002.
Tags: Cancer
Increasing Life Span, Wealth Is Killing Westerners
As the media regularly remind us, the West faces an “epidemic of cancer.” Why is it that Europe, the United States and other countries have such high rates of cancer while people in places like Africa or Eastern Europe have such low rates? According to new study there are primarily two reasons: 1. Westerners live long enough to have a high risk of cancer and 2. Western countries are usually wealthy enough to devote significant resources for caring for cancer patients.
In a study published in Annals of Oncology, researchers examined cancer data from 17 countries from 1970 to 1992. According to the authors of the study,
In countries with well-developed economies, general mortality is falling, life expectancy is increasing, and the age distribution of the population is shifting towards the elderly. Because the incidence of almost all cancers rises steeply with age, the number of cancer cases is increasing, while major investment in early detection and treatment contributes to the long survival of cancer patients. All these factors result in higher cancer prevalence.
The last point — early detection and treatment is the most perverse. Imagine two countries, X and Y, of equal population where every year 10,000 new cases of cancer are diagnosed. But country X is wealthy with a 10 year average survival time, whereas country Y is a poor country with only a 1 year survival time. After 10 years, cancer prevalence in country X is 100 times as high as in country Y and its media start wondering why it is suffering from an epidemic of cancer while it’s poorer cousin is relatively cancer free.
Source
Longer lives in richer nations ‘increases incidence of cancer’. Lorna Duckworth, The Independent (UK), June 6, 2002.
Tags: Cancer